December 1991 

Building Air Quality 

A Guide for Building Owners and Facility Managers 

&EPA 

U.S. Environmental Protection Agency 

Office of Air and Radiation 

Office of Atmospheric and Indoor Air Programs 

Indoor Air Division 

U.S. Department of Health and Human Services 

Public Health Service 

Centers for Disease .Control 

National Institute for Occupational Safety and Health 

coc 

CENTERS FOR DISEASE CONTROL 

NID!!iH 

~ 

For sale by the U.S. Government Printing Office 

Superintendent of Documents, Mail Stop: SSOP, Washington, DC 20402-9328 

ISBN 0-16-035919-8 

@ Printed on Recycled Paper 

Contents 

Foreword ............................................................................................................................. vii 

Note to Building Owners and Facility Managers ................................................................ .ix 

Acknowledgements ............................................................................................................ xiii 

TAB 1: BASICS 

Section 1: About This Document ......................................................................... 1 

Section 2: Factors Affecting Indoor Air Quality .................................................. 5 

Sources of Indoor Air Contaminants ..................................................................................... 5 

HV AC System Design and Operation .................................................................................. 6 

Pollutant Pathways and Driving Forces ................................................................................ 9 

Building Occupants ............................................................................................................ 10 

Section 3: Effective Communication ................................................................ 13 

Communicating to Prevent IAQ Problems ......................................................................... 13 

Communicating to Resolve IAQ Problems ........................................................................ 15 

TAB II: PREVENTING IAQ PROBLEMS 

Section 4: Developing an IAQ Profile ............................................................... 19 

Skills Required to Create an IAQ Profile ........................................................................... 20 

Steps in an IAQ Profile ....................................................................................................... 21 

Section 5: Managing Buildings for Good IAQ ................................................... 31 

Developing an IAQ Management Plan ............................................................................... 31 

TAB Ill: RESOLVING IAQ PROBLEMS 

Section 6: Diagnosing IAQ Problems ............................................................... 45 

Overview: Conducting an IAQ Investigation .................................................................... 46 

Initial Walkthrough ............................................................................................................ 47 

Collecting Additional Information ... . ... .. ...... .... .. .... .. .. .... ......... ....... ... ... .. .... ........ .. . ... . . .... .... 49 

Collecting Information about Occupant Complaints .......................................................... 50 

Using the Occupant Data .................................................................................................... 53 

Collecting Information abm.~t the HV AC System ............................................................... 57 

Using the HV AC System Data ............................................................................................ 62 

Collecting Information about Pollutant Pathways and Driving Forces ............................... 68 

Using Pollutant Pathway Data ............................................................................................. 70 

Collecting Information on Pollutant Sources ...................................................................... 72 

Using Pollutant Source Data ............................................................................................... 74 

Contents iii 
Sampling Air for Contaminants and Indicators ............................................................ ' ....... 74 

Complaints Due to Conditions Other Than Poor Air Quality ............................................. 77 

Forming and Testing Hypotheses ........................................................................................ 78 

Section 7: Mitigating IAQ Problems .................................................................. 81 

Background: Controlling Indoor Air Problems .................................................................. 81 

Sample Problems and Solutions .......................................................................................... 86 

Judging Proposed Mitigation Designs and Their Success ................................................. 102 

Section 8: Hiring Professional Assistance to Solve an lAO Problem ............ 105 

Make Sure That Their Approach Fits Your Needs ............................................................ 105 

Selection Criteria ............................................................................................................... 106 

TAB IV: APPENDICES 

Appendix A: Common lAO Measurements - A General Guide ..................... 109 

Overview of Sampling Devices ......................................................................................... 109 

Simple Ventilation/Comfort Indications ........................................................................... 110 

Air Contaminant Concentrations ....................................................................................... 115 

Appendix B: HVAC Systems and Indoor Air Quality ...................................... 121 

Background ........................................................................................................................ 121 

Types of HV AC Systems .................................................................................................. 122 

Basic Components of an HV AC System ........................................................................... 123 

AS:HRAE Standards and Guidelines ................................................................................. 137 

Appendix C: Moisture, Mold and Mildew ....................................................... 141 

Background on Relative Humidity, Vapor Pressure, and Condensation ........................... 141 

Taking Steps to Reduce Moisture ...................................................................................... 143 

Identifying and Correcting Common Problems From Mold and Mildew ......................... 145 

Appendix D: Asbestos ....................................................................................... 147 

EPA and NIOSH Positions on Asbestos ........................................................................... 148 

Programs for Managing Asbestos In-Place ....................................................................... 149 

Where to Go for Additional Information ........................................................................... 150 

Appendix E: Radon ............................................................................................ 151 

Building Measurement, Diagnosis and Remediation ........................................................ 151 

Where To Go for Additional Information ......................................................................... 152 

Appendix F: Glossary and Acronyms .............................................................. 153 

Appendix G: Resources ..................................................................................... 157 

Federal Agencies with Major IAQ Responsibilities .......................................................... 157 

Other Federal Agencies with Indoor Air Responsibilities ................................................ 160 

State and Local Agencies .................................................................................................. 160 

Private Sector Contacts ...................................................................................................... 161 

Publications ....................................................................................................................... 164 

Training ............................................................................................................................. 167 

iv Contents 
TAB V: INDOOR AIR QUALITY FORMS 

IAQ Management Checklist ····························································-~·································171 Pollutant Pathway Record For IAQ Profiles ..................................................................... 175 

Zone/R.oom Record ........................................................................................................... 177. 

Ventilation Worksheet ....................................................................................................... 179 · 

Indoor Air Quality Complaint Form .................................................................................. 181 .. 

Incident Log ···········································································:···········································183 

Occupant Interview .................................................................................... ; ...................... 185 

Occupant Diary .................................................................................................................. 187 

Log of Activities and System Operation ........................................................................... 189 

HV AC Checklist-Short Form ................................................................................... ;:; ... 191 

HV AC Checklist-Long Form .......................................................................................... 195 

Pollutant Pathway Form For Investigations .............. ,; ...................................................... 211 

Pollutant and Source Inventory ......................................................................................... 213 

Chemical Inventory· ........................ : ......................................................... _ ..... : ...... _ ............. 221. 

Hypothesis Form ............................................................................................................... : 223 

This document is in the public domain. It may be reproduced in whole or in part by an individual or organization without permission. If it 

is reproduced, however, EPA and NIOSH would appreciate knowing how it is used. Write the Indoor Air Division (ANR-445W), Office 

of Air and Radiation, U.S. Environmental Protection Agency, Washington, DC 20460. 

Contents v 

Foreword 

In the past two decades, the number of 

people requesting information and assistance on health and comfort concerns 

related to indoor air quality from the U.S. 

Environmental Protection Agency (EPA) 

and the National Institute for Occupational 

Safety and Health (NIOSH) has risen 

steadily. Although many studies on indoor 

air quality have been reported in technical 

publications and proceedings during these 

years, little indoor air-related information 

has been targeted at owners and facility 

managers of public and commercial 

buildings who are the people in the best 

position to prevent and resolve indoor air 

problems. 

In recognition of the need for practical 

indoor air quality advice for building 

owners and facility managers, EPA and 

NIOSH decided to work jointly to produce 

written guidance on preventing, identifying, and correcting indoor air quality 

problems'. The distinct perspectives of the 

two agencies are reflected in this document. 

Since 1971, NIOSH has conducted 

more than 600 indoor air quality investigations in office (non-industrial, nonresidential) buildings under the Health 

Hazard Evaluation Program. Over time, 

NIOSH has developed a "solutionoriented" approach to these investigations. 

This document draws extensively on the 

experience of NIOSH in investigating and 

correcting indoor air quality problems in 

these types of buildings. 

In 1986, Congress mandated that EPA 

conduct research and develop information 

on indoor air quality. To carry out its 

information dissemination responsibilities, 

EPA's Indoor Air Division has produced a 

number of publications which have been 

distributed to a wide range of audiences 

and will launch an indoor air quality 

information clearinghouse in 1992. In 

addition, the Indoor Air Division is 

developing several guidance documents on 

building design and management practices. 

This publication is part of that effort. 

The guidance presented here is based 

on what is known and generally accepted 

at this time in the relevant fields of 

building science and indoor air quality. 

EPA and NIOSH anticipate that this 

document may later be revised to include 

more detailed guidance as research 

continues and our knowledge grows. In 

the meantime, building owners and facility 

managers can use the resources listed in 

Appendix G to supplement and update the 

information presented here. 

Foreword vii 

Note to Building Owners and 

Facility Managers 

. "' . ',' . 

from marketing and negoti~ting leases 

and maintenance contracts to planning for 

future expansion, operating a commercial 

or public building is a complex process 

that leaves you little time for unnecessary 

activities. working with your f~ility sraff, 

you make an effort to provide a pleasant 

setting and are accustomed to dealing 

with occupant complaints about room 

temperature, noise, plumbing system 

problems, and other elements of the 

building environment. 

A healthy indoor environment is one in 

which the surroundings contribute to 

productivity, comfort, and a sense of health 

and well being. The indoor air is free from 

significant levels of odors, dust and contaminants and circulates to prevent 

stuffiness without creating drafts. Temperature and humidity are appropriate to 

the season and to the clothing and activity 

of the building occupants. There is enough 

light to illuminate work surfaces without 

creating glare and noise levels do not 

interfere with activities. Sanitation, 

drinking water, fire protection, and other 

factors affecting health and safety are wellplanned and properly managed. 

Good air quality is an important 

component of a healthy indoor environment. For the purposes of this document, 

the definition of good indoor air quality 

includes: 

• introduction and distribution of adequate 

ventilation air 

• control of airborne contaminants 

• maintenance of acceptable temperature 

and relative humidity 

A practical guide to indoor air quality 

(IAQ) cannot overlook temperature and 

humidity, because thermal comfort 

concerns underlie many complaints about 

"poor air quality." Furthermore, temperature and humidity are among the many 

factors that affect indoor contaminant 

levels. 

lt is important to remember that while 

occupant complaints may be related to 

time at work, they may not necessarily be 

due to the quality of the air. Other factors 

such as noise, lighting, ergonomic stressors 

(work station and task design), and jobrelated psychosocial stressors can -

individually and in combinationcontribute to the complaints. These 

problems are briefly addressed in this 

document. 

Good indoor air quality enhances 

occupant health, comfort, and workplace 

productivity. Rental properties can gain a 

marketing advantage if they are known to 

offer a healthy and pleasant indoor environment. Failure to respond promptly and 

effectively to IAQ problems can have 

consequences such as: 

• increasing health problems such as 

cough, eye irritation, headache, and 

allergic reactions, and, in some rare 

cases, resulting in life-threatening 

conditions (e.g., Legionnaire's disease, 

carbon monoxide poisoning) 

• reducing productivity due to discomfort 

or increased absenteeism 

• accelerating deterioration of furnishings 

and equipment 

• ·straining relations between landlords and 

tenants, employers and employees 

• creating negative publicity that could put 

rental properties at a competitive 

disadvantage 

• opening potential liability problems 

(Note:'Insurance policies tend to exclude 

pollution-related claims) 

Note to Building Owners and Facility Managers ix 
Provision of good air quality requires 

conscientious effort by both building staff 

and occupants. The commitnient to 

address IAQ problems starts with the 

building owner or facility manager, the 

person who has an overview of the 

organization, sets policy, and assigns staff 

responsibilities. You have the authority to 

see that an IAQ policy is articulated and 

carried out, the ability to identify staff with 

skills that enable them to reactpromptly 

and effectively to complaints, and the 

incentive to initiate a program that will 

prevent indoor air problems in the future. 

As you decide how best to respond to the 

challenge of preventing and resolving 

indoor air quality problems in your 

building, it will be helpful to keep in mind 

the following thoughts: 

It is important to establish a process 

that encourages an active exchange of 

information. 

Without an open communications policy, 

an atmosphere of distrust may be created 

that complicates your efforts to diagnose 

and correct problems. 

FaciUty staff are in a position to notice 

malfunctioning equipment or accidental 

events that could produce indoor air 

quality problems. 

They can play a critical role in identifying 

problem situations and averting IAQ 

crises. On the other hand, if staff are not 

aware of IAQ issues, their activities can 

also create indoor air quality problems. 

Facility staff are often instructed to keep 

energy costs to a minimum. 

Changes in building operation intended to 

save energy have sometimes contributed to 

IAQ problems (for example, by reducing 

the flow of outdoor ventilation air without 

taking action to maintain the quality of the 

recirculated air). The correction of IAQ 

problems has sometimes led to reduced 

energy use due to the efficiency associated 

with a cleaner and better controlled 

heating, ventilation, and air conditioning 

(HV AC) system. The energy needed to 

condition and distribute ventilation air is 

only a small part of total building energy 

consumption and is far overshadowed by 

other operating costs (such as personnel). 

Attempting to limit operating costs by 

reducing ventilation can be a false 

economy, if it leads to problems such as 

increased occupant complaints, reduced 

productivity, and absenteeism. 

Every complaint merits a response. 

Many indoor air quality problems are not 

difficult to correct and can be solved with 

in-house expertise. However, gathering 

relevant information about the problem 

and identifying appropriate corrective 

actic;ms are likely to require a coordinated 

effort by people ·with a variety of skills. 

An indoor air quaUty problem may 

be the direct or indirect result of an 

apparently minor modification. 

Actions such as the placement of interior 

room dividers, the introduction of new 

office equipment, and personal activities 

such as cooking can have an impact on 

indoor air quality. Communication 

between building management and 

building occupants regarding their respective responsibilities is a critical element in 

the management of indoor air quality. 

Indoor air quality in a large building is 

the product of multiple influences, and 

attempts to bljng problems under control 

do not always produce the expected result. 

Some indoor air quality problems are 

complex and may require the assistance of 

outside professionals. When contracting 

for services, you need to be an informed 

client to avoid unnecessary costs and 

delays in solving the problem. 

x Note to Building Owners and Facility Managers 
If there is reason to believe that an IAQ 

problem may have serious health implications, appropriate exp¥rts such as occupational physicians, industrial hygienists, 

and mechanical engineers should be 

called in as soon as possible. 

In-house investigations by non-professionals are not recommended in such cases 

(e.g., if individuals are being hospitalized 

because of exposure inside the building). 

Public and commercial buildings can 

present a wide range of IAQ problems. 

The variety of unique features in their 

design and usage (e.g., apartment buildings, hospitals, schools, shopping malls) 

make a wide range of IAQ problems possible. In apartment buildings, for example, 

each residential unit can produce cooking 

odors and the operation of kitchen exhaust · 

fans is generally outside the control of 

building management. The basic informa- · 

tion and problem-solving processes in this 

guide can be applied, with necessary adaptations, to a wide range of building types. 

This document was written to be a u~eful resource for you and your staff in preventing and resolving occupants' complaints that may be related in some way to 

the quality of the indoor air. It provides 

background information followed by 

"how-to" guidance for you and your inhouse staff. The practical problem-solving 

techniques it describes have been applied 

successfully by NIOSH and other investigators. If complaints are not resolved after 

careful application of this guidance, outside help will probably be needed. Information on possible sources of outside help 

is included. As you read this document, or 

tum it over to your staff to implement, 

EPA and NIOSH urge you to maintain a 

personal involvement in this issue. 

Note to Building Owners and Facility Managers xi 
"'"""~"""' '·"'~"""'''- R.!-.lil<;fil:l9 owners and facility managers get ........ , • .,.,.,.. indicators and associated ~-"~~'"'=·=-~~-~~-~~-h"·-~-~-'-'' 

""""''~·.,-~~"··. " . .ItutiYillPtoms described suggest an 

IAQ problem that is not life-threaten- ··· ·· !Qg, but it would be wise to respond 

;:,_ ___ promptly. 

xii Note to Building Owners and Facility Managers 
Acknowledgements 

l:e development of this document, 

Building Air Quality: A Guide for 

Building Owners and F acUity Managers, 

has been a joint undertaking of the 

Indoor Air Division in the Office of 

Atmospheric and Indoor Air Programs of 

the United States Environmental 

Protection Agency and the National 

Institute for Occupational Safety and 

Health. The document was prepared 

under the direction of Robert Axelrad, 

Director, EPA Indoor Air Division and 

Philip J. Bierbaum, Director, NIOSH 

Division of Physical Sciences and 

Engineering. 

EPA and NIOSH appreciate the time 

that many organizations and individuals 

took to share ideas, discuss their own 

practical experiences, and review many 

drafts of this document. Many of the 

ideas raised by these reviewers have 

been incorporated into this document. 

Two people,had primary responsibility 

for developing the content and format of 

the document. Elizabeth Agle, the EPA 

project manager, developed the structure 

of the document, assembled the teams of 

contributors and reviewers, and provided 

direction and untiring support as the project came to fruition. Susan Galbraith, 

Cogito Technical Services, served as the 

principal writer. She brought to the task 

both considerable writing skills and a 

basic understanding of how buildings 

operate that proved invaluable throughout the process of conceptualizing and 

creating this document. 

EPA and NIOSH gratefully acknowledge the important contributions of Terry 

Brennan, Camroden Associates; Ed 

Light, Pathway Diagnostics; and William 

A. Turner, The H. L. Turner Group, who 

served as the team of core technical 

adviso~ for tqis document.. These. indi~ 

viduals contributed a substantial amount of 

written material and thoughtful comments 

on the many drafts and, most importantly, 

their considerable practical experience in 

identifying and re.solving indoor air quality 

problems. Joseph Lstiburek, Building 

Science Corporation, contributed much of 

the material on the problem of moisture. 

EPA and NIOSH particularly wish to thank 

the staff of The Charles E. Smith Companies who reviewed numerous drafts of the · 

document and made invaluable comments 

from a building management perspective. 

The photographs were donated by: Terry 

Brennan, 'Camroden Associates; Michael 

Crandall, NIOSH; Ed Light, Pathway 

Diagnostics; Joseph Lstiburek, Building 

Science Corporation; Phil Morey, Clayton 

Environmental Services; Tedd Nathanson, 

Public Works Canada; Robert Olcerst, 

Brujos SCientific Inc.; Stall Salisbury, 

NIOSH; William A. Turner, The H. L. 

Turner Group; anci Kenneth Wallingford, 

NIOSH. Additional slides came from the 

NIOSH Health Hazard Evaluation Program 

and from the Occupational Safety and 

Health Administration. 

A large number of people within both 

EPA and NIOSH commented on the drafts 

of the document. EPA and NIOSH 

recognize the following staff for their 

particular contributions: John Girman, 

Elissa Feldman, Pauline Johnston, Sue 

Perlin, David Mudarri, Jack Primack, Bob 

Thompson, Kevin Teichman, Charles 

Truchillo, and Jim Wilson, EPA; and 

Michael Crandall, Jerome Flesch, Richard 

Gorman, Joseph Hurrell, Pantelis Rentos 

and Mitchell Singal, NIOSH. 

Acknowledgements xiii 
The draft document was widely circulated for review outside these agencies. 

EPA and NIOSH thank the following 

individuals who reviewed all or part of the 

document and submitted comments: 

Allen C. Abend 

Maryland Department of Education 

Charles A. Achilles 

Institute of Real Estate Management 

Heruy A. Anderson 

Wisconsin Department of Health and 

Social Services 

David W. Bearg 

Life Energy Associates 

W. David Bevirt 

Sheet Metal and Air Conditioning 

Contractors Association 

Barbara Billauer 

International Council of Shopping Centers 

Bob Bockholt 

National Apartment Association 

H. E. Burroughs 

H. E. Burroughs & Associates, Inc. 

Harriet Burge 

University of Michigan Medical Center 

Paul A. Cammer 

Business Council on Indoor Air 

James L. Coggins 

Energy Applications, Inc. 

Geraldine V. Cox 

Chemical Manufacturers Association 

Baron S. Davis 

Environmental Health Consultant 

John E. DiFazio, Jr. 

Chemical Specialties Manufacturers 

Association 

James C. Dinegar 

Building Owners and Managers 

Association International 

Stephen D. Driesler 

National Association of Realtors 

Sandra Eberle 

U.S. Consumer Product Safety 

Commission 

Paul C. Fiduccia 

International Council of Shopping Centers 

Richard B. Gammage 

Oak Ridge National Laboratory 

Matthew Gillen 

Occupational Health Foundation 

xiv Acknowledgements 

William H. Groah 

Hardwood Plywood Manufacturers 

Association 

Shirley J. Hansen 

Hansen Associates 

Steven B. Hayward 

Indoor Air Quality Program, California 

Department of Health Services 

John Henshaw 

American Industrial Hygiene Association 

BionHoward 

Alliance to Save Energy 

W. T.Irwin 

CertainTeed Corporation 

Paul Jacobetz 

Briiel & Kjaer Instruments, Inc. 

William D. Kelley 

American Conference of Governmental 

Industrial Hygienists, Inc. 

Jay Kirihara 

The Trane Company 

Daniel A. La Hart 

Maryland Department of the Environment 

Mary Lamielle 

National Center for Environmental 

Health Strategies 

Ellen Larson 

Air Conditioning Contractors of America 

David Lee 

Association of Local Air Pollution 

Control Officials 

Eugene L. Lehr 

U.S. Department of Transportation 

Hal Levin 

Indoor Air Bulletin 

William H. McCredie 

National Particleboard Association 

Jean F. Mateson 

Mateson Environmental Management, Inc. 

Keith Mestrich 

Food and Allied Service Trades 

Eugene M. Moreau 

Indoor Air Program, . 

Maine Department of Human Services 

Niren L. Nagda 

GEOMET Technologies, Inc. 

Fred Nelson 

National Foundation for the 

Chemically Hypersensitive 
Laura Oatman 

Indoor Air Quality Program, 

Minnesota Department of Health 

Andrew Persily 

National Institute for Standards and 

Technology 

George R. Phelps 

Thennal Insulation Manufacturers 

Association, Inc. 

William A. Pugsley 

Lincoln-Lancaster County Health 

Department (Nebraska) 

G.S. Rajhans 

Ontario Ministry of Labour 

Susan Rose 

U.S. Department of Energy 

Steven A. Scala 

U.S. Public Health Service 

James Sharpe 

The Charles E. Smith Companies 

Richard J. Shaughnessy,.IU 

Indoor Air Program, University of Tulsa 

Thomas J. Shepich 

Occupational Safety and Health 

Administration 

Henry J. Singer 

General Services Administration 

Philip A,. Squair 

Air-Conditioning' and Refrigeration 

Institute 

John H. Stratton 

Sheet Metal and Air Conditioning 

Contractors Association 

Keuneth M. Sufka 

Associated Air Balance Council 

John M. Talbott 

U.S. Department of Energy 

Simon Turner 

Healthy Buildings International, Inc. 

Richard.A Versen 

Manville Technical Center 

Davidge Warfield 

National Air Duct Cleaners Association 

Lewis Weinstock 

Forsyth County Environmental Affairs 

Department (Georgia) 

John F. Welch 

Safe Buildings Alliance 

Arthur E. Wheeler 

Wheeler Engineering Company 

Jim H. White 

Canada Mortgage and Housing 

Corporation 

W. Curtis White 

Aegis Environmental Management, Inc. 

AlexanderJ.Willman 

National Energy Management Institute 

Myra Winfield 

Veterans Administration (Texas) 

James E. Woods 

College of Architecture and Urban Studies, 

Virginia Polytechnic Institute 

Rita Cohen, ofiCF, Inc., assisted in the 

project management for the development 

of this document. Marie O'Neill, of The 

Bruce Company, provided editorial and 

coordination assistance. EPA and NIOSH 

extend special thanks to Linda Berns, 

Terry Savage, and others at the firm of 

Berns and Kay, Ltd. for their effort and 

enthusiasm in designing and producing the 

document under tight deadlines. 

Acknowledgements XV 

About This Document 

BEFORE YOU BEGIN 

The goal of this guidance document is to 

help you prevent indoor air quality 

problems in your building and resolve such 

problems promptly if they do arise. ·It 

recommends practical actions that can be 

carried out by facility staff, outside 

contractors, or both. The document will 

help you to integrate IAQ-related activities 

into your existing organization and identify 

which· of your staff have the necessary 

skills to carry out those activities. 

This is a long document. It would be 

convenient if all of the ideas it contains 

could be summed up in a few short 

recommendations, such as: "check for 

underveptilation" and "isolate pollutant 

sources." However, such statements 

would only be helpful to people who are 

already familiar with indoor air quality 

concerns. If the owner's manual for your 

car said to check your pollution control 

valves every year, but didn't say how to 

find out whether they were working 

properly, you would need either a more 

detailed manual or the money to hire a 

mechanic. Don't be discouraged by the 

number of pages in your hands. Once you 

begin to understand the factors that 

influence indoor air quality in your 

building, you can move from section to 

section, reading what you need to know at 

the moment and leaving the rest until later. 

Some Basic Assumptions 

EPA and NIOSH recognize that many 

factors influence how an individual owner 

or manager can put the information in this 

guide to use. The skills of facility staff and 

the uses of the. building can vary widely, 

affecting the types of IAQ problems that 

are likely to arise and the most effective 

approach to resolving those problems. 

The assumptions used in preparing this 

guide include: 

• The expense and effort required to 

prevent most IAQ problems is much less 

than the expense and effort required to 

resolve problems after they develop. 

• Many IAQ problems can be prevented 

by educating facility management, staff, 

and occupants about the factors that 

create such problems. When IAQ 

problems do arise, they can often be 

resolved using skills that are available 

in-house. 

• The basic issues and activities involved 

in preventing and resolving IAQ problems are similar for buildings of many 

different designs and uses. 

• If outside assistance is needed to solve 

an IAQ problem, the best results will be 

achieved if building owners·and managers are informed consumers. 

How this Guide is Organized 

This guide is divided into topic areas 

marked by tabs. Tab I marks introductory 

material directed toward all users of the 

document. Tab IT is directed to building 

owners and facility managers who do not 

have a current IAQ problem and want to 

prevent such problems from arising. If you 

currently have an indoor air quality 

problem, Tab ill provides guidance to 

help resolve that problem. The appendices 

marked by Tab IV present information 

that may not be critical to resolving most 

indoor air quality problems but could be 

useful reading for additional background 

About This Document 1 
on major IAQ topics. Abbreviated sample 

forms are included throughout the text so 

that readers can see what types of information can be collected using the forms provided in this document. Tab V contains 

the complete forms discussed in the text. 

These can be photocopied for use by you 

and your staff. 

As you read this document, you will find 

that some guidance points are repeated. 

This was intentional, as it allows you to 

use the sections on prevention, diagnosis, 

and mitigation as :~<stand-alone" guides. 

Tab 1: Basics 

Section 2: Factors Affecting Indoor Air 

Quality 

Indoor air quality is not a simple, easily 

defined concept like a desk or a leaky 

faucet. It is a constantly changing interaction of a complex set of factors. Four of 

the most important elements involved in 

the development of indoor air quality 

problems are: a source of odors or 

contaminants; a problem with the design or 

operation of the HV AC system; a pathway 

between the source and the location of the 

complaint; and the building occupants. 

Read Section 2 for an introduction to the 

factors that influence indoor air quality. A 

basic understanding of these factors is 

critical to investigating and resolving IAQ 

problems. 

Section 3: Effective Communication 

An effective communication system helps 

facility managers, staff, contractors, and 

occupants to clarify their responsibilities 

and cooperate in identifying potential IAQ 

problems. Building occupants can be 

valuable allies in resolving indoor air quality problems. On the other hand, even 

small problems can have disruptive and 

potentially costly consequences if occupants become frustrated and mistrustful. 

Effective communication is the key to 

cooperative problem-solving. 

2 Section 1 

Good communication can be promoted 

through a group that represents all of the 

interested parties in the building. Many 

organizations have health and safety committees that can fill this role. Section 3 

suggests ways to work productively with 

building occupants to prevent IAQ problems and to maintain good communication 

during IAQ investigations. 

Tab II: Preventing IAQ 

Problems 

Section 4: Developing an IAQ Profile 

An IAQ profile is a "picture" of building 

conditions from the perspective of indoor 

air quality. A review of construction and 

operating records, combined with an 

inspection of building conditions, helps to 

reveal potential indoor air problems and 

identify building areas that require special 

attention to prevent problems in the future. 

Baseline data collected for the IAQ profile 

can facilitate later investigations, should 

problems arise. Section 4 suggests a threestage approach to developing an IAQ 

profile and describes the products of each 

stage. 

Section 5: Managing Buildings for Good 

IAQ 

Many indoor air problems can be prevented by following common sense 

recommendations, such as: maintain good 

sanitation, provide adequate ventilation, 

and isolate pollutant sources. Other 

preventive measures may require a careful 

review of job descriptions, contracts, 

supplies, and schedules. It is important to 

designate an IAQ manager to bear responsibility for coordinating the effort in your 

building. Section 5 discusses key elements 

to include in your IAQ management plan. 

Tab Ill: Resolving IAQ Problems 

Section 6: Diagnosing IAQ Problems 

Most IAQ investigations begin in response 

to a complaint from one or more building 
occupants. IAQ complaints can affect 

entire buildings or be limited to areas as 

small as an individual work station. The 

goal of the investigation is to resolve the 

complaint without causing other problems. 

Section 6 describes a variety of information-gathering strategies used to identify 

the cause of an IAQ problem. This section 

provides suggestions for in-house staff 

who have been given the responsibility of 

investigating the problem. It will also help 

building management to understand .and · 

oversee the activities of any outside 

professionals who may be brought in to 

assist in the investigation. 

Section 7: Mitigating IAQ Problems 

The basic approaches to mitigating indoor 

air quality problems are: control of 

pollutant sources; modifications to the 

ventilation system; air cleaning; and 

control of exposures to occupants. Successful mitigation often involves a combination of these techniques. 

Section 7 provides criteria for judging 

potential mitigation strategies and for 

determining whether a problem has been 

solved. It includes brief descriptions of 

common indoor air quality problems and 

possible solutions. 

Section 8: Hiring Professional Assistance to Solve an IAQ Problem 

Indoor air quality is an emerging and 

interdisciplinary field. Section 8 provides 

guidance in hiring professional assistance 

if you decide that outside expertise is 

needed to determine the cause of an IAQ 

problem. 

Tab IV: Appendices 

Appendix A: Common IAQ 

Measurements- A General Guide 

Appendix A describes measurement 

techniques that are commonly used for 

IAQ investigations. If you are responsible 

for developing an IAQ profile or investigating an IAQ complaint, Appendix A 

provides suggestions for collecting and 

interpreting information on: temperature 

and humidity; airflow patterns; carbon 

dioxide; ventilation (outdoor) air quantities; and commonly measured environmental contaminants. 

Appendix B: HVAC Systems and IAQ 

Appendix B presents basic information on 

HV AC system designs and components 

and their effects on indoor air quality. 

This appendix is designed to accompany 

the HVAC Checklists in Tab V. · 

Appendix C: Moisture, Mold and 

Mildew 

Appendix C discusses indoor moisture and 

its relationship to mold and mildew 

growth. The role of humidity in creating 

mold and mildew problems is often 

misunderstood because relative humidity 

readings taken in the breathing zone of an 

occupied space give little indication of 

condition~> at the wall and ceiling surfaces 

or in the wall cavities. This appendix 

describes ways in which to evaluate how 

moisture may be causing indoor air quality 

problems and how successful different 

mitigation measures may be in reducing 

those problems. 

Appendix D: Asbestos 

Appendix D is a brief discussion of 

asbestos. If asbestos is a concern in your 

building, this appendix and the Appendix G 

section will direct you to sources of 

detailed guidance. 

Appendix E: Radon 

Appendix E is a brief discussion of radon. 

To learn more about how to check for 

radon in your building, refer to this 

appendix. Appendix G will direct you to 

other sources of information. 

About This Document 3 
Appendix F: Glossary and Acronyms 

Appendix F explains scientific and 

engineering terminology that may be 

unfamiliar to some readers. 

Appendix G: Resources 

Appendix G is intended for readers who 

want to pursue more detailed information 

about indoor air quality. It includes the 

names, addresses, and telephone numbers 

of Federal, State, and private sector organizations with interests related to IAQ, as 

well as a list of selected publications. 

Contaminant emission and movement in 

buildings is an emerging field of study. 

Building owners, facility managers, and 

engineers are urged to keep abreast of new 

information through professional journals 

and seminars in addition to relying on the 

guidance presented in this document. 

Tab V: Indoor Air Quality Forms 

Tab V contains a full set of the forms 

described in Tabs II and III. Building 

managers are encouraged to reproduce and 

use these blank forms. You may want to 

modify elements of these forms to reflect 

conditions in your particular building. 

4 Section I 

WARNING 

Please note the following as you prepare to 

use this manual: 

• Modification of building functions to 

remedy air quality complaints may create 

other problems. A thorough understanding of all of the factors that interact to 

create indoor quality problems can help 

to avoid this undesirable outcome. 

• The guidance in this document is not 

intended as a substitute for appropriate 

emergency action in the event of a 

hazardous situation that may be 

imminently threatening to life or safety. 

• The implementation of mitigation 

recommendations reached as a result of 

an indoor air quality evaluation should 

always be done in accordance with local 

laws and good practice. Changes to the 

overall design and operation of the 

building may necessitate the involvement of a registered professional engineer or other registered or certified 

professionals. 

• In the event that medical records are 

utilized in the course of evaluating an 

IAQ problem, appropriate legal confidentiality must be maintained. 
Factors Affecting Indoor Air Quality 

l:e indoor environment in any building is 

a result of the interaction between the site, 

climate, building system (original design . 

and later modifications in the structure and 

mechanical systems), construction tech- . 

niques, contaminant sources (building 

materials and furnishings, moisture, 

processes and activities within the building, 

and outdoor sources), and building occupants. 

The following four elements are involved 

in the development ofindoor air quality 

problems: 

Source: there is a source of contamination 

or discomfort indoors, outdoors, or within 

the mechanical systems of the building. 

HV AC: the HV AC system is riot able to 

control existing air contaminants and ensure 

thermal comfort (temperature and humidity 

conditions that are comfortable for most 

occupants). 

Pathways: one or more pollutant pathways 

connect the pollutant source to the occupants and a driving force exists to move 

pollutants along the pathway(s). 

Occupants: building occupants are present. 

It is important to understand the role that 

each of these factors may play in order to 

prevent, investigate, and resolve indoor air 

quality problems. 

SOURCES OF INDOOR AIR 

CONTAMINANTS 

Indoor air contaminants can originate 

within the building or be drawn in from 

outdoors. If contaminant sources are not 

controlled, IAQ problems can arise,.even if 

the HV AC system is properly designed and 

well-maintained. It may be helpful to think 

of air pollutant sources as fitting into one of 

the categories that follow. The examples 

given for each category are not intended to 

be a complete list. 

Sources Outside Building 

Contaminated outdoor air 

• pollen, dust, fungal spores 

• industrial pollutants 

• general vehicle exhaust 

Emissions from nearby sources 

• exhaust from vehicles on nearby roads 

or in parking lots or garages 

• loading docks 

• odors from dumpsters 

• re-entrained (drawn back into the 

building) exhaust from the building 

itself or from neighboring buildings 

• unsanitary debris near the outdoor air 

intake 

Soil gas 

• radon 

• leakage from underground fuel tanks 

• contaminants from previous uses of the 

site (e.g., landfills) 

• pesticides 

Moisture or standing water promoting 

excess microbial growth 

• rooftops after rainfall 

• crawlspace 

Equipment 

HVACsystem 

• dust or dirt in ductwork or other 

components 

• microbiological growth in drip pans, 

humidifiers, ductwork, coils 

• improper use of biocides, sealants, and/ 

or cleaning compounds 

• improper venting of combustion 

products 

• refrigerant leakage 

Factors Affecting Indoor Air Quality 5 

Four elementssources, the HVAC 

system, pollutant 

pathways, and 

occupants -are 

involved ,in the 

development of IAQ 

problems. 
Given our present 

knowledge, it is 

difficult to relate 

complaints of 

specific health 

effects to exposures 

to specific pollutant 

concentrations, 

especially since the 

significant exposures 

may be to low levels 

of pollutant mixtures. 

Non-HV AC equipment 

• emissions from office equipment (volatile organic compounds, ozone) 

• supplieS (solvents, toners, ammonia) 

• emissions from shops, labs, cleaning 

processes 

• elevator motors and other mechanical 

systems 

Human Activities 

Personal activities 

• smoking 

• cooking 

• body odor 

• cosmetic odors 

Housekeeping activities 

• cleaning materials and procedures 

• emissions from stored supplies or trash 

• use of deodorizers and fragrances 

• airborne dust or dirt (e.g., circulated by 

sweeping and vacuuming) 

Maintenance activities 

• microorganisms in mist from improperly maintained cooling towers 

• airborne dust or dirt 

• volatile organic compounds from use of 

paint, caulk, adhesives, and other 

products 

• pesticides from pest control activities 

• emissions from stored supplies 

Building Components and Furnishings 

Locations that produce or collect dust or 

fibers 

• textured surfaces such as carpeting, 

curtains, and other textiles 

• open shelving 

• old or deteriorated furnishings 

• materials containing damaged asbestos 

Unsanitary conditions and water damage 

• microbiological growth on or in soiled 

or water-damaged furnishings 

• microbiological growth in areas of 

surface condensation 

• standing water from clogged or poorly 

designed drains 

• dry traps that allow the passage of 

sewer gas 

6 Section2 

Chemicals released from building 

components or furnishings 

• volatile organic compounds or 

· • inorganic compounds 

Other Sources 

Accidental events 

• spills of water or other liquids 

• microbiological growth due to flooding 

or to leaks from roofs, piping 

• fire damage (soot, PCBs from electrical 

equipment, odors) 

Special use areas and mixed use buildings 

• smoking lounges 

• laboratories 

• print shops, art rooms 

• exercise rooms 

• beauty salons 

• food preparation areas 

Redecorating/remodeling/repair activities 

• emissions from new furnishings 

• dust and fibers from demolition 

• odors and volatile organic and inorganic 

compounds from paint, caulk, adhesives 

• microbiologicals released from demolition or remodeling activities 

Indoor air often contains a variety of 

contaminants at concentrations that are far 

below any standards or guidelines for 

occupational exposure. Given our present 

knowledge, it is difficult to relate complaints ofspecific health effects to exposures to specific pollutant concentrations, 

especially since the significant exposures 

may be to low levels of pollutant mixtures. 

HVAC SYSTEM DESIGN AND 

OPERATION 

The HV AC system includes all heating, 

cooling, and ventilation equipment serving 

a building: furnaces or boilers, chillers, 

cooling towers, air handling units, exhaust 

fans, ductwork, filters, steam (or heating 

water) piping. Most of the HV AC discussion in this document applies both to central 

HV AC systems and to individual components used as stand-alone units. 
A properly designed and functioning 

HV AC system: · 

• provides thermal comfort 

• distributes adequate amounts of outdoor 

air to meet ventilation needs of all 

building occupants 

• isolates and removes odors and contaminants through pressure control, 

filtration, and exhaust fans 

Thermal Comfort 

A number of variables interact to determine whether people are comfortable with 

the temperature of the indoor air. The 

activity level, age, and physiology of each 

person affect the thermal comfort requirements of that individual. The American 

Society of Heating, Refrigerating, and AirConditioning Engineers (ASHRAE) 

Standard 55-1981 describes the temperature and humidity ranges that are comfortable for most people engaged in largely 

sedentary activities. That information is 

summarized on page 57. The ASHRAE 

standard assumes "normal" indoor 

clothing. Added layers of clothing reduce 

the rate of heat loss. 

Uniformity of temperature is important 

to comfort When the heating and cooling 

needs of rooms within a single zone 

change at different rates, rooms that are 

served by a single thermostat may be at 

different temperatures. Temperature 

stratification is a common problem caused 

by convection, the tendency of light, warm 

air to rise and heavier, cooler air to sink. If 

air is not properly mixed by the ventilation 

system, the temperature near the ceiling 

can be several degrees warmer than at 

floor level. Even if air is properly mixed, 

uninsulated floors over unheated spaces 

can create discomfort in some climate 

zones. Large fluctUations of indoor 

temperature can also occur when controls 

have a wide "dead band" (a temperature 

range within which neither heating nor 

cooling takes place). 

Radiant heat transfer may cause Pf.':Ople 

located near very hot or very cold surfaces 

to be uncomfortable even though the 

thermostat setting and the measured air 

temperature are within the comfort range. 

Buildings with large window areas 

sometimes have acute problems of discomfort due to radiant heat gains and losses, 

with the locations of complaints shifting 

during the day as the sun angle changes. 

Large vertical surfaces can also produce a 

significant flow of naturally-convecting air, 

producing complaints of draftiness. 

Adding insulation to walls helps to . 

moderat~ the temperature of interior wall 

surfaces. Closing curtains reduces heating 

from direct sunlight and isolates building 

occupants from exposure to window 

surfaces (which, lacking insulation, are 

likely to be much hotter or colder than the 

walls). 

Humidity is a factor in thermal comfort. 

Raising relative humidity reduces the 

ability to lose heat through perspiration and 

evaporation, so that the effect is similar to 

raising the temperature. Humidity t:Xtremes can also create other IAQ problems. 

Excessively high or low relative humidities 

can produce discomfort, while high relative 

humidities can promote the growth of mold 

and mildew. (See Appendix C.) 

Ventilation to Meet Occupant 

Needs 

Most air handling units distribute a blend 

of outdoor air and recirculated indoor air. 

HV AC designs may also include units that 

introduce 100% outdoor air or that simply 

transfer air within the building. Uncon- . 

trolled quantities of outdoor air enter 

buildings by infiltration through windows, 

doors, and gaps in the exterior construction. Thermal comfort and ventilation 

needs are met by supplying "conditioned" 

air (a blend of outdoor and recirculated air 

that has been filtered, heated or cooled, and 

sometimes humidified or dehumidified). 

Factors Affecting Indoor Air Quality 7 

A number of 

variables, including 

personal activity 

l~vels, uniformity of 

temperature, radiant 

heat gain or loss, and 

humidity, interact to 

determine whether · 

people are comfortable 

with th·e temperature 

of the indoor air. 
The amount of 

outdoor air 

considered adequate 

for proper ventilation 

has varied 

substantially over 

time. Tho current 

guideline issued by 

ASHRAE is Standard 

62-1989. 

Large buildings often have interior 

("core") spaces in which constant cooling 

is required to compensate for heat generated by occupants, equipment, and 

lighting, while perimeter rooms may 

require heating or cooling depending on 

outdoor conditions. 

Two of the most common HV AC 

designs used in modem public and 

commercial buildings are constant volume 

and variable air volume systems. Constant volume systems are designed to 

provide a constant airflow and to vary the 

air temperature to meet heating and 

cooling needs. The percentage of outdoor 

air may be held constant, but is often 

controlled either manually or automatically 

to vary with outdoor temperature and 

humidity. Controls may include a minimum setting that should allow the system 

to meet ventilation guidelines for outdoor 

air quantities under design conditions. 

Variable air volume (VA V) systems 

condition supply air to a constant tempera-. 

ture and ensure thermal comfort by varying 

the airflow to occupied spaces. Most early 

VA V systems did not allow control of the 

outdoor air quantity, so that a decreasing 

amount of outdoor air was provided as the 

flow of supply air was reduced. Some 

more recent designs ensure a minimum 

supply of outdoor air with static pressure 

devices in the outdoor air stream. Additional energy-conserving features such as 

economizer control or heat recovery are 

also found in some buildings. 

Good quality design, installation, and 

testing and balancing are critically important to the proper operation of all types 

of HV AC systems, especially VA V 

systems, as are regular inspections and 

maintenance. (See Appendix B for further 

discussion of HV AC system types.) 

The amount of outdoor air considered 

adequate for proper ventilation has varied 

substantially over time. The current 

guideline issued by ASHRAE ·is ASHRAE 

Standard 62-1989. The building code that 

was in force when your building HV AC 

8 Section2 

system was designed may well have 

established a lower amount of ventilation 

(in cubic feet of outdoor air per minute per 

person) than is currently recommended. 

(A table of outdoor air quantities recommended by ASHRAE is reproduced on 

page 136 in Appendix B. Note that other 

important aspects of the standard are not 

included in this table.) 

Control of Odors and 

Contaminants 

One technique for controlling odors and 

contaminants is to dilute them with 

outdoor air. Dilution can work only if 

there is a consistent and appropriate flow 

of supply air that mixes effectively with 

room air. The term "ventilation efficiency" is used to describe the ability of 

the ventilation system to distribute supply 

air and remove internally generated 

pollutants. Researchers are currently 

studying ways to measure ventilation 

efficiency and interpret the results of those 

measurements. 

Another technique for isolating odors 

and contaminants is to design and operate 

the HV AC system so that pressure 

relations~ps between rooms are controlled. This control is accomplished by 

adjusting the air quantities that are 

supplied to and removed from each room. 

If more air is supplied to a room than is 

exhausted, the excess air leaks out of the 

space and the room is said to be under 

positive pressure. If less air is supplied 

than is exhausted, air is pulled into the 

space and the room is said to be under 

negative pressure. 

Control of pressure relationships is 

critically important in mixed use buildings 

or buildings with special use areas. 

Lobbies and buildings in general are often 

designed to operate under positive pressure 

to prevent or minimize the .infiltration of 

unconditioned air, with its potential to 

cause drafts and introduce dust, dirt, and 

thermal discomfo1t. Without proper 

operation and maintenance, these pressure 
differences are not likely to remain as 

originally designed. 

. A third technique is to use local exhaust 

systems (sometimes known as dedicated 

exhaust ventilation systems) to isolate and 

remove contaminants by maintaining 

negative pressure in the area around the 

contaminant source. Local exhaust can be 

linked to the operation of a particular piece 

of equipment (such as a kitchen range) or 

used to treat an entire room (such as a 

smoking lounge or custodial closet). Air 

should be exhausted to the outdoors, not 

recirculated, from locations which produce 

significant odors and h(gh concentrations 

of contaminants (such as copy rooms, 

bathrooms, kitchens, and beauty salons). 

Spaces where local exhaust is used must 

be provided with make-up air and the local 

exhaust must function in coordination with 

the rest of the ventilation system. Under 

some circumstances, it may be acceptable 

to transfer conditioned air from reiatively 

clean parts of a building to comparatively 

dirty areas and use it as make-up air for a 

local exhaust system. Such a transfer can 

achieve significant energy savings. 

Air cleaning and filtration devices 

designed to control contaminants are found 

as components of HV AC systems (for 

example, filter boxes in ductwork) and can 

also be installed as independent units. The 

effectiveness of air cleaning depends upon 

proper equipment selection, installation, 

operation, and maintenance. Caution 

should be used in evaluating the many new 

technological developments in the field of 

air cleaning and ftltration. 

POLLUTANT PATHWAYS AND 

DRIVING FORCES 

Airflow patterns in buildings result from 

the combined action of mechanical 

ventilation systems, human activity, and 

natural forces. Pressure differentials 

created by these forces move airborne 

contaminants from areas of relatively 

higher pressure to areas of relatively lower · 

pressure through any available openings. 

The HV AC system is generally the 

predominant pathway and driving force for 

air movement in buildings. However, all 

of a building's components (walls, ceilings, 

floors, penetrations, HV AC equipment, and 

occupants) interact to affect the distribution 

of contaminants. 

For example, as air moves from supply 

registers or diffusers to return air grilles, it 

is diverted or obstructed by partitions, 

walls, and furnishings, and redirected by 

openings that provide pathways for air 

movement. On a localized basis, the 

movement of people has a major impact on 

the movement of pollutants. Some of the 

pathways change as doors and win~ows 

open and close. It is useful to think of the 

entire building the rooms and the 

connections (e.g., chases, corridors, 

stairways, elevator shafts) between them 

as part of th~ air, distribution system. 

Natural forces exert an important 

influence on air movement between zones 

and between the building's interior and 

exterior. Both the stack effect and wind 

can overpower a building's mechanical 

system and disrupt air circulation and 

ventilation, especially if the building 

envelope is leaky. 

Stack effect is the pressure driven flow 

produced by convection (the tendency of 

Factors Affecting Indoor Air Quality 9 

Chases, craw/spaces, and 

other hidden spaces can be 

both sources and pathways 

for pollutants. 
The basic principle of 

air movement from 

areas of relatively 

higher pressure to 

area• of relatively 

lower pressure can 

produce many 

patterns of 

contaminant 

distribution. 

warm air to rise). The stack effect exists 

whenever there is an indoor-outdoor 

temperature difference and becomes 

stronger as the temperature difference 

increases. As heated air escapes from 

upper levels of the building, indoor air 

moves from lower to upper floors, and 

replacement outdoor air is drawn into 

openings at the lower levels of buildings. 

Stack effect airflow can transport contaminants between floors by way of stairwells, 

elevator shafts, utility chases, or other 

openings. 

Wind effects are transient, creating local 

areas of high pressure (on the windward 

side) and low pressure (on the leeward 

side) of buildings. Depending on the 

leakage openings in the building exterior, 

wind can affect the pressure relationships 

within and between rooms. 

The basic principle of air movement from 

areas of relatively higher pressure to areas 

of relatively lower pressure can produce 

many patterns of contaminant distribution, 

including: 

• local circulation in the room containing 

the pollutant source 

• air movement into adjacent spaces that 

are under lower pressure (Note: Even if 

two rooms are both under positive 

pressure compared to the outdoors, one 

room is usually at a lower pressure than 

the other.) 

• recirculation of air within the zone 

containing the pollutant source or in 

adjacent zones where return systems 

overlap 

• movement from lower to upper levels of 

the building 

• air movement into the building through 

either infiltration of outdoor air or 

reentry of exhaust air 

Air moves from areas of higher pressure 

to areas of lower pressure through any 

available openings. A small crack or hole 

can admit significant amounts of air if the 

pressure differentials are high enough 

(which may be very difficult to assess). 

10 Section2 

Even when the building as a whole is 

maintained under positive pressure, there is 

always some location (for example, the 

outdoor air intake) that is under negative 

pressure relative to the outdoors. Entry of 

contaminants may be intermittent, occurring only when the wind blows from the 

direction of the pollutant source. The 

interaction between pollutant pathways and 

intermittent or variable driving forces can 

lead to a single source causing IAQ 

complaints in areas of the building that are 

distant from each other and from the 

source. 

BUILDING OCCUPANTS 

The term "building occupants" is generally 

used in this document to describe people 

who spend extended time periods (e.g., a 

full workday) in the building. Clients and 

visitors are also occupants; they may have 

different tolerances and expectations from 

those who spend their entire workdays in 

the building, and are likely to be more 

sensitive to odors. 

Groups that may be particularly susceptible to effects of indoor air contaminants 

include, but are not limited to. 

• allergic or asthmatic individuals 

• people with respiratory disease 

• people whose immune systems are 

suppressed due to chemotherapy, 

radiation therapy, disease, or other 

causes 

• contact lens wearers 

Some other groups are particularly 

vulnerable to exposures of certain 

pollutants or pollutant mixtures. For 

example, people with heart disease may be 

more affected by exposure at lower levels 

of carbon monoxide than healthy 

individuals. Children exposed to environmental tobacco smoke have been shown to 

be at l)igher risk of respiratory illnesses 

and those exposed to nitrogen dioxide have 

been shown to be at higher risk from 

respiratory infections. 
. Because of varying sensitivity among 

people, one individual may react to a 

particular IAQ problem while surrounding 

occupants have no ill effects. (Symptoms 

that are limited to a single person can also 

occur when only one work station receives 

the bulk of the pollutant dose.) In other 

cases, complaints may be widespread. 

A single indoor air pollutant or problem 

can trigger different reactions in different 

people. Some may not be affected a~ all. 

Information about the types of symptoms 

can sometimes lead directly to solutions. 

However, symptom information is more 

likely to be useful for identifying the timing 

and conditions under which problems 

occur. 

Types of Symptoms and 

Complaints 

The effects of IAQ problems are often nonspecific symptoms rather than clearly 

defined illnesses. Symptoms commonly 

attributed to IAQ problems include: 

• headache 

• fatigue 

• shortness of breath 

• sinus congestion 

• cough 

• sneezing 

• eye, nose, and throat irritation 

• skin irritation 

• dizziness 

• nausea 

All of these symptoms, however, may also 

be caused by other factors, and are not 

necessarily due to air quality deficiencies. 

"Health" and "comfo:J:t" are used to 

describe a spectrum of physical sensations. 

For example, when the air in a room is 

slightly too warm for a person's activity 

level, that person may experience mild 

discomfort. If the temperature continues to 

rise, discomfort increases and symptoms 

such .as fatigue, stuffiness, and headaches 

can appear. 

Some complaints by building occupants 

are clearly related to the discomfort end of 

the spectrum. One of the most common 

IAQ complaints is that "there's a funny 

smell in here." Odors are often associated 

with a perception of poor air quality, 

whether or not they cause symptoms. 

Environmental stressors such as improper 

lighting, noise, vibration, overcrowding, 

ergonomic stressors, and job-related 

psychosocial problems ,(such as job stress) 

can produce symptoms that are similar to 

those associated with poor air quality. 

The term sick building syndrome (SBS) 

is sometimes used to describe cases in 

which building occupants experience acute 

health and comfort effects that are apparently linked to the time they spend in the 

building, but in which no specific illness or 

cause can be identified. The complaints 

may be localized in a particular room or 

zone or may be widespread throughout the 

building. Many different symptoms have 

been associated with SBS, including 

respiratory complaints, irritation, and 

fatigue. Analysis of air samples often fails 

to detect high concentrations of specific 

contaminants. The problem may be caused 

by any or all of the following: 

• the combined effects of multiple 

pollutants at low concentrations 

• other environmental stressors 

(e.g., overheating, poor lighting, noise) 

• ergonomic stressors 

• job-related psychosocial stressors 

(e.g., overcrowding, labor-management 

problems) 

• unknown factors 

BJ,lilding-related illness (BRI) is a term 

referring to illness brought on tiy exposure 

to the building air, where symptoms of 

diagnosable illness are identified (e.g., 

certain allergies or infections) and can be 

directly attributed to environmental agents 

in the air. Legionnaire's disease and 

hypersensitivity pneumonitis are examples 

of BRI tbat can have serious, even lifethreatening consequences. 

Factors Affecting Indoor Air Quality 11 

Environmental 

stressors such as 

improper lighting, 

noise, vibration, · ·. · 

overcrowding, · 

ergonomic stressors,. · 

and job-related · 

psychosocial 

problems (such as job . 

stress) can produce·· 

symptoms that are 

similar to those 

associated with poor 

air quality. 
A small percentage of the population 

may be sensitive to a number of chemicals 

in indoor air, each of which may occur at 

very low concentrations. The existence of 

this condition, which is known as multiple 

chemical sensitivity (MCS), is a matter of 

considerable controversy. MCS is not 

currently recognized by the major medical 

organizations, but medical opinion is 

divided, and further research is needed. 

The applicability of access for the disabled 

and worker's compensation regulations to 

people who believe they are chemically 

sensitive may become concerns for facility 

managers. 

12 Section2 

Sometimes several building occupants 

experience rare or serious health problems 

(e.g., cancer, miscarriages, Lou Gehrig's 

disease) over a relatively short time period. 

These clusters of health problems are 

occasionally blamed on indoor air quality, 

and can produce tremendous anxiety 

among building occupants. State or local 

Health Departments can provide advice 

and assistance if clusters are suspected. 

They may be able to help answer key 

questions such as whether the apparent 

cluster is actually unusual and whether the 

underlying cause could be related to IAQ. 
Effective Communication 

This section discu~ses establishing and 

maintaining a communication system that 

can help prevent indoor air quality 

problems and resolve problems cooperatively if they do arise. If you. are currently 

responding to an indoor air quality 

complaint, you may want to skip ahead to 

the discussion of Communicating to 

Resolve IAQ Problems on page 15. 

COMMUNICATING TO PREVENT 

IAQ PROBLEMS 

Effective communication can encourage 

building occupants to improve their work 

environment through positive contributions. The following objectives should be 

kept in mind while reviewing and revising 

your current approach to communicating 

with occupants: 

• provide accurate information about 

factors that.affect indoor air quality 

• clarify the responsibilities of each party 

(e.g., building management, staff, tenants, contractors) 

• establish an effective system for logging 

and responding to complaints should 

they occur 

Provide Accurate Information 

Many indoor air quality problems can be 

prevented if staff and building occupants 

understand how their activities affect IAQ. 

You may already have a health and safety 

committee functioning to promote good 

working conditions. If so, it is easy to add 

indoor air quality to their list of concerns. 

If you do not have a health and safety 

committee, consider establishing one or 

setting up a joint management-tenant IAQ 

task force. Whatever its official designation, such a group can help to disseminate 

information about indoor air quality, bring 

potential problems to the attention of 

building staff and management, and foster 

a sense of shared responsibility for 

maintaining a safe and comfortable indoor 

environment. 

The group will be most successful ifit 

represents the diverse interests in the 

building, including: 

• building owner 

• building manager 

• facility personnel 

• health and safety officials 

• tenants and/or other occupants who are 

not facility staff 

• union representatives (or other worker 

representatives) 

Clarify Responsibilities 

It is important to derme the responsibilities 

of building management, staff, and 

occupants in relation to indoor air quality. 

These responsibilities can be formalized by 

incorporating them into documents such as 

employee manuals or lease agreements. 

Effective Communication 13 

The occupant in this room 

covered the supply air vents 

with papers. Whether this 

was done to reduce uncomfortable drafts or to provide 

more shelf space, the result 

can disrupt the air flow, not 

only through this room but 

elsewhere in the building. 

By tampering with the air 

handling system, occupants 

can unintentionally cause 

complaints in other areas. 
Use of space: Educate occupants about the 

pennitted uses and maximum occupancy of 

different areas within the building and 

make sure that appropriate ventilation is 

provided for the activities that are permitted. Indoor air quality complaints often 

arise in mixed-use buildings. For example, 

kitchen staff expect food odors as part of 

their work, but nearby office workers may 

fmd cooking odors distracting and unpleasant. Problems can also arise when old 

tenants leave and new arrivals introduce 

new uses of the building. 

Occupancy Rate: Inform occupants about 

the importance of keeping the building 

management informed about significant 

changes in the number of people regularly 

using particular areas of the building. The 

ventilation systems in buildings are 

designed and operated to supply air to 

1,' I "•,' 1 

· ih~ State. of Wisconsin's "Quality Buildin9 Management" system 

qa!S heiped to unite the diverse interests involved in operating 

:~n41.!SlJ'l9 State office buildin9s. Tenants and facility personnel 

Yolunteered to serve on t~:~ams, working cooperatively to improve 

the quality of the indoor environment. 

!'!,;,;,;,, .. , .. , ... 5.~9ti!.~~.rn W~~ Cl~f;igned a specific area for whi<?h it drafted 

~ld~al ~ .. '-!ilding Standards." Air quality was one such area; 

· ,, arslnCiudeCI elevato..S; est rooms ana work spaces. the IAQ 111•',:""1!11111111!11~:11111~~1,11"1,"1''1•1!1"'•'11' •'l•llllll"':l,'l"'l' •' '" •I'' h II •llll,ll'"llliiillil[,'',ll I" ,,.jm •" i•'"illl ,:•i( "'"i'l"''• • 11 ill,,l'l'illl: •'' ,,j'.,l''''l •Ill'"" 'I "II'"'"""''' II' '" '""' 

s ~ere trained in corductjng research; toured mechanical 

;;,!!, ..... , .:~· 'iX:I~rns fq. a~hie~.E! a bette~ ~pdersti'Jn9ing of building operations; 

''II;. •· 11 .. @q.~ arti~l~~; ~md.li~t!;!I1E!g to presentations on IAQ, ventilation, 

'1' ,:' a{ld r,elated topics. . . 

::::::::,· ::: ::::' :: 'Tlle'Eroposed "Ideal still ding standards" wererevieweC!.witll. 

1

, \]~ther t~nants !)nd tbE!n Us!3d as a basis for Quality Improvement 

::~i''"!"' .. ,,,, ;!!h,f,,9,Q!~''.,I"I§e,OJ,~.,,,~l~,[l,~u!Jui~,, g!:,,l~~Et,u9,~.~~~U~,,, ~,~,P.f2.Y~~~~"~! .. ,~,~,~~~~ ~~~~~~~·~ •!!li: 1

:,,, " .[~~pdn~lpiHties of the teqants, such as 13dopting good houseg~epln~' p~actices t() ifl1 p~()Ve t~e w~:>r~. t:lll\fi ror1 .. rl1e.!:l.t ... an~. f":'cilitate 

· qjf~~hlrig. Responsibilities identified as belonging to buildin~;J 

.. man8QE)ment are reflected in work plans and budget decisions. 

Sl~ce Implementation of this management system, interactions 

Petw~QO builgjng management and tenants have improved. 

'tenants actively seek out management staff to discuss con~erns~ 

.Howev~r, they are also more willing to review their own actions _ 

Wht:! .. l'llooking for potential causes of IAQ problems. 

14 Section3 

projected ranges of occupants. If the 

occupancy rate becomes a problem, it may 

be helpful to refer to a standard reference 

such as ASHRAE Standard 62-1989 to 

show occupants that keeping occupancy 

within the ventilation capacity serves the 

goal of providing a quality work environment and is not an arbitrary decision by 

building management. 

Modifications: Review plans that may 

involve increases in the number of occupants, relocation of walls or partitions, 

installation of new equipment, or changes 

in the use of space. Building owners, 

facility managers, and occupants share 

responsibility for monitoring new equipment installation and changes in the use of 

space. The review process allows potential 

indoor air quality problems to be identified 

so that the HV AC system can be modified 

as needed. Only authorized maintenance 

personnel should adjust air supply or 

exhaust vents; however, if occupants are 

expected to follow such a "hands-off' 

policy, facility management must respond 

promptly to IAQ complaints. 

Notification ofplarmed activities: 

Establish a procedure for infonning tenants 

before the start of activities that produce 

odors or contaminants (e.g., maintenance, 

pest control, repair, remodeling, 

redecorating). 

Establish a System for 

Responding to Complaints 

Many organizations have established 

procedures for responding to occupant 

complaints that can be modified to include 

indoor air quality concerns. To avoid 

frustrating delays, building occupants need 

to know how to express their complaints 

about IAQ. Most importantly, they need to 

know how to locate responsible staff and 

where to obtain complaint forms. This 

information can be posted on bulletin 

boards, circulated in memos or newsletters, 

or publicized by some other means. 
Complaints should be handled 

promptly, with every incident given 

serious attention. It is advisable to 

establish a recordkeeping system that 

cross-references documentation on 

complaints with records of equipment 

operation and maintenance. The 

recordkeeping system carl. help to resolve· 

complaints by collecting information in a 

form that highlights patterns of problems 

{for example, complaints that occur at a 

regular time of day or in the same area of 

the building). The IAQ Complaint Form 

and Incident Log shown here and on the 

following page (and also reproduced in 

Tab V) can be used to track complaints 

related to the indoor environment. 

COMMUNICATING TO RESOLVE 

lAO PROBLEMS 

In many cases, building managers may be 

alerted to potential indoor air quality 

problems by complaints from occupants. 

The complaints can be vague, to the effect 

that one or more people feel "sick" or 

"uncomfortable" or that someone has 

noticed an unusual odor. They may be 

specific, blaming a particular material as 

the cause of discomfort or health problems. 

People are usually reacting to a real 

problem, so their complaints should be 

taken seriously. However, they may 

attribute their symptoms to the wrong 

cause, so their theories about the problem 

sh~uld be heard respectfully but weighed 

cautiously. 

Indoor air quality problems can 

sometimes be identified and resolved 

quickly. On other occasions, complaints 

originate from the interaction of several 

variables, and detailed investigation may 

be necessary in order to resolve the 

problem. 

The Importance of Responding 

to lAO Complaints 

Listening and responding to building 

occupants is critical to achieving a 

............ ,... , · J~Qrc9ryt~laiJlt triavb~ related to .· 

"'""'''t-" . air qti~lit.}f pr()blems in.clude con9erns ··.· 'ventilation, ;,mdairpollutants. Your 

· .. resolve th"e problem .as;quickly as possible. 

. tO:'describ~th'e nature of the complaint • _ _.._ ·- j> - :~-. - 1 ••• • • • • 

. :.~: . ·: ,:·-.: ' 

"<"• •• ~ 

<\~; :;~/~\>" >~ ·. 

:.' ,.., :~;>::;· -~!~--- ., . . ,.w;; 

·-·- ·>> -.-;:._·f-.:~r :· .. 

··-"~· ..... ·.~·.--..nT,,,.T'·Yo~ fq dlscussxourcomplaint. What is the · 

successful resolution of indoor air quality 

complaints. IAQ complaints may be 

grounded in poor indoor air quality, 

thermal conditions, noise, glare, or even 

job stresses. However, it is in the building 

.manager's best interest to respond to all 

complaints about the indoor environment 

promptly and seriously and to establish 

credibility through open communication 

with building occupants. The biggest 

mistake that building managers can make 

in the face or an IAQ complaint is to 

underestimate the problems that can result 

if building occupants believe that no action 

is being taken or that important information is being withheld. Without open 

communication, any IAQ problem can 

become complicated by anxiety, frustration, and distrust, delaying its resolution. 

Paying attention to communication, as 

well as problem-solving, helps to ensure 

Effective Communication 15 

SEE' 

.·COMPLETE 

FORM 

·PAGE 181 
Tho messages to 

convey are that 

management believes 

lt Is important to 

provide a healthy and 

ufo building, that 

good indoor air 

quality is an essential 

component of a 

healthful indoor 

environment, and that 

complaints about 

Indoor air quality are 

taken seriously. 

Investigation R.ecord 

(check the forms that were used) 

i~ 1: fl) 

(,)~ !~ 'S.!! a.~ :J.!! Q~ ~1$ §~ gc 

0 .9cc B 

the support and cooperation of building 

occupants as the complaint is investigated 

and resolved. The messages to convey are 

that management believes it is important to 

provide a healthy and safe building, that 

good indoor air quality is an essential 

component of a healthful indoor environment, and that complaints about indoor air 

quality are taken seriously. 

Communications, whether they occur in 

conversations or in writing, should include 

the following information: 

• what types of complaints management 

has received 

• management's policy in regard to 

providing a healthy and safe environment and responding to occupant 

complaints 

• what management has done to date (e.g., 

collecting data, responding to the 

problem) 

• what management plans to do in order to 

further investigate and correct the 

problem {including the fact that outside 

consultants have been called in, if they 

have been) 

• the names and telephone numbers of 

appropriate facility management, 

16 Section3 

1:> 

:.a. ~~ 

~ Outcome/ 

~~ Comments 

0> =· (l).e 

medical, or health and safety staff to 

whom the occupants should tum if they 

have additional complaints or questions, 

or if they have information that may help 

in resolving the complaints 

Maintaining th•:. Lines of 

Communication 

Make certain that occupants know how to 

contact the responsible personnel who can 

receive and respond to IAQ complaints. 

Tenants may also have an internal system 

for channeling complaints, for example 

through a health and safety representative, 

supervisor, or company doctor. 

Indoor air quality complaints that can 

be resolved quickly and that involve small 

numbers of people (e.g., annoying but 

harmless odors from an easily-identified 

source) can be handled matter-of-factly 

like other minor problems without risking 

confusion and bad £eeling among other 

building occupants. Communication 

becomes a more critical issue when there 

are delays in identifying and resolving the 

problem and when serious health concerns 

are involved. 
If the problem seems to be widespread 

or potentially serious, it is advisable to 

work with your health and safety committee. If you do not have a health and safety 

committee, consider forming one, or 

establishing a joint management -tenant 

IAQ task force. (See the discussion on. 

page 13.) 

Productive relations will be enhanced if 

occupants are given basic information 

during the process of investigation and 

mitigation. Potential critics can become 

allies if they are invited to be part of the 

problem-solving process and become 

better educated about IAQ and building 

operations. Building managers may be 

understanda~ly reluctant to share test 

results or consultants' reports with their 

tenants or employees, but secrecy in such 

matters can backfire if information leaks 

out at a later time. 

Building management staff can be 

encouraged to talk directly with occupants 

both at the time a complaint occurs and 

later during a diagnostic investigation. 

Their observations about patterns of 

symptoms or building conditions may 

provide helpful information. 

Confidentiality of records can be 

important to occupants, especially if they 

are concerned that IAQ complaints will 

lead to negative reactions from their 

employers. There may be legal penalties 

for violating confidentiality of medical 

records. By reassuring occupants that 

privacy will be respected, investigators are 

more likely to obtain honest and complete 

information. 

It is advisable to explain the nature of 

investigative activities, so that rumors and 

suspicions can be countered with factual 

information. ·Notices or memoranda can 

be delivered directly to selected occupants 

or posted in general use areas. Newsletter 

articles or other established communication channels can also be used to keep 

building occupants up-to-date. 

Problems can arise from saying either 

too little or too much. Premature release 

of information when data-gathering is still 

incomplete can produce confusion, 

frustration, and mistrust at a later date. 

Similar problems can result from incorre~t 

representation of risk- assuming the. 

worst case (or the best). However, if 

progress reports are not given, people may 

think nothing (or something terrible) is 

happening. It is good practice to clear 

each piece of information with the facility 

manager, building owner, or legal counsel. 

Management should attempt to be factual 

and to the point when presenting information such as: 

• the definition of the complaint area 

based upon the location and distribution 

of complaints (this may be revised as the 

investigation progresses) 

• the progress of the investigation, 

including the types of information that 

are being gathered and ways that 

occupants can help 

• factors that have been eyaluated and 

found not to be causing or contributing 

to the problem 

• how long the investigation might t*e 

• attempts that are being made to improve 

indoor air quality 

• work that remains to be done and the 

schedule for its completion 

Vague discomfort, intermittent symptoms, and pomp lex interactions of job 

stress with environmental factors, which 

make IAQ problems difficult to investigate, can also obscure the effects of 

mitigation efforts. Even after the proper 

mitigation strategy is in place, it may take 

days or weeks for contaminants to dissi~ 

pate and symptoms to disappear. If 

building occupants are informed that their 

symptoms may persist for some time after 

mitigation, the inability to bring instant 

relief is less. likely to be seen as a failure. 

Effective Communication 17 

If the problem seems 

to be widespread or 

potentially serious, it 

is advisable to work 

with your health and 

safety committee. If 

you do not have a 

health and safety 

committee, consider 

forming one, or 

establishing a joint 

management-tenant 

lAO task force. 

Developing an lAO Profile 

An IAQ profile is a description of the 

features of the building structure, function, 

and occupancy that impact indoor air 

quality. When you have completed the 

IAQ profile, you should have an understanding of the current status of air quality 

in the building and baseline information on 

the factors that have a potential for causillg 

problems in the future. 

The IAQ profile can help building 

management to identify potential problem 

areas and prioritize budgets for maintenance and future modifications. Combined 

with information on lighting, security, and 

other important systems, it can become an 

owner's manual that is specific to your 

building and that will serve as a reference 

in a variety of situations. 

The key questions to answer while 

developing the IAQ profile are: 

• How was this building originally 

intended to function? Consider the 

building components and furnishings, 

mechanical equipment (HV AC and nonHV A C), and the occupant population 

and associated activities. 

• Is the building functioning as designed? 

Find out whether it was commissioned. 

Compare the information from the 

commissioning to its current condition. 

• What changes in building layout and use 

have occurred since the original design 

and construction? Find out if the HV AC 

system has been reset and retested to 

reflect current usage. 

• What changes may be needed to prevent 

IAQ problems from developing in the 

future? Consider potential changes in 

future uses of the building. 

After reading this manual to develop a 

feel for the issues involved in maintaining 

good indoor air quality in a building, the 

development of an IAQ proflle should 

become a priority. The process of 

developing an IAQ profile should require 

only a modest effort, from a few days to a 

few weeks of staff time, depending on the 

complexity of your building and the 

amount of detailed information collected. 

The work can be done in pieces over a 

longer period, if necessary, to fit into a 

building manager's busy schedule. 

Over time, it is desirable to make some 

actual measurements of airflow, temperature, relative humidity, carbon dioxide 

(C02), and/or pressure differentials (e.g., in 

each of the air handling zones or other subareas of the building). These measurements provide far better information on 

current conditions than can be obtained 

from the plans and specifications, even if 

· as-built records are available. 

In addition, few buildings have been 

adequately commissioned, so the system 

may never have delivered the airflows 

shown on the design drawings. In the 

event of litigation around future IAQ 

complaints, the value of the IAQ proflle as 

a resource document will be enhanced by 

real-world measurements. (Refer to 

Appendix G and the ASHRAE standard on 

commissioning. The EPA document on 

designing forgood indoor air quality, 

which is due to be published in 1992, will 

contain a more complete discussion of the 

process of commissioning buildings.) 

Developing an IAQ Profile . 19 
FIGURE 4-1: Developing an IAQ Profile 

1. Collect and 

Reviaw Existing 

Records 

Review design, 

construction, and 

operating documents 

Chock HVAC malntenzmce records against 

equipment lists 

Review complaint 

record 

2. Conduct a 

Walkthrough 

Inspection of the 

Building 

Talk with staff and 

other occupants 

Look for IAQ problem 

Indicators 

3. Collact Detailed 

Information 

HVACsystem 

condition and 

operation 

Pollutant pathways 

Pollutant sources 

Occupants 

Go to Section 6 

PRODUCTS 

• Description of HVAC system 

design and operation; set of 

operating instructions, manuals 

• Set of maintenance and calibration 

records 

• Inventory of locations where 

occupancy, equipment, or building 

have changed 

• Inventory of complaint locations 

• List of responsible staff and/or 

contractors; evidence of training; 

job descriptions 

• Identification of areas where 

positive or negative pressures 

should be maintained (sketch 

plan) 

• Record of locations that need 

monitoring or correction 

• Inventory of HVAC system 

components needing repair, 

adjustment or replacement 

• Record of control settings and 

operating schedules 

• Completed plan showing airflow 

directions or pressure differentials in significant areas 

• Inventory of significant 

pollutant sources and their 

locations 

• Set of Material Safety Data 

Sheets for supplies and 

hazardous substances that are 

stored or used in the building 

• Zone/Room Record 

Yes 

Did 

you find 

anyiAQ 

problems 

? 

Develop an IAQ management plan (see Section 5) 

20 Section4 

SKILLS REQUIRED TO CREATE 

AN lAO PROFILE 

Many of the resources necessary for the 

IAQ profile should already be on hand 

within your organization. Additional 

information can be collected by the staff 

person or persons who have the following 

skills: 

• basic understanding of HV AC system 

operating principles 

• ability to read architectural and mechanical plans and understand manufacturer's 

catalog data on equipment 

• ability to identify items of office 

equipment 

• ability to work cooperatively with 

building occupants and gather information about space usage 

• ability to collect information about . 

HV AC system operation, equipment 

condition, and maintenance schedules 

• authority to collect information from 

subcontractors about work schedules 

and materials used (particularly cle~ing 

and pest control activities) 

• ability to understand the practical 

meaning of the information contained in 

the Material Safety Data Sheets 

(MSDSs) 

If direct measurements are to be 

included in the IAQ profile, the staff 

should have the tools and training to make 

the following measurements (see Appendix 

A for guidance on air sampling): 

• air volumes at supply diffusers and 

exhaust grilles 

• C02 concentration 

• temperature 

• relative humidity 

• pressure differentials 

• assessment of thermal and ventilation 

load requirements 

Section 8 provides guidance on hiring 

IAQ professionals if you prefer to use 

outside expertise to develop your IAQ 

profile. 
STEPS IN AN IAQ PROFILE 

The information needed for an IAQ profile 

is similar to that which is collected when 

solving indoor air quality problems, but 

includes the entire building rather than 

focusing on areas that may have caused an 

identified problem. The IAQ·proflle 

should be an organized body of records 

that can be referred to in planning for 

renovations, negotiating leases and 

contracts, or responding to future complaints. 

The process of gathering information 

for the IAQ profile can be divided into 

three major stages: 

1. Collect and review existing records. 

2. Conduct a walkthrough inspection of 

the building. 

3. Collect detailed information on the 

HV AC system, pollutant pathways, 

pollutant sources, and building 

occupancy. 

The first two stages should be carried 

out as quickly as possible, but the third 

stage can be handled as time allows so that 

it does not interfere with other staff 

responsibilities. 

1. Collect and Review Existing 

Records 

Review.construction and operating 

documents 

Collect any available documents that 

describe the construction and operation of 

the building: architectural and mechanical 

plans, specifications, submittals, sheet 

metal drawings, commissioning reports, 

adjusting and balancing reports, inspection 

records, and operating manuals. Many 

buildings may lack some or all of these 

documents. If there are no commissioning 

reports or balancing reports, actual ventilation quantities may be quite different 

from those indicated on mechanical design 

l"!lll'rAr~t QCriup~nC'/Qf 

sysiterir:i otper•atk.ri repr~s~int:s · .. fro in the 

:~t;r+tpt~i~t~ .6~ve'I>een . ,.~f ~-;,.. ':·~·>· .. - ' •' . 

... { \-.·-:· =>-;(··---~ ~:-~ .- •''- ·,__h __ ,._ 

> -~ .... : •. ,. ~-~_:_-_,;_::;,~:::.wi;::~.~- ~:~ ~;:;..~:.~~L.::2'::~·/.t~~~-- . ·:· ~ 0 .-· :-:;::.-.\, • --

drawings. If there are no operating or 

maintenance manuals for HV AC equipment, it is difficult for staff to carry out an 

adequate preventive maintenance program. 

Study the original architectural and 

mechanical design so that you understand 

the building's layout and intended functions. Identify and note locations in which 

changes in equipment or room usage create 

a potential for indoor air quality problems 

and give them special attention during the 

walkthrough inspection. 

Items of interest and the questions they 

suggest could include the following: 

Commissioning reports 

• Was the building properly commissioned 

when it was first constructed, including . 

testing and balancing of the HV AC 

system? 

Operating manuals 

• Do staff members understand how the 

HV AC equipment is intended to operate? 

Remodeled areas 

• Has the HV AC system layout been 

changed to accommodate new walls, 

rearranged partitions, or similar architec-

. tural modifications? 

Developing an IAQ Profile 21 
AtldiiiiJn, removal, or replacement of 

HV AC equipment 

• Where the original equipment has been 

replaced, do the newer units have the 

same capacity as the originals? 

• Has new equipment been properly 

installed and tested? Where equipment 

has been removed, is it no longer 

needed? 

Changes in room use 

• Is there a need for additional ventilation 

(supply and/or exhaust) due to increased. 

occupant population or new activities 

within any area of the building? 

• Have new items of equipment (nonHV A C) been provided with local exhaust 

where needed? Look for unusual types 

or quantities of equipment such as copy 

machines or computer terminals. 

Cheek HV AC maintenance records 

against equipment lists 

Collect your existing maintenance and 

calibration records and check them against 

the construction documents (e.g., equipment lists and mechanical plans). See 

whether all components appear to be 

receiving regular attention. Equipment that 

22 Section4 

has been installed in inaccessible or out-ofthe-way locations is frequently overlooked 

during routine maintenance. This is 

particularly true of items such as filter 

boxes and small capacity exhaust fans. 

Review records of complaints 

If there is an organized record of past 

occupant complaints about the building 

environment, review those complaints to 

identify building. areas that deserve 

particular attention. 

2. Conduct a Walkthrough 

Inspection of the Building 

The intent of the walkthrough inspection is 

to acquire a good overview of occupant 

activities and building functions and to 

look for IAQ problem indicators. No 

specific forms are suggested for this stage 

of IAQ profile development. However, 

the investigator should have a sketch plan 

of the building, such as a small floor plan 

showing fire exits, so that his or her notes 

can be referenced to specific iocations. 

Detailed measurements of temperature, 

humidity, airflow, or other parameters are 

more appropriate to a later stage of profile 

development. However, chemical smoke 

can be used to observe airflow patterns and 

pressure relationships between special use 

areas or other identified pollutant sources 

and surrounding rooms. Odors in inappropriate locations (e.g., kitchen odors in a 

lobby) may indicate that ventilation system 

components require adjustment or repair. 

(See Appendix A for further discussion of 

the use of chemical smoke.) 

The value of IAQ ventilation measurement tools to your operation will grow as 

you become more familiar with handling 

indoor air quality concerns. For example, 

if you do not own a direct-reading carbon 

dioxide monitor, it is not necessary to 

acquire one for the IAQ profile. Those 

who already have access to this type of 

instrument can take readings during the 

walkthrough as a way to obtain baseline 
information about normal operating 

conditions or identify problem locations. 

If you begiq to suspect that unde:rventil~~ 

tion is a consistent problem, you may 

decide that it would be helpful to obtain 

more ventilation monitoring equipment. 

(See Appendix A for further discussion of 

carbon dioxide and other ventilation 

measurements.) 

Talk with staff and other occupants 

A walkthrough inspection provides an 

opportunity to introduce facility staff and 

other building occupants to the topic of 

indoor air ql;lality and to understand current 

staff (and contractor) responsibilities in 

relation to housekeeping and maintenance 

activities. Advance notice of the inspection will make it seem less intrusive and 

may encourage staff and other occupants to 

remember important information. 

Discussion of routine activities in the 

building will help to clarify elements that 

should be included in the IAQ management plan. Ask staff members about their 

job responsibilities, training and experience. It will be helpful to meet with 

responsible staff and contractors to 

discuss: 

Facility operation and maintenance 

(e.g., HVAC, plumbing, electric, interior 

maintenance) 

• HVAC operating schedule (e.g., occupied/unoccupied cycles) 

• HV AC maintenance schedule (e.g., filter 

changes, drain pan maintenance) 

• use and storage of chemicals 

• schedule of shipping and receiving, 

handling of vehicles at loading dock 

• scheduling and other procedures for 

isolating odors, dust, and emissions from 

painting, roof repair, and other contaminant-producing activities 

• budgeting (e.g., including staff influence 

on budget decisions) 

Housekeeping 

• cleaning schedule 

• trash storage and schedule of refuse 

removal · 

• use and storage of chemicals 

Pest control 

• schedule and location of pesticide 

applications 

• use and storage of chemicals 

• pest control activities other than use of 

pesticides 

Look for IAQ problem indicators 

The walkthrough inspection can be used to 

identify areas with a high potential for IAQ 

problems. The following are general 

indicators of IAQ problems: 

• odors 

• dirty or unsanitary conditions (e.g., 

excessive dust) 

• visible fungal growth or moldy odors 

(often associated with problem of too 

much moisture) 

Developing an IAQ Profile 23 

Maintenance is more likely 

to be performed on a 

routine basis when there is 

good access to HVAC 

equipment such as that 

shown in this photo. 
Building occupants who are 

uncomfortable may try to 

Improve the situation by 

themselves. The small fans 

shown above indicate an air 

circulation or thermal 

discomfort problem. The 

Irony of this situation is that 

the fan motors add heat to 

the air. 

• sanitary conditions in equipment such as 

drain pans and cooling towers 

• poorly-maintained ftlters 

• signs of mold or moisture damage at 

walls (e.g., below windows, at columns, 

at exterior comers), ceilings, and floors 

• staining and discoloration (Note: Make 

sure that stains are removed after leaks 

are repaired so that there will be visible 

evidence if the leak recurs.) 

• smoke damage (Note: If a frre has 

occurred involving electrical equipment, 

determine whether PCBs (polychlorinated biphenyls) may have been released 

from the equipment.) 

• presence of hazardous substances 

• potential for soil gas entry (e.g., unsealed 

openings to earth, wet earth smells) 

• unsanitary mechanical room, or trash or 

stored chemicals in mechanical room 

• unusual noises from light fixtures or 

mechanical equipment 

In addition to these general indications, 

some comn1on problems deserve mention: 

24 Section4 

Inadequate maintenance: Look for leaks 

of oil, water, or refrigerants around HV AC 

equipment. Also be aware of signals such 

as unreplaced burned-out light bulbs in fan 

chambers and staff members who have 

difficulty locating specific pieces of 

equipment. Dry drain traps can also cause 

indoor air quality problems. If traps are 

not kept charged with liquid, they could be 

allowing sewer gas to enter occupied 

spaces. 

Signs of occupant discomfort: Notice · 

uneven temperatures, persistent odors 

(including tobacco smoke), drafts, sensations of stuffiness. You may find that 

occupants are attempting to compensate 

for an HV AC system that doesn't meet 

their needs. Look for propped-open 

corridor doors, blocked or taped-up 

diffusers, popped-up ceiling tiles, people 

using individual fans/ heaters or wearing 

heavier (or lighter) clothing than normal. 

Overcrowding: Future occupant density is 

estimated when the ventilation system for a 

building is designed. When the actual 

number of occupants approaches or 

exceeds this occupant design capacity, 

managers may find that IAQ complaints 

increase. At that point, the outdoor air 

ventilation rate will have to be increased. 

However, the ventilation and cooling 

systems may not have sufficient capacity 

to handle the increased loads from the 

current use of the space. 

Blocked airflow: Check for underventilation caused by obstructed vents, 

faulty dampers or other HV AC system 

malfunctions, or from problems within the 

occupied space. Furniture, papers, or other 

materials can interfere with air movement 

around thermostats or block airflow from 

wall or floor-mounted registers. If office 

cubicles are used, a small space (i.e., two 

to four inches) between the bottom of the 

partitions and the floor may improve air 

circulation. 

Ceiling plenums: Lift a ceiling tile and 

examine the plenum for potential prob-
lems. Walls or full-height partitions that 

extend to the floor above can obstruct or 

divert air movement in ceil~g plenums 

unless transfer grilles have been provided. 

If fire dampers have been installed to 

allow air circulation through walls or 

partitions, confirm that the dampers are. 

open. Constru~tion debris and damaged or 

loose material in the plenum area may 

become covered with dust and can release 

particles and fibers. 

Heat sources: Be aware of areas that 

contain unusual types or quantities of 

equipment such as copy machines or 

computer terminals. Also look for 

instances of over-illumination. High 

concentrations of electrical fixtures and 

equipment can overwhelm the ventilation 

and cooling systems. 

Special use areas: Confirm that the 

HV AC system maintains appropriate 

pressure relationships to isolate and 

contain odors and contaminants in mixeduse buildings and around special use areas. 

Examples of special use areas include 

attached parking garages, loading docks, 

print shops, smoking lounges, janitorial 

closets, storage areas, and kitchens. 

Improperly located vents, exhausts and 

air intakes: Check the outdoor air intakes 

to see whether they are located near 

contaminant sources (e.g., plumbing vents, 

exhaust outlets, dumpsters, loading docks, 

or other locations where vehicles idle). 

Unsanitary mechanical rooms: See if the 

space containing the HV AC system is 

clean and dry. Examples of problems 

include: cleaning or other maintenance 

supplies stored in mechanical room; dust 

and dirt buildup on floors and equipment; 

moisture in mechanical room because of 

inadequate insulation, lack of conditioned 

air, or failure to provide for air movement. 

Unsanitary conditions in the mechanical 

room are particularly a problem if 

unducted return air is dumped into and 

circulated through the mechanical room. 

~ •. , J»,R~DUCTS ()F COLLt:CTIHG DETAILED INFORMATION . 

:'~~-~~,~~jn~ent~& of livAc ~ystem.compone~ts that n·~ed to be.·· 

s~fErepaired, adjusted; orreplace<:t •. ~ . • •. . . . . 

~: ..... a. c~.rrenf'n:~cord of controrsettings and operating schedules. 

W;K~ iftoqr plan of the buildln9 sh~wing airflow direqtionsor ·. ·. ~;;,"·pressure diffE~rerytials around areas intended to ruri positive or ~ •. {i;i,e~ative (e:g;,specialuse areas}· . · .··· · . . . · · 

~1 ~ri t'1verrto,Y of pollutant sources and their locations . 

~l Mat~iial ~afety D~ta S~e9t~ for products used or sto~ed within ~"·"•~="~!~~.':?,tl!!d!~Jr. · . " ·. · ..•. · · ·.. .· .·.... ... . · · . . ~r¢~ord qfusage for· each zone or room, including the source of 

1f;~~'%:Yt~i~.~:~ir_~~.?: thl3pres~nc~ of lo~~~.~xnau.st (ifany} 

~i2El~I:·?~:~~~~~-~~,!~t··,< , .. ··- '; :.-~: .. -·· __ ~" ,.,.~.·~--·:'w····- .q· .,.:······ 

Collect Detailed Information 

The collection of detailed information for 

theJAQ profile can be handled as time is 

available. Areas that have been identified 

as presenting potential IAQ problems 

should be given the highest priority. You 

may want to review Section 2 for background information on the factors that 

contribute to indoor air quality. 

Inspect HV AC system condition and 

operation 

Use your current maintenance records in 

combination with one or both of the 

HV AC Checklists to inspect HV AC 

Developing an IAQ Profile 25 

Occupants or staff 

sometimes open ceiling 

tiles into return plenums 

when.attempting to 

eliminate odors . . Bu}/ding 

managers should be alert to 

such signs of occupant 

dissatisfaction in order to 

remedy the original 

problem and prevent 

additional problems, such 

as the short-circuiting of 

supply air. 
~~ ',, ''~"r~:~~·'l"l" 'i''ll• ~·· w•<Jc""'""'"''''l' if""~~· '•·'""':~~.~~:.~·:~ ,, ''!~~~ .. ~~ ·~::'::~.~:(~::·. ">;::·; :' ' 

:''Saropte.~Form 

~ HVAC Ch(Jt;klhrt -$bplj F~~ . ' ,:·' ' ' 

Mechanical R09m 

r 's.ulldtng Are• 

(zone, room) 

SEE 

COMPLETEj 

.FQR~S ... I P.f'~ES 1914 

·AND 175 i 

Use 

26 Section4 

v ',fcj!...wt")W,1i :;t<' / 

,wft;&,' ·-~ ' 1 '¢Jh?, .~ 

Commen1s 

' :t::• equipment and make sure that it is in good 

operating condition. A portion of the 

HVAC Checklist - Short Form is shown 

on this page, with the entire form repro~ 

duced in Tab V. The HVAC ChecklistLong Form (also reproduced in Tab V) is 

recommended where a more detailed 

examination is needed. You may want to 

create a new form incorporating elements 

from your existing inspecti9n forms. 

Identify items of equipment that need to 

be repaired, adjusted, or replaced. Record 

control settings and operating schedules for 

HV AC equipment for comparison to 

occupancy schedules and current uses of 

space. 

Inventory pollutant pathways 

Using the sketch plan of the building 

that was begun during the walkthrough 

inspection, indicate architectural 

connections (e.g., chases) and mechanical 

connections (e.g., ductwork, temperature 

control zones). Observe and record airflow 

between spaces intended to run positive or 

negative and the areas that surround them 

(including airflow between perimeter 

rooms and outdoors). Note that hidden 

pathways such as chases may travel both 

vertically and horizontally and transport 

pollutants over long distances. Record the 

results on the Pollutant Pathway Record 

for IAQ Profiles, the sketch plan, or both. 

The form is shown at the left (and in Tab 

V), and a sample sketch plan is shown on 

the opposite page. 

Inventory pollutant sources 

Use the Pollutant and Source 

Inventory (shown in part on page 28 and 

reproduced in full in Tab V) to record 

potential pollutant sources in the building. 

As you fill out the inventory form, note the 

locations of major sources. Major sources 

such as large items' of equipment can be 

recorded on the floor plan. The Chemical 

Inventory Form (shown on page 28 and 

reproduced in Tab V) can be used to record 

the names and locations of chemicals or 

hazardous substances used or stored within 
I! 

Reception 

Area 

Elevator Bank 

Office 

Conference 

·Room 

Vestibule 

Computer Room 

Lounge 

Bathroom 

e 

~-7 l 

I ~--MAii~iir.Rt-.._ I 

l 

, ......... -----

Office 

Developing an IAQ Profile 27 

A fire escape f/oorplah is 

very useful for recording 

information collected 

· during JAQ profile development or while investigating 

IAQ complaints. The facility 

manager has begun to 

identify the areas in which 

air pressure relationships 

are {or should be) controlJed and some ventilation 

and has noted source fnformation. Symbols ate 8 for 

negative pressure, ® for 

positive pressure, and.,._.. 

for observed direction of 

airflow. Utility chases, 

tunnels, and suspended 

ceilings could also be 

drawn in to show pollutant 

pathways and driving 

forces; 
•" * ' ;··~ ~· i' ~· ';' '' 

Sample Form .:. 

Pollutant and so ... tC$ ln~ventQry . . ·• '~ '' 1 _._~.' ' ~!~i··~~!·:/i·~J.·:-~?\!>~-~~;[~~~:~~.'~~~~~~~~~):_-~J·_~L~f~:~~~.~'!~~~~~~:c":,~~-:~~~~~-¥1#J4J 

Using the list of potential source categories below, record any 

fndicaUQn$_of ~9nta.roin~_tion or suspected pollutants that may 

require further lnvestig~tion or tre!it_me,n~,· . ., .~1, > ;,~ ·f',;,,r 

~~·-'" 

,__ "<t ~· -'-'-·S,-f ·:~·iR>Jf,:'l!:",·.~tf"l ~· :''!i'FL:~'"''"'" ~t-F:'!t~·~:rwf·-t~·ij!J\,~~,~~81'7;,·:,.,;:'f•~,~;;;~~;~"'--"'"~~}~'lt·~'u~~:~~\~ 

~ . Samp!~ ~~rm · ,. '"c;lt:arui~·· JpvQJ»JJrYF~rm '·"" ,: ... :,:11:,,;., 

-~liil~~~-

' , , '"'".,''' ';;;;,_~·:::l~,;,.;~:;,·::::~A 

The inventory should include chemi~l~. stqr~cl or the. 

building for cleaning, maintenance, operations, ~.nd pest control. 

If you have an f..1SO_S, (Ma,~rial S~f!'!~ J.?~ia ·sh~et) for the c~-~mi<;aJ, _ 

put a cheek m~~ in the ~i,ght-hand col.umn .... I( not, ask the chet:niqal ~ 

supplier to provide the MSDS, if one is availf:!ble •. 

" ' ' ~(~~~6~>~::;'"",",~~~·~"-.:;~f~;;~ ,c ' ... ·· ' ' w_.:,;.:.i,I--;;T, . '·'.' . ' ~ . " ' 

.. Date 

.. 

SEE J 

COMPLETE· 

AND221 

~==~131 

Chemlcaf/ 

Brand Name 

. . . 

Use Storage MSDS 

Locatlon(s} on File? ~. 

' 

"'"" ... -~:: . '.-., . ····•··.· ... ·.· 

' .. . (; :. '. :.:1 

28 Section4 

the building, such as those that may be 

contained in cleaning materials, biocides, 

paints, caulks, and adhesives. Ask your 

suppliers to provide you with Material 

Safety Data Sheets. 

You may be unaware of the potential 

hazards of some materials that are 

commonly used in public and commercial 

buildings. For example: 

• In 1990, EPA eliminated the sale of 

mercury-containing interior latex paint. 

(Enamel paints do not contain mercury.) 

People are urged not to use exterior latex 

paint indoors, as it may contain mercury. 

If you have paint in storage that may 

have been manufactured before August 

20, 1990, you may contact the 

manufacturer, the National Pesticide 

Telecommunication Network (1-800-

858-7378), or your State Health 

Department for guidance. 

• In 1990, EPA banned the use of 

hexavalent chromium chemicals in 

cooling towers, because the chemicals 

have been shown to be carcinogenic. 

• Heating system steam should not be used 

in the HV AC humidification system, as 

it may contain potentially harmful 

chemicals such as corrosion inhibitors. 

Collect information on bnilding 

occupancy 

The Zone/Room Record shown on the 

following page (and also reproduced in 

Tab V) can be used during IAQ profile 

development to maintain an up-to-date 

record of the way each area of the building 

is used, its source of outdoor air, and 

whether or not it is equipped with local 

exhaust. If underventilation is suspected, 

the form can be used to estimate ventilation mtes in cubic feet per minute per 

person or per square foot floor area, for 

comparison to guidelines such as design 

documents, applicable building codes, or 

the recommendations of ASHRAE 62-

1989 (see the table that is reproduced in 

Appendix B). 
~l':c Sample Form ~~=-· :: ··. ,• . .--·:· ._,_;,> ';• 

:;;;zoneJRoom Record. .• . . . . . . . . . · ·· .. · .. . . ;._~i/--.-_ --_- -~- ' ;._' . .:-··- ,; .;::·: _·'> -.---· _::+'< -::>'·_._<;:'·~ .. .->' __ :;-<:~ .. -->~;'·.:~----,~. __ ·; -~: __ .><::- _. :":,_--.f-i>- .'; _::_·_:·:·.;/''-~-_--:: _-:,. -, __ ,. _. __ ' -,-'.- ,-:' .. 

lMT~is.fqrm is to be u<;ed differently depending on whether, the goal is,tO prevent or diagnose lAO problems. 

•. D.il.nng development of a profile, this form shouid be bse.d to recorcl more generafinform~ion about the entire 

,~~ I:Jullding; during an investigation; the form should be l!sed to r,ec:()rd more detailed inform~;~tion about the 

:Ecomplaint area and areas surroi.u1ding the i::omplahit area on:ioonected to it bY, pathways.. .. . . -~-:--:-:.=--- . . . ;~ ----" .. -- ""· : -:~ "" - - .-. j • • -- •' ---. - -. - • 

-.. . ~>-. ~ . 4 

Underventilation problems can occur 

even in areas where ventilation rates 

apparently meet ASHRAE guidelines; 

proper distribution and mixing of supply 

air with room air are also essential for 

good ventilation. 

If the information collected as you 

develop the IAQ profile indicates that you 

have one or more IAQ problems, Sections 

6~8 provide guidance to help you deal with 

them. If you need to prioritize these prob~ 

lems, consider the apparent seriousness of 

their consequences. For example, combustion gas odors demand a more rapid 

·response than thermostats that are out of 

calibration. 

Developing an IAQ Profile 29 

SEE 

COMFILETE' 

FORM 

PAGJE177 

Managing Buildings for Good IAQ 

~e relationships among building owners, 

management, staff, and occupants are an 

important factor in decisions that affect 

indoor air quality. The objectives of the 

major players in these relationships may be 

very different. Occupants want the 

building to be pleasant, safe, and attractive; 

if they are paying tenants, they also want 

to get the maximum use out of the space 

they rent for the least cost. Building 

owners .and management want to maintain 

a reputation for providing quality property 

at reasonable cost, but also need to derive a 

profit. Facility staff are often caught in the 

middle, trying to control operating and 

maintenance costs while still keeping 

occupants satisfied. 

Regardless of the points on which they 

may disagree, building occupants, staff, 

and management share the goal of providing a healthy indoor environment. Recognition of this common goal may help avoid 

conflict when discussing IAQ-related 

policies. 

Any IAQ management system will be 

successful only if it is organized to fit your 

specific building. It would not be appropriate for this document to prescribe any 

single approach. However, the skills 

associated with IAQ management activities 

will be identified to help building management decide who will be best able to carry 

them out. Education and training programs 

for staff and building occupants should be 

provided to ensure that new procedures are 

understood and adopted. 

Managing a building for good indoor air 

quality involves reviewing and amending 

current practice (and establishing new 

procedures, if necessary) to: 

Operate and maintain HV AC equipment 

• keep all equipment and controls in proper 

working order 

• keep interior of equipment and ductwork 

clean and dry 

Oversee activities of staff, tenants, contractors, and other building occupants that 

impact indoor air quality 

• smoking 

• housekeeping 

• building maintenance 

• shipping and receiving 

• pest control 

• food preparation and other special uses 

Maintain communications with occupants 

so that management will be informed of 

complaints about the indoor environment 

in a timely way 

• identify building management and staff 

with IAQ responsibilities 

• use health and safety committees 

Educate staff, occupants, and contractors 

about their responsibilities in relation to 

indoor air quality 

• staff training 

• lease arrangements 

• contracts 

Identify aspects of planned projects that 

could affect indoor air quality and 

manage projects so that good air quality 

is maintained 

• redecorating, renovation, or remodeling 

• relocation of personnel or functions 

within the building 

• new construction 

DEVELOPING AN IAQ 

MANAGEMENT PLAN 

The chart on page 32 shows the elements 

of an IAQ management plan. Development of the management plan involves 

reviewing and revising staff responsibiliti~s so that IAQ considerations become 

incorporated into routine procedures. 

Managing Buildings for Good IAQ 31 

IAQ management 

systems will only be 

successful if they are 

organized to fit your 

specific building. 
Organizations may assign responsibility for 

operations,recordkeeping,purchasing, 

communications, planning, and policymaking in many different ways. However, 

the key elements of good IAQ management 

remain the same: 

Reach an understanding of the fundamental influences that affect indoor air 

quality in your building by: 

• becoming familiar with literature on IAQ 

• keeping abreast of new information 

Select an IAQ manager with: 

• clearly deflned responsibilities 

• adequate authority and resources · 

FIGURE 5-1: Developing an IAQ Management Plan 

Select an IAQ Manager 

Review IAQ Profile 

and Existing Records 

Assign Staff 

Responsibilities/Train Staff 

Facilities Operation 

and Maintenance 

32 SectionS 

Housekeeping 

Pest Control 

Tenant Relations 

Renovation 

Redecorating 

Remodeling 

Smoking 

Use the IAQ profile and other available 

infonnation to: 

• evaluate the design, operation, and usage 

of the building 

• identify potential IAQ problem locations 

• identify staff and contractors whose 

activities affect indoor air quality 

Review and revise staff responsibilities to 

ensure that responsibilities that may affect 

indoor air quality are clearly assigned. In 

addition, establish lines of communication 

for sharing information pertaining to: 

• equipment in need of repair or 

replacement 

• plans to remodel, renovate, or redecorate 

• new uses of building space or increases in 

occupant population 

• installation of new equipment 

Review standard procedures and make 

necessary revisions to promote good 

indooroir quality, such as: 

• terms of contracts (e.g., pest control, 

leases) 

• scheduling of activities that produce dust, 

emissions, odors 

• scheduling of equipment operation, 

inspection, and maintenance 

• specillcations for supplies (e.g., cleaning 

products, construction materials, furnishings) 

• policy regarding tobacco smoking within 

the building 

Review the existing recordkeeping system 

and make necessary revisions to: 

• establish a system for logging IAQrelated complaints 

• obtain Material Safety Data Sheets for 

hazardous materials used and stored in the 

building 

Educate building staff, occupants, and 

contractors about their influence on 

indoor air quality by: 

• establishing a health and safety committee 

• instituting training programs as needed 
IAQ problems may occur even in 

buildings whose owners and managers 

conscientiously apply the best available 

information to avoid such problems. 

Those who can demonstrate their ongoing 

efforts to provide a safe indoor environ~ 

ment are in a strong legal and ~thical 

position if problems do arise. 

Select an IAQ Manager 

IAQ management will be facilitated if one 

individual is given overall responsibility 

for IAQ. ·Whether or not this person is 

given the title of "IAQ Manager," he or 

she should have a good understanding of 

the building's structure and function and 

should be able to communicate with 

tenants, facility personnel, and building 

owners or their representatives about IAQ 

issues. 

The IAQ manager's ongoing responsibilities might include: 

• developing the IAQ profile 

• overseeing the adoption of new 

procedures 

• establishing a system for communicating 

with occupants about IAQ issues 

• coordinating staff efforts that affect 

indoor air quality, and making sure that 

staff have the information (e.g., operating manuals, training) and authority to 

carry out their responsibilities 

• reviewing all major projects in the 

building for their IAQ implications 

• reviewing contracts and negotiating with 

contractors (e.g., cleaning services, pest 

control contractors) whose routine 

activities in the building could create 

IAQ problems 

• periodically inspecting the building for 

indicators of IAQ problems · 

• managing IAQ-related records 

• responding to complaints or observations 

regarding potential IAQ problems 

• conducting an initial walkthrough 

investigation of any IAQ complaints 

Review IAQ Profile and Other 

Existing Records 

If the IAQ manager was not actively 

involved in developing the IAQ profile, 

one of the first tasks will be to review the 

profile carefully. The manager can start by 

also identifying building locations with a 

potential for IAQ problems, staff and 

contractors whose activities impact indoor 

air quality, and other building occupants 

whose activities impact indoor air quality. 

In addition to information from the IAQ 

profile, it may be helpful to review lease 

forms and other contractual agreements for 

an understanding of the respective legal 

responsibilities of the building management, tenants, and contractors. Incorpora- · 

tion of IAQ concerns into legal documents " 

helps to ensure the use of proper materials 

and procedures by contractors and can help 

to limit the load placed on ventilation 

equipment by occupant activities. 

Assign Responsibilities/ 

Train Staff 

The assignment of responsibilities varies 

widely between organizations, depending 

upon the routine activities to be carried out 

.and the capabilities of the available 

personnel. It would not be appropriate for 

this document to suggest how IAQ-related 

responsibilities should be allocated in your 

organization. For example, issues of 

access in buildings with tenant-occupied 

space highlight the need for cooperation 

between building managers and the 

Managing Buildings for Good IAQ 33 

IAQ management will 

be facilitated if one 

individual is given 

overall responsibility 

for IAQ. 
A clean mechanical room, 

free of tracked-in dirt and 

stored chemicals, is an 

Important element in the 

prevention of indoor air 

quality problems. Airborne 

contaminants in the 

mechanical room can be 

drawn Into ductwork 

through return air openings 

or unsealed seams in return 

ducts and circulated 

throughout the building. 

tenants' office managers. The building 

staff may be limited in its access to tenant 

spaces and tenants ~ay not have access to 

building operations areas such as mechanical rooms, yet both tenants and building 

management have responsibilities for 

maintaining good indoor air quality. 

Facility personnel are not generally 

trained to think about IAQ issues as they 

go about their work. Even though building 

staff may be observing events and conditions that would indicate potential problems to an experienced IAQ investigator, 

the staff member's attention may br 

directed elsewhere. As new practices are 

introduced to prevent indoor air quality 

problems, an organized system of 

recordkeeping will help those practices to 

become part of routine operations and to 

"flag" decisions that could affect IAQ 

(e.g., renovations, new tenants). The best 

results can be achieved by taking time to 

think about the established channels of 

communication within your organization, 

so that new forms can be integrated into 

decisionmaking with minimum disruption 

of normal procedures. 

34 SectionS 

Using information from the IAQ 

proflle, the IAQ manager should work 

with staff and contractors to ensure that 

building operations and planning processes 

incorporate a concern for indoor air 

quality. New procedures, recordkeeping 

requirements, or staff training programs 

may be needed. (Growing interest in IAQ 

is stimulating government agencies and 

private sector organizations to develop 

training programs. See Appendix G for 

additional information.) The flow of 

information between the IAQ manager and 

staff, occupants, and contractors is 

particularly important. Good indoor air 

quality requires prompt attention to 

changing conditions that could cause IAQ 

problems, such as installation of new 

equipment or furnishings, increases in 

occupant population, or new uses of 

rooms. 

Facility Operation and Maintenance 

Indoor air quality can be affected both 

by the quality of maintenance and by the 

materials and procedures used in operating 

and maintaining the building components 

including the HV AC system. 

Facility staff who are familiar with 

building systems in general and with the 

features of their building in particular are 

an important resource in preventing and 

resolving indoor air quality problems. 

Facility personnel can best respond to 

indoor air quality concerns if they understand how their activities affect indoor air 

quality. It may be necessary to change 

existing practices or introduce new 

procedures in relation to: 

Equipment operating schedules: Confirm 

that the timing of occupied and unoccupied cycles is compatible with actual 

occupied periods, and that the building is 

flushed by the ventilation system before 

occupants arrive. ASHRAE 62-1989 

provides guidance on lead and lag times 

for HV AC equipment. In hot, humid 
climates, ventilation may be needed during 

long unoccupied periods to prevent mold 

growth. 

Control of odors and contaminants: 

Maintain appropriate pressure relationships 

between building usage areas. Avoid 

recirculating air from areas that are strong 

sources of contaminants (e.g., smoking 

lounges, chemical storage areas, beauty 

salons). Provide.adequate local exhaust 

for activities that produce odors, dust, or 

contaminants, or confme those activities to 

locations that are maintained under 

negative pressure (relative to adjacent 

areas). For example, loading docks are a 

frequent source of combustion odors. 

Maintain the rooms surrounding loading 

docks under positive pressure to prevent 

vehicle exhaust from being drawn into the 

building. Make sure that paints, solvents, 

and other chemicals are stored and handled 

properly, with adequate (direct exhaust) 

ventilation provided. If local f:tlter traps 

af\d adsorbents are used, they require 

regular maintenance. Have vendors 

provide Material Safety Data Sheets 

(MSDSs). 

Ventilation quantities: Compare outdoor 

air quantities to the building design ~oal 

and local and State building codes and 

make adjustments as necessary. It is also 

informative to· see how your ventilation 

rate compares to ASHRAE 62-1989, 

because that guideline was developed with 

the goal of preventing IAQ problems. 

(Note: Increasing ventilation quantities to 

meet ASHRAE guidelines may exceed the 

capacity of HV AC equipment to condition 

the air.) 

HVA.C equipment maintenance·sched-· 

ules: Inspect all equipment regularly (per 

recommended maintenance schedule) to 

ensure that it is in good condition and is 

operating as designed (i.e., as close to the 

design setpoints for controls as possible). 

Most equipment manufacturers provide 

recommended maintenance schedules for 

their products. Components that are 

exposedto water (e.g~, drainage pans, 

coils, cooling towers, and humidifiers) 

require scrupUlous maintenance to prevent 

microbiological growth and the entry of 

undesired microl>iologicals or chemicals 

into the indoor airstream. 

HV AC 'inspections: Modify the HV AC 

Checklists (reproduced in Tab V) as 'I 

necessary so that they are appropriate for · 

inspection of the specific equipment in 

your building. Be thorough in conducting 

these ~spections. Items sue~· as small 

exhaust fans may operate independently· 

from the rest of the HV AC system and are 

often ignored during inspections. As 

equipment is added, removed, or replaced, 

document any changes· in function, 

capacitY, or operating schedule for future 

reference. It may also be helpful to store 

equipment manuals and records of equipment operation and maintenance iri the . 

same location as records of occupant 

complaints for easy comparison if IAQ 

problems arise. 

Building maintenance schedules: Try 

to schedule maintenance activities that 

interfere with HV AC operation or produce 

odors and emissions (e.g., painting, ~oofiUg 

operations) so that they occur when the· 

building is unoccupied. Inform occupants · 

when such activities are scheduled and, if 

possible, use ·local ventilation to en8ure. . 

that dust and odors are commed to the. 

work area. 

Purchasing: Review the general information provided by MSDS and request 

information from suppliers about the 

chemical emissions of materials being 

considered for purchase. . 

Note: At present there is no general 

syst,emfor certity~g ~r labeling lowemission prodQcts nor is there a standard 

. procedure for:b,uilding managers to use in 

gathering emissions data on products they. 

are considering for purchase. Limited · 

information on some materials such as 

Managing Buildings for Good IAQ 35 

Be thorough in 

conducting HVAC 

inspections. Items 

such as small exhaust 

fans may operate 

independently from 

the rest of the system 

and are often Ignored 

during. inspections. 
, PREVf:~1"1VE MAII\I]i:{!IA~~E . . . . . 

'An HVAC system reqtilre~'adeq~'afe'preventive mainte~ance (PM) 

::; ·and prompt attention to repairs in order to operate correctly and 

, provide suitable comfort conditiqns and good indoor air quality. 

The. HVAC system operator(s) must have an adequate understandIng ohhe overall system design, its intended function, and its 

limitations. The preventive maintenance program must be prop-

.!~Jrly b~dpeted and implemente~, pot mE;?rEl,ly_ planl)ed on paper: . 

A WEtll~lmplemented PM plan will improve the functioning of the 

mech~£l.lcal systems and t,.~suaUy save money when evaluated on a 

~·]ife-qcl,! basis~. Howeve_r,.Jn_§QITI~ b!li!!=!tngs, because of budgetary 

r:; ~nstr@,nt$, rnl!int~.n~.nc!lls put off until breakdowns occur or ~·'complaints arise, following the uif it isn't broken, don't fix it" 

: · '~hilos,ophy. This type of program represents a false economy and 

,.... often •ncre~;~ses the eventual cost of repairs. " " , .. . ~~ .. ~:: .. :~ .. : .. ~ ... , ,' ; 0 ~',11.fi::l1. 7', "'.·.~· :'J;.,,,,.;.,':'i'~>G.'~~.~·m:~illllll'l,. :,4 "iiii; ' , '' ! '" ' :' - ! J ,,;, ; 'C 

!'f~ , Poor nltflr mainteotmce Is a common example of this phenom-

~:,1'\()h. .Ei!te~ that ~r.e nOlQh~oged regularly can become a bed for ~fu.ngaiJ~rowth, sometime.s allowing particles or microorganisms to 

i!,, .. ,ii ·.~ qi~~!Jte\:1 witbJJJJheJ;~uilcllng. When filters become clogged, 

~+·to' ..... f .. ~ ... • 'l'!H~e more. eper.gyt. o ~perate and move less air. If the filters tllk · re ~.n lPJ!~pensJve, low-.effic1ency type that becomes clogged and 

en "pi()W$ out"' the coils then aceMmulate dirt, causing another nciease in energy oonsumption.~~Poor airfilter efficiency and poor 

;:~,,~(nat.otenll!1Ce may c.al!s.e_cjirtto bu!fcl t,tp in ducts and become 

~ confaf1'l1Q!lted with J1lQI9.f!~ possibly requiring an expensive duct 

f'.i",~leanlnq.operation. ,,~, . , , . . .· .. 'f•':~':' " '1 < ' ,, :'· { ~ .. '! ~-' )\_c ',/,'.,.,,,,:. :.. ' 

~ , Gel,lel!~l elemeot~ .9f a ef!l1 pla,n, iiJ2,1.udi\F .... .. . .. , . 

~,;; ~· perio.~.ic inspection( cte.li!J'ing, and service as warranted 

ic·••···· • adjustment and calibration of.cont~ol system components • maintenance equipment and replacement parts that are of good 

quality and properly selected for the intended function ,, 'w ,, , "; ' ~ , i ' ' ' 

Critical HVAC system components that require PM in order to 

maintain comfort and deliver adequateventila~ion air include:, 

"'w outdoor air intake openl~g · ·· · · • ~ · · ·• · · ·· · 

damper controls 

: .. ~ ~tc filters . 11 drip pans 

;'.'li cooling and heating coils 

fall.~~~~ . . ·-'"" ~· . ....... ~· humtd1fication equipment and controls 

dJfit;Jl~~tfon' iystems 

exh~t~t fans .. 

~·"ii $orof!private sector organizations have developed guidance on 

~i~raventtye matnten~ru;e. ($ee discussion in Guidelines of Care 

t'" l{tweloped by Trade Associati~ns on page 43.) 

36 SectionS 

pressed-wood products is available, and 

more may be expected in the future. 

Public and private sector organizations are 

working to develop product testing 

procedures for acceptance by such organizations as the American Society for 

Testing and Materials (ASTM). 

Preventive maintenance management: 

Maintenance "indicators" are available to 

help facility staff detennine when routine 

maintenance is required. For example, air 

filters are often neglected (sometimes due 

to reasons such as difficult access) and fail 

to receive maintenance at proper intervals. 

Installation of an inexpensive manometer, 

an instrument used to monitor the pressure 

loss across a filter bank, can give an 

immediate indication of filter condition 

without having to open the unit to visually 

observe the actual filter. 

Computerized systems are available that 

can prompt your staff to carry out maintenance activities at the proper intervals. 

Some of these programs can be connected 

to building equipment so that a signal is 

transmitted to your staff if a piece of 

equipment malfunctions. Individual areas 

can be monitored for temperatur~, air 

movement, humidity, and carbon dioxide, 

and new sensors are constantly entering the 

market. These sensors can be programmed 

to record data and to control multiple 

elements of the HV AC system. 

Housekeeping 

Indoor air quality complaints can arise 

from inadequate housekeeping that fails to 

remove dust and other dirt. On the other 

hand, cleaning materials themselves 

produce odors and emit a variety of 

chemicals. 

As they work throughout your building, 

cleaning staff or contractors may be the 

frrst to recognize and respond to potential 

IAQ problems. Educate them about topics 

such as the following: 
Cleaning schedules: Consider how 

cleaning activities are scheduled. Managers may want to schedule the use of some 

cleaning agents that introduce strong odors 

or contaminants during unoccupied 

periods. However, make sure that fumes 

from cleaning products are eliminated 

before air handling systems switch to their 

"unoccupied" cycles. 

Purchasing: Become more familiar with 

the chemicals in cleaning and maintenance 

products and their potential toxicity. 

Select the safest available materials that 

can achieve your purpose.' Review the 

information provided by product labels 

and Material Safety Data Sheets. Request 

information from suppliers about the 

chemical emissions of products being 

considered for purchase. 

Materials handling and storage: Review 

the use of cleaning materials to ensure 

proper use and storage. 

Trash disposal: Follow proper trash 

disposal procedures. If there is a restaurant in the building, require daily pick-up 

of perishable refuse. Ensure that the 

containers are covered, pest control is 

effective, and that the trash collection area 

is cleaned at least daily. 

Shipping and Receiving 

Shipping and receiving areas can create 

indoor air quality problems regardless of 

the types of materials being handled. 

Vehicle exhaust fumes can be minimized 

by prohibiting idling at the loading dock. 

This is particularly important if the loading 

dock is located upwind of outdoor air 

intake vents. You can also reduce drafts 

and pollutant entry by pressurizing interior 

spaces (e.g., corridors) and by keeping 

doors closed when they are not in use. 

A good preventive maintenance 

program can help a facility manager 

identify and correct problems before 

they occur. If this fan belt breaks, the 

area served by the air handling unit may 

be without ventilation. If it is slipping, it 

is already reducing the airflow. 

A termiticide misapplication resulted in 

an indoor air quality problem in this 

school. Detectable levels of chlordane 

were found in both wipe (surface) and 

air samples near the injection holes 

drilled into the ground floor. Note the 

small white circles near the wall. (Under 

an agreement with EPA, manufacturers 

have withdrawn chlordane from sale.) 

Proper application methods are 

important for all pesticides. 

Managing Buildings for Good IAQ 37 
uses a 

monitoriog, habitat 

ao·olil:ati;on of pesticides when 

Pest Control 

Pest control activities that depend upon 

the use of pesticides involve the storage, 

handling, and application of materials that 

can have serious health effects. Common 

construction, maintenance practices, and 

occupant activities provide pests with air, 

moisture, food, warmth, and shelter. 

Caulking or plastering cracks, crevices, or . 

holes to prevent harborage behind walls 

can often be more effective than pesticide 

application at reducing pest populations to 

a practical minimum. 

Integrated Pest Management (IPM) is a 

low-cost approach to pest control based 

upon knowledge of the biology and 

behavior of pests. Adoption of an IPM 

program can significantly reduce the need 

for pesticides by eliminating conditions 

that provide attractive habitats for pests. 

38 SectionS 

If an outside contractor is used for pest 

control, it is advisable to review the terms 

of the contract and include IPM principles 

where possible. The following items 

deserve particular attention. 

Pest control schedule: Schedule pesticide 

applications for unoccupied periods, if 

possible, so that the affected area can be 

flushed with ventilation air before occupants return. Pesticides should only be 

applied in targeted locations, with minimum treatment of exposed surfaces. They 

should be used in strict conformance with 

manufacturers' instructions and EPA 

labels. General periodic spraying may not 

be necessary. If occupants are to be 

present, they should be notified prior to the 

pesticide application. Particularly susceptible individuals could develop serious 

illness even though they are only minimally exposed. 

Materials selection, handling, and 

storage: Select pesticides that are speciesspecific and attempt to minimize toxicity 

for humans and non-target species. Ask 

contractors or vendors to provide EPA 

labels and MSDSs. Make sure that 

pesticides are storc~d and handled properly 

consistent with their EPA labels. 

Ventilation of areas where pesticides are 

applied: If only limited areas of the 

building are being treated, adjust the 

HV AC system so that it does not distribute 

contaminated air throughout the rest of the 

building. Consider using temporary 

exhaust systems to remove contaminants 

during the work. It may be I1ecessary to 

modify HV AC system operation during 

and after pest control activities (e.g., 

running air handling units on 100% 

outdoor air for some period of time or 

running the system for several complete air 

exchanges before occupants re-enter the 

treated space). 
~: 

lp.,.:. 

t,,,,,. 

.. , . . . •.. . ... . : ., • :~ .. ; ·<·.,:;·,., ... XL: ··. , ;; "'"' ;,; , . · ... ·. . . . . .• ~ RIAL SAF~ . Wn~er QSI-IA regulations; responsible parties'are requirec)to di)cument information on ·: 

A SHEETS · · potehtially hazardous· produ~s. These Material Safety Data SheErts (MSDSs) may be ". , ··· -· · · .. , , >· <;?'~L of_,f~lited1ietp_.Jn-identi1)ting- sQJ:ne -~~odUct~-th~~m~Y P:os~-_IAO·.~o~~~rn~~_.< H_~wev~r, 

. . ... · ... ·.·.·•.·· professional judgment and coHecticii'l Qfaadlfh:mai lnrormation'mW be necessary in 

·· ; <t··9rd,~rto.~al_{efuli:H~e9HI'l~.,\\i1.~1;'?~·· · .. ~inQ"tabl~summarizesson:e oft~e ... ·. ·.;: }tssv~stokeepmmt[ldwhendectdt r. mfo~mat1on from IVJSDSs.ts applicable 

•.··: ;r;t}4 ~~~{3~!·~P ~~:~~:.~R;~~~~~j·~~~~X'f~~:~~~~:t: n in·.~··liu.ildi~~~·: .. « "''' · 

,,,,, ' •:>1 ··'' ;;.•,>4''/·'·' ~~~~~~~~~~~~~~~·~ •::\:•:·•( ,;c;;:., ·,,·.,:., >' ,,. ·•. . ·. ·. ' ';!j 

. · • odordescripti<,m may help identify·,· • reference material on how to use physical · ··s,aurce$' : ·· · .· .. · ·· ···.. · · · . :. ·.·.• ~ ·• Qat~Jnte>rrnation ~o predict IAQ impacts ... ·>.<~~ . · :_~:· __ >-.. :·\·)-~;:- :·.:-~ ~;:~: __ <: .. · · :·:t:?~~--~~y-be~ SeBree· · · · · · · --~ 

• voll.'ltility' may suggest which prod- • ' ·· .~ ·. c • , •• · ., · • -

ucts' are likely to be airborn~ . • . ' ;.. . ·~"'•".;:> • '"c'• -•. ·-..;· .. : ·_·,~·--:--~ · • -:-'';w'J:\~_--,_)"'f-:_·--~\.;-:·:<':: 

,'c~nta~inan~s tQ· e~pecti~t ~~eotqr'a· · 

.•. ·.fire. or decompo~ition il:i~y be listed, . 

• 4 !(re~c~~ity dat;·may ~~~:~~~t ~~~;ri~Yal··· · 

pro~lem~ .with ~or,a9e or us~ . • ·. :".:-·-, , ... , •.'':>' .,.., 

· .. -~a~yriffige ch~mirials ar~ kept in much 

.... ··· sin'aiiEn· ar;nounts than .found iri industrial 

;; . ; ·. . ;C:• ~~:ttiQ9S .. : . 

.•• •' • spill cle~mu~ may not ,eliminate airborne ,, ':::,>.:. : ••. '. •' .. :>:~.:contamination ' , •. ' ,. '•· -~- --~ - ,, - ~-",• . f •• ;_:: ·_:·-_ ·.: __ :>_~:~/-~·::--:·:·:·._>j'-;y'---_>:-- -·<-_:~·:-.--· .. -:-_-- .. ' " ' .. . . - ' 

.•.. ~ .· '-i<·:;~,c!c:l~s.not,specifyro~tine emission contiols • ::··:::: ~·::·-~-:·.~;~:·_,j,·.-~;:·;--_~_~1;.\·;:;_:·-<,(··:.:';<-,----~--~·:·.::.;· __ :·_~.- >·:' ,',' ·. ··- .-· ·-:·:_-- . -,··· 

•·. A~fis6~ab1~.9'ffrirt~hotild he ~~~~·t~ ~6fl~ct~~l!l'il'~b~I~.MS0Ss dtiring 1..'\a profile. · ·.~ : ..•. development •. ·tare should be taken to consid~r fnfcrrrpation that is relevant to IAQ 

· .co11cerns: • Other irnportan(indicators ~f.~.o~.ap.~rtic,~;~~a~ pr:oduct may affect IAQ are . availabl.e from direct odor.and dust.observations,a review of work practices, and ·· . · 

. interviews with operators and occupants. The' manufaqturer is a good source of .follow~· 

up information on.a given product (phone number should be' included on each MSDS). ·_ . - . . . . - , , ' r:';' , ; ' . . -• . ,- :. ·;· ••- - ' ;, <~· • , • , •' . 0 

-·- '-':. .: < ~""''-''"~"~'/;'., ::..::.·: ~ ::;~~-1-~~ .··::•,• ~'"''"'"".;.:.:- .. ~::. ,;_; ;,::: '

0

, ~,;,,.,;,.:::...:-: ,j '•m' ~ 

Managing Buildings for Good IAQ 39 
It is important for building 

occupants to understand 

that their activities can 

create indoor air quality 

problems. Smoking 

rs/eases both carcinogenic 

and irritating substances 

Into the air. 

Occupant Relations 

Managing occupant relations to prevent 

IAQ problems involves: allocating space 

and monitoring the use of building areas to 

isolate odor- and contaminant-producing 

activities and avoid re-entrainment; establishing a communication strategy that is 

responsive to complaints and provides 

tenants with information about their t:ole in 

preventing indoor air quality problems; 

and modifying employee manuals or lease 

agreements as necessary to clarify the 

responsibilities of occupants and building 

management. A health and safety committee or joint tenant-management IAQ task 

force that represents all of the major interest groups in the building can be very 

helpful in disseminating information and 

fostering a cooperative approach to IAQ 

management. See Section 3 for a discussion of these points. 

Renovation, Redecorating, and 

Remodeling 

Renovation, redecorating, and remodeling activities can create indoor air 

problems by producing dust, odors, microbiologicals and their spores, and emissions. 

It is difficult to prevent IAQ problems if 

some building areas are undergoing renovation while adjoining areas continue 

normal operations. 

40 SectionS 

Close monitoring of renovation, 

redecorating, and remodeling projects is 

recommended. The following suggestions 

may be helpful: 

Working with professional consultants: 

Communicate your concern about preventing indoor air quality problems to the 

engineer, architect, interior designer, or 

other professionals involved in the project. 

Product selection: Specify products and 

processes that minimize odors and emissions, while maintaining adequate safety 

and efficacy. Review the general information provided by the product labels and 

MSDSs. Request information from 

suppliers about the chemical emissions of 

products being considered for purchase. 

Work schedules: Schedule activities that 

produce dust, odors, or emissions for 

unoccupied periods if possible. 

Isolation of work areas: Block off return 

registers so that contaminants are not 

recirculated from the demolition/construction area into adjoining areas, and install 

temporary barriers to confine dust and 

noise. If possible, install temporary local 

exhaust to remove odors and contaminants, 

and check to confirm that the temporary 

ventilation system is operating as planned. 

InstaUation of new furnishings: Ask 

suppliers to store new furnishings in a 

clean, dry, ventilated location so that 

volatile organic compounds will be emitted 

before installation. Minimize the use of 

adhesives during installation or specify 

low-emitting products. After new furnishings are installed, increase the ventilation 

rate to flush the area with outdoor air and 

dilute emissions. 

Smoking 

Although there are many potential 

sources of indoor air pollution, both 

research and fteld studies have shown that 

environmental tobacco smoke (ETS) is one 

of the most widespread and harmful indoor 

air pollutants. Environmental tobacco 

smoke is a combination of sidestream 
smoke from the burning end of the 

cigarette, pipe, or cigar and the exhaled 

mainstream smoke from the smoker. ETS 

contains over 4,000 chemicals; 43 of these 

chemicals are known animal or human 

carcinogens. Many other chemicals in 

ETS are tumor promoters, tumor initiators, 

co-carcinogens (i.e.; chemicals that are · 

able to cause cancer when combined with 

another substance), or cancer precursors 

(i.e., compounds that can make it easier to 

form other carcinogenic chemicals). 

In 1986, The Health Consequences of 

Involuntary Smoking: A Report of the 

Surgeon General on Environmental 

Tobacco Smoke conCluded that ETS was a 

cause of lung cancer in healthy nonsmokers and that "the scientific case 

against involuntary smoking as a public 

health risk is more than sufficient to justify 

appropriate remedial action, and the goal 

of any remedial action must bf? to protect 

the non-smoker from em;ironmental 

tobacco smoke." In th~ same year, the 

National Research Council of the National 

Academy of Sciences issued a report, 

Environmental Tobacco Smoke: Measuring Exposures and Assessing Health 

Effects, which also concluded that passive 

smoking increases the risk of lung cancer 

in adults. 

In June 1991, NIOSH issued a Current 

Intelligence Bulletin (#54) on ETS in the 

workplace that dealt with lung cancer and 

other health effects. In its Bulletin, 

NidSH stated that the weight of evidence 

is sufficient to conclude that ETS can 

cause lung cancer in non-smokers.(i.e., 

those who inhale ETS). It recommended 

that the preferable method to protect nonsmokers is the elimination of smoking 

indoors and that the alternative method 'is 

to require that smoking be permitted only 

in separately ventilated smoking areas. 

The NIOSH Bulletin emphasized that 

provision of such isolated areas should be 

viewed as an interim measure until ETS 

can be completely eliminated indoors. 

Smoking areas must be separately 

ventilated, negatively pressurized in 

relation to surrounding interior spaces, and 

supplied with much more ventilation than 

non-smoking areas. The NIOSH Bulletin 

also recommends that the air from the 

smoking area should be exhausted directly 

outdoors and not recirculated within the 

building or vented with the general exhaust 

for the building. ASHRAE Standard 62-

1989 recommends that smoking areas be 

supplied with 60 cubic feet per minute (60 

cfm) per occupant of outdoor air; the 

standard also recognized that using transfer 

air, which is pulled in from other parts of 

the building, to meet the standard is 

common practice. 

Both EPA and NIOSH advise that 

building owners or facility managers 

considering the introduction of smoking 

restrictions should implement smoking 

cessation programs. In addition, employees and labor unions should be involved in 

the development of non-smoking policies 

in the workplace. 

(Refer to Appendix G for citations on 

publications mentioned in this section, 

especially NIOSH Current Intelligence 

Bulletin (#54): Environmental Tobacco 

Smoke in the Workplace- Lung Cancer 

and Other Health Effects. Additional 

resources on ETS, including an assessment 

of respiratory disorders in children and 

lung cancer risks in adults, and a guide to 

developing effective smoking policies, will 

be available from EPA early in 1992.) 

Managing Buildings for Good IAQ 41 

According to a 1986 

report of the Surgeon 

General, .. the case 

against involuntary 

smoking is more than 

sufficient to justify 

appropriate remedial 

action to protect the 

non-smoker from 

environmental tobacco 

smoke." 
- Sample Form 

Management Checklist 

Item 

IAQPROFILE 

Collect and Review 

Existing Records 

HVAC design data, operating 

instructions, and manuals 

HVAC maintenance and calibration 

records, testing and balancing reports 

Inventory of locations where 

occupancy, equlptment, or building 

use has changed 

Inventory of complaint locations 

Conduct a Walkthrough 

Inspection of the Building 

List of responsible staff and/or 

contractors, evidence of training, 

and job descriptions 

fdentification of areas where positive 

or negative pressure should be 

maintained 

Date Begun 

or Completed 

{as applicable) 

Responsible Person 

(name, telephone) 

SEE 

COMPLETE! 

FORM · PAGE 171 1 

The IAQ Management Checklist 

shown in part here and included in full 

within Tab V can be used to help 

confirm that you have accounted for the 

major factors that could cause IAQ 

problems in your building. 

42 SectionS 

Location 

("NA" if the item is not 

applicable to this building) 
~-~~~A, :,:.f·.r::· :· : ,·~~;;:.'\_/".·:;~~})F.~~:;~.· .~.j;.::;·(·~./~ :~ 2-~~·,t:,·)·,~; :1~;.~t~~~:p~~p~.~1ff,}~-~~1[f 

Air .Conditionintl and.Refrjsjer. . . . . . tpmf,nt General .. ·. . naJICe . . . r · ·· · Jmpio1fliiiJ the lndo()r Enlfironmel)t (1$~1}.> Ge.n~ral mainf~n~ulce,requirem~nts.for ·. 

h~atiilg ventilation,;-aircondificming, ,and refrigeration {HVACRt equipment; .•.... ·. ~·peciflc'equipment/corrif:iorienFmai~feha'rice 'is. ~rve:n .1orthe following: air Qle~ning 

. stems; ducts; registers/diffusers Eind ajr:terrriin~rs; dampers/econorriiiEifs;·drain ·· . . • : .. ,.·.<:·, :•.:< p , .. 5 airhandlers; hurnidiner.s; p~ckage,~ermih<.\1 unit~Yand l;i.vaJ>or~()r,ci)ndenser, ,<;'''~:T(,;>.\}ii;:,, liy(ironic' and ecOnomizer coils. The guideline$)JO not;superseaEf:aily m~intenance. 

· · ·· ·~ ., '·'"'~;.i: !,n$.trYctio:n!?th!:IJ:8.re pr0yidecfby'fne'manufacture'r• lna'dd.it[on; thEflnstitute has' ·. · ;; .. X/:.),{ •. i~s(le!]'~nJnqogrAlr·au~litY Briefing.•Papei that a((dresses the.lnteractioo~V · ·. •··. · ·· · ·· · 

·> • j"'~,~~~~~;~;~~~~,· ... :~~~~iltandthe< u'alit\lofi~dcio:fair.''. -.· ···= --

Managing Buildings for Good IAQ 43 

Diagnosing IAQ Problems 

l:e goal of the diagnostic building 

investigation is to identify and solve the 

indoor air quality complaint in a way that 

prevents it from recurring and that does not 

create other problems. This section 

describes a method for discovering the 

cause of the complaint and presents a 

"toolbox" of diagnostic activities to assist 

you in collecting information. 

Just as a carpenter uses only the tools 

that are needed for any given job, an IAQ 

investigator should use only the investigative techniques that are needed. Many 

indoor air quality complaints can be 

resolved without using all of the diagnostic 

tools described in this chapter. For 

example, it may be easy to identify the 

source of cooking odors that are annoying 

nearby office workers and solve the 

problem by controlling pressure relationships (e.g., installing exhaust fans) in the 

food preparation area. Similarly, most 

mechanical or carpentry problems probably require only a few of the many tools 

you have available and are easily accomplished with in-house expertise. 

The use of in-house personnel builds 

skills that will be helpful in minimizing 

and resolving future problems. On the 

other hand, some jobs may be best handled 

by contractors who have specialized 

knowledge and experience. In the same 

way, diagnosing some indoor air quality 

problems may require equipment and skills 

that are complex and unfamiliar. Your 

knowledge of your organization and 

building operations will help in selecting 

the right tools and deciding whether inhouse personnel or outside professionals 

should be used in responding to the 

specific IAQ problem. 

! 

Star:t (reason for concern) 

Initial walkthrough 

• preparation 

• visual inspection 

• talk with occupants and staff 

Collect additional 

information about 

•,building occupants 

• the HVAC system 

• pollutant pathways 

• pollutant sources 

(sample contaminants if needed) 

Develop one or more hypotheses 

to explain the problem. Test by 

manipulating building conditions 

or exposure, qr by performing 

appropriate tests. 

No Attempt 

a control 

strategy 

FIGURE 6-1: 

Conducting an IAQ Investigation 

Note: Outside assistance may be needed at 

any point in the investigation, depending 

upon the complexity of the problem, the skills 

available in-house, time pressures, or other 

factors. 

Diagnosing IAQ Problems 45 

No 

Follow-up 

validation 

Make necessary 

changes so that 

the problem will 

not recur. 

Finish 
The IAQ investigation 

is often a repetitive 

cycle of informationgathering, hypothesis 

formation, and 

hypothesis testing. 

OVERVIEW: CONDUCTING AN 

IAQ INVESTIGATION 

An IAQ investigation begins with one or 

more reasons for concern, such as occupant complaints. Some complaints can be 

resolved very simply (e.g., by asking a few 

common sense questions of occupants and 

facility staff during the walkthrough). At 

the other extreme, some problems could 

require detailed testing by an experienced 

IAQ professional. In this section "the 

investigator" refers to in-house staff 

responsible for conducting the IAQ 

investigation. 

The flowchart on page 45 shows that 

the IAQ investigation is a cycle of information-gathering, hypothesis formation, 

and hypothesis testing. The goal of the 

investigation is to understand the IAQ 

problem well enough so that you can solve 

it. Many IAQ problems have more than 

one cause and may respond to (or require) 

several corrective actions. 

Initial Walkthrough 

An initial walkthrough of the problem area 

provides information about all four of the 

basic factors influencing indoor air quality 

(occupants, HV AC system, pollutant 

pathways, and contaminant sources). The 

initial walkthrough may provide enough 

information to resolye the problem. At the 

least, it will direct further investigation. 

For example, if the complaint concerns an 

odor from an easily identified source (e.g., 

cooking odors from a kitchen), you may 

want to study pollutant pathways as a next 

step, rather than interviewing occupants 

about their patterns of discomfort. 

Developing and Testing 

Hypotheses 

As you develop an understanding of how 

the building functions, where pollutant 

sources are located, and how pollutants 

move within the building, you may think 

of many "hypotheses," potential explana46 Section6 

tions of the IAQ complaint. Building 

occupants and operating ~taff are often a 

good source of ideas about the causes of 

the problem. For example, they can 

describe changes in the building that may 

have occurred shortly before the IAQ 

problem was noticed (e.g., relocated 

partitions, new furniture or equipment). 

Hypothesis development is a process 

of identifying and narrowing down 

possibilities by comparing them with your 

observations. Whenever a hypothesis 

suggests itself, it is reasonable to pause 

and consider it. Is the hypothesis 

consistent with the facts collected so far? 

You may be able to test your hypothesis 

by modifying the HV AC system or 

attempting to control the potential source 

or pollutant pathway to see whether you 

can relieve the symptoms or other conditions in the building. If your hypothesis 

successfully predicts the results of your 

manipulations, then you may be ready to 

take corrective action. Sometimes it is 

difficult or impossible to manipulate.the 

factors you think are causing the IAQ 

problem; in that case, you may be able to 

test the hypothesis by trying to predict how 

building conditions will change over time 

(e.g., in response to extreme outdoor 

temperatures). 

Collecting Additional 

Information 

If your hypothesis does not seem to be a 

good predictor of what is happening in the 

building, you probably need to collect 

more information about the occupants, 

HV AC system, pollutant pathways, or 

contaminant sources. Under some 

circumstances, detailed or sophisticated 

measurements of pollutant concentrations 

or ventilation quantities may be required. 

Outside assistance may be needed if 

repeated efforts fail to produce a successful 

hypothesis or if the information required 

calls for instruments and procedures that 

are not available in-house. 
Results of the Investigation 

Analysis of the information collected 

during your IAQ investigation could 

produce any of the following results: 

The apparent cause(s) of the complaint(s) 

is (are) identified. 

Remedial action and follow-up evaluation 

will confmn whether the hypothesis is 

correct. 

Other IAQ problems are identified that 

are not related to the original complaints. 

These problems (e.g., HV AC mulfunctions, strong pollutant sources) should be 

corrected when appropriate. 

A better understanding of potential IAQ 

problems is needed in order to develop a 

plan for corrective action. . 

It may be necessary to collect more 

detailed· information and/or to expand the 

scope of the investigation to include 

building areas that were previously 

overlooked. Outside assistance may be 

needed. 

The cause of the original complaint 

cannot be identified. 

A thorough investigation has found no 

deficiencies in HV AC design or operation 

or in the control of pollutant sources, and 

there have been no further complaints. In 

the absence of new complaints, the original 

complaint may have been due to a single, 

unrepeated event or to causes not directly 

related to IAQ. 

Using Outside Assistance 

Some indoor air quality problems may be 

difficult or impossible for in-house 

investigators to resolve. Special skills or 

instruments may be needed. Other factors 

can also be important, such as the benefit 

of having an impartial outside opinion or 

the need to reduce potential liability from a 

serious IAQ problem. You are best able to 

make the judgment of when to bring in an 

outside consultant. See Section 8 for a 

discussion of hiring professional assistance 

to solve an IAQ problem. 

INITIAL WALKTHROUGH 

An investigation may require one or many 

visits to the complaint area. The amount 

of preparatory work needed before the 

initial walkthrough varies with the nature 

and scope of the complaint and the 

expertise of the investigator, among other 

factors. For example, an in-house investigator who is already familiar with the 

layout and mechanical system in the 

building may begin responding to a 

. complaint about discomfort by going 

directly to the complaint area to check the 

thermostat setting and see whether air is 

flowing from the supply outlets. 

If the investigator is not familihr with 

the building or is responding to complaints 

that suggest a serious health problem, more 

preparation may be needed before the 

initial walkthrough. The activities listed 

below can be directed at a localized 

"problem area" or extended to include the 

entire building: 

Collect easily-available information about 

the history of the building and the 

complaints. 

Identify known HV AC zones and complaint areas. 

Begin to identify potential sources and 

pollutants (e.g., special use areas near the 

complaint location). Having a copy of 

mechanical and floor plans can be helpful 

at this stage, especially if they are 

reasonably up-to-date. 

Notify the building occupants of the 

upcoming investigation. 

Tell them what it means and what to 

expect. 

Diagnosing IAQ Problems 47 
This improvised catch basin 

Is Intended to collect water 

seeping Into the building 

from below grade. Although 

the catch basin "solves" the 

problem of uncontrolled 

water leakage, it also provides an Indoor location 

that could support the 

growth of microbio/ogica/s 

and create lAO problems. 

Identify key individuals needed for access 

and infonnation. 

A person familiar with the HV AC systems 

in the building should be available to assist 

the investigator at any time during the 

onsite phase. Individuals who have 

complained or who are in charge of 

potential sources (e.g., housekeeping, nonHV AC equipment) should be aware that 

their information is important and should 

be contacted for appointments or telephone 

interviews if they will not be available 

during the onsite visit. 

The initial walkthrough provides an 

opportunity to question complainants about 

the nature and timing of their symptoms 

and to briefly examine the immediate area 

of the complaint. The investigator 

attempts to identify pollutant sources and 

types and observes the condition and 

layout of the HV AC system serving the 

complaint area. Facility staff can be asked 

48 Section6 

to describe the operating schedule of 

equipment. Obvious problems (e.g., 

blocked diffusers, malfunctioning air 

handlers) can be corrected to see if the 

complaints disappear. The walkthrough 

can solve many routine IAQ problems and 

will suggest directions for a more complex 

investigation, should one be necessary. 

Some investigators avoid taking any 

measurements during the initial walkthrough so that they are not distracted from 

"getting the big picture." Others find that 

using smoke sticks, digital thermometers, 

and direct reading C02 meters or detector 

tubes to take occasional measurements 

helps them develop a feel for the building. 

It may help to keep the following 

questions in mind during the initial 

walkthrough: 

Are there obvious pollutant sources? Do 

they appear to be adequately controlled? 

• Are pollutant indicators present, such as 

odors, excessive dust, or staining? 

• Are there sanitation problems (e.g., 

debris near outdoor air intake, visible 

mold growth, major water damage) that 

could be introducing air contaminants? 

• Are there any conditions or activities 

occurring in or near the bUilding that 

could be related in timing, location, and 

health effects to the complaints? 

Are there any deficiencies in the HV AC 

system that serves the complaint area? 

• Does equipment serving the area (e.g., 

thermostats, diffusers, fans, dampers, 

filters) appear to be operating, clean, and 

in good condition? 

• Do operating procedures exist, and does 

the staff follow them? 

• Do records indicate that the system was 

commissioned (set, tested, and balanced) 

after construction? 

• Do records indicate that system components are regularly inspected, calibrated, 

and adjusted? 
Are there pathways and pressure differences which could be moving contaminants into the complaint area from the 

outdoors or from other parts of the 

building? 

COLLECTING ADDITIONAL 

INFORMATION 

Additional information will be needed if 

the initial walkthrough does not identify 

the cause of the problem .. The following 

pagys present techniques for collecting 

information about the occupant complaints, HV AC system, pollutant pathways, 

and pollutant sourqes and using that . 

information to develop a hypothesis that 

could explain the problem.· Common sense 

will suggest the appropriate sequence of 

steps during this part of the investigation. 

For example, if the complaint is limited to 

a single room,. it makes sense to evaluate 

pollutant pathways into that room before 

attempting to inventory sources in locations outside 9£', but collllected to, the. 

complaint area. On the other hand, if the 

complaint involves a recognizable odor 

(e.g., exhaust fumes), it may be more 

practical to begin by locating the potential 

source(s) of the odor before trying to 

identify pollutant pathways. 

: Sample Form · 

!ilncident. Log·_. [ ''. ·. 

;:~·-

Forms and checklists such as the 

samples provided in this document (modified if needed) can help investigators to 

record information in an organized way. 

Small copies of basic floor plans, such as 

fire evacuation plans, are convenient for 

noting locations of observations. 

Any instruments that will be used 

should be inspected to makf) sure they are 

in working order and calibrated. IAQ. 

investigations generally include the use of, 

at a minimum: beatless chemical smoke 

devices and instruments for measuring 

temperature and humidity. 

Carbon dioxide measuring devices 

(detector tubes with a h~d pump or a 

direct reading meter) are helpful for most 

investigations. Other instruments may be 

needed as the investigation progresses. 

See Appendix A for additional guidance on 

common IAQ measurements. 

Tools for Collecting Information 

The following pages present strategies, 

tools, and forms for the investigator to use 

during an in-depth investigation. The 

Incident Log shown below (and in :fab V) 

can be used to track the course of an investigation fr()m the receipt Qf the original 

complaint~· 

.:<~---.:.-:··-· .::" ;<<: ,·->-_.; ;, , .. ; .. ";" "''· ' "hi,-- : 

Diagnosing IAQ Problems 49 

·' . :. ·. 

SEI: 

COMPLETE 

FORM . 

PAGJa 18$ •. 
An initial walkthrough may 

uncover problems such as 

this unsanitary condition in 

the HVAC system. Bird 

droppings have collected in 

an air supply plenum near 

an outdoor air intake that 

was not protected by a 

birdscreen. 

The discussion that follows has been 

divided into categories of occupant data, 

HV AC system data, pollutant pathway 

data, and source data. However, the 

suggestions for collecting and using 

information reflect the interdependence of 

these factors. For example, the operation 

of the air distribution system affects 

pollutant pathways, and the air distributior 

system can also be a source of pollutants. 

Indoor air quality related complaints 

may develop from a variety of causes. 

Neither the discussion of strategies for 

collecting information nor the suggestions 

for interpreting data can present the full 

range of possible situations encountered in 

50 Section6 

buildings. They are intended to present a 

problem-s<:>lving approach that can help 

facility staff to understand and resolve 

many common indoor air quality problems. If you decide to hire outside 

professionals to resolve your IAQ complaint, this discussion of strategies and 

tools should help you to understand and 

oversee their investigative work. 

COLLECTINtG INFORMATION 

ABOUT OCCUPANT 

COMPLAIN1rS 

Occupant data falls into two categories: 

complaints of discomfort or other symptoms (e.g., teary eyes, chills) and perceptions of building conditions (e.g., odors, 

draftiness). Investigators can gather 

valuable information about potential 

indoor air problems by listening to 

occupants, and use that information for: 

• defming the complaint area within the 

building 

• suggesting directions for furth~r investigation, either by identifying other events 

that seem to happen at the same time as 

the incidents of symptoms or discomfort, 

or by identify:iflg possible causes for the 

types of symptoms or discomfort that are 

occurring 

• indicating potential measures to reduce 

or eliminate the problem 

Review Existing Records of 

Complaints 

If there is a record of occupant complaints, 

a review of that record can help to defme 

the location of the IAQ problem and 

identify people who should be interviewed 

as part of the investigation. Information 

about the history of complaints could also 

stimulate theories about potential causes of 

the problem. 

Interview Occupants 

The most obvious way to collect information from building occupants is to talk to 
them in person. If it is not possible to 

interview everyone who has complained 

about building conditions, the investigator 

should attempt to interview a group of 

individuals that reflects the concerns of the 

affected areas. 

The investigation may also include 

occupant interviews with building 

occupants who do not have complaints. 

Then conditions in the complaint area can 

be compared to conditions in similar 

building locations where there are no 

complaints. 

A sample Occupant Interview form is 

shown here (there is another copy in 

Tab V). It can also be presented in a 

written form in order to get information 

from more people than can be interviewed. 

The following key points will help 

interviews to be productive: 

• Read the discussion of evaluating 

occupant data before you conduct 

interviews to be certain that you 

understand what sort of information is 

needed. 

• Make a copy of the interview form for 

each person you speak with, and use the 

form to record the answers to your 

questions. 

• Choose a location in which the person 

you are interviewing feels comfortable to 

speak freely. 

• Explain that the interview is intended to 

help discover and correct the cause of the 

complaints. Encourage the person you 

are interviewing to join in this cooperative problem-solving effort. 

• Give the person you are interviewing 

enough time to think about your questions. 

• If complainants are reluctant to answer 

questions about health symptoms, 

respect their desire for privacy. Planning 

for how to maintain this privacy is 

warranted, and in some cases may be 

mandated. 

• Feel free to expand the interview by 

adding questions that help to improve 

~{:s~m11te Form . . .. . .. .· .. · ~,:;::.:oc~upant lnt•rview ~.::~:::::-~ : . .. . ........ ·. ' : . . ·. . ; 

YMPTOMPATTERNS ' .. -

'af kina. of symrnorris or disc9_rr1fort are yo~ experiencing? .. 

other pe6pl~ With similar ~ymptoms or _f\lo~· ··.··.·.·.· .. ·: ··.·.··• 

whata~etheknam.esand locations?. 

'· . ' : . ' ' 

~X:" bo you have ~mv health c6n~itiob~ thiit.inav rna~e you particularly f;~,c susceptible to environrrientalprobJems?, ... 

~ .. ).{L, 

L::"'" , , 

your understanding or explore their 

hypotheses (or your own) about what 

may be causing the problem. Always be 

open to answers that may not fit your . 

hypotheses. 

• You may sometimes need to clarify a 

question by giving examples of the sort 

of information you are interested in. Try 

to provide more than one example so that 

you don't seem to be telling the person 

the answer you want. Be particularly 

cautious about mentioning specific 

health effects. 

The Occupant Interview includes 

many basic points that are found in 

questionnaires used by professional IAQ 

investigators. It is important to note, 

however, that this form is not called a 

"questionnaire." Formal questionnaires 

may be useful for quantitative epidemiology, IAQ research, complex IAQ investigations, or when litigation is a possibility. 

In these cases, questionnaires must be 

carefully designed and executed by people 

with an understanding of representative 

sampling and expertise in pnblic health, 

industrial hygiene, or medicine. Use of 

questionnaires for such purposes is beyond 

the scope or expertise of most in-house 

Diagnosing IAQ Problems 51 

SEE 

·cOMPLETE 

FORM 

PAGE185 
Severity/Duration 

Sample Form·· · ·' 

l.,og ''of.ACtividos and System Operation 

1l '•:hll~ I' ,, '1''1 " :11::" :,:,::,,:,11;;;,~:;,:; ::~:::":,:: ·,:~;:::::::::::,;:~:'1,, ~~~::::, ",:,~,:::;;;~~~:~ ' • !: :,·, ::;:: ·:: ::::;:"~" ';:, ::," ,,;,.:::~,~::·:;·,,,, ', II'~~~:·,::;,:,~~;:·_:, I :::::~, ::':;1~1:' •II I ''•II I ~:' ~. "W' '"· '1•! ,,,·,,,,,:,:,' :~: ' 

I ""II II I 1h I •I ·~, ' I '' 1 ::'11, 1111, ,'~ I " " ' '11:1·11:::!::::~::::::1 II' ,: 1111 11 11• 'l'•~llli,ll,h :1 'hll:l :;:., 'Ji'',,: ,.':":'" ,:1: •::::: 't" ::.::~~ 'l!i::.'. ~:: ": ' ' ' "'" ' ""' " 

1 

On tbe ~or~below, please record your observations of HVAC 

tiWJ:m~~~~:~~(tvo~1m~~~ai6~~~~~~1f~rd:~~~~~~\he caus~ of IAQ complaint~JI'l thi~'bijilding~ Please ~eport any other ' , ... . . 

obstUYati<:ms (e.g., weather, other associated events) that you think 

may be important as well. ·· · · · 

Equipment and activities of particular interest: 

Air Handler(s}: ---------,---,-.,------,-,------,-,.---

Exhaust Fan(s): --~----------.,.--,---__,..,.=--___, Other Equipment or Activities:-------------

Datemm• Day of Week 

SEE 

COMPLETE 

FORMS 

PAGES187 

AND 189 

Equipment Item/Activity Comments 

52 Section6 

',, .1111 

investigations; if such questionnaire data is 

needed, building owners and managers 

should use professionals. 

Ask Occuparnts and Facility 

Staff to Keep More Detailed 

Records 

Many events occur simultaneously in and 

around a complex building, and it can be 

very difficult to judge which of those 

events might be related to the IAQ 

complaints. In trying to resolve stubborn 

problems, professional investigators 

sometimes ask occupants and facility staff 

to keep day-by-day records. Occupants are 

asked to record the date and time of 

symptoms, where they are when the 

symptoms appear, and any other information that might be useful. Such information could include observations about the 

severity and duration of symptoms and 

comments on weather conditions, events, 

and activities that are happening at the 

same time. Facility staff are asked to 

record the date and time of events such as 

maintenance work, equipment cycles, or 

deliveries. If symptoms seem to occur at 

particular times of day, staff can focus 

their attentions on recording events that 

occur before and during those periods. 

Such records are likely to produce more 

accurate and detailed information than can 

be obtained by relying on memory. (Use 

the Occupant Diary and the Log of 

Activities and System Operation shown 

here and included in Tab V.) 
USING THE OCCUPANT DATA· 

The pattern of complaints within the 

building helps to defme the complaint area. 

The timing of symptoms and the types of 

symptoms reported may provide clues 

about the cause of the problem. 

Strategies for Using Occupant Data 

• Define the complaint area 

• Look for timing patterns 

• Look for symptom patterns 

Diagnosing IAQ Problems 53 

Exhaust fumes are drawn 

into this bpi/ding's outdoor 

air intake when trucks are 

idling at the nearby loading 

dock. Tools such as the 

Occupant Diary and Log of 

Activities and System 

Operation can help to 

identify intermittent 

pollutant sources such as 

this one. 
54 Section6 

Define the Complaint Area 

Use the spatial pa.ttetn (locations) of 

complaints to define $e complaint ar~. 

Building locations where symptoms or 

discomfort occur de:fme the rooms or zones 

that should be given particular ~ttention 

during the initial investigation. However, 

the complaint area may need to be revised 

as the investigation progresses. Pollutant 

pathways can cause occupant complaints 

in parts of the building that are far 

removed from the source of the problems. 
Look for Timing Patterns 

Look for patterns in. the timing of complaints. The timing of symptoms and 

complaints can in.dicate potential causes 

for the complaints and provide directions 

for further in.vestigation. Review the data 

for cyclic patterns of symptoms (e.g., 

worst during periods of min.imum ventilation or when specific sources are most 

active) that may be related to HV AC 

system operation or to other activities in. 

and around the building. 

Diagnosing IAQ Problems 55 
Look for Symptom Patterns which toxicology has found specific 

effects. Therefore, it may be more useful 

to look for patterns of symptoms than 

The following chart lists 

some common symptom 

groups that can be related 

to Indoor air quality, along 

with possible sources or 

causes of those symptoms. 

Building managers are 

cautioned that this is only a 

partial listing. 

Look for patterns in the types of symptoms 

or discomfort. IAQ investigations often 

fail to prove that any particular pollutant 

or group of pollutants are the cause of the 

problem. Such causal relationships are 

extremely difficult to establish. There is 

little information available about the health 

effects of many chemicals. Typical indoor 

levels are much lower than the levels at 

for specific pollutant and health effect 

relationships. 

Investigators who are not medically 

trained cannot make a diagnosis and should 

not attempt to interpret medical records. 

Also, confidentiality of medical information is protected by law in some jurisdictions and is a prudent practice everywhere. 

SYMPTOM PATTERNS 

THERMAL DISCOMFORT 

COMMON SYMPTOM GROUPS 

Headache, lethargy, nausea, 

drowsiness, dizziness 

Congostion; swelling, itching or 

Irritation of eyes, nose, or 

throat; dry throat; may be 

accompanied by non-specific 

symptoms (e.g. headache, 

fatigue, nausea) 

Cough; shortness of breath; 

fever, chills and/or fatigue after 

return to the building 

Diagnosed infection 

Suspected cluster of rare or 

serious health problems such 

as cancer, miscarriages 

OTHER STRESSORS 

Discomfo.rt and/or health 

complaints that cannot be 

readily ascribed to air contami· 

mmu or thermal conditions 

SUGGESTIONS 

• Check HVAC condition and operation. 

• Measure indoor and outdoor temperature and humidity (see Figure 6-2 on 

the opposite page). See if extreme conditions exceed design capacity of 

HVAC equipment. 

• Check for drafts and stagnant areas. 

• Check for excessive radiant heat gain or loss. 

If onset was acute (sudden and/or severe), arrange for medical evaluation, 

as the problem may be carbon monoxide poisoning. 

• Check combustion sources for uncontrolled emissions or spillage. Check 

outdoor air intakes for nearby sources of combustion fumes. 

• Consider evacuation/medical evaluation if problem isn't corrected quickly. 

• Consider other pollutant sources. 

• Check overall ventilation; see if areas of poor ventilation coincide with 

complaints. 

May be allergic, if only small number affected; more likely to be irritations/ 

response if large number are affected. 

• Urge medical attention for allergies. 

• Check for dust or gross microbial contamination due to sanitation 

problems, water dC~mage, or contaminated ventilation system. 

• Check outdoor allergen levels (e.g., pollen counts). 

• Check closely for sources of irritating chemicals such as formaldehyde or 

those found in some solvents. 

May be hypersensitivity pneumonitis or humidifier fever. A medical 

evaluation can help identify possible causes. 

• Check for gross microbial contamination due to sanitation problems, water 

damage, or contaminated HVAC system. 

May be Legionnaire's disease or histoplasmosis, related to bacteria or fungi 

found in the environment. 

• Contact your local or State Health Department for guidance. 

• Contact your local or State Health Department for guidance. 

• Check for problems with environmental, ergonomic, and job-related 

psychosocial stressors. 

56 Section6 
Figure 6-2 shows the range of temperatures and relative humidities that fall 

within the comfort zone for most individuals dressed in "typical'' clothing and 

involved in light, mostly sedentary 

activity. Recent research suggests that 

indoor air quality is judged to be worse as 

temperatures rise above 76°F, regardless of 

the actual air quality. 

There is considerable debate among 

researchers, IAQ professionals, and health 

professionals concerning recommended 

levels of relative humidity. In general, the 

range of humidity levels recommended by 

different organizations seems to be 30% to 

60% RH. Relative humidities below this 

level may produce discomfort from 

dryness. On the other hand, maintaining 

relative humidities at the lowest possible 

level helps to restrict the growth of mold 

and mildew. The concerns (comfort for 

the ~ost part) associated with dry air n1ust 

be balanced against the risks (enhanced 

microbiological growth) associated with . 

humidification. If temperatures are 

maintained at the lower end of the comfort 

range (68 - 70°F) during heating periods, 

relative humidity in most climates will not 

fall much below 30% (also within the 

comfort range) in occupied buildings. 

COLLECTING INFORMATION 

ABOUT THE HVAC SYSTEM 

IAQ complaints often arise because the 

quantity or distribution of outdoor air is 

inadequate to serve the ventilation needs of 

building occupants. Problems may also be 

traced to air distribution systems that are 

introducing outdoor contaminants or 

transporting pollutants within the building. 

The investigation should begin with the 

components of the HV AC system(s) that 

serve the complaint area and surrounding 

rooms, but may need to expand if connections to other areas are discovered. Your 

goal is to understand the design and 

operation of the HV AC system well 

.:fiE;~;£~r~:~~~t,if.;~.d~,..,.,.,h,j,g .. &.~.·· · )f!Jft f()r di8cusfifqn. (Jf ie{~tiye hrimfditi~ .. 

, -:'~--::·_::_:;7.:.~:-~~:i:~:.:o-·::------_;~A~;~-~-:-. _ ~crt.~_:,}:;;; :~:~::,·y:··-~-?:<:_ ~--~:·:·-::_·.~ ·"?_-·:·. _ _ _ ._ :·~-~-\~h:·_-: _ _ __ ··: _ . 

6a¢;;.·.r.;~apted'frol11 A.SI·II;iAE Standard 55-19131~ Th~rmal Environmen-

)i.nd[tfgf!~/orJ-IT.mian Occ:,(Jpancy ... . . . . , · . . · · ·• . . · .. '· '·;~-'··~-·: .. 'L 

·:::: ... .:-k ,···· '.·-,.: . ..;;. ~"<-•_,,~: 

enough to answer the following questions: 

• Are the components that serve the 

immediate complaint area functioning 

properly? 

• Is the HV AC system adequate for the 

current use of the building? 

• Are there ventilation (or therffial comfort} deficiencies? 

• Should the definition of the complaint 

area be expanded based ·upon the HV AC 

layout and operating characteristics? 

An evaluation of the HV AC system 

may include limited measurements of 

temperature, humidity, airflow, and C02

, 

as well as smoke tube observations. 

Complex investigations may ·require more 

extensive or sophisticated measur~nients of 

the same variables (e.g., repeated C02 

measurements taken at the same location 

under different operating conditions, 

continuous temperature and relative 

huinidity measurements recorded with a 

data logger). A detailed engineering study 

may be needed if the investigation discovers problems such as the following: 

• airflows are low 

• HV AC controls are not working or are 

working according to inappropriate 

strategies 

• building operators do not under~tand (or 

are unfamiliar with) the HV AC system 

Diagnosing IAQ Problems 57 

• U$e.the Hypothesis 

Forrn on page 223 to 

make .brief Ootes.·after 

rE:lviewing the. occupant 

data. · 

• Decide whether·you 

·.have a hypothesis that 

might explain the . 

complaints~ If so, test 

it. (See page 78 for a 

di,scu5sion of . ·. ·· · 

hypothesis testing~) 

. • Decide what else you . neecl to know. '· 

Consider whether . 

in-house expertise is. 

sufficient or outside 

assistance is. needed. 

· (See Section 8 tor 

guidanceon hiring 

· outside as::,dstance.) 
' ,. ' '" '' 

COLLECTING HVAC SYSTEM INFORMATION 

Strategies 

Review existing documentation on HVAC 

design, installation, and 

operation 

Talk to facilities staff 

- Inspect system layout. 

- condition, and operation 

Use additional instru· 

ments as appropriate 

Tools 

Coll~t: 

• design documents, testing and 

balancing reports 

• operating instructions, control 

manufE!cturer's installation data. ' ' ' ' • ' ••• '<'',,', ~·' ,, 

Ask facilities staff to. reco.rd their 

observations of equipment cycles~ weather conditions, and other events 

usir:Jg Log of Activities and System 

Operations 

Use: 

• Zone/Room R~ord 

• HVAC Checklist- Short Form and/or 

• HVAC Checklist - Long Form 

• thermometer and 'sling psychrometer (or electronic equivale-nt) to 

measure temperature and humidity 

• micromanometer (or equivalent) to 

measure pressure differentia is 

• 0-2" and 0-10" water gauge (w.g.) 

to measure at fans and intakes 

• 0-.26" w.g. with pitot tube to check 

airflow in ducts 

• chemical smoke for observing 

airflow patterns 

• a device to assess airflow from 

diffusers · · · 

• rough quantitative: anemometer; 

velometer 

• accurate quantitative: flow hood 

• carbon dioxide measurement 

devices 

• detector tub_es with a.l'lcmd pump 

• ,dire~ reading me~er 

Instruments often used by professional lAO consultants include: 

• a hygrothermograph to log temperature' and humidity 

II tracer gas and measurement 

equipment 

• a device to measure airborne 

particulates · · 

11 measurement devices for carbon 

monoxide ·and other contaminants of interest · · · ·· · · · · · · · · 

58 Section6 

Review Documentation on 

HVAC Design, Installation, and 

Operation 

A review of existing documentation (e.g., 

plans, specifications, testing and balancing 

reports) should provide information about 

the original design and later modifications, 

particularly: 

• the type of HV AC system (e.g., constant 

volume, VA V) 

• locations and capacities of HV AC 

equipment serving the complaint area 

• the planned use of each building area 

• supply, return, and exhaust air quantities 

• location of the outdoor air intake and of 

the supply, return, and exhaust registers, 

diffusers, and grilles that serve the 

complaint area 

The most useful way to record this 

information is to make a floor plan of the 

complaint area and surrounding rooms. 

You may be able to copy an existing floor 

plan from architectural or mechanical 

drawings, fire evacuation plans, or some 

other source. 

If there is no documentation on the 

mechanical system design, much more onsite inspection will be required to understand the HV AC system. The HV AC 

system may have been installed or 

modified without being commissioned, 

so that it may never have performed 

according to design. In such cases, good 

observations of airflow and pressure 

differentials are essential. In addition, load 

analyses may be required. 

Talk to Facility Staff 

Facility staff can provide important current 

information about equipment operating and 

maintenance schedules and breakdowns or 

other incidents. There may be inspection 

r~ports or other written records available 

for review. Staff members who are 

familiar with building systems in general 

and with the specific features of the 
building under investigation can be very 

helpful in identifying conditions that may 

explain the indoor air quality complaints. 

Some facility operators have extensive 

preventive maintenance programs. On the 

other hand, discussion could reveal that 

facility staff are not operating the building 

according to its design, because: 

• they do not understand the design logic 

of the HV AC system 

• they have been asked to run the HV AC 

system at the lowest possible energy cost 

• they do not have the manpower to 

operate the building properly 

• the HV AC system has not been modified 

to accommodate changes in the use of 

space or increases in the occupant 

population 

Staff may have noticed occupant 

activities that are indicators of inadequate 

ventilation or poorly controlled temperatures, such as: 

• desktop fans, heaters, or humidifiers 

• supply diffusers blocked off with tape or 

cardboard 

• popped-up ceiling tiles 

• interference with thermostat settings 

IAQ complaints are often intermittent. 

Discussions with staff may reveal patterns 

that relate the timing of complaints to the 

cycles of equipment operation or to other 

events in the building such as painting, 

installation of new carpeting, or pest 

control. These patterns are not necessarily 

obvious. Keeping a day-to-day record may 

help to clarify subtle relationships between 

occupant symptoms, equipment operation, 

and activities in and around the building. 

(See Occupant Diary and Log of 

Activities and System Operations on 

page 52 and in Tab V.) Staff members 

may have theories about the cause of 

the problem. 

Inspect System Layout, 

Condition, and Operation 

If the building is new or if there is a preventive maintenance program with recent 

Above: An investigation of this building 

revealed no problems with the HVAC 

system, although the amount of outdoor 

air was very low. In a more thorough 

inspection of the HVAC system, investigators found that the wiring to this outdoor air damper motor had never been 

connected. No outdoor air was entering 

the building through the intake controlled 

by this damper. Below: These investigators are examining a perimeter fan-coil 

unit. Self-contained heating or cooling 

units such as this one are often overlooked during routine maintenance. 

There may be many such units in a single 

building, sometimes in remote or inaccessible locations. 

Diagnosing IAQ Problems 59 
The design specifications 

for this building called for a 

minimum 20% setting on 

the outdoor air damper 

control. Facility staff lowered the minimum outdoor 

sir setting to 10% in order 

to save energy and reduce 

operating costs. As a result, the building was 

underventilated whenever 

outdoor temperatures were 

either very hot or very cold. 

test and balance reports, it is possible (but 

not necessarily likely) that the HV AC 

system is functioning according to its 

original design. Otherwise it is probable 

that one or more features of building usage 

or system operation have changed in ways 

that could affect indoor air quality. 

Elements of the on-site investigation 

can include (but are not limited to) the 

following: 

Check temperature and/or humidity to see 

whether the complaint area is in the comfort range. 

Take more than one measurement to account for variability over time and from 

place to place. Compare to Figure 6-2 on 

page 57 (see also Appendix B ). 

• Check thermostat operation. 

• Check whether the supply air temperature corresponds to the design criteria. 

• Use a hygrothermograph (if available) to 

log temperature and humidity changes in 

the complaint area. 

60 Section 6 

Check for indicators of inadequate 

ventilation. 

• Check supply diffusers to see if air is 

moving (using chemical smoke). If it is 

not, confirm that the fan system is operating, and then look for closed dampers, 

clogged filters, or signs of leaks. 

• Compare design air quantities (if available) to building codes for the current 

occupancy or ventilation guidelines (e.g., 

ASHRAE 62-1989, see Appendix B). If 

the HV AC system, performing as designed, would not provide enough ventilation air for current needs, then there is 

good reason to believe that actual ventilation rates are inadequate. 

• Measure carbon dioxide (C02

) in the 

complaint area to see whether it indicates 

ventilation problems. (See Appendix A 

for a discussion of techniques for measuring and interpreting C02 concentrations.) 

• Measure air quantities supplied to and 

exhausted from the complaint area, including calculation of outdoor air quantities (see Appendix A for further guidance). Be aware of damper settings and 

equipment cycles when you are measuring (e.g., are you evaluating minimum 

outdoor air, "normal" conditions, or 

maximum airflow?). Note that evaluation of variable air volume (VA V) systems requires considerable expertise. 

Compare the measured air quantities to 

your mechanical system design specifications and applicable building codes. Also 

compare ventilation rates to ASHRAE 

62-1989. Some of the ventilation recommendations of ASHRAE 62-1989 are 

reproduced in Appendix B. 

Check that equipment serving the complaint area (e.g., grilles, diffusers, fans) is 

operating properly. 

• Confirm the accuracy of reported operating schedules and controls sequences; for 

example, power outages may have disrupted time clocks, fans reported as 

"always running" may have been accidentally switched off, and controls can be 

in need of calibration. 
• Check to see that equipment is properly 

installed. For' example, look for shipping 

screws that were never removed or fans 

that were reversed during installation, so 

that they move air in the wrong direction. 

Compare the current system to the 

original design. 

• Check to see that all equipment called 

for in the original design was actually 

installed. 

• See whether original equipment may 

have been replaced by a different model 

(i.e., a model with less capacity or different operating characteristics). 

See whether the layout of air supplies, 

returns, and exhausts promotes efficient 

air distribution to all occupants and 

isolates or dilutes contaminants. 

(See Appendix A for guidance on using 

chemical smoke to study airflow and mixing patterns and C02 to help determine the 

adequacy of ventilation.) 

• If supplies and returns are close together, 

heatless chemical smoke can be used to 

check for short-circuiting (supply air that 

does not mix properly with air in the · 

breathing zone, but moves directly to the 

return grille). C02 can also be used to 

evaluate air mixing. 

• Use heatless chemical smoke to observe 

airflow patterns within the complaint 

area and between the complaint area and 

surrounding spaces, including outdoors. 

Compare airflow directions under various operating conditions. 

• If the system layout includes ceiling 

plenums, look above the ceiling for interruptions such as walls or full-height 

partitions. 

Consider whether the HV AC system itself 

may be a source of contaminants. 

• Check for deterioration or unsanitary 

conditions (e.g., corrosion, water damage 

or standing water, mold growth or excessive dust in ductwork, debris or damaged 

building materials in ceiling plenums). 

• If the mechanical room serves as a mix-· 

ing plenum (i.e., return and outdoor air · 

are drawn through the room into the air 

handler), check very carefully for potential contaminants such as stored solvents 

and deteriorated insulation. 

Use the forms provided in this document 

to inspect the HV AC system. 

• Use the Zone/Room Record to describe 

the ventilation system serving the com~ 

plaint area and surrounding rooms or 

zones. The Zone/Room Record is 

reproduced on page 62 and in Tab V. 

• Use the HV AC Checklist (short and/or 

long form) to evaluate the condition of 

HV AC system components that affect air 

distribution and IAQ in the complaint 

area. A portion of the HV AC ChecklistShort Form is reproduced on page 62. 

The HV AC Checklist - Long Form is 

useful for more detailed examination of 

the system. Complete copies of both 

forms can be found in Tab V. 

Diagnosing lAQProblems 61 

The dark streaks at the 

outlet of this supply diffuser 

could indicate a filtration 

problem. Poorly maintained 

or improperly sized filters 

can allow dirt to be distributed through the building. 
62 Section6 

(Write "No'" 

or estimate 

cfm airflow) 

Outdoor Air 

SUpplied 

•"'"'''***' per Person or per150Sq. 

Ft. Area**** 

USING THE HVAC SYSTEM 

DATA 

As you review the HV AC data, consider 

whether the system is adequate to serve 

the use of the building and whether the 

timing, location, and impact of apparent 

deficiencies appeM related to the IAQ 

complaint. Deficiencies in HV AC 

design, operation, or maintenance may 

exist without producing the complaint 

under investigation; some defects may 

not cause any apparent IAQ problems. 

Strategies for Using tl1e HV AC 

System Data 

• Compare the original design to the 

current system. 

• Compare the original uses of space to 

current uses. 

• Consider the condition ofthe HV AC 

system. 
Diagnosing IAQ Problems 63 

When the lAO investigator is not familiar 

with the mechanical 

equipment in that 

particular facility, an 

operator or engineer 

should be present at . 

. . all times i.n equipment 

areas. 
~,ALL SYSTEMS 

, Ventilation and 

:ctemperature 

-'control zones 

; Change• in 

equipment 

Operating 

cycles 

SUGGESTIONS 

• Revise definition of complaint area 

(if needed) to add spaces linked to 

the original complaint area by 

ductwork or controls. 

• Check to see that thermostats 

are properly located and function 

properly. 

• Note equipment changes 

could be affecting the system's 

performance {e.g., removal or 

addition of equipment, replacement 

by a different model). 

• Review operating procedures for 

occupied and unoccupied periods. 

• Compare timing of occupied/ 

unoccupied periods to equipment 

cycles and occupant complaints. 

Confirm that time clocks are 

reading the actual time. See 

ASHRAE 62-1989 for suggested lead 

times to allow proper flushing 

before occupants arrive. In some 

cases {e.g., warm, humid climates), 

fans may need to operate during 

unoccupied periods to prevent 

mold growth or other problems. 

64 Section6 

Compare the Original Design to 

the Current HVAC System 

Consider the original HV AC design and 

compare it to the current equipment, 

layout, and controls. A variety of HV AC 

system designs have been used in public 

and commercial buildings. The type of 

system used in your building affects the 

control of ventilation air quantities and 

distribution, as well as thermal comfort. 

See Appendix B for a discussion of HV AC 

system types. 
Use HVAC Data to Evaluate 

Mitigation Measures . · 

As you use the HV AC data to evaluate 

potential mitigation measures, review the 

suggestions made in both the box on the 

facing page for all HV AC systems and in 

the box on this page for the type of HV AC 

system in your building. 

. '~.-... · .· .. 1 

.1 SUGGESTIONS · ~~~~~~~~~~~~~~~~~~~~~~ : ~J~i:O me"h~ni~i ~i·v~ntilation or 

~~~~~~~~t~?ly .. fl.-i/~',~.:.~-".::~_·;:;··-~!.' - , __ ,_.._ 

f'~>"' .. 

•• i~entlfy tf:i~ so'u~ce(s) ofve~tii~tlo~ ' . i 

·. air (e~~p; operable windows, doors .. propped open}; ' .. ·. . . 

. ·· i.' Ch~rikwh~the~th.el~caii6~··.;fopen -~ 

· .. · ..Windows,_doors, or other openings 

···'·•/·.~·:,.f~~~~~~:~_.:n_i~Jr~alictlo:n·of odo~s · ,. • . ., v.' -~ 

;.i ct1e~~.~6~tll~i}:>ui~~9r airJ6~~~~~-,~ ·: 

are obstructed. Does their location .. , .. promote the intrqduction of odors· 

:; .. :';:?r;.~~n~~'l?Jr<l.t:!'~?."·.:·;. • .• ··· .. _._..· ... _ •...•.. ; 

};'.-Notedesign ·aiiflows In the 

·' . :.;-:.compiaint area (outdoor air, supply, ,·:·::···\: .. ~<'·_~;J·eii.l'rn~,~anc;re~68U.s~>··and ~Urr91i~a~ · ·~ 

:··~ ,·,':ff19'5i>acesi'compare to AsH RAE··· · • "62~1989 ~rid to actual riu~asu'red ' , ~irl!o~s~ ' . · . · . . .. ,_, . . ' ' '· . ~ 

.;·Note de;i~~ ~irftows intne ·.·... · · ~ 

. . .·.· •.. q~'mpiainfa~ea(outdoorair, supply,, ~. 

0 : . <:;·:·r~turr},•-ari~ exlla"uSi)' ~ncl surt'q~Qd::. -~ 

•_:;:~ .)~g_spa~es;compa'i'e, to applicable . '-~ ,;(: p~Jfgipg ~odes, ASH RAE 62-1989; .· ·-.- -. ·/and'tO·a-ctuar·measureCf81rfrows~· :. "~-~ 

. •• Check whether o~tdoor air i~takes , ar~ obstructed. boes their-location 

p'r6mo1:ethe intrqduction of odors . ·;;if6J-.~ciniaminant8? theCidor · · · : u'nsanfia·iv conditions. · . . ... . 

it 'Che~k ciutdcior aird~mper Cdntrols .. . ;.' - "·_ : . . :'•":: '~.,.~ - :'- . .· '-.~ - .: .. ·. .. ·. . . . . . . . ,, ' :; 

.Ia additlon :to.all sugg~stions made . Jor .¢on~a.nt volume sv_stertls:.. • . ... 

• Confirm. Whether the system design ,, · ... ·allows regulation· of outdoor· air 

. quantities. Do VAVboxes have · .• 'stops to ensure thair:ninimum ·.~· amotiht~•of outdoor air aredelly-: . eredJ~tall ti,n:u3~'clurll1g occupied 

periods?, Are thesystemcontrois 

providing a constant ventilation rate ' 

per person regardless of total sys- ten{airfiows? · ·· ·· ·· \ 

.119b~e.rve.chan~fe;;.(if ariy) in airflow ........ patterns\N:Iihin and arOund the 

' ci:)hlpl~in:tarea as theVAV system· 

throttles frorn maximum to 

minirr\umfio"": ' . . . . 

Diagnosing IAQ Problems 65 
ROOM USE CHANGES 

,11 l 

Increased occupant 

density 

Change in type of 

occupant population 

SUGGESTIONS 

'' . ~ ' '"' ... , " ' "' "' 

• Compare temperature and humidity 

t()~9mf9J1: zone .in AS,Hf!AE 1)5-1981 

guidelines. 

• Co~rnpare minimum outdoor air 

-·'qOantitfes to the original design, 

applicable building codes, and . AStiRAE 62-1989 guidelines . ... ""'" ' ., ' 

Example: Introduction of a more 

physically active group of occupants · qan change thermal comfort requirements. 

II Corn pare temperature and humidity .. to comfort zone in ASHRAE 55-1981 

····---···'·····--·· gulaelfnes. · · · · 

Additlcmal non-HVAC 

equipment 

. Rearrangement of · · stations (e.g., relocation 

of partitions) 

. ~ C9rnpare minimum outdoor air 

quantities to the original design, · applicable building codes, and 

A~J-:IJI.AI; 1?2-:-W~9 guidelines. 

• C~e~:kj9r lqw-tevf'll contaminant . sources. 

• Compare temperature and humi(jity . to comfort zone in ASHRAE 55-1981 

'Q'oid.etlnes. ····· · · · · · · 

II Consid"Eir {he need for local exhaust 

at point sources of contaminants. 

example: Modifications that convert 

.or add. sl!ch special uses as smoking 

lounges, print shops, or kitchen 

facilities may also require changes in 

the operation of the HVAC system. 

• Check pressure relationships 

between special use areas and· 

surrounding spaces. 

• Consider the need for local exhaust 

at point sources of contaminant.s. 

• Check that thermostats are properly 

!.ocated. Compare temperature and 

burrddityto comfort zone in 

··)\S.HrU\J: 55·1~S.1 guidelines. 

Iii Check l~yout of supplies, returns, ··· an-d exhausts . 

• ·cllec"f<tomai<e.sure tll~ai partitions 

do ,n<?t block£ proper air circulation. 

66 Section6 

Compare the Original Uses of 

Space to Cu1·rent Uses 

Compare the original uses of the complaint 

area and surrounding rooms to current 

uses of those areas. Indoor air quality 

problems often arise when the usage of 

rooms changes without corresponding 

adjustments to the HV AC system. For 

example, if ventilation appears to be a 

problem despite a properly functioning 

HV AC system, the existing system may 

be inadequate to meet current needs. 
Consider the Condition of the 

HVAC~ystem 

Consider whether the HV AC system is 

reasonably clean and functioning properly. 

Review the results of the onsite inspection. 

If you identified sanitary or operating 

problems in the HV AC system serving the 

complaint area, you may want to correct 

those problems and see whether the 

complaints are resolved before continuing 

with the investigation. 

Diagnosing IAQ Problems 67 

W ATDOYOU 

K OWSOFAR? 

· · .U~e the Hypothesis. 

· Form on page 223 to .. ·make brief notes 

· after r:eviewing the 

HVACdata. 

• Decide whether you ···· have a hypothesis 

tt'!atmight explain 

the complaints. If 

. so~ test it. (Sef:l page · . 78 for a discussion · 

ofbypothesis · ·· testing.):' · · 

'1!1 Decide what else 

you n~ed to know. . 

Consider whether in· 

~ouse expertise is . sufficient or outside 

.assistance is needed. 

(See Section 8 for 

:guidance on hiring· . 

outside assistance.): . 
COLLECTING INFORMATION 

ABOUT POLLUTANT PATHWAYS 

AND DRIVING FORCES 

Unless the IAQ problem is caused by an 

obvious contaminant located in the 

complainant's immediate workspace, you 

will need to understand the patterns of 

airflow into and within the complaint area. 

Correction of IAQ problems often involves 

controlling pollutant movement through 

sealing of pollutant pathways or manipulation of the pressure relationships. 

If the complaints being investigated are 

limited to a few areas of the building, pollutant pathways can be evaluated so that the 

complaint area is properly defmed before 

conducting the source inventory. If complaints are spread throughout the building, 

COLLECTING PATHWAY INFORMATION 

Strategies 

Identify pollutant 

pathways 

Observe direction 

of air movement 

Chemical smoke is being 

used to detect the direction 

and amount of airflow 

through this closed 

doorway. A building 

Investigator must know 

how the ventilation in the 

building Is designed to 

operate in order to decide 

whether the observed flow 

of smoke Is appropriate. 

Tools 

• Architectural and mechanical 

drawings 

• Pollutant Pathway Form for Investigations 

• Sketch plan of complaint area 

• Testing and balancing reports 

• Chemical smoke tests 

• Micromanometer or equivalent 

68 Section6 

evaluation of pathways could be a very 

time-consuming process, and it may be 

more practical to look for major contaminant sources before trying to discover how 

the contaminants move within the building. 

Identify Pollutant Pathways 

Architectural and mechanical pathways 

allow pollutants to enter the complaint area 

from surrounding spaces, including the 

outdoors. An examination of architectural 

and mechanical plans can help in developing a list of connections to surrounding 

areas. These include: 

• doors 

• operable windows 

• stairways 

• elevator shafts 

• utility chases 

• ductwork and plenums 

• areas served by common HV AC controls 

(e.g., shared thermostats) 

Onsite inspection is needed to confirm 

the existence of these connections and to 

identify other openings (e.g., accidental 

openings such as cracks and holes). Fire 

codes usually require that chases and hidden openings be frrestopped. Check for the 

existence and condition of firestops in 

chases, especially those that connect both 

vertically and horizontally. 
The Pollutant Pathway Form for 

Investigations shown to the right can be 

used along with a sketch plan of the 

complaint area (similar to the example on 

page 70) to record pathways and directions 

of pollutant movement. A blank copy of 

the form is included in Tab V. 

Observe Air Movement 

Direction 

The airflow quantities shown in mechanical plans or in testing and balancing 

reports can be used to determine the 

direction of air movement intended by the 

designer. Onsite examination is necessary· 

to determine the actual direction of airflow 

at each available pathway. 

Chemical smoke tubes can be used to 

determine airflow directions between the 

complaint area and surrounding spaces 

(including the outdoors), and to reveal air 

circulation patterns within the complaint 

area. A micromanometer (or equivalent) 

can measure the magnitude of pressure 

differences between these areas. The 

sketch plan and the Pollutant Pathway 

Form for Investigations can be used to 

record the results. 

It may be necessary to make observations under different conditions, as airflow 

direction can change depending upon 

weather conditions, windspeed and 

direction, equipment operation within the 

building, traffic through doors, and other 

factors (e.g., as VAV systems throttie 

back). Switching air handlers or exhaust 

fans on and off, opening and closing doors, 

and simulating the range of operating 

conditions in other ways can help to show 

the different ways that airborne contaminants move within the building. Dust 

tracking patterns around door frames can 

reveal the dominant direction of air and 

pollutant ·movement. 

Some investigators study air movement 

by releasing a small amount of peppermint 

oil at the opening to a suspected pathway 

and asking an assistant to sniff for the 

s~"'-pte l:~rm 

, Pollutant Pathway Form. for Investigations 

::=tllis form should be used in combination with a floor plan such as a fire 

C'e~acuation plan.·· 

:>·BI.I,ildingareas that appear isolated from each other may be connected by 

· alifiow passages such as air distribution zones, utility tunnels or chases, party 

walls, spaces above suspended ceilings (whether or not those spaces are 

serving as air plenums}, elevator shafts, and crawl spaces. :.; • > ; .. ·. . 

k Rooms or Zones Pressure Relative to . Comments 

;; Connected to the Use Complaint Area (e.g., potential 

~:' Complaint Area by polluntant 

·· Pathways +/- date/time sources) 

q_ f ~~~~~~--~------------+--1--------~~--~~~---1 ' 

~~~------~~~~.~--~----~--4---------~~--------~ 

.. 

~~--·· __ ··--~~-+--~---=----~--+---~----~--~----~~1! J·. 

,, 1--:___,. ______ __;,___,.f--__:.,..· ··---,-------1----l---------~~--------,---1 

"toothpaste" smell. If this technique is 

used, it is important that the assistant have 

an acute sense of smell. If the building is 

in use during the investigation, occupants 

may also notice the odor and could find it 

distracting. Some investigators prefer to 

use methods that release an odor during 

unoccupied periods. Investigators should 

note two common causes of false negative 

results (falsely concluding that no pathway 

exists): 

• The nose quickly becomes tolerant of 

strong odors, so that the assistant may 

need to take a long rest (breathing fresh 

air) between tests. 

• If there is substantial airflow through the 

pathway, the peppermint oil odor could 

be diluted so that it is imperceptible. 

Tracer gases such as sulfur hexafluoride (SF6

) can provide qualitative and 

quantitative information on pollutant pathways and ventilation rates. Use of tracer 

gases to. obtain quantitative results 

requires considerable technical expert~se. 

If it appears that a sophisticated study of 

pathways (or ventilation rates) is required, 

you need to use trained,investigators. 

Diagnosing IAQ Problems 69 

SEE 

COMPLETE 

FORM 

PAGE211 
Reception 

Area 

Elevator Bank 

Office 

Conference 

Room 

Vestibule 

--- ---1'-~ 

Aw~ Computer Room 

(£) r-7-

Lounge 

e 

Mechanical 

Room 

USING POLLUTANT PATHWAY 

DATA 

Pollutant pathway infonnation helps the 

investigator to understand airflow patterns 

in and around the complaint area. The 

pollutant pathway data may indicate a need 

to enlarge the complaint area, or may direct 

attention toward contaminant sources that 

deserve close study. 

Strategies for Using Pathway 

Information 

• Evaluate airflow patterns 

• Confirm or revise boundaries of the complaint area 

~~~~~~-~~~ Supply 

Storage 

The receptionist and office occupants in 

Zone 1 have complained of food odors. 

The investigator is using a fire escape 

plan to record air movement, sources, 

and complaint information. The investigator has noted one hypothesis about 

the cause of the complaints in the room 

marked "Lounge." 

70 Section6 
Evaluate Airflow Patterns 

Evaluate airflow patterns into and 

within the complaint area. Because of 

the complexity and variability of airflow patterns, investigators cannot be 

expected to understand how air moves 

within the building under all potential · 

operating conditions. However, data 

on pathways and driving forces can 

help to locate potential pollutant 

sources and to understand how contaminants are transported to building 

occupants. 

Confirm or Revise Boundaries 

of the Complaint Area 

The discovery of unexpected pollutant 

pathways can show a need to study 

areas of the building that may be 

distant from the original complaint 

area. 

• . . . wh~~her pressure relati6n~ . 

: . ships. betWeen complaint are~ ari'd~ 

s~rroundirig locations follows '.··--~ 

intent of ventilation design. • 

IICh~cKwhef:herair from.other . 

. location$ flows into the complaint 

. .. · atec<'Ct.ln~er some conditions •. If so, . 

·consider expanding the investiga-

.. tion .to inventory pollutant sources, 

.. , : .' , " . ~-· Lhmd perhaps collect HVAC or . ' 

· (}.':~i:' :;)~ ·; ~?c4p'antdata) in those location~~·· 

Diagnosing IAQ Problems 71 

.WHATDOVO 

K OWSOFA? 

• Use the Hypothesis 

Form on page 223 to 

make brief notes after 

reviewing the pollutant ' 

pathway data. · 

• Decid.e whether you · 

·· have a hypothe~:~is that ·. might explain the . 

· complaints. If so, test 

it. {See page 78 for a 

discussion of hypoth- . esis testing.) 

• Decide what else you < < need to know. Considerwhetner in-house, .. 

expertise is sufficient . · or outside assistance is · · 

needed. (See Section .8 ; 

for guidance on hiring 

outsi<fe assistance.) 
cot.LECnNG SOURCE INFORMATION 

Strateg,_ Tools 

Conduct onalte 

inspection 

Talk wfth building ~ occupants. facilities - $taff, and contmctors 

S.mpleFonn 

• ~ollutantand Source Inventory 

• Chemical (nventory · · 

• Pollutant and Source Inventory . 

• Chemical Inventory 

Pollutant and So~rce ~nvei)~O"V 

Using the list of potentiD:I s~urce categories below, r6C?~rd any 

indications of contamin!ltion or suspected pollutants that may 

require further investigation or tr~at~ent. 

. ;; ,. ; i· '' · . . '.<,,<·" ... :•); ,,+, .Y .·; ,' .· 

Source c.tqory CIMK:fced NMda Attention 

IOUftCES otJl'SI)E THE BUilDING 

Contammated Ambient Air 

Pollen~ dutt 

lndu&trfal 

contaminants 

Gen~n~l vehicular 

contaminants 

....... Fonn 

Chemle~~llnventory 

Location Comments 

The Inventory should include chemicals stored or used In the 

building for cleaning;-malnte~ance, operations, and pest control. 

o.t. 

sa 

.. COMPLETE 

. FORMS 

PAOES213 

AND221 

CMmical/ 

BnlndNIImo 

Use Storage MSDS 

Locatlon(s) on File? 

72 Section6 

< .. 1 

·. 

COLLECTING INFORMAnON ON 

POLLUTANT SOURCES 

Throughout the investigation, the building 

investigator will try to identify pollutant 

sources that may be causing the occupant 

complaints. Any public or commercial 

building is likely to contain a number of 

sources that produce odors, contaminants, 

or both. The investigator's task is to 

identify the source(s) that may be responsible for the complaint(s). 

The area included in the pollutant source 

inventory should be defmed by the investigator's understanding of the building's 

architectural and mechanical layout and 

pollut~t pathways. Common sense will 

help to differentiate unusual sources (e.g., 

spills, strong odors from new furnishings 

or equipment) from those that are normally 

found within or near the building. 

Remember that very few sources of 

indoor air contaminants are both continuous and constant in volume over time. 

Pollutant concentrations often vary in 

strength over time, and may not be evident 

at the time of the site visit. Some sources 

are subtle and might only be noticed by a 

trained investigator. As the investigation 

progresses, the inventory of pollutant 

sources may need to be revised by expanding the defmition of the complaint area or 

examining specific locations more closely 

(e.g., under various operating conditions). 

Onsite 1nspection 

Depending upon the nature of the com- · 

plaint, the investigator m~y find some of 

the following activities to be useful. This 

list is not intended to be complete. 

Inventory outdoor sources 

• Examine the area around the outdoor air 

intake for unsanitary conditions, standing 

water, or nearby pollutant sources such 

as exhaust vents or motor vehicles. 

• Observe patterns of traffic, construction 

activity, and other potential sources in 

the neighborhood of the building. 
• 'Inquire about outdoor ambient air 

problems in the area. (This information 

may be available from your local Health 

Department.) 

• Observe soil gas entry points. 

Inventory equipment sources 

• Review non-HV AC equipment, particularly large office equipment such as 

engineering drawing reproduction 

machines and wet-process copiers. 

Learn about usage patterns and 'identify 

items that are not equipped with local 

exhaust. 

• Review biocides and water treatments 

used on HV AC equipment. 

Review building components and 

furnishings 

• Check drain traps to make sure they are 

not dry. 

• Identify areas of excessive dust and/or . 

deteriorated furnishings. 

• IdentifY areas of soil or water damage. 

• Identify locations of new furnishings. 

Inventory other potential sources 

• Identify special use areas such as 

smoking lounges, laboratories, print 

shops. 

• Identify areas where remodeling, repair, 

or redecorating activities are in progress 

or recently completed. Check procedures being used to isolate demolition 

dust, paint fumes, and other contaminants related to the process. 

• Inventory cleaning materials used in the 

building. 

(See Section4 for another discussion of 

problem indicators and common problems 

that may become obvious during a 

walkthrough of the building.) 

The Pollutant and Source Inventory 

can be used to record your observations. 

The Chemical Inventory form is intended 

to serve as a record of materials such as 

solve~ts, biocides, pesticides, and cleaning 

compounds that may require special care in 

storage and handling. Material Safety 

Data Sheets (MSDSs) should be collected 

on these materials whenever possible. 

(See Section 4 for further discussion of 

MSDSs.) Portions of both forins are 

shown on the opposite page; the complete 

form is included in Tab V. 

Talk With Building Occupants 

and Facility Staff 

Building occupants and facility staff can 

provide valuable information about the 

location and timing of activities that 

produce odors or contaminants (e.g., 

smoking, cooking, housekeeping, maintenance). They may also suggest explanations for the IAQ problem that can help in 

the development of hypotheses. Facility 

staff and outside contractors (e.g., persons 

involved in housekeeping, pest control, or 

remodeling) should be interviewed or 

asked to provide a current list of materials, 

procedures, and schedules used for 

cleaning and pest control. 

It may be useful to discuss the following 

items with building occupants: 

Inventory activities 

• Review smoking policy (and actual 

practice; cleaning staff may know where 

smoking occurs in violation of policy, 

especially in private offices). 

• Identify areas of overcrowding. 

• Review products used for housekeeping, 

maintenance, and pest control and the 

schedules of their use. 

• Inquire about housekeeping schedules 

and procedures. 

• Identify supply storage areas and check 

for well-sealed containers and proper 

ventilation. 

Discuss incidents that could be sources 

• Inquire about prior and neighboring uses 

of land (e.g., landfills, underground fuel 

tanks). 

• Inquire about events such as spills, fires, 

or leaks. 

• If such events have occurred, learn what 

remedial actions were taken to clean up 

after the incidents and to prevent their 

recurrence. 

Diagnosing IAQ Problems 73 
PATIERNS SUGGESTIONS 

Location(s) 

~ ofsources 

• Compare locations of sources to locations of 

complaint(s). 

I 

I 

I, 

' 

! 

• Identify pathways linking potential sources to the 

complaint area. 

• Revise definition of complaint area if. necessary. __________ ........; _ __,;.,,.._,...,....:;__..;......__-'"--'-"'-c._::.""'--"'----"--"-,c..;:.c=' .~, 

Timing 

of emissions 

• Note whether the sources emit on a continuous 

or intermittent basis. 

• Compare the timing of emissions to the timing 

of complaints. 

• Identify occasions when the source is likely to be 

strongest. 

• Determine whether pathways between the 

source(s) and the complaint location could 

account for the occasions of complaints. 

WHAT DO YOU 

KNOW SO FAR? 

• Use the Hypothesis Form on page 223 

to make brief notes 

after reviewing the 

pollutant source 

data. 

• Decide whether you 

have a hypothesis 

that might explain 

the complaints. If 

so, test it. (See page 

78 for a discussion 

of hypothesis 

testing.) 

• Decide what else 

you need to know. 

Consider whether inhouse expertise is 

sufficient or outside 

assistance is needed. 

(See Section 8 for 

guidance on hiring 

outside assistance.) 

'I 

I 

,[ 

I 

" 

USING POLLUTANT SOURCE 

DATA 

If a strong pollutant source is identified in 

the immediate vicinity of the complaint, a 

simple test (e.g., sealing, covering, or 

removing the source) can sometimes reveal 

whether or not it is the cause of the IAQ 

problem. If a number of potential sources 

have been found in and around the 

complaint area, other data (e.g., the pattern 

of symptoms, the HV AC system design 

and operation, and pollutant pathway~) 

may be needed in order to determine which 

source(s), if any, may be related to the 

complaint. 

Strategies for Using Source 

Information 

• Identify patterns linking emissions to 

complaints 

• Evaluate unrelated sources 

Identify Patterns Linking 

Emissions to Complaints 

Look for patterns linking emissions from 

potential sources to the IAQ complaints. 

Evaluate Unrelated Sources 

Evaluate sources that appear unrelated to 

the complaints. It is not unusual to 

74 Section6 

identify potential contaminant sources that 

are unrelated to the present IAQ complaint 

(i.e., either the location of the source, the 

timing of emissions, or both fit poorly with 

the pattern of complaints). These should 

be prioritized for remedial work according 

to their potential for causing health 

problems or complaints in the future. 

A detailed study of pollutants and 

sources may involve an engineering 

evaluation of equipment that is releasing 

IAQ contaminants, diagnostic sampling to 

assess sources in operation, or other 

measurements. These may require skills or 

instruments that are not available in-house. 

SAMPLING AIR FOR 

CONTAMINANTS AND 

INDICATORS 

Although air sampling might seem to be 

the logical response to an air quality 

problem, such an approach may not be 

required to solve the problem and can even 

be misleading. Air sampling should not be 

undertaken until some or all of the other 

investigative activities mentioned previously have been used to collect considerable information. Before beginning to take 

air samples, investigators should develop a 

sampling strategy that i~ based on a 

comprehensive understanding of how the 

building operates, the nature of the 

complaints, and a plan for interpreting the 

results. 

It may be desirable to take certain 

routine air quality measurements during an 

investigation to obtain a "snapshot" of 

current conditions. These tests should be 

limited to those that are indicative of very 

common IAQ concerns such as temperature, relative humidity, air movement, or 

carbon dioxide (C02). Unusual readings 

may or may not indicate a prol;llem, and 

should always be interpreted in perspective, based upon site-specific conditions. 

Measurement of specific chemical or 

biological contaminants can be very 

expensive. Before expending time and 
money to obtain measurements of indoor 

air pollutants, you must decide: 

• how the results will be used 

(e.g., comparison to standards or 

guidelines, comparison to levels in 

complaint-free areas) 

• what substances(s) should be measured 

• where to take samples 

• when to take samples 

• what sampling and analysis method to 

use so that the results provide useful 

information 

It is often worthwhile for building staff 

to develop skills in making temperature, 

humidity, airflow, and C02 measurements 

and assessing patterns of air movement 

(e.g., using chemical smoke). Appendix A 

provides a brief introduction to ventilation 

and thermal measurement strategies and to 

methods of sampling for specific air 

contaminants. 

How Will the Results Be Used? 

Although air sampling will generate 

numbers, it will not necessarily help 

resolve the IAQ problem. Many IAQ 

complaints are resolved without sampling 

or with inconclusive sampling results. 

The design of an air sampling strategy 

should fit the intended use of the measurements. Potential uses of indoor air 

measurements include: 

1. Comparing different areas of the building 

or comparing indoor to outdoor conditions in order to: 

Confirm that a control approach has 

the desired effect of reducing pollutant 

concentrations or improving ventilation 

Establish baseline conditions so that 

they can be compared to concentrations 

at other times or locations, such as 

• concentrations in outdoor air 

• concentrations in areas where no 

symptoms are reported 

• expected "background" range for 

typical buildings without perceived 

IAQ problems 

Test a hypothesis about the source of 

the problem, such as 

• checking emissions from a piectr of 

equipment 

2. Testing for "indicator" compounds 

associated with particular cypes of 

building conditions: 

Peak carbon dioxide (CO z) concentrations over 1000 ppm (parts per million) 

are an indicator of underventilation 

Carbon monoxide (CO) over several 

ppm indicates inappropriate presence 

of combustion by-products (which may 

also account for high C02 readings) 

3. Comparing measured concentrations to 

guidelines or standards 

Occupational exposure standards and 

guidelines, such as 

• OSHA PELs (Occupational Safety and 

Health Administration's Permissible 

Exposure Limits) 

• NIOSH RELs (National Institute for 

Occupational Safety and Health's 

Recommended Exposure Limits) 

• ACGll:I TL V s (American Conference 

of Governmental Industrial Hygienists' 

Threshold Limit Values) 

Diagnosing IAQ Problems 75 

Occupants in this one-story 

office building were complaining of intermittent 

gasoline odors. Exhausts 

from underground gasoline 

storage tank vent pipes 

(visible in the lower right 

portion of this photograph) 

were being drawn into the 

office building through 

outdoor air intakes on this 

roof. The gasoline storage 

tanks belonged to an adjacent service station. 
It is prudent to begin 

a program of chemical 

sampling only if 

symptoms or observations strongly suggest 

that a specific pollutant or a specific 

source may be the 

cause of the complaint and if sampling 

results are important 

in determining an 

appropriate corrective 

action. 

Public health guidelines for specific 

poUutants 

• EPA National Ambient Air Quality 

Standards 

• World Health Organization Air 

Quality Guidelines 

• Canadian Exposure Guidelines for 

Residential Air Quality 

There are no widely accepted procedures 

to defme whether IAQ test results are ac~ 

ceptable. Extreme caution must be used in 

comparing contaminant concentrations to 

existing occupational standards and guidelines. Although a contaminant concentration above those guidelines is a clear problem indicator, occupants may still experience health and comfort problems at concentrations well within those guidelines. It 

is extremely rare for occupational standards to be exceeded -or even approached-in public and commercial 

buildings, including those experiencing 

indoor air quality problems. 

Where specific exposure problems are 

suspected, more detailed diagnostic testing 

may be needed to locate or understand 

major sources, confmn the exposure, and 

to develop appropriate remedial actions. 

For example, the control of microbial or 

pesticide contamination may involve surface or bulk sampling. (Surface sampling 

involves wiping a measured surface area 

and analyzing the swab to see what organisms are present, while bulk sampling 

involves analyzing a sample of suspect 

material.) Specialized skills, experience, 

and equipment may be needed to obtain, 

analyze, and interpret such measurements. 

What Substance(s) Should Be 

Measured? 

Measurement of "indicator" compounds 

such as C02 or CO can be a cost-effective 

strategy. Such measurements can help the 

investigator understand the nature of the 

problem and define the complaint area. 

76 Section6 

Air sampling for specific pollutants 

works best as an investigative tool when it 

is combined with other types of information-gathering. It is prudent to begin a 

program of chemical sampling only if 

symptoms or observations strongly suggest 

that a specific pollutant or a specific source 

may be the cause of the complaint and if 

sampling results are important in determining an appropriate corrective action. 

Where Should Air Samples Be 

Taken? 

The identified problem area is an obvious 

site for air sampling. Measurements taken 

outdoors and in a control location (e.g., a 

complaint-free area of the building) are 

helpful in interpreting results from the 

complaint area. 

The conditions experienced by building 

occupants are best simulated by sampling 

air from the "breathing zone" away from 

the influence of any particular individual. 

However, if an individual sits at a desk all 

day (except for brief periods), samplers 

placed on the desk when the individual is 

elsewhere can provide a good estimate of 

that person's exposure. 

There are several ways to locate sampling sites for an IAQ investigation. One 

approach first divides the building into 

homogeneous areas based on key factors 

identified in the building inspection and 

interviews. Examples of how a building 

might be divided include: 

• control zones (e.g., individual rooms) 

• types ofHVAC zones (e.g., interior vs. 

perimeter) 

• complaint vs. non-complaint areas 

• relationship to major sources 

(e.g., spaces directly, indirectly, or not 

impacted by smoking areas) 

• complaint types 

Test sites can then be selected to represent complaints, controls, and potential 

sources with a reasonable number of 

samples. 
When Should Air Samples Be 

Taken? 

Samples may be designed to obtain "worstcase" conditions;. such as measurements 

during periods of maximum equipment 

emissions, minimum ventilation, or disturbance of contaminated surfaces. Worstcase sample results can be very helpful in 

characterizing maximum conc~ntrations to 

which occupants are exposed and identifying sources for corrective measures. 

It is also helpful to obtain sample; during 

average or typical conditions as a basis of 

comparison. It may, however, be difficult 

to know what conditions are typical. Research shows that exposure to some pollutants may vary drarriatically as building 

conditions change. Devices that allow 

continuous measurements of key variables 

can be helpful. 

Symptoms or odors that only occur occasionally will not generally be seen during 

the IAQ investigation. Air samples should 

not be taken if an incident is not occurring, 

unless the purpose of the sample is to establish a baseline for future comparisons. 

One approach to intermittent IAQ problems is for the IAQ investigator to ask 

appropriate building staff or other occupants to document changes over time using 

day-to-day records such as the Occupant 

Diary and Log of Activities and System 

Operation. When an odor episode does 

occur, the building engineer could inspect 

the air handler and intake area while another staff member documents the status of 

several potential sources. 

Another strategy is to manipulate 

building conditions to create worst-case 

conditions during the building investigation (e.g., arrange for the trash truck to idle 

at the loading dock or close outdoor air 

dampers to minimum settings). Chemical 

smoke and tracer gases can be used to 

assess where emissions may travel under 

various building conditions. (Such 

strategies should be carried out in ways 

that minimize occupant exposure.) 

What Sampling and Analysis 

Method Should Be Used? 

Take care to select appropriate measurement techniques and to provide interpretations so that the results provide useful 

information. Appendix A provides 

guidance on measurement techniques that 

are commonly used in IAQ investigations. 

COMPLAINTS DUE TO 

CONDITIONS OTHER THAN 

POOR AIR QUALITY 

Complaints that initially seem to be linked 

to thermal discomfort, underventilation, or 

indoor air pollutants may actually be 

caused or complicated by factors such as: 

• environmental stressors (e.g., lighting, 

noise, vibration) 

• ergonomic stressors 

IIi job-related psychosocial (human rehl.-

tioris) stressors 

The following briefly discusses each of 

these three kinds of stressors. Investigators should bear in mind that complaints 

produced by these stressors are sometimes 

mistakenly blamed on contaminated air. 

To complicate matters, such stressors also 

can produce a heightened sensitivity to 

poor indoor air quality. Thus, even when 

specific stressors are obvious, the investigator should not assume that they are the 

only reason for the complaints. 

Lighting 

Stresses from inadequate or poorly 

designed lighting (e.g., glare, flicker, poor 

illumination of work surfaces) can produce 

symptoms such as eyestrain and headaches. Lack of natural sunlight can also be 

a source of stress. These complaints are 

sometimes mistakenly interpreted as signs 

of poor indoor air quality. Lighting 

problems may be evident in large areas or 

localized in particular workspaces. 

Diagnosing IAQ Problems 77 

Investigators should 

bear in mind that 

complaints produced 

by these stressors ·are 

sometimes mistakenly 

blamed on contaminated air. To complicate matters, such 

stressors also can 

produce a heightened 

sensitivity to poor 

indoor air quality. 
The glare from the windows 

was causing a variety of 

occupant complaints in this 

building and was disrupting 

the workers' ability to use 

the video display terminals. 

Complaints such as 

headaches are sometimes 

incorrectly blamed on poor 

indoor air quality. 

Noise 

Noisy surroundings can reduce the ability 

to concentrate and produce stress-related 

symptoms such as headaches. Noise can 

also contribute to job dissatisfaction, 

particularly if the problem is caused by 

overcrowding or other factors likely to 

produce a sense of substandard work 

conditions. 

The ear gets used to sounds quickly, so it 

is possible for a complainant to be unaware 

of a constant or regular sound. Investigators should recognize that noise can be a 

source of stress, even if it is not reported as 

a problem and is within current industrial 

exposure criteria (which are designed 

primarily to prevent hearing loss). 

Vibration 

Low-frequency vibration is another source 

of stress that may go unreported by 

building occupants or become confused 

with pollutant problems. Vibration can be 

caused by nearby machinery or movement 

of the building as a whole; motion sickness 

has been reported in some high rise 

buildings that sway in the wind. 

78 Section6 

Ergonomic Stressors 

Fatigue, circulatory problems, and other 

physical problems can be produced by 

furniture that is mismatched to the task, 

such as chairs that are the wrong height for 

computer terminals. If IAQ investigators 

inquire about whether new furniture has 

recently been installed in the problem area 

(to determine if the furniture could be 

contributing to increased contaminant 

levels), they should also ask about 

whether the occupant finds the furniture 

comfortable. 

Job-related Psychosocial 

Stressors 

It is well documented that various jobrelated psychosocial conditions can 

produce symptoms in workers. Excessive 

workload and work pressure are easily 

recognized job stressors. Lack of clarity 

about what is expected of the worker (role 

ambiguity) and the presence of conflicting 

expectations (role conflict) are also 

commonly encountered stressors in 

modem organizations. Poor interpersonal 

relations, management styles that allow 

little participation in decision-making, and 

factors related to career development are 

also thought to be potentially stressful. 

FORMING AND TESTING 

HYPOTHESES 

As the building investigation progresses, 

you should be developing one or more 

hypotheses that could explain the occupan~ 

complaints. The investigation can then be 

shaped to collect information that will 

either support or refute your hypotheses. 

The Hypothesis Form on the opposite 

page is designed to pull together the 

separate pieces of information that have 

been collected by summarizing the results 

of the investigation. More pages can be 

added if desired, but the form is designed 

for brief notes that can be scanned easily. 

As you review the information, write down 
any explanation(s) of the IAQ problem that 

make sense, and think about how tbe 

pieces of the puzzle fit together when 

building conditions are compared to 

occupant complaints. 

Is all (or most) of your information 

consistent with your hypothesis? If not, is 

there a reasonable explanation for the 

inconsistencies? A different hypothesis 

might provide a better fit with your 

information. 

You may find that there are several IAQ 

problems (e.g., underventilatlon in one 

zone, a strong contaminant source in . 

another room). If you have discovered. 

potential IAQ problems that do not appear 

related to the original complaint, they can 

be prioritized and corrected as time and 

funding permit. 

Think of ways to test your hypotheses. 

You may want to change ventilation rates, 

change the pressure relationship between 

spaces, cover or remove suspected sources, 

seal pathways, or temporarily relocate 

affected individuals. If your manipulations 

can reduce occupant complaints, you have 

found a reasonable hypothesis. Sometimes 

it is not possible (or not practical) to 

manipulate important factors. You can 

also test your hypothesis by seeing how 

accurately you can predict changes in 

building conditions (e.g., as outdoor 

temperature changes). 

If you are having difficulty developing 

hypotheses, review the information you 

have collected and the suggestions about 

how to use that information. For suggestions on using occupant complaint data, 

see pages 53-57; on using HV AC system 

information, see pages 62-67; on using 

pollutant pathway information, see pages 

70-71; on using pollutant/source inventory 

data, see page 74; on using air sampling 

information, see pages 75-76. 

The changes that are made during 

hypothesis testing may offer a practical 

solution to the IAQ problem, or may be 

only temporary measures. The mitigation 

chapter presents a variety of approaches 

that have been used in correcting some 

selected categories of IAQ problems and 

discusses how to evaluate those strategies. 

Diagnosing IAQ Problems 19 

Mitigating IAQ Problems 

Over the years many types of mitigation 

(correction) strategies have been implemented to solve indoor air quality problems. The purpose of this section is to 

provide an understanding of basic approaches to mitigation and the various 

solutions that can be effective in treating 

commonly encountered IAQ problems. It 

is not intended to provide detailed instructions for using each type of mitigation 

approach but rather to give guidance in 

selecting a mitigation strategy and in 

judging proposals from in-house staff or 

outside consultants. 

Mitigation of indoor air quality problems may require the involvement of 

building management and staff representing such areas of responsibility as: 

• facility operation and maintenance 

• housekeeping 

• shipping and receiving 

• purchasing 

• policymaking 

• staff training 

Successful mitigation of IAQ problems 

also requires the cooperation of other 

building occupants, including the employees of building tenants. Occupants must be 

educated about the cause(s) of the IAQ 

problems and about actions that must be 

taken or avoided to prevent a recurrence of 

the problems. 

BACKGROUND: CONTROLLING 

INDOOR AIR PROBLEMS 

Section 2 introduced the idea that indoor 

air quality problems result from interactions between contaminant source, 

building site, building structure, activities 

within the building, mechanical equipment, 

climate, and occupants. Efforts to control 

indoor air contaminants change the 

relationships between these factors. There 

are many ways that people can intervene in 

these relationships to prevent or control 

indoor air contaminant problems. Control 

strategies can be categorized as: 

• source control 

• ventilation 

• air cleaning 

• exposure control 

Successful mitigation often involves a 

combination of these strategies. Possible 

remedies for the other environmental 

stressors discussed in Section 6 are 

discussed briefly below. 

Source Control 

All efforts to prevent or correct IAQ 

problems should include an effort to 

identify and control pollutant sources. 

Source control is generally the most cost 

effective approach to mitigating IAQ 

problems in which point sources of 

contaminants can be identified. ·In the case 

of a strong source, source control may be 

the only solution that will work. 

The following are categories and 

examples of source control: 

. Remove or reduce the source 

• prohibit smoking indoors or limit · 

smoking to areas from which air is 

exhausted, not recirculated (NIOSH 

regards smoking areas as an interim 

solution) 

• relocate contaminant-producing equipment to an unoccupied, better ventilated, 

or exhaust-only ventilated space 

• select products which produce fewer or 

less potent contaminants while maintaining adequate safety and efficacy 

Mitigating IAQ Problems 81 
• modify other occupant activities 

Seal or cover the source 

• improve storage of materials that 

produce contaminants 

• seal surfaces of building materials that 

emit VOCs such as formaldehyde 

Modify the environment 

• after cleaning and disinfecting an area 

that is contaminated by fungal or 

bacterial growth, control humidity to 

make conditions inhospitable for 

regrowth 

Source removal or reduction can 

sometimes be accomplished by a one-time 

effort such as thorough cleaning of a spill. 

In other cases, it requires an ongoing 

process, such as establishing and enforcing 

a non-smoking policy. 

Sealing or covering the source can be a 

solution in some cases; application of a 

barrier over formaldehyde-emitting 

building materials is an example. Sealing 

may also involve educating staff or 

building occupants about the contaminantproducing features of materials and 

supplies and inspecting storage areas to 

ensure that containers are properly 

covered. 

In some cases, modification of the 

environment is necessary for effective 

mitigation. If the indoor air problem 

arises from microbiologicill contaminants, 

for example, disinfection of the affected 

area may not eliminate the problem. 

Regrowth of microbiologicals could 

occur unless humidity control or other 

steps, such as adding insulation to prevent 

surface condensation, are taken to make 

the environment inhospitable to microbiologicals. 

Ventilation 

Ventilation modification is often used to 

correct or prevent indoor air quality 

problems. This approach can be effective 

either where buildings are underventilated 

or where a specific contaminant source 

82 Section7 

cannot be identified. Ventilation can be 

used to control indoor air contaminants by: 

Diluting contaminants with outdoor air 

• increase the total quantity of supply air 

(including outdoor air) 

• increase the proportion of outdoor air to 

total air 

• improve air distribution 

Isolating or removing contaminants by 

controlling air pressure relationships 

• install effective local exhaust at the 

location of the source 

• avoid recirculation of air that contains 

contaminants 

• locate occupants near supply diffusers 

and sources near exhaust registers 

• use air-tightening techniques to maintain 

pressure differentials and eliminate 

pollutant pathways 

• make sure that doors are closed where 

necessary to separate zones 

Diluting contaminants by increasing 

the flow of outdoor air can be accomplished by increasing the total supply 

airflow in the complaint area (e.g., opening 

supply diffusers, adjusting dampers) or at 

the air handling unit, (e.g., cleaning the 

filter on the supply fan). An alternative is 

to increase the proportion of outdoor air 

(e.g., adjusting the outdoor air intake 

damper, installing minimum stops on 

variable air volume (VA V) boxes so that 

they satisfy the outdoor air requirements of 

ASHRAE 62-1989). 

Studies have shown that increasing 

ventilation rates to meet ASHRAE 

Standard 62-1989 (e.g., from 5 to 15 or 20 

cfm/person) does not necessarily significantly increase the total annual energy 

consumption. The increase appears to be 

less than 5% in typical commercial 

buildings. The cost of ventilation is 

generally overshadowed by other operating 

costs, such as lighting. Further, improved 

maintenance can produce energy savings 

to balance the costs that might otherwise 

result from increased ventilation. 
The cost of modifying an existing 

HV AC system to condition additional 

outdoor air can vary widely depending 

upon the specific sitUation. In some 

buildings, HV AC equipment may not have 

sufficient capacity to allow successful 

mitigation using this approach., Original 

equipment is often oversized so that it can 

be adjusted to handle the increased load, 

but in some cases additional capacity is 

required. 

Most ventilation deficiencies appear to 

be linkvd to inadequate quantities of 

outdoor arr. However, inadequate distribu~ 

tion of ventilation air can also produce 

IAQ problems. Diffusers should be 

properly selected, located, installed, and 

maintained so that supply air is evenly 

distributed and blends thoroughly with 

room air in the breathing zone. Short~ 

circuiting occurs when clean supply air is 

drawn into the return air plenum before it 

has mixed with the dirtier room air and 

therefore fails to dilute contaminants. 

Mixing problems can be aggravated by 

temperature stratification. Stratification 

can occur, for example, in a space with 

high ceilings in which ceiling~mounted 

supply diffusers distribute heated air. 

Note the side effects of increased 

ventilation: 

• mitigation by increasing the circulation 

of outdoor air requires good outdoor air 

quality 

• increased supply air at the problem 

location might mean less supply air in 

other areas 

• increased total air in the system and 

increased outdoor air will both tend to 

increase energy consumption and may 

require increased equipment capacity 

• any approach which affects airflow in the 

building can change pressure differences 

between rooms (or zones) and between 

indoors and outdoors, and might lead to 

increased infiltration of unconditioned 

outdoor air 

• increasing air in a VA V system may 

overcool an area to the extent that 

terminal reheat units are needed 

Ventilation equipment can be used to 

isolate or remove contaminants by 

controlling pressure relationships. If the 

contaminant source has been identified, 

this strategy can be more effective than 

dilution. Techniques for controlling air 

pressure relationships range from adjustment of dampers to installation of local 

exhaust. 

Using local exhaust confmes the spread 

of contaminants by capturing them near the 

source and exhausting them to the outdoors. It also dilutes the contaminant by 

drawing cleaner air from surrounding areas 

into the exhaust airstream. If there are 

return grilles in a room equipped with local 

exhaust, the local exhaust should exert 

enough suction to prevent recirculation of 

contaminants. Properly designed and 

installed local exhaust results in far lower 

contaminant levels in the building than 

could be accomplished by a general 

increase in dilution ventilation, with the 

added benefit of costing less. 

Note that replacement air must be able 

to flow freely into the area from which the 

exhaust air is being drawn. It may be 

necessary to add door or wall louvers in 

order to provide a path for the make~up air. 

(Make sure that this action does not violate 

fire codes.) 

Correct identification of the pollutant 

source and installation of the local exhaust 

is critically important. For example, an 

improperly designed local exhaust can 

draw other contaminants through the 

occupied space and make the problem 

worse. 

The physical layout of grilles and 

diffusers relative to room occupants and 

pollutant sources can be important. If 

supply diffusers are all at one end of a 

room and returns are all at the other end, 

the people located near the supplies may 

be provided with relatively clean air while 

those located near the returns breathe air 

that has already picked up contaminants 

from all the sources in the room that are 

not served by local exhaust. 

Mitigating /AQ Problems 83 
Elimination of pollutant pathways by air 

sealing (e.g., caulking cracks, closing 

holes) is an approach that can increase the 

effectiveness of other control techniques. 

It can be a difficult technique to implement 

because of hidden pathways (e.g., above 

drop ceilings, under raised flooring, 

against brick or block walls). However, it 

can have other benefits such as energy 

savings and more effective pest control (by 

eliminating paths used by vermin). 

Air Cleaning 

The third IAQ control strategy is to clean 

the air. Air cleaning is usually most effective when used in conjunction with either 

source control or ventilation; however, it 

may be the only approach when the source 

of pollution is outside of the building. 

Most air cleaning in large buildings is 

aimed primarily at preventing contaminant 

buildup in HV AC equipment and enhancing equipment efficiency. 

Air cleaning equipment intended to 

provide better indoor air quality for occupants must be properly selected and designed for the particular pollutants of interest (for example, gaseous contaminants can 

be removed only by gas sorption). Once 

installed, the equipment requires regular 

maintenance in order to ensure good performance; otherwise it may become a 

major pollutant source in itself. This maintenance requirement should be borne in 

mind if an air cleaning system involving a 

large number of units is under consideration for a large building. If room units are 

used, the installation should be designed 

for proper air recirculation. 

There are four technologies that remove 

contaminants from the air: 

• particulate filtration 

• electrostatic precipitation 

• negative ion generation 

• gas sorption 

84 Section7 

The first three approaches are designed 

to remove particulates, while the fourth is 

designed to remove gases. 

Particulate filtration removes suspended liquid or solid materials whose 

size, shape and mass allow them to remain 

airborne at the air velocity conditions 

present. Filters are available in a range of 

efficiencies, with higher efficiency indicating removal of a greater proportion of 

particles and of smaller particles. Moving 

to medium efficiency pleated filters is 

advisable to improve IAQ and increase 

protection for equipment. However, the 

higher the efficiency of the filter, the more 

it will increase the pressure drop within the 

air distribution system and reduce total 

airflow (unless other adjustments are made 

to compensate). It is important to select an 

appropriate fllter for the specific 

application and to make sure that the 

HV AC system will continue to perform as 

designed. Filters are rated by different 

standards (e.g., arrestance and dust spot) 

which measure different aspects of 

performance. 

Electrostatic precipitation is another 

type of particulate control. It uses the 

attraction ofcharged particles to oppositely 

charged surfaces to collect airborne particulates. In this process, the particles are 

charged by ionizing the air with an electric 

field. The charged particles are then collected by a strong electric field generated 

between oppositely-charged electrodes. 

This provides relatively high efficiency 

filtration of small respirable particles at 

low air pressure losses. 

Electrostatic precipitators may be installed in air distribution equipment or in 

specific usage areas. As with other filters, 

they must be serviced regularly. Note, 

however, that electrostatic precipitators 

produce some ozone. Because ozone is 

harmful at elevated levels, EPA has set 

standards for ozone concentrations in outdoor air, and NIOSH and OSHA have 
established guidelines and standards, respectively, for ozone in indoor air. The 

amount of ozone emitted from electrostatic 

precipitators varies .from model to mo~el. 

Negative ion generators use static 

charges to remove particles from the indoor 

air. When the particles become charged, 

they are attracted to surfaces such as walls, 

floors, table tops, draperies, and occupants. 

Some designs include collectors to attract 

the charged particles back to the unit. 

Negative ion generators are not available 

for installation in ductwork, but are sold as 

portable or ceiling-mounted units. As with 

electrostatic precipitators, negative ion 

generators may produce ozone, either intentionally or as a by-product of use. 

Gas sorption is used to control compounds that behave as gases rather than as 

particles (e.g., gaseous contaminants such 

as formaldehyde, sulfur dioxide, ozone, and 

oxides of nitrogen). Gas sorption involves 

one or more of the following processes 

with the sorption material (e.g., activated 

carbon, chemically treated active clays): a 

chemical reaction between the pollutant 

and the sorbent; a binding of the pollutant 

and the sorbent; or diffusion of the contaminant from areas of higher concentration 

to areas of lower concentration. Gas sorption units are installed as part of the air 

distribution system. Each type of sorption 

material performs differently with different 

gases. Gas sorption is not effective for 

removing carbon monoxide. There are no 

standards for rating the performance of 

gaseous air cleaners, making the design and 

evaluation of such systems problematic. 

Operating expenses of these units can be 

quite high, and the units may not be effective if there is a strong source nearby. 

Ex.,osure Control 

Exposure control is an administrative approach to mitigation that uses behavioral 

methods, such as: 

Scheduling contaminant-producing activities to avoid complaints 

• schedule contarninant-producirig activities to occur during unoccupied periods 

• notify susceptible individuals about upcoming events (e.g., roofmg, pesticide 

application) so that they can avoid contact 

with the contaminants 

Scheduling contaminant-producing activities for unoccupied periods whenever 

possible is simple common sense. It may 

be the best way to limit complaints about 

activities (such as roofmg or demolition) 

which unavoidably produce odors or dust. 

Relocating susceptible individuals 

• move susceptible individuals away from 

the area where they experience symptoms 

Controlling exposure by relocating susceptible individuals may be the only practical approach in a limited number of cases, 

but it is probably the least desirable option 

and should be used only when all other 

strategies are ineffective in resolving complaints. 

Remedies for Complaints Not 

Attributed to Poor Air Quality 

Specific lighting deficiencies or localized 

sources of noise or vibration can sometimes 

be readily identified, and remedial action 

may be fairly straightforward (more or 

fewer lights on, adjustments for glare; relocating, replacing or acoustically insulating a 

noise or vibration source). Similarly, flagrant ergonomic stress or blatant 

psychosocial stress may be apparent even to 

an untrained observer. 

In other cases, however, problems may 

be more subtle or solutions more complex. 

Since specialized knowledge, skills, and 

instrumentation are usually needed to 

evaluate lighting, noise, vibration, ergonomic stress, or psychosocial stress, such 

evaluations are generally best done by a 

qualified professional in that particular 

field. 

Mitigating IAQ Problems 85 
Remedial actions for lighting, noise, 

and vibration problems might range from 

modifications of equipment or furnishings 

to renovation of the building. Ergonomic 

deficiencies may require furniture or 

equipment changes or different work 

practices. The solution to psychosocial 

problems may involve new management 

practices, job redesign, or resolution of 

underlying labor-management problems. 

SAMPLE PROBLEMS AND 

SOLUTIONS 

In the investigation section you were 

introduced to a variety of problems that are 

often found in buildings. This section 

presents fifteen categories of IAQ problems. Specific problem "examples" are 

given, followed by "solutions" that have 

been used for that category of problem. 

Most of the problems presented here are 

common and do not have serious, lifethreatening consequences. At the end of 

the section is a brief description of 

problems that can have severe health 

impacts. The basic correction principles 

that apply to these serious problems are 

similar to those used in less critical 

situations. 

Reading these examples may help you 

think about the best way to solve your 

indoor air quality problems. Remember 

that these are brief sketches, and apparent 

parallels to your building could be misleading. It is better to carry out a building 

investigation and learn the specific facts in 

your own case, rather than adopt a mitigation approach that might not be appropriate. Attempting to correct IAQ problems 

without understanding the cause of those 

problems can be both ineffective and 

expensive. 

86 Section 7 

You will note that some solutions are 

simple and low-cost, while others are 

complex and expensive. Do not assume 

that each solution listed would be an 

effective treatment for all of the problems 

in its category. 

The example problems and solutions are 

presented in the following sequence: 

Problem # 1: Outdoor air ventilation rate 

is too low 

Problem #2: Overall ventilation rate is 

high enough, but poorly 

distributed and not sufficient 

in some areas 

Problem #3: Contaminant enters building 

from outdoors 

Problem #4: Occupant activities contribute to air contaminants or to 

comfort problems 

Problem #5: HV AC system is a source of 

biological contaminants 

Problem #6: HV AC system distributes 

contaminants 

Problem #7: · Non-HV AC equipment is a 

source or distribution mechanism for contaminants 

Problem #8: Surface contamination due to 

poor sanitation or accidents 

Problem #9: Mold and mildew growth 

due to moisture from condensation 

Problem #10: B_uilding materials and 

furnishings produce 

contaminants 

Problem #11: Housekeeping or maintenance activities contribute to 

problems 

Problem #12: Specialized use areas as 

sources of contaminants 

Problem #13: Remodeling or repair activities produce problems 

Problem #14: Combustion gases 

Problem #15: Serious building-related 

illness 
Problem #1: 

Outdoor Air Ventilation 

Rate is Too low 

Examples 

Routine odors from occupants and 

normal office activities result in problems 

(e.g., drowsiness, headaches, discomfort) 

Measured outdoor air ventilation rates do 

not meet guidelines for outdoor air supply 

(e.g., design specifications, applicable 

codes, or ASHRAE 62-1989) 

J>eak C02 concentrations above 1000 

ppm indicate inadequate ventilation 

Co"osion of fan casing causes air 

bypassing and reduces airflow in system 

Solutions 

Open, adjust or repair air distribution 

system 

• outdoor air intakes 

• mixing and relief dampers 

• supply diffusers 

• fan casings 

Increase outdoor air within the design 

capacity of 

• air handler 

• heating and air conditioning equipment 

• distribution system 

Modify components of the HV AC system 

as needed to allow increased outdoor air 

(e.g., increase capacity of heating and 

cooling coils) 

Design and install an updated ventilation 

system 

Reduce the.pollutant and/or thermal load 

on the HVAC system 

• reduce the occupant density: relocate 

some occupants to other spaces to 

redistribute the load on the ventilation 

system 

• relocate or reduce usage of heatgenerating equipment 

Malfunctioning controls such as this 

broken damper linkage can virtually 

eliminate intake of outdoor air. Such 

problems may go undetected for years 

without a careful investigation of the 

HVAC system components. · 

Mitigating IAQ Problems 87 
Problem #2: 

Overall Ventilation Rate Is 

High Enough, But Poorly 

Distributed and Not 

Sufficient in Some Areas 

Complaining of discomfort, building 

occupants blocked air supply diffusers in 

their work areas. The HVAC system in 

this building was in poor condition and 

was not balanced. 

88 Section7 

Examples 

Measured outdoor air meets guidelines at 

building air inlet, but there are zones 

where heat, routine odors from occupants, and normal office activities result 

in complaints 

(e.g., drowsiness, headaches, comfort 

complaints) 

Solutions 

Open, adjust, or repair air distribution 

system 

• supply diffusers 

• return registers 

Ensure proper air distribution 

• balance the air handling system 

• make sure that there is an air gap at tops 

and bottoms of partitions to prevent dead 

air space 

• relocate supply and/or return diffusers to 

improve air distribution 

Seal leaky ductwork 

Remove obstructions from return air 

plenum 

Control pressure relationships 

• install local exhaust in problem areas 

and adjust HV AC system to provide 

adequate make-up air 

• move occupants so that they are closer to 

supply diffusers 

• relocate identified contaminant sources 

closer to exhaust intakes 

Reduce source by limiting activities or 

equipment use that produce heat, odors, 

or contaminants 

Design and install an appropriate 

ventilation system 
Problem #3: 

Contaminant Enters Building 

From Outdoors 

Examples 

Soil gases 

(e.g., radon, gasoline from tanks, methane 

from landfills) 

Contaminants from nearby activities 

(e.g., roofmg, dumpster, construction) 

Outdoor air intake near source 

(e.g., parking, loading dock, building 

exhaust) 

Outdoor air contains pollutants or excess 

moisture 

(e.g., cooling tower mist entrained in 

outdoor air intake) 

Solutions 

Remove the source (if it can be moved 

easily) 

• remove debris around outdoor air intake 

• relocate dumpster 

Reduce source (for example, shift time of 

activity to avoid occupied periods) 

• painting, roofing, demolition 

• housekeeping, pest control 

Relocate elements of the ventilation 

system that contribute to entry of outdoor 

air contaminants 

• separate outdoor air intakes from sources 

of odors, contaminants 

• separate exhaust fan outlets from 

operable windows, doors, air intakes 

• make rooftop exhaust outlets taller than 

intakes 

Change .air pressure relationships to 

control pollutant pathways 

• install subslab depressurization to 

prevent entry of soil gas contaminants 

(radon, gases from landfills and underground tanks) 

• pressurize the building interior relative to 

outdoors (this will not prevent contaminant entry at outdoor air intakes) 

• close pollutant pathways (e.g., seal 

cracks and holes) 

Add special equipment to HV AC system 

• filtration equipment to remove pollutants 

(select to fit the situation) 

Mitigating IAQ Problems 89 

For cosmetic reasons, air 

intakes are frequently · located on rooftops or near. 

the ground. This air intake 

could become a means of 

drawing lawn cuttings, 

vehicle exhaust, and 

pesticides into the building. 
Problem #4: 

Occupant Activities 

Contribute to Air 

Contaminants or to 

Comfort Problems 

Personal equipment such as humidifiers 

brought in by building occupants can 

become a source of contaminants if not 

properly maintained. An effective 

communication strategy can help 

occupants to understand their role in 

causing indoor air quality problems and 

in correcting those problems. 

90 Section? 

Examples 

Smoking 

Special activities such as print shops, 

laboratories, kitchens 

Interference with HV AC system 

operation: 

• blockage of supply diffusers to eliminate 

drafts 

• turning off exhaust fans to eliminate 

noise 

• use of space heaters, desktop humidifiers 

to remedy local discomfort. 

(Note: While such interference can cause 

IAQ problems, it is often initiated in 

response to unresolved ventilation or 

temperature control problems.) 

Solutions 

Remove the source by eliminating the 

activity 

(Note: This may require a combination of 

policy-setting and educational outreach.) 

• smoking 

• use of desktop humidifiers and other 

personal HV AC 'equipment 

• unsupervised manipulation of HV AC 

system 

Reduce the source 

• select materials and processes which 

minimize release of contaminants while 

maintaining adequate safety and efficacy 

(e.g., solvents, art materials) 

Install new or improved local exhaust to 

accommodate the activity, adjust HV AC 

system to ensure adequate make-up air, 

and verify effectiveness 

• smoking lounge, storage areas which 

contain contaminant sources 

• laboratory hoods, kitchen range hoods 

(venting to outdoors, not recirculating) 
Problem #5: 

HVAC System is a Source of 

Biological Contaminants 

The HV AC system can act as a source of 

contaminants by providing a hospitable 

environment for the growth of microorganisms and then distributing biologicallycontaminated air within the building. 

Examples 

Surface contamination by molds (fungi), 

bacteria 

• drain pans 

• interior of ductwork 

• air filters and filter media (collected 

debris). 

Solutions 

Remove source by improving maintenance procedures 

• inspect equipment for signs of corrosion, 

high humidity 

• replace corroded parts 

• clean drip pans, outdoor air intakes, 

other affected locations 

• use biocides, disinfectants, and sanitizers 

with extreme caution and ensure that 

occupant exposure is minimized 

(Note: See discussion of duct cleaning in 

Appendix B.) 

Provide access to all the items that 

must be cleaned, drained, or replaced 

p{triodically 

This blackish deposit was scraped from 

a poorly maintained air handling unit 

drain pan. The pan contained nutrients 

caused by poor upstream filtration and 

stagnant water that fostered the growth 

of microbiological contaminants. 

Mitigating IAQ Problems 91 
Problem #6: 

HVAC System Distributes 

Contaminants 

Standing water on a roof can cause 

water damage and potential mold 

growth sites inside the building as well 

as providing a breeding area for insects 

and microbiologicals such as Legionella. 

The outside air intake (near the far left of 

this photograph) is located close to the 

standing water and could be drawing in 

insects and microbiological 

contaminants. 

92 Section7 

Examples 

Unfiltered air bypasses filters due to 

problems 

• filter tracks are loose 

• poorly maintained filters sag when they 

become overloaded with dirt 

• fllters are the wrong size 

Recirculation of air that contains dust or 

other contaminants 

• system recirculates air from rooms 

containing pollutant sources 

• return air plenum draws air from rooms 

that should be exhausted (e.g., janitor's 

closets) 

• return air plenums draw soil gases from 

interiors of block corridor walls that 

terminate above ceilings 

Solutions 

Modify air distribution system to 

minimize recirculation of contaminants 

• provide local exhaust at point sources of 

contaminants, adjust HVAC system to 

provide adequate make-up air, and test to 

verify performance 

• increase proportion of outdoor air 

• seal unplanned openings into return air 

plenums and provide alternative local 

ventilation (adjust HV AC system to 

provide adequate make-up air and test to 

verify performance) 

Improve housekeeping, pest control, 

occupant activities, and equipment use to 

minimize release of contaminants from 

all sources 

Install improved filtration equipment to 

remove contaminants 

Check filter tracks for any gaps 
Problem #7: 

Non-HVAC Equipment is 

a Source or Distribution 

Mechanism for Contaminants 

This discussion pertains to medium- to 

large-scale pieces of equipment. 

Examples 

Non-HV AC equipment can produce 

contaminants, tis in the case of: 

• wet process copiers 

• large dry process copiers 

• engineering drawing reproduction 

machines 

It can also distribute contaminants, as in 

the case of: 

• elevators, which can act as pistons and 

draw contaminants from one floor to 

another 

Solutions 

Install local exhaust near machines 

(Note: Adjust HV AC system to provide 

adequate make-up air, and test to verify 

performance.) 

Reschedule use to occur during periods of 

low occupancy 

Remove source 

• relocate occupants out of rooms 

that contain contaminant-generating 

equipment 

• relocate equipment into special use 

areas equipped with effective exhaust 

ventilation (test to verify control of air 

pressure relationships) 

Change air pressure relationships to 

prevent contaminants from entering 

elevator shaft 

Sometimes there are unusual sources of 

indoor air quality problems. An 

inspection of the HVAC system revealed 

air filters covered with a graphite dust 

deposit from a broken elevator motor 

generator. The motor generator was 

repaired and corrections were made to 

prevent the'crossover of ventilation air 

from the motor generator into the HVAC 

mechanical room. 

Mitigating IAQ Problems 93 
Problem #8: 

Surface Contamination 

Due to Poor Sanitation or 

Accidents 

The carpet on this floor was flooded 

and an outbreak of humidifier fever 

occurred. To eliminate microbiologicals, 

the contaminated carpet was removed 

and new carpet was installed. 

94 Section7 

Examples 

Biological contaminants result in allergies or other diseases 

• fungal, viral, bacterial (whole organisms 

or spores) 

• bird, insect, or rodent parts or droppings, 

hair, dander (in HV AC, crawlspace, 

building shell, or near outdoor air 

intakes) 

Accidents 

• spills of water, beverages, cleansers, 

paints, varnishes, mastics or speci~lizeq 

products (printing, chemical art supplies) 

• ftre damage: soot, odors, chemicals 

Solutions 

Clean 

• HV AC system components 

• some materials and furnishings (others 

may have to be discarded) 

(Note: Use biocides, disinfectants, and 

sanitizers with caution and ensure that 

occupant exposure is minimized.) 

Remove sources of microbiological 

contamination 

• water-damaged carpet, furnishings, or 

building materials 

Modify environment to prevent recurrence of microbiological growth 

• improve HV AC system maintenance 

• control humidity or surface temperatures 

to prevent condensation 

Provide access to all items that require 

periodic maintenance 

Use local exhaust where corrosive 

materials are stored 

Adjust HV AC system to provide adequate 

make-up air, and test to verify performance 
Problem #9: 

Mold and Mildew Growth 

Due to Moisture from 

Condensation 

Examplf.'S 

Interior surfaces of walls near thermal 

bridges 

(e.g., uninsulated locations aronnd structural members) 

Carpeting on cold floors 

Locations where high surface humidity 

promotes condensation 

Solutions: 

Clean and disinfect to remove mold and 

mildew 

(Note: Follow up by taking actions to 

prevent recurrence of microbiological 

contamination. Use biocides,.disinfectants, and sanitizers with caution and 

ensure that occupant exposure is minimized.) 

Increase suiface temperatures to treat 

locations that are subject t!J condensation 

• insulate thermal bridges 

• improve air distribution 

Reduce moisture levels in locations that 

are subject to condensation 

• repair leaks 

• increase ventilation (in cases where 

outdoor air is cold and dry) 

• dehumidify (in cases where outdoor air 

is warm and humid) 

Dry carpet or other textiles promptly after 

steam cleaning 

(Note: Increase ventilation to accelerate 

drying.) 

Discard. contaminated materials 

This is a school crawlspace in which 

moisture should be controlled. The 

fungus is Fusarium, some species of 

which are toxigenic and should not be 

inside. The spores were distributed by 

the air handler because the return 

plenum was open to the crawlspace. 

Mitigating IAQ Problems 95 
Problem # 10: 

Building Materials and 

Furnishings Produce 

Contaminants 

Low levels of contaminants are emitted 

from many of the building materials 

and furnishings in an office. Dust can 

accumulate on stacks of papers and 

open shelves. Depending on how 

they are cared for, plants potentially 

add moisture, soil microbiologicals, 

and pesticides. 

96 Section7 

Examples 

Odors from newly installed carpets, 

furniture, wall coverings 

Newly drycleaned drapes or other textiles 

Solutions 

Remove source with appropriate cleaning 

methods 

• steam clean carpeting and upholstery, 

then dry quickly, ventilating to accelerate the drying process 

• accept only fully dried, odorless 

drycleaned products 

Encapsulate source 

• seal surfaces of building materials that 

emit formaldehyde 

Reduce source 

• schedule installation of carpet, furniture, 

and wall coverings to occur during 

periods when the building is unoccupied 

• have supplier store new furnishings in a 

clean, dry, well-ventilated area until 

VOC outgassing has diminished 

Increase outdoor air ventilation 

• total air supplied 

• proportion of fresh air 

Remove the materials that are producing 

the emissions and replace with lower 

emission alternatives 

(Note: Only limited information on 

emissions from materials is available at 

this time. Purchasers can request that 

suppliers provide emissions test data, but 

should use caution in interpreting the test 

results.) 
Pr()blem # 11: 

Housekeeping or Maintenance 

Activities Contribute to 

Problems 

Examples 

Cleaning products, emit chemicals, odors 

Particulates become airborne during 

cleaning (e.g., sweeping, vacuuming) 

Contaminants are released from painting, 

caulking, lubricating · 

Frequency of maintenance is insufficient 

to eliminate contaminants 

Solutions 

Remove source by modifying standard 

procedures or frequency of maintenance 

(Note: Changing procedures may require a 

combination of policy-setting and training 

in IAQ impacts of staff activities;) 

• improve storage practices 

• shift time of painting, cleaning, pest 

control, other contaminant-producing 

activities to avoid occupied periods 

• make maintenance easier by improving 

access to filters, coils, and other components 

Reduce source 

• ,select materials to minimize emissions of 

contaminants while maintaining adequate safety and efficacy 

• use portable HEPA("high efficiency 

particulate arrestance") vacuums vs. lowefficiency paper-bag collectors 

Use local exhaust 

• on a temporary basis to remove contaminants from work areas 

• as a permanent installation where 

contaminants are stored 

Indoor air quality problems pan be 

caused by Jack of adequate housekeeping practices, Ori the other hand, 

deodorizers, cleansers (lnd other 

· products can also produce odors and 

contaminants. 

Mitigating IAQ Problems 97 
Problem #12: 

Specialized Use Areas as 

Sources of Contaminants 

This chemical storage room should be 

maintained under negative pressure. 

Properly designed and maintained local 

exhaust wi/1 achieve the proper air 

pressure relationship with surrounding 

areas. Otherwise, such storage areas 

can be a source of occupant exposure to 

many airborne contaminants. 

98 Section7 

Examples 

Food preparation 

Art or print rooms 

Laboratories 

Solutions 

Change pollutant pathway relationships 

• run specialized use area under negative 

pressure relative to surrounding areas 

• install local exhaust, adjust HV AC 

system to provide make-up air, and test 

to verify performance 

Remove source by ceasing, relocating, or 

rescheduling incompatible activities 

Reduce source by selecting materials to 

minimize emissions of contaminants 

while maintaining adequate safety and 

efficacy 

Reduce source by using proper sealing 

and storage for materials that emit 

contaminants 
Problem #13: 

Remodeling or Repair 

Activities Produce Problems 

Examples 

Temporary activities produce odors and 

contaminants 

• installation of new particleboard, 

partitions, carpet, or furnishings 

• painting 

• reroofing 

• demolition 

Existing HV AC system does not provide 

adequate ventilation for new occupancy 

or arrangement of space 

Solutions 

Modify ventilation to prevent 

recirculation of contaminants 

• install temporary local exhaust in 

work area, adjust HV AC system to 

provide make-up air, and test to 

verify petformance 

• seal off returns in work area 

• close outdoor air damper during 

re-roofmg 

R,educe source by scheduling work for 

unoccupied periods and keeping ventt1ation system in operation to remove odors 

and contaminants 

Reduce source by careful materials 

selection and installation 

• select materials to minimize emissions 

of contaminants while maintaining 

adequate safety and efficacy 

• have supplier store ne~ furnishings in a 

· clean, dry, well-ventilated area until 

VOC outgassing has diminished 

• request installation procedures (e.g., 

adhesives) that limit emissions of 

contaminants 

Modify HV AC or wall partition layout if 

necessary 

• partitions should not interrupt aitflow 

• relocate supply and return diffusers 

• adjust supply and return air quantities 

• adjust total air and/or outdoor air supply 

to serve new occupancy 

Mitigating IAQ Problems 99 

Remodeling may involve 

many activities that can 

cause IAQ problems. 

Ventilation modifications 

can be used to isolate the 

work area and prevent 

pollutant build-up in 

occupied spaces. Proper 

storage practices can 

minimize the release of 

contaminants. 
Problem # 14: 

Combustion Gases 

Combustion odors can indicate the 

existence of a serious problem. One 

combustion product, carbon monoxide, is 

an odorless gas. Carbon monoxide 

poisoning can be life-threatening. 

Air intakes are frequently located near 

the loading dock for aesthetic reasons. 

Unfortunately, this air intake placement 

can draw car and truck exhaust into the 

building, causing a variety of indoor air 

quality complaints. 

100 Section 7 

Examples 

Vehicle exhaust 

• offices above (or connected to) an 

underground parking garage 

• rooms near (or connected by pathways 

to) a loading dock or service garage 

Combustion gases from equipment 

(e.g., spillage from inadequately vented 

appliances, cracked heat exchanger, reentrainment because local chimney is too 

low) 

• areas near a mechanical room 

• distributed throughout zone or entire 

building 

Solutions 

Seal to remove pollutant pathway 

• close openings between the contaminant 

source and the occupied space 

• install well-sealed doors with automatic 

closers between the contaminant source 

and the occupied space 

Remove source 

• improve maintenance of combustion 

equipment 

• modify venting or HV AC system to 

prevent backdrafting 

• relocate holding area for vehicles at 

loading dock, parking area 

• tum off engines of vehicles that are 

waiting to be unloaded 

Modify ventilation system 

• install local exhaust in underground 

parking garage (adjust HV AC system to 

provide make-up air and test to verify 

performance) 

• relocate fresh air intake (move away 

from source of contaminants) 

• elevate chimney exhaust outlet 

Modify pressure relationships 

• pressurize spaces around area containing 

source of combustion gases 
Problem # 15: 

Serious Building-Related 

Illness 

Some building-related illnesses can be lifethreatening. E:ven a single confirmed 

diagnosis (which involves results from 

specific medical tests) should provoke an 

immediate and vigorous response. 

Examples 

Legionnaire's disease 

(Note: If you suspect Legionnaire's 

disease, call the local public health 

department, check for obvious problem 

sites, and take ~orrective action. There is 

no way to be certain that a single case of 

this disease is associated with building 

occupancy; therefore, public health 

agencies usually do not investigate single 

cases. Watch for new cases.) 

Hypersensitivity pneumonitis 

(Note: Affected occupant(s) should be 

removed and may not be able to return 

unless the causative agent is removed from 

the affected person's environment.) 

Solutions 

Work with public health authorities 

• evacuation may be recommended or 

required 

Remove source 

• drain, clean, and decontaminate drip 

pans, cooling towers, room unit air 

conditioners, humidifiers, dehumidifiers, 

and other habitats of Legionella, fungi, 

and other organisms using appropriate 

protective equipment 

• install drip pans that drain properly 

• provide access to all the items that must· 

be cleaned, drained, or replaced periodically 

• modify schedule and procedures for 

improved maintenance 

Discontinue processes that deposit 

potentially contaminated moisture in air 

distribution system 

• air washing 

• humidification 

• cease nighttime shutdown of air handlers 

Mitigating IAQ Problems 101 

This air intake is located 

between the cooling 

towers. If the water in the 

cooling towers becomes 

contaminated with 

Legionella, there is 

potential for Legionnaire's 

disease in the building. 
The most economical 

and successful 

solutions to IAQ 

problems are those 

in which the operating principle of the 

correction strategy 

makes sense and is 

suited to the problem. 

JUDGING PROPOSED 

MITIGATION DESIGNS 

AND THEIR SUCESS 

Mitigation efforts should be evaluated at 

the planning stage by considering the 

following criteria: 

• permanence 

• operating principle 

• degree to which the strategy fits the job 

• ability to institutionalize the solution 

• durability 

• installation and operating costs 

• conformity with codes 

Permanence 

Mitigation efforts that create permanent 

solutions to indoor air problems are clearly 

superior to those that provide temporary 

solutions (unless the problems are also 

temporary). Opening windows or running 

'air handlers on full outdoor air may be 

suitable mitigation strategies for a temporary problem such as outgassing of volatile 

compounds from new furnishings, but 

would not be good ways to deal with 

emissions from a print shop. A permanent 

solution to microbiological contamination 

involves not only cleaning and disinfection, but also modification of the environment to prevent regrowth. 

Operating Principle 

The most economical and successful 

solutions to IAQ problems are those in 

which the operating principle of the 

correction strategy makes sense and is 

suited to the problem. If a specific point 

source of contaminants has been identified, 

treatment at the source (e.g., by removal, 

sealing, or local exhaust) is almost always 

a more appropriate correction strategy than 

dilution of the contaminant by increased 

general ventilation. If the IAQ problem is 

caused by the introduction of outdoor air 

that contains contaminants, increased 

general ventilation will only make the 

102 Section 7 

situation worse (unless the outdoor air is 

cleaned). 

Degree to Wlhich the Strategy 

Fits the Job 

It is important to make sure that you 

understand the IAQ problem well enough 

to select a correction strategy whose size 

and scope fit the job. If odors from a 

special use area such as a kitchen are 

causing complaints in a nearby office, 

increasing the ventilation rate in the office 

may not be a successful approach. The 

mitigation strategy should address the 

entire area affected. 

If mechanical equipment is needed to 

correct the IAQ problem, it must be 

powerful enough to accomplish the task. 

For example, a local exhaust system 

should be strong enough and close enough 

to the source so that none of the contaminant is drawn into nearby returns and 

recirculated. 

Ability to Institutionalize 

the Solution 

A mitigation strategy will be most successful when it is institutionalized as part of 

normal building operations. Solutions that 

do not require exotic equipment are more 

likely to be successful in the long run than 

approaches that involve unfamiliar 

concepts or delicately maintained systems. 

If maintenance or housekeeping procedures or supplies must change as part of 

the mitigation, it may be necessary to plan 

for additional staff training, new inspection 

checklists, or modified purchasing practices. Operating schedules for HV AC 

equipment may also require modification. 

Durability 

IAQ mitigation strategies that are durable 

and low-maintenance are more attractive to 

owners and building staff than approaches 

that require frequent adjustment or 
specialized maintenance skills. New items 

of equipment should be quiet, energyefficient, and durable, so that the operators 

are encouraged to keep them running. 

Installation and Operating Costs 

The approach with the lowest initial cost 

may not be the least expensive over the 

long run. Other economic considerations 

include: energy costs for equipment operation; increased staff time for maintenance; 

differential cost of alternative materials 

and supplies; and higher hourly rates if 

odor-producing activities (e.g., cleaning) 

must be scheduled for unoccupied periods. 

Although these costs will almost certainly 

be less than the cost of letting the problem 

continue, they are more readily identifiable, so an appropriate presentation to 

management may be required. 

Conformity with Codes 

Any modification to building components 

or mechanical systems should be designed 

and installed in keeping with applicable 

frre, electrical, and other building codes. 

Judging the Success of a 

Mitigation Effort 

Two kinds of criteria can be used to judge 

the success of an effort to correct an indoor 

air problem: 

• reduced complaints 

. • measurement .of properties of the indoor 

air (often only of limited usefulness) 

Reduction or elimination of complaints 

appears to be a clear indication of success, 

but that is.not necessarily the case. 

Occupants who see that their concerns are 

being heard may temporarily stop reporting discomfort or health symptoms, even if 

the ac11Ial cause of their complaints has not 

been addressed. Lingering complaints may 

also continue after successful mitigation if 

people have become upset over the 

Locating the.origlnal source of a 

. chemical release or microbiological 

.; groVI/th rruiy only b,e the tip ofthe 

· ig~berg •. Polhrtants often tend to . . . . 

migratethrou~h·a 6uildin~ and collect ~ 

i.n '~.sinksi' jfrqm.whichth~y .can be · ···· · 

~esuspended into the air. For ex- ample~ particles accumulate on • 

horiiontal surfaces that are riot subject 

torf!gular housekeeping; odors may 

· .. adsorb~stick)'to'porous material~. . 

·.• .. D~t~~!E;}d surface and/or bulk sampling 

may he needed to locate such "sec~ 

<:lndarv/1 sourcesYn ori:ferto solve an · problem~ · · 

In the Elventofsevere contamination,· 

representative air samples should be 

. coll~cted to e~sure t~at k~y indicators 

,.;.have·returnedto background levels · 

an<;tthatth~ space can be safely 

r~o¢cupied. . . . 

Many routine /AQ problems can be 

corrected by a common sense approach 

not requiring special expertise. However, when complex exposure or 

contamination issues are involved, more 

detailed technical assistance may be 

needed for successful remediation. 

Efforts such as those outlined above 

are sometimes needed to deal with 

severe contamination. 

Mitigating IAQ Problems 103 
If you have made 

several unsuccessful 

efforts to control a 

problem, then it may 

be advisable to seek 

outside assistance. 

handling of the problem. Ongoing (but 

reduced) complaints could also indicate 

that there were multiple IAQ problems and 

that one or more problems are still unresolved. 

However, it can be very difficult to use 

measurements of contaminant levels as a 

means of determining whether air quality 

has improved. Concentrations of indoor 

air pollutants typically vary greatly over 

time; further, the specific contaminant 

measured may not be causing the problem. 

If air samples are taken, readings taken 

before and after mitigation should be 

interpreted cautiously. It is important to 

keep the "before" and "after" conditions as 

identical as possible, except for the 

operation of the control strategy. For 

example, the same HV AC operation, 

building occupancy and climatic conditions should apply during both measurement periods. "Worst-case" conditions 

identified during the investigation should 

be used. 

Measurements of airflows, ventilation 

rates, and air distribution patterns are the 

more reliable methods of assessing the 

results of control efforts. Airflow measurements taken during the building 

investigation can identify areas with poor 

ventilation; later they can be used to 

evaluate attempts to improve the ventilation rate, distribution, or direction of flow. 

Studying air distribution patterns will show 

whether a mitigation strategy has successfully prevented a contaminant from being 

transported by airflow. 

Persistent Problems 

Solving an indoor air quality problem is a 

cyclical process of data collection and 

104 Section 7 

hypothesis testing. Deeper and more 

detailed investigation is needed to suggest 

new hypotheses after any unsuccessful or 

partially-successful control attempt. 

Even the best-planned investigations 

and mitigation actions may not produce a 

resolution to the problem. You may have 

made a careful investigation, found one or 

more apparent causes for the problem, and 

implemented a control system. Nonetheless, your correction strategy may not have 

caused a noticeable reduction in the 

concentration of the contaminant or 

improvement in ventilation rates or 

efficiency. Worse, the complaints may 

persii!t even though you have been 

successful at improving ventilation and 

controlling all of the contaminants you 

could identify. When you have pursued 

source control options and have increased 

ventilation rates and efficiency to the limits 

of your expertise, you must decide how 

important it is to pursue the problem 

further. 

If you have made several unsuccessful 

efforts to control a problem, then it may be 

advisable to seek outside assistance. The 

problem is probably fairly complex, and it 

may occur only intermittently or cross the 

borders that divide traditional fields of 

knowledge. It is even possible that poor 

indoor air quality is not the actual cause of 

the complaints. Bringing in a new 

perspective at this point can be very 

effective. 

The next section provides guidance on 

hiring professional indoor air quality 

assistance. An interdisciplinary team (such 

as people·with engineering and medical or 

health backgrounds) may be needed to 

solve particularly difficult problems. 
Hiring Professional Assistance to 

Solve an IAQ Problem 

Many IAQ problems are simple to 

resolve when facility staff have been 

educated about the investigation process. 

In other cases, however, a tim.e comes 

when outside assistance is needed. Professional help might be necessary or desirable 

in the following situations, among others: 

• Mistakes or delays could have serious 

consequences (e.g., health hazards, 

liability exposure, regulatory sanctions). 

• Building management feels that an independent investigation would be better 

received or more effectively documented 

than an in-house investigation. 

• Investigation and mitigation efforts by 

facility staff have. not relieved the 

IAQ problem. 

• Preliminary fmdings by staff suggest the 

need for measurements that require 

specialized equipment and training 

beyond in-house capabilities. 

You may be able to fmd help by 

looking in the yellow pages of your 

telephone book (e.g., under "Engineers," 

"Environmental Services," "Laboratories -

Testing," or "Industrial Hygienists"). 

Local or State health or air pollution 

agencies may have lists of flnns offering 

IAQ services in your area. It may also be 

useful to seek out referrals from other 

building management flnns. 

Local, State, or Federal government 

agencies may be able to provide expert 

assistance or direction in solving IAQ 

problems. It is particularly important to 

contact your local or State Health 

Department if you suspect that you have a 

serious building-related illness potentially 

linked to biological contamination in your 

building. 

If available government agencies do not 

have personnel with the appropriate skills 

to assist in solving your IAQ problem, they 

may be able to direct you to flnns in your 

area with experience in indoor air quality 

work. Note that even certifled 

professionals from disciplines closely 

related to IAQ issues (such as industrial 

hygienists, ventilation engineers, and 

toxicologists) may not have the specific 

expertise needed to investigate and resolve 

indoor air problems. Individuals or groups 

that offer services in this evolving field 

should be questioned closely about their 

related experience and their proposed 

approach to your problem. 

As with any hiring process, the better 

you know your own needs, the easier it 

will be to select a flnn or individual to 

service those needs. Finns and individuals 

working in IAQ may come from a variety 

of disciplines. Typically, the skills of , 

IN AC engineers and industrial hygienists 

are useful for this type of investigation, 

although input from other disciplines such 

as chemistry, chemical engineering, 

architecture, microbiology, or medicine 

may also be important. If problems other 

than indoor air quality are involved, 

experts in lighting, acoustic design, interior 

design, psychology, or other flelds may be 

helpful in resolving occupant complaints 

about the indoor environment. 

MAKE SURE THAT THEIR 

APPROACH FITS YOUR NEEDS 

As yo9 prepare to hire professional 

services in the area of indoor air quality, be 

aware it is a developing area of knowledge. 

Most consultants working in the fleld 

received their primary training in other 

areas. A variety of investigative methods 

may be employed, many of which are 

ineffective for resolving any but the most 

As you prepare to hire 

professional services 

in the area of indoor 

air quality, be aware 

that it is a developing 

area of knowledge. 

Hiring Professional Assistance to Solve an IAQ Problem 105 
Diagnostic outcomes 

to avoid Include an 

evaluation that overemphasizes measuring concentrations of 

pollutants and a 

report that links all 

the deficiencies in the 

building to the 

problem without 

considering their 

actual association 

with the complaints. 

obvious situations. Inappropriately designed 

studies may lead to conclusions that are 

either false negative (e.g., falsely concludes that there is no problem associated 

with the building) or false positive (e.g., 

incorrectly attributes the cause to building 

conditions). 

Diagnostic outcomes to avoid include: 

• an evaluation that overemphasizes 

measuring concentrations of pollutants 

and comparing those concentrations to 

numerical standards, and 

• a report that lists a series of major and 

minor building deficiencies and links all 

the deficiencies to the problem without 

considering their actual association with 

the complaints 

Considerable care should be exercised 

when interviewing potential consultants to 

avoid those subscribing to these strategies. 

A qualified IAQ investigator should have 

appropriate experience, demonstrate a 

broad understanding of indoor air quality 

problems and the conditions which can 

lead to them, and use a phased diagnostic 

approach. 

SELECTION CRITERIA 

Most of the criteria used in selecting a 

professional to provide indoor air quality 

services are similar to those used for other 

professionals: 

• company experience in solving similar 

problems, including training and 

experience of the individuals who would 

be responsible for the work 

• quality of interview and proposal 

• company reputation 

• knowledge of local codes and regional 

climate conditions 

• cost 

106 Section 8 

Experience 

An EPA survey of firms providing IAQ 

services found that almost half had been 

providing IAQ diagnostic or mitigation 

services in non-industrial settings for ten or 

fewer years. 

• Ask how much IAQ work and what type 

of IAQ work the finn has done. 

• Have the firm identify the personnel who 

would be responsible for your case, their 

specific experience, and related 

qualifications. Contract only for the 

services of those individuals, or require 

approval for substitutions. 

Quality of Interview and 

Proposal 

Several guidelines may be of assistance in 

hiring IAQ professionals. 

1. Competent professionals will ask 

questions about your situation to see 

whether they feel they can offer services 

that will assist you. 

The causes and potential remedies for 

indoor air quality problems vary greatly. 

A finn needs at least a preliminary 

understanding of the facts about what is 

going on in your building to evaluate if it 

has access to the professional skills 

necessary to address your concerns and to 

make effective use of its personnel from 

the outset. Often a multi-disciplinary team 

of professionals is needed. 

2. The proposal for the investigation 

should emphasize observations rather 

than measurements. 

Section 6 describes the four types of 

information that may need to be gathered 

in an investigation in order to resolve an 

indoor air quality problem: the occupant 

complaints, the HV AC system, pollutant 

pathways, and pollutant sources. There is 

also a discussion of the role of monitoring 
within an investigation. Non-routine 

measurements (such as relatively expensive sampling for VOCs) should not be 

provided without site-specific justification. 

3. The staff responsible for building investigation should have a good understanding of the relationship between IAQ 

and the building structure, mechanical 

systems, and human activities. 

For example, lack ofadequate ventilation is at least a contributing factor in 

many indoor air quality problem situations. 

Evaluating the performance of the ventilation system depends on understanding the 

interaction between the mechanical system 

and the human activity within the building. 

In some cases building investigators 

may have accumulated a breadth of 

knowledge. For example, a mechanical 

engineer and an industrial hygienist see 

buildings differently. However, a 

mechanical engineer with several years of 

experience in IAQ problem investigations 

may have seen enough health-related 

problems to cross the gap; likewise, an 

industrial hygienist with years of 

experience studying problems in an office 

setting may have considerable expertise in 

HV AC and other building mechanical 

systems. 

Either in the proposal or in discussion, 

the consultant should: 

• Describe the goal(s), methodology, and 

sequence of the investigation, the 

information to be obtained, and the 

process of hypothesis development and 

testing, including criteria for decisionmaking about further data-gathering. 

The proposal should include an explanation of the need for any proposed 

measurements. The goal is to reach a 

successful resolution of the complaints, 

not simply to generate data. 

• Identify any elements of the work that 

will require a time commitment from the 

client's own staff, including information 

to be collected by the client. 

• Identify additional tasks (and costs) 

which are part of solving the IAQ 

problem but are outside the scope of the 

contract. Examples might include 

medical examination of complainants, 

laboratory fees, and contractor's fees for 

mitigation work. 

• Describe the schedule, cost, and work 

product(s), such as a written report, 

specifications, and plans for mitigation 

wor:K; supervision of mitigation work; 

and training program for building staff, 

• Discuss communication between the 

IAQ professional and the client: How 

often will the contractor discuss the 

progress of the work with the client? 

Who will be notified of test results and 

other data? Will comri:mnications be in 

writing, by telephone, or face-to-face? 

Will the consultant meet with building 

occupants to collect information? Will 

the consultant meet with occupants to 

discuss fmdings if requested to do so? 

Reputation 

There are no Federal regulations covering 

professional services in the general field of 

indoor air quality, although some disciplines (e.g., engineers, industrial hygienists) whose practitioners work with IAQ 

problems have licensing and certification 

requirements. 

Building owners and managers who 

suspect that they may have a problem with 

a specific pollutant (such as radon, 

asbestos, or lead) may be able to obtain 

assistance from local and State Health 

Departments. Government agencies and 

affected industries have developed training 

programs for contractors who diagnose or 

mitigate problems with these particular 

contaminants. 

Firms should be asked to provide references from clients who have received 

comparable services. In exploring referThe goal of the 

investigative process 

is to reach a successful resolution of the 

complaints, not 

simply to generate 

data. 

Hiring Professional Assistance to Solve an IAQ Problem 107 
ences, it is useful to ask about long-term 

follow-up. After the contract was completed, did the contractor remain in contact 

with the client to ensure that problems did 

not recur? 

Knowledge of Local Codes and 

Regional Climate Conditions 

Familiarity with State and local regulations 

and codes helps to avoid problems during 

mitigation. For example, in making 

changes to the HV AC system, it is 

important to conform to local building 

codes. Heating, cooling, and humidity 

control needs are different in different 

geographic regions, and can affect the 

selection of an appropriate mitigation 

approach. Getting assurances that all firms 

under consideration have this knowledge 

becomes particularly important if it 

becomes necessary to seek expertise 

from outside the local area. 

108 Section 8 

Cost 

It is impossible for this document to give 

specific guidance on the cost of professional services. If projected costs jump 

suddenly during the investigation process, 

the consultants should be a?le to justify 

that added cost. 

The budget will be influenced by a 

number of factors, including: 

• complexity of the problem 

• size and complexity of the building and 

its HV AC system(s) 

• quality and extent of recordkeeping by 

building staff and management 

• type of report or other product required 

• number of meetings required (formal 

presentations can be quite expensive) 

• air sampling (e.g., use of instruments, 

laboratory analysis) if required 
Appendix A: 

Common IAQ Measurements - A General G id 

~e following is a brief introduction to 

making measurements that might be 

needed in the course of developing an IAQ 

profile or investigating an IAQ complaint. 

Emphasis has been placed on the parameters most commonly of interest in nonresearch studies, highlighting the more 

practical methods and noting some 

inappropriate tests to avoid. Most of the 

instruments discussed in this section are 

relatively inexpensive and readily available 

from many local safety supply companies. 

Consult the guidance in Section 6 on pages 

74-77 before determining whether to 

proceed with air sampling. 

OVERVIEW OF SAMPLING 

DEVICES 

Air contaminants of concern in IAQ can be 

measured by one or more of the following 

methods: 

Vacuum Pump: 

A vacuum pump with a known airflow rate 

draws air through collection devices, such 

as a filter (catches airborne particles), a 

sorbent tube (which attracts certain 

chemical vapors to a powder such as 

carbon), or an impinger (bubbles the 

contaminants through a solution in a test 

tube). Tests originated for industrial 

environments typically need to be adjusted 

to a lower detection limit for IAQ work. 

Labs can be asked to report when trace 

levels of an identifiable contaminant are 

present below the limit of quantification 

and detection. 

In adapting an industrial hygiene 

sorbent tube sampling method for IAQ, the 

investigator must consider at least two 

important questions. First: are the 

emissions to be measured from a product's 

S.ELECTING MEASUREMENT DEVICES 

The growing interest in indoor air quality is stimulating the develop- · · 

. ment of inst~uments for IAQ research ~nd building investigations. As 

.~~you evaluate the available measun:linent devices, it may be helpful to 

consider the following criteria: · · 

. Ease of. use 

• • portability 

,:.;li_direct-reading vs. analysis required ·. 

~.ruggedness . . . . . 

'; .• time required for each measurement <:::'1: .. ,~--~ 

' Quality assurance . 

:'·~.··availability of service and customer support 

:··..-maintenance and calibration· requirements 

()utput . ... . ... time~aver~gea vs. instantaneous readings 

; • sensitivity . 

. . Ill compatibility with computer or data logging accessories 

cost.· 

single use only vs. reusable 

·• purchase vs. rental 

: .. ::. 

end use the same as those of concern 

during manufacturing? Second: is it 

necessary to increase the air volume 

sampled? Such an increase may be needed 

to detect the presence of contaminants at 

the low concentrations usually found in 

non~ industrial settings. For example, an 

investigator might have to increase 

sampling time from 30 minutes to 5 hours 

in order to detect a substance at the low 

concentrations found during IAQ investigations. In cases where standard sampling 

methods are changed, qualified industrial 

hygienists and chemists should be consulted to ensure that accuracy and precision remain acceptable. 

Direct-reading Meter: 

Direct-reading meters estimate air concentrations through one of several detection 

Common /AQ Measurements- A General Guide 109 
Above: A smoke tube, which is one type 

of chemical smoke device. Used to observe patterns of air movement and the 

direction (negative or positive) of pressure differences. Below: A micromanometer. Used for measuring pressure 

differentials to learn about airflow. Provides quantitative data, as compared to 

the qualitative information provided by 

chemical smoke. 

11 0 Appendix A 

principles. These may report specific 

chemicals (e.g., C02 by infrared light), 

chemical groups (e.g., certain volatile 

organics by photoionization potential), or 

broad pollutant categories (e.g., all respirable particles by scattered light). Detection limits and averaging time developed 

for industrial use may or may not be appropriate for IAQ. 

Detector tube kit: 

Detector tube kits generally include a hand 

pump that draws a known volume of air 

through a chemically treated tube intended 

to react with certain contaminants. The 

length of color stain resulting in the tube 

correlates to chemical concentration. 

Personal monitoring devices: 

Personal monitoring devices (sometimes 

referred to as "dosimeters") are carried or 

worn by individuals and are used to measure that individual's exposure to particular 

chemical(s). Devices that include a pump 

are called "active" monitors; devices that 

do not include a pump are called "passive" 

monitors. Such devices are currently used 

for research purposes. It is possible that 

sometime in the future they may also be 

helpful in IAQ investigations in public and 

commercial buildings. 

SIMPLE VENTILATION/COMFORT 

INDICATIONS 

Thermal Comfort: Temperature 

and Relative Humidity 

The sense of thermal comfort (or discomfort) results from an interaction between 

temperature, relative humidity, air movement, clothing, activity level, and individual physiology. Temperature and 

relative humidity measurements are 

indicators of thermal comfort. 

Methodology 

Measurements can be made with a simple 

thermometer and sling psychrometer or 

with electronic sensors (e.g., a thermohygrometer). Accuracy of within + or - 1 °F 
is recommended for temperature measurements. For each measurement, time should 

be allowed for the ~eading to stabilize to . 

room conditions. Refer to the specifications for the measuring device; some take 

several minutes to stabilize. Electronic 

relative humidity (RJI) meters must be 

calibrated frequently. 

Indoor relative humidity is influenced 

by outdoor conditions. A single indoor 

measurement may not be a good indication 

of' long-term relative humidity in the build- . 

ing. Programmable recording sensori can 

be used to gain an understanding of temperature or humidity conditions as they 

change over time. · 

Using the Results 

Temperature and humidity directly affect 

thermal comfort. They may also provide 

indirect indications of HV AC condition 

and the potential for al.rborne contamination from biological or organic compounds. There is considerable debate 

among researchers, IAQ professionals, and 

health professionals concerning recommended levels of relative hunndity; however, the humidity levels recommended by 

different organizations generally range 

between 30% and 60% RH. 

Comparison of indoor and outdoor 

temperature and humidity readings taken 

during complaint periods can indicate 

whether thermal discomfort might be due 

to extreme conditions beyond the design 

capacity of HV AC equipment or the building envelope. 

Measure next to thermostats to confirm 

calibration. Measure at the location of 

complaints to evaluate whether or not 

temperature and humidity at that location 

are within the comfort zone (see Figure 6-2 

onpage57. · 

Readings that show large variations 

within the space may indicate a room air 

distribution or mixing problem. Readings 

that are highly variable over time may 

indicate control or balance problems with 

the HV AC systems. 

Tracking Air Movement with 

Chemical Smoke 

Chemical smoke can be helpful in evaluat" 

ing HV AC systems, tracking potential 

contaminant movement, and identifying; 

pre~sure ·differentials. Chemical smoke· 

moves. from areas of higher pressure to 

areas oflower pressure if there is an 

opening between them(e.g., door, utility 

penetration). :&ecause it is heatle~; . 

chemical smoke is extremely se~sitive to· 

air currents. Investigators can learn about 

alrflowpattemsby observing the direction 

and. speed of smoke movement. Puffs of 

smoke reieased at the shell of the building 

(oy doors, windows, or gaps) will indicate 

wheth<?r the HV AC systems are maintain-. 

ing ihteriorspaces under positive pressure 

relative ~o the outdoors. 

Methodology~ 

Chemical smoke is available with various 

dispensing mechanisms, including smoke 

"bottles," "guns," "pencils," or "tubes." 

The dispensers allow smoke to be released 

in controlled quantities and directed at 

specific locations. It is often mo~e 

informative to use a number of small puffs 

of smoke as you niove along an air 

A psychrometer. Used to 

measure dry bulb and wet 

bulb temperatures and to 

determine relative humidity 

based upon a psychometric 

chart. The NIOSH protocol 

for indoor air investigations 

always includes measurement of indoor and outdoor 

relative humidity. There are 

two types of psychrometers: 

aspirated (with a fan} or 

sling (without a fan). 

Common IAQ Measurements-:A General Guide 111 
pathway rather than releasing a large 

amount in a single puff. (Note: Avoid 

direct inhalation of chemical smoke, 

because it can be irritating. Do not release 

smoke directly on smoke detectors.) 

Using the Results 

Smoke released mid-room: Observation 

of a few puffs of smoke released in midroom or mid-cubicle can help to visualize 

air circulation within the space. Dispersal 

of smoke in several seconds suggests good 

air circulation, while smoke that stays 

essentially still for several seconds 

suggests poor circulation. Poor air 

circulation may contribute to sick building 

syndrome complaints or may contribute to 

comfort complaints even if there is 

sufficient overall air exchange. 

Smoke released near diffusers, grilles: 

Puffs of smoke released near HV AC vents 

give a general idea of airflow. (Is it in or 

out? Vigorous? Sluggish? No flow?) 

This is helpful in evaluating the supply and 

return system and determining whether 

ventilation air actually reaches the breathing zone. (For a variable air volume 

system, be sure to take into account how 

the system is designed to modulate. It 

could be on during the test, but off for 

much of the rest of the day.) "Shortcircuiting" occurs when air moves 

relatively directly from supply diffusers to 

return grilles, instead of mixing with room 

air in the breathing zone. When a substantial amount of air short-circuits, occupants 

may not receive adequate supplies of 

outdoor air and source emissions may not 

be diluted sufficiently. 

Carbon Dioxide (C02 ) as an 

Indicator of Ventilation 

C02 is a normal constituent of the atmosphere. Exhaled breath from building 

occupants is an important indoor C02 

source. Indoor C02 concentrations can, 

under some test conditions, provide a good 

112 Appendix A 

indication of the adequacy of ventilation. 

Comparison of peak C02 readings between 

rooms, between air handler zones, and at 

varying heights above the floor, may help 

to identify and diagnose various building 

ventilation deficiencies. 

Methodology 

C02 can be measured with either a directreading meter or a detector tube kit. The 

relative occupancy, air damper settings, 

and weather should be noted for each 

period of C02 testing. 

C02 measurements for ventilation 

should be collected away from any source 

that could directly influence the reading 

(e.g., hold the sampling device away from 

exhaled breath). Individual measurements 

should be short-term. As with many other 

measurements of indoor air conditions, it is 

advisable to take one or more readings in 

"control" locations to serve as baselines for 

comparison. Readings from outdoors and 

from areas in which there are no apparent 

IAQ problems are frequently used as 

controls. Outdoor samples should be taken 

near the outdoor air intake. 

Measurements taken to evaluate the 

adequacy of ventilation should be made 

when concentrations are expected to peak. 

It may be helpful to compare measurements taken at different times of day. If 

the occupant population is fairly stable 

during normal business hours, C02 levels 

will typically rise during the morning, fall 

during the lunch period, then rise again, 

reaching a peak in mid-afternoon. In this 

case, sampling in the mid- to late-afternoon is recommended. Other sampling 

times may be necessary for different 

occupancy schedules. 

Using the Results 

Peak C02 concentrations above 1000 ppm 

in the breathing zone indicate ventilation 

problems. Carbon dioxide concentrations 

below 1000 ppm generally indicate that 

ventilation is adequate to deal with the 
routine products of human occupancy. 

However, there are several reasons not to 

conclude too quickly that a low C02 

reading means no IAQ problem exists. 

Problems can occur in buildings in which 

measured cq, concentrations are below 

1000 ppm. Although C02 readings 

indicate good ventilation, for example, if 

strong contaminant sources are present, 

some sort of source control may be needed 

to prevent IAQ problems. Errors in 

measurement and varying C02 concentrations over ~me can also cause low readings 

that may be misleading. 

Elevated C02 may be due to various 

causes alone or in combination, such as: 

increased occupant population, air exchange rates below ASHRAE guidelines, 

poor aiJ: distribution, and poor air mixing. 

A higher average C02 concentration in the 

general breathing zone (at least two feet 

from exhaled breath) than in the air 

entering return grilles is an indication of 

poor air mixing. Smoke tubes and 

temperature profiles will help to clarify air 

circulation patterns. 

If C02 measurements taken before the 

occupied period begins are higher than 

outdoor readings taken at the same time, 

there may be an operating problem with 

the HV AC system. Potential problems 

include the following: 

• ventilation terminated too early the 

evening before (as compared with the 

occupancy load on the space) 

• combustion by-products from a nearby 

roadway or parking garage are drawn 

into the building 

• a gas-fired heating appliance in the 

building has a cracked heat exchanger 

Outdoor C02 concentrations above 400 

ppm may indicate an outdoor contamination problem from traffic or other combustion sources. Note, however, that detector 

tubes cannot provide accurate measurements of C02 in hot or cold weather. 

Measuring Airflow 

Measurements of airflow allow investigators to estimate the amount of outdoor air 

that is entering the building and to evaluate 

HVAC system operation. ~The most 

appropriate measurement technique 

depends on the characteristics of the 

measurement location. 

Methodology 

Airflow quantities can be calculated by 

measuring the velocity and cross-sectional 

area of the airstream. For example, if air is 

A flow hood. Used to 

measure the total air flow 

(outdoor plus recirculated 

air} from a diffuser. 

Cornmon IAQ Measurements-A General Guide 113 
A vacuum pump with 

attachments for sampling 

with a filter, a sorbent tube, 

and an impinger. Use in a 

non-industrial setting may 

require a larger volume of 

air. Consult with qualified 

industrial hygienists and 

chemists if adapting 

ssmpling methods. 

moving at 100 feet per minute in a 24" x 

12" duct, the airflow is: 

I 00 feet/minute x 2 square feet duct area 

= 200 cubic feet/minute 

Air velocity can be measured with a pitot 

tube or anemometer. Air velocity within 

an airstream is likely to vary considerably. 

For example, it is extremely difficult to 

measure air velocity at supply diffusers 

because of turbulence around the mixing 

vanes. The best estimates of air velocity 

can be achieved by averaging the results of 

a number of measurements. ASTM 

Standard Practice D 3154 provides 

guidance on making such measurements. 

This method is available from ASTM. 

(See Appendix G for ASTM' s address and 

phone number.) The cross-sectional area 

of the airstream is sometimes easy to 

calculate (e.g., in a straight run of rectangular ductwork), but can be very complicated at other locations such as mixing 

boxes or diffusers. 

Flow hoods can be used for direct 

measurement of airflows at locations such 

as grilles, diffusers, and exhaust outlets. 

They are not designed for use in ductwork. 

Using the Results 

Airflow measurements can be used to 

determine whether the HV AC system is 

114 Appendix A 

operating according to design and to 

identify potential problem locations. 

Building investigations often include 

measurements of outdoor air quantities, 

exhaust air quantities, and airflows at 

supply diffusers and return grilles. 

Estimating Outdoor Air 

Quantities 

Outdoor air quantities can be evaluated by 

measuring airflow directly. Investigators 

often estimate the proportion of outdoor air 

quantities using techniques such as thermal 

mass balance (temperature) or C02 

measurements. Estimation of outdoor air 

quantity using temperature measurements 

is referred to as "thermal balance" or 

sometimes "thermal mass balance." 

Thermal Balance: Methodology 

Use of this test requires the following 

conditions: 

1. Airstreams representing return air, 

outdoor air, and mixed air (supply air 

before it has been heated or cooled) are 

accessible for separate measurement. 

Some systems are already equipped with 

an averaging thermometer that is strung 

diagonally across the mixed air chamber; 

the temperature is read out continuously on 

an instrument panel. Some panels read out 

supply, return, outdoor, and/or mixed air 

temperature. 

2. There is at least a several degree 

temperature difference between the 

building interior and the outdoor air. 

3. Total air flow in the air handling system 

can be estimated either by using recent 

balancing reports or pitot tube measurements in ductwork. As an alternative, the 

supply air at each diffuser can be estimated 

(e.g., using a flow measuring hood), and 

the results can be summed to calculate 

total system air flow. 

Temperature measurements can be made 

with a simple thermometer or an electronic 
sensor. Several measurements should be 

taken across each airstream and averaged. 

It is generally easy to obtain a good temperature reading in the outdoor air and 

return airstreams. To obtain a good average temperature reading of the mixed airstream, a large number of measurements 

must be taken upstream of the point at 

which the airstream is heated or cooled. 

This may be difficult or impossible in 

some systems. 

The percentage or quantity of outdoor air 

is calculated using thermal .measurements 

as shown to the right. 

Methodology: Carbon Dioxide 

Measurements 

C02 readings can be taken at supply outlets 

or air handlers to estimate the percentage 

of outdoor air in the supply airstream. The 

percentage or quantity of outdoor air is calculated using C02 measurements·as shown 

to the right. 

Using the Results 

The results of this calculation can be 

compared to the building design specifications, applicable building codes, or 

ventilation recommendations such as 

ASHRAE 62-1989 (see page 136 in 

Appendix B) to see whether underventilation appears to be a problem. 

AIR CONTAMINANT 

CONCENTRATIPNS 

Volatile Organic Compounds 

(VOCs) 

Hundreds of organic (carbon-containing) 

chemicals are found in indoor air at trace 

levels. VOCs may present an IAQ 

problem when individual organics or 

mixtures exceed normal background 

concentrations. 

.ESTIMATING OUTDOOR AIR QUA~TITIES 

'· .. · -'--"-------'----'------'---------'-----__:__ __ Using Thermal Mass Balance 

;;;:::. . T . T . d . Outdoor air (percent)= return a!r- mlxe air x100 

-~~- T return air -T oUtdoor air 

. .. , .. JIVhere: T =temperature (degrees Farenheit) 

Using Carbon Dioxide Measurements . . 

·.. . CS-CR 

Outdoor air (percent)=-- x .100 · · ·· · c ~c 

0 . R 

Where: C5 = ppm C02 in the supply air (if measured in a room), or 

C5 = ppm of C02 in the mixed air (if measured at an air .· handler) . 

· CR = ppm of C02 in the return air 

C0 ::=ppm of C02 in the outdoor air 

. ·(All these concentrations must be measured, not assumed.) 

., .CoJ'lVerting Percent To CFM 

Where:cfm =cubic feet per minute 

· The number used for total airflow may be the air quantity supplied to 

.. a room or zone, the capacity of an air handler, or the total airflow of 

:, theHVAC system. Note: The actual amount of airflow in ari air 

· handler is often different froin the quantity in design documents. 

Methodology: Total Volatile Organic 

Compounds (TVOCs) 

Several direct-reading instruments are 

available that provide a low sensitivity 

"total" reading for different types of 

organics. Such estimates are usually 

presented in parts per million and are 

calculated with the assumption that all 

chemicals detected are the same as the one 

used to calibrate the instrument. A 

photoionization detector is an example of a 

direct-reading instrument used as a 

screening tool for measuring TVOCs. 

A laboratory analysis of a sorbent tube 

can provide an estimate of total solvents in 

Common/AQ Measurements-A General Guide 115 
the air. Although methods in this category 

report "total volatile organic compounds" 

(TVOCs) or "total hydrocarbons" (THC), 

analytical techniques differ in their 

sensitivity to the different types of organics. (For discussion of measurement 

devices and their sensitivity, see Overview 

of Sampling Devices on page 109.) 

Using the Results 

Different measurement methods are useful 

for different purposes, but their results 

should generally not be compared to each 

other. Direct-reading instruments do not 

provide sufficient sensitivity to differentiate normal from problematic mixtures of 

organics. However, instantaneous readouts 

may help to identify "hot spots," sources, 

and pathways. TVOCs or THC determined from sorbent tubes provide more 

accurate average readings, but are unable 

to distinguish peak exposures. A directreading instrument can identify peak 

exposures if they happen to occur during 

the measurement period. 

Methodology: Individual Volatile 

Organic Compounds (VOCs) 

High concentrations of individual volatile 

organic compounds (VOCs) may also 

cause IAQ problems. Individual VOCs 

can be measured in indoor air with a 

moderate degree of sensitivity (i.e., 

measurement in parts per million) through 

adaptations of existing industrial air 

monitoring technology. Examples of 

medium sensitivity testing devices include 

XAD-4 sorbent tubes ( for nicotine), 

charcoal tubes (for solvents), and 

chromosorb tubes (for pesticides). Mter a 

sufficient volume of air is pumped through 

these tubes, they are sent to a lab for 

extraction and analysis by gas 

chromatography. Variations use a passive 

dosimeter (charcoal badge) to collect the 

sample or a portable gas chromatograph 

onsite for direct injection of building air. 

These methods may not be sensitive 

116 Appendix A 

enough to detect many trace level organics 

present in building air; 

High sensitivity techniques have 

recently become available to measure 

"trace organics"- VOCs in the air (i.e. 

measurements in parts per billion.) 

Sampling may involve Tenax and multiple 

sorbent tubes, charcoal tubes, evacuated 

canisters, and other technology. Analysis 

involves gas chromatography followed by 

mass spectroscopy. 

Using the Results 

Guidelines for public health exposure (as 

opposed to occupational exposure) for a 

few VOCs are available in the World 

Health Organization (WHO) Air Quality 

Guidelines for Europe. These guidelines 

address noncarcinogenic and carcinogenic 

effects. Occupational exposure standards 

exist for many other VOCs. No rule-ofthumb safety factor for applying these 

occupational limits to general IAQ is 

currently endorsed by EPA and NIOSH. 

Measurement of trace organics may 

identify the presence of dozens to hundreds 

of trace VOCs whose significance is 

difficult to determine. It may be helpful to 

compare levels in complaint areas to levels 

in outdoor air or non-complaint areas. 

Formaldehyde 

Formaldehyde is a VOC that has been 

studied extensively. Small amounts of 

formaldehyde are present in most indoor 

environments. Itching of the eyes, nose, or 

throat may indicate an elevated concentration. Sampling may be helpful when 

relatively new suspect materials are 

present. 

Methodology 

A number of measurement methods are 

available. Sensitivity and sampling time 

are very important issues in selecting a 

method; however, many methods allow 

detection of concentrations well below 
0.1 ppm (see Using the Results below). 

Measurement of short-term peaks (around 

a two-hour sample time) is ideal for 

evaluating acute irritation. Dosimeters 

may accurately record long-term exposure 

but may miss these peaks. 

Two commonly used methods that are 

generally acceptable for IAQ screening 

involve impmgers and sorbent tubes. 

Other appropriate methods are also 

available. 

Using the Results 

Various guidelines and standards are 

available for formaldehyde exposure. 

Several organizations have adopted 

0.1 ppm as guidance that provides 

reasonable protection against irritational 

effects in the normal population. 

Hypersensitivity reactions may occur at 

lower levels of exposure. Worst-case 

conditions are created by minimum . 

ventilation, maximum temperatures, and. 

high source loadings. 

Biological Contaminants 

Human health can be affected by exposure 

to both living and non-living biological 

contaminants. The term "bioaerosols" 

describes airborne material that is or was 

living, such as mold and bacteria, parts of 

living organisms (e.g., insect body parts), 

and animal feces. 

Testing for biological contaminants 

should generally be limited to: 

• cases where a walkthrough investigation 

or human profile study suggests microbiological involvement 

• cases in which no other pollutant or 

physical condition can account for 

symptoms 

Methodology 

Inspection of building sanitary conditions 

is generally preferred over sampling, 

because direct sampling can produce 

misleading results. Any sampling should 

be accompanied by observations of 

sanitary conditions and a determination as 

to whether any health problems appear 

likely to be related to biological contamination. 

No single technique is effective for 

sampling the many biological contaminants found in indoor environments. A 

variety of specific approaches are used to 

retrieve, enumerate, and identify each kind 

of microorganism from water, surfaces, 

and air. Other specific methods :ire used 

for materials such as feces or insect parts. 

The utility of these techniques depends 

upon their use by professionals who have a 

thorough understanding of the sample site 

and the target organism. 

Where air sampling is desired, several 

approaches are available. The most 

common type of air sampler uses a pump 

to pull air across a nutrient agar, which is 

then incubated. Any bacterial or fungal 

colonies that subsequently grow can be 

counted and identified by a qualified 

microbiologist. Different types of agar and 

incubation temperatures are used to culture 

different types of organisms. Only living 

organisms or spores in the air are counted 

by this method. Settling plates, which are 

simply opened to room air and then 

incubated, are sometimes used to identify 

which bioaerosols are present in different 

A viable impactor. Used to 

sample for biologicals. 

Training is required in order 

to analyze the results. 

Common IAQ Measurements- A General Guide 117 
High-flow indoor particulate 

sampler. Used to measure 

particles 10 microns and 

smaller that are readily 

inhaled. 

locations. The drawbacks to this technique 

are that it does not indicate the quantity of 

bioaerosols present and that only the 

bioaerosols that are heavy enough to fall 

out onto the agar will be recorded. 

Using the Results 

Quantities and types of bioaerosols can 

vary greatly over time in any given 

building, making sampling results difficult 

to interpret. Comparison of relative 

numbers and types between indoors and 

outdoors or between complaint areas and 

background sites can help to establish 

trends; however, no tolerance levels or 

absolute guidelines have been established. 

Low bioaerosol results by themselves are 

not considered proof that a problem does 

not exist, for a variety of reasons: 

• the sampling and identification techniques used may not be suited to the 

type(s) ofbioaerosols that are present 

• biological growth may have been 

inactive during the sampling period 

118 Appendix A 

• the analysis technique used may not 

reveal non-living bioaerosols (e.g., feces, 

animal parts) that can cause health 

reactions 

Airborne Dust 

Particles and fibers suspended in the air 

generally represent a harmless background 

but can become a nuisance or cause serious 

health problems under some conditions. 

Methodology 

A variety of collection and analytical 

techniques are available. Dust can be 

collected by using a pump to draw air 

through a filter. The filter can then be 

weighed (gravimetric analysis) or examined under a microscope. Direct readouts 

of airborne dust are also available (such as 

using meters such as those equipped with a 

"scattered light" detector). 

Using the Results 

IAQ measurements for airborne dust will 

be well below occupational and ambient 

air guidelines except under the most 

extreme conditions. Unusual types or 

elevated amounts of particles or fibers can 

help identify potential exposure problems. 

Combustion Products 

Combustion products are released by 

motor vehicle exhaust, tobacco smoke, and 

other sources, and contain airborne dust 

(see the previous section) along with 

potentially harmful gases such as carbon 

monoxide and nitrogen oxides. 

Methodology 

Direct-reading meters, detector tubes, and 

passive dosimeters are among the techniques most commonly used to measure 

carbon monoxide and nitrogen oxides. 
Using tbe Results 

Comparison with oc:;cupational standards 

will reveal only whether an imminent 

danger exists. Any readings that are 

elevated above outdoor concentrations.or 

background building levels may indicate a 

mixture of potentially irritating combustion 

products, especially if susceptible individuals are exposed. · · 

Other Inorganic Gases 

Although they are not routinely sampled in 

most IAQ studies, a variety of other gases 

may be evaluated where conditions 

warrant. Examples might include ammonia, ozone, and me~cury. 

Methodology 

EPA, NIOSH, and.ASTM references 

should be consulted for specific sampling 

techniques. Detector tubes or impinger 

methods are applicable 1n some cases. 

Using tbe Results 

No generalization·can be applied to this 

diverse group of substances. 

Common IAQ Measurements-A General Guide 119 

Appendix B: 

HVAC Systems and Indoor Air Quality 

This appendix provides information 

about specific HV AC system designs and 

components in relation to indoor air 

quality. It also serves as introductory 

material for building owners and managers 

who may be unfamiliar with the terminology and concepts associated with HV AC 

(heating, ventilating, and air conditioning) 

system design. Further detailed information can be found in ASHRAE manuals 

and guides and in some of the guidance 

developed by other trade and professional 

associations. (See Guidelines of Care 

Developed by Trade Associations in 

Section 5.) Additional information can be 

obtained using Appendix G or through 

discussion with your facility engineer. 

BACKGROUND 

All occupied buildings require a supply of 

outdoor air. Depending on outdoor 

conditions, the air may rteed to be heated 

or cooled before it is distributed into the 

occupied space. As outdoor air is drawn 

into the building, indoor air is exhausted or 

allowed to escape (passive relief), thus 

removing air contaminants. 

The term "HV AC system" is used to 

refer to the equipment that can provide 

heating, cooling, filtered outdoor air, and 

humidity control to maintain comfort 

conditions in a building. Not all HV AC 

systems are designed to accomplish all 

of these functions. Some buildings rely 

only on natural ventilation. Others lack 

mechanical cooling equipment (AC), and 

many function with little or no humidity 

control. The features of the HV AC system 

in a given building will depend on several 

variables, including: 

• age of the design 

• climate 

• building codes in effect at the time of 

the design 

• budget that was available for the project 

• planned use of the building 

• owners' and designers' individual 

preferences 

• subsequent modifications 

HV AC systems range in complexity 

from stand-alone units that serve 

individual rooms to large, centrally 

controlled systems serving multiple zones 

in a building. In large modem office 

buildings with heat gains from lighting, 

people, and equipment, interior spaces 

often require year-round cooling. Rooms 

at the perimeter of the same building (i.e., 

rooms with exterior walls, floors, or roof 

surfaces) may need to be heated and/or 

cooled as hourly or daily outdoor weather 

conditions change. In buildings over one 

story in height, perimeter areas at the lower 

levels also tend to experience the greatest 

uncontrolled air infiltration. 

HV AC Systems and Indoor Air Quality 121 

Working with the electrical 

components of an HVAC 

system involves the risk of 

electrocution and fire. A 

knowledgeable member of 

the building staff should 

oversee the inspection of 

the HVAC controls. 
Some buildings use only natural 

ventilation or exhaust fans to remove odors 

and contaminants. In these buildings, 

thermal discomfort and unacceptable 

indoor air quality are particularly likely 

when occupants keep the windows closed 

because of extreme hot or cold temperatures. Problems related to underventilation 

are also likely when infiltration forces are 

weakest (i.e., during the "swing seasons" 

and summer months). 

Modem public and commercial buildings generally use mechanical ventilation 

systems to introduce outdoor air during the 

occupied mode. Thermal comfort is 

commonly maintained by mechanically 

distributing conditioned (heated or cooled) 

air throughout the building. In some 

designs, air systems are supplemented by 

piping systems that carry steam or water to 

the building perimeter zones. As this 

document is concerned with HV AC 

systems in relation to indoor air quality, 

the remainder of this discussion will focus 

on systems that distribute conditioned air 

to maintain occupant comfort. 

Roles of the HVAC System 

Operator and Facility Manager 

The system operator(s) and facility 

manager(s) (or IAQ manager) are among 

the most significant factors in determining 

whether IAQ problems will occur in a 

properly designed, constructed, and 

commissioned HV AC system. HV AC 

systems require preventive maintenance and 

prompt repairs if they are to operate 

correctly and provide comfortable conditions. The operator(s) must have an 

adequate understanding of the overall 

system design and its limitations. The 

HV AC system capacity and distribution 

characteristics should be evaluated before 

renovations to the building, changes in its 

occupancy, or changes in the use of an area. 

System operators must be able to 

respond appropriately to occupant complaints. For example, if an occupant 

122 Appendix B 

complains that it is too cold or too hot and 

the· observed (measured) conditions are 

outside of the ASHRAE comfort zone, 

then the HV AC system needs to be 

evaluated. Sometimes the problem can be 

relieved by fine tuning or repairing the 

HV AC system, but in some cases the 

system cannot perform as expected, and a 

long-term solution must be investigated. 

. TYPES OF HVAC SYSTEMS 

Single Zone 

A single air handling unit can only serve 

more than one building area if the areas 

served have similar heating, cooling, and 

ventilation requirements, or if the control 

system compensates for differences in 

heating, cooling, and ventilation needs 

among the spaces served. Areas regulated 

by a common control (e.g., a single 

thermostat) are referred to as zones. 

Thermal comfort problems can result if the 

design does not adequately account for 

differences in heating and cooling loads 

between rooms that are in the same zone. 

This can easily occur if: 

• The cooling load in some area(s) within a zone changes due to an increased 

occupant population, increased lighting, 

or the introduction of new heat-producing equipment (e.g., computers, copiers). 

• Areas within a zone have different solar 

exposures. This can produce radiant heat 

gains and losses that, in tum, create 

unevenly distributed heating or cooling 

needs (e.g., as the sun angle changes 

daily and seasonally). 

Multiple Zone 

Multiple zone systems can provide each 

zone with air at a different temperature by 

heating or cooling the airstream in each 

zone. Alternative design strategies involve 

delivering air at a constant temperature 

while varying the volume of airflow, or 

modulating room temperature with a 
supplementary system (e.g., perimeter hot 

water piping). 

Constant Volume 

Constant volume systems, as their name 

suggests, generally deliver a constant 

airflow to each space. Changes in space 

temperatures are made by heating or 

cooling the air or switching the air handling unit on and off, not by modulating 

the volume of air supplied. These systems 

often operate with a fixed minimum 

percentage of outdoor air or with an "air 

economizer" feature (described in the 

Outdoor Air Control discussion that 

follows). 

Variable Air Volume 

Variable air volume systems maintain 

thermal comfort by varying the amount of 

heated or cooled air delivered to each 

space, rather than by changing the air 

temperature. (However, many VA V 

systems also have provisions for resetting 

the temperature of the delivery air on a 

seasonal basis, depending on the severity 

of the weather). Overcooling or 

overheating can.occur within a given zone 

if the system is not adjusted to respond to 

the load. Underventilation frequently 

occurs if the system is not arranged to 

introduce at least a minimum quantity (as 

opposed to percentage) of outdoor air as 

the VA V system throttles back from full 

airflow, or if the system supply air 

temperature is set too low for the loads 

present in the zone. 

BASIC COMPONENTS OF AN 

HVACSYSTEM 

The basic components of an HV AC system 

that delivers conditioned air to maintain 

thermal comfort and indoor air quality are: 

• outdoor air intake 

• mixed-air plenum and outdoor air control 

• air filter 

• heating and cooling coils 

• humidification and/or de-humidification 

equipment 

~~TI~G AND BALANCING . 

~;JV,Io<!~rr' HVAC systems typically use sophisticated, automatic controls 

t;;~fo~sypply the proper amounts of air for heating, cooling, and ventilat1}Too in commercial buildings. Problems during installation, operation, 

i!!t€\!ntJ:lmmce; and servicing of the HVAC system could prevent it from 

~':':'o'perating as designed. Each system should be tested to ensure its 

'if"tnitial and continued performance. In addition to providing acceptable 

~il~rrn~l ~oriditions an(;! veri.tilation air; ii properly adjusted and 

~~afariced system m:in also reduce operating costs and increase 

J;;~qfiipinentlife. . · ··. •. . . . . . . · · 

::;;:~Testing and balancing involves the testing, adjusting, and balanc-

!ilng of HVAC system components so that the entire system provides 

~aj_rflq.ws th(lt a~e in accordance with the design specifications. Typical 

~PH'Ppon.entsar1d sys~em parameters te_sted include: 

~"all ~ll-ppiy, return,'exn.a!lst, and outdoor airflow rates 

;~ control settings andoperation ' 

'· ,d~_mperatur~s · .. · .. . 

f.. 'fan speeds and power consumption 

~.,ITiter or C()llector resistance ·. . 

~~i~The typical test and balance age~~y~r co~tra~tor coordinates with. 

~:tfie.controlcontractorto accomplish three goals: verify and ensure 

[th~.most effectiv:e system operation within the design specifications, 

~.J9:.~nt.:.~fy a~·d correct any problef!ls~ and ensure 1:h'e safety of the . 

UY.s_em. ... . . 

~;,::A,Jest~!l.cl. balance reportshollld provide a complete record ofthe 

1ige5ign, preliminary measurements~ and final test data. The report 

: shouldh1clude any discrepancies between the test data and the 

~<;t,eJ~igf1 specifications, along with re~sons for those discrepancies. To 

~facilitate future performance checks and adjustments, appropriate 

f·r~ccm;l§. §!lo!,!l~:t b~ k!'lpt on all damper positions, equipment capacities, 

t'~o~trol types and locations; control settings and operating logic, 

[~airflow rates, static pressures, fan speeds, and horsepowers; 

~:-T~~ting and balancing of existing building systems should be 

~:pertor:med whenever there is reason to believe the system is not 

fii!Jn~tionjng as designed ()rwhencurrent reco,rds qo not accurately 

s:rE:lflectthe actual operation of the system, The Associated Air Balance 

E':!::o,uncil recommends the following guidelines in determining whether 

f'testing and balancing is required: . 1&7;;;:;.7> , . < , • •.. . . •• . ·.. ·. . . . , .. . •. 

;;,jJI\fh~n. §pace has been renovated or charigedto provide for new 

;t:,;:;:gccupancy. ·. . · . · 

)~n J-iVAC 'equipment has been replaced or modified. · 

'h;;;:. ......... he_n control settings have been readjusted by maintenance or ~:'~:,other personnel. · · · 

,.,,A,fter_th~ air conyeyance system has peen cleaned. 

~~,\1\(h~e~ac_c~rate records are required to conduct an lAO investigation. 

J~~)/,\1'1}~11 t'1e bui!ding owner is unable to ob!ain des.ign documents or 

,;,Tappropnate atr~exchange rates for compliance wtth IAQ standards or 

~;~~ui"~el~~es. • · · · .. . . . .. ·. . . •· . · 

P:S' Because of the diversity ofsystem types and the interrelationship 

k(of system components, effective balancing requires a skilled techni-

~t::i:an yvith the proper experience and instruments. Due to the nature of 

!!!le.work, w!J.ich involves. the detection and remediation of problems, 

~it is recommended that an independent test and balance contractor be 

~~used, and that this contractor report directly to the building owner, 

;:facilitY manager, or IAQ manager~ . .. :~..,. 

HV AC Systems and Indoor Air Quality 123 
FIGURE B-1: Typical HVAC System Components Exhaust Air 

Outdoor 

Air Intake 

Supply Air 

Diffusers 

'-If--Outdoor Air 

Temperature Sensor 

Courtesy of Terry Brennan, 

Cam rod en Associates, 

Oriskany, NY 

.___ __ Mixed Air Stat 

Humidifier Heating Coil 

Cooling Coil and Drip Pan 

Air Handling Unit 

• supply fan 

• ducts 

• terminal device 

• return air system 

• exhaust or relief fans and air outlet 

• self-contained heating or cooling unit 

• control 

• boiler 

• cooling tower 

• water chiller 

The following discussion of these 

components (each of which may occur 

more than once in any total HV AC system) 

emphasizes features that affect indoor air 

quality. It may be helpful to refer to this 

section when using the HV AC Checklists. 

124 Appendix B 

The illustration above shows the 

general relationship between many of 

these components; however, many 

variations are possible. 

Outdoor Air Intake 

Build_ing codes require the introduction of 

outdoor air for ventilation in most buildings. Most non-residential air handlers are 

designed with an outdoor air intake on the 

return side of the ductwork. Outdoor air 

introduced through the air handler can be 

filtered and conditioned (heated or cooled) 

before distribution. Other designs may 

introduce outdoor air through air-to-air 

heat exchangers and operable windows. 
Indoor air quality problems can be 

produced when contaminants enter a 

building with the outdoor air. Rooftop or 

wall-mounted air intakes are sometimes 

located adjacent to or downwind of 

building exhaust outlets or other contaminant sources. Problems can also result if 

debris (e.g., bird droppings) accumulates at 

the intake, obstructing airflow and potentially introducing microbiological contaminants. 

If more air is exhausted than is 

introduced through the outdoor air intake, 

then outdoor air will enter the building at 

any leakage sites in the shell. Indoor air 

quality problems can occur if the leakage 

site is a door to a loading dock, parking 

garage, or some other area associated with 

pollutants. 

Mixed-Air Plenum and Outdoor 

Air Controls 

Outdoor air is mixed with return air (air 

that has already circulated through the 

HV AC system) in the mixed-air plenum of 

an air handling unit. Indoor air quality 

problems frequently result if the outdoor 

air damper is not operating properly (e.g., 

if the system is not designed or adjusted to 

allow the introduction of sufficient outdoor 

air for the current use of the building). The 

amount of outdoor air introduced in the 

occupied mode should be sufficient to 

meet needs for ventilation and exhaust 

make-up. It may be fixed at a constant 

volume or may vary with the outdoor 

temperature. 

When dampers that regulate the flow of 

outdoor air are arranged to modulate, they 

are usually designed to bring in a minimum amount of outdoor air (in the 

occupied mode) under extreme outdoor 

temperature-conditions and to open as 

outdoor temperatures approach the desired 

indoor temperature. Systems that use 

outdoor air for cooling are called "air 

economizer cooling" systems. Air 

economizer systems have a mixed air 

Above: The air intake in the background 

is located too close to the sanitary vents 

(the straight pipes to the left and in the 

center foreground) and the bathroom 

exhaust vent (next to the sanitary vent 

on the right side). Below: The return air 

dampers in this mixed-air plenum are 

open (top), but the outdoor air damper 

(left) is almost completely closed. Complaints in the building indicate that 

underventilation is a problem. 

HV AC Systems and Indoor Air Quality 125 
temperature controller and thermostat 

that are used to blend return air (typically 

at 74 °F} with outdoor air to reach a mixed 

air temperature of 55° to 65°F. (Mixed air 

temperature settings above 65°F may lead 

to the introduction of insufficient quantities of outdoor air for office space use.) 

The mixed air is then further heated or 

cooled for delivery to the occupied spaces. 

Air economizer systems have a sensible 

or enthalpy control that signals the outdoor 

air damper to go to the minimum position 

when it is too warm or humid outdoors. 

Note that economizer cycles which do not 

provide dehumidification may produce 

discomfort even when the indoor temperature is the same as the thermostat setting. 

If outdoor air make-up and exhaust are 

balanced, and the zones served by each air 

handler are separated and well defmed, it is 

possible to estimate the minimum flow of 

outdoor air to each space and compare it to 

ventilation standards such as ASHRAE 62-

1989. Techniques used for this evaluation 

include the direct measurement of the 

Proper air filtration can play an important role in protecting the rest of the 

HVAC system and in maintaining good 

indoor air quality in occupied spaces. 

Air filters should be selected and maintained to provide maximum filtration, 

while not overtaxing the supply fan 

capability or leading to "blow out" situations with no air filtration. Shown above 

are, roll filter (top) and bag, panel and 

pleated filters (below). 

126 Appendix B 

outdoor air at the intake and the calculation 

of the percentage of outdoor air by a 

temperature or C02 balance. Carbon 

dioxide measured in an occupied space is 

also an indicator of ventilation adequacy. 

Some investigators use tracer gases to 

assess ventilation quantities and airflow 

patterns. There are specific methods for 

each of these assessments. See Appendix A 

for more information. 

Many HV AC designs protect the coils 

by closing the outdoor air damper if the 

airstream temperature falls below the 

setpoint of a freezestat. Inadequate 

ventilation can occur if a freezestat trips 

and is not reset, or if the freezestat is set to 

trip at an excessively high temperature. 

Stratification of the cold outdoor air and 

warmer return air in the mixing plenums is 

a common situation, causing nuisance 

tripping of the freezes tat. Unfortunately, 

the remedy often employed to prevent this 

problem is to close the outdoor air damper. 

Obviously, solving the problem in this way 

can quickly lead to inadequate outdoor air 

in occupied parts of the building. 

Air Filters 

Filters are primarHy used to remove 

particles from the air. The type and design 

of a filter determine its efficiency at 

removing particles of a given size and the 

amount of energy needed to pull or push 

air through the fllter. Filters are rated by 

different standards and test methods such 

as dust spot and arrestance which measure 

different aspects of performance. See the 

discussion of ASHRAE Standard 52-76 on 

page 138 of this appendix. 

Low efficiency fllters (ASHRAE Dust 

Spot rating of 10% to 20% or less) are 

often used to keep lint and dust from 

clogging the heating and cooling coils of a 

system. In order to maintain clean air in 

occupied spaces, fllters must also remove 

bacteria, pollens, insects, soot, dust, and 

dirt with an efficiency suited to the use of 

the building. Medium efficiency fllters 

(ASHRAE Dust Spot rating of 30% to 
60%) can provide much better filtration 

than low efficiency filters. To maintain the ,'fi:: 

proper airflow and minimize the amount of 

additional energy required to move air 

through these higher efficiency filters, 

pleated-type extended surface filters are 

recommended. In buildings that are 

designed to be exceptionally clean, the 

designers may specify the equipment to 

utilize both a medium efficiency pre-filter 

and a high efficiency extended surface 

filter (ASHRAE Dust Spot rating of 85% 

to 95%). Some manufacturers recommend 

high efficiency extended surface filters 

(ASHRAE Dust Spot rating of 85%) 

without pre-filters as the most cost 

effective approach to minimizing energy 

consumption and maximizing air quality in 

modem HV AC VA V systems that serve 

office environments. 

Air filters, whatever their design or 

efficiency rating, require regular maintenance (cleaning for some and replacement 

for most). As a filter loads up with 

particles, it becomes more efficient at 

particle removal but increases the pressure 

drop through the system, therefore 

reducing airflow. Filter manufacturers can 

provide information on the pressure drop 

through their products under different 

conditions. Low efficiency filters, if 

loaded to excess, will become deformed. 

and even "blow out" of their filter rack. 

When filters blow out, bypassing of 

unfiltered air can lead to clogged coils and 

dirty ducts. Filtration efficiency can be 

seriously reduced if the filter cells are not 

properly sealed to prevent air from 

bypassing. 

Filters should be selected for their 

ability to protect both the HV AC system 

components and general indoor air quality. 

In many buildings, the best choice is a 

medium efficiency, pleated filter because 

these filters have a higher removal 

efficiency than low efficiency filters, yet 

they will last without clogging for longer 

than high efficiency filters. 

Choice of an appropriate filter and 

proper maintenance are important to 

keeping the ductwork clean. If dirt 

accumulates in ductwork and if the relative 

humidity reaches the dewpoint (so that 

condensation occurs), then the nutrients 

and moisture may support the growth of 

microbiologicals. Attention to air filters is 

particularly important in HV AC systems 

with acoustical duct liner, which is 

frequently used in air handler fan housings 

and. supply ducts to reduce sound transmission and provide thermal insulation. Areas 

of duc:t lining that have become contaminated with microbiological growth must be' 

replaced. (See later discussion of ducts 

and duct cleaning.) Sound reduction can 

also be accomplished with the use of 

special duct-mounted devices such as 

attenuators or with active electronic noise 

control.. 

Air handlers that are located in difficultto-access places,( e.g., in places which 

require ladders for access, have inconvenient access doors to unbolt, or are located 

on roofs with no roof hatch access) will be 

HV AC Systems and Indoor Air Quality 127 

Pleated medium efficiency 

filtitt<P are often preferred 

over low efficiency filters 

because they offer added 

protection to both the 

HVAC equipment and to 

indoor air quality, yet they 

do not clog as easily as 

high efficiency filters. 

Medium efficiency filters do 

need routine maintenance, 

however, which the filter in 

this photo did not receive. 
Without proper installation 

and maintenance, rust and 

corrosion may accumulate 

In condensate pans under 

ileating and cooling coils. 

The rust in this pan indicates that it was installed 

without a pitch or was 

pitched in the wrong 

direction, so that water 

did not drain out properly. 

more likely to suffer from poor air filter 

maintenance and overall poor maintenance. Quick release and hinged access 

doors for maintenance are more desirable 

than bolted access panels. 

Filters are available to remove gases 

and volatile organic contaminants from 

ventilation air; howev<?r, these systems are 

not generally used in normal occupancy 

buildings. In specially designed HV AC 

systems, permanganate oxidizers and 

activated charcoal may be used for gaseous 

removal filters. Some manufacturers offer 

"partial bypass" carbon filters and carbon 

impregnated filters to reduce volati~e 

organics in the ventilation air of office 

environments. Gaseous filters must be 

regularly maintained (replaced or regenerated) in order for the system to continue to 

operate effectively. 

128 Appendix B 

Heating and Cooling Coils 

Heating and cooling coils are placed in the 

airstream to regulate the temperature of the 

air delivered to the space. Malfunctions of 

the coil controls can result in thermal 

discomfort. Condensation on underinsulated pipes and leakage in piped 

systems will often create moist conditions 

conducive to the growth of molds, fungus, 

and bacteria. 

During the cooling mode (air conditioning), the cooling coil provides dehumidification as water condenses from the airstream. Dehumidification can only take 

place if the chilled fluid is maintained at a 

cold enough temperature (generally below 

45°F for water). Condensate collects in the 

drain pan under the cooling coil and exits 

via a deep seal trap. Standing water will 

accumulate if the drain pan system has not 

been designed to drain completely under 

all operating conditions (sloped toward the 

drain and properly trapped). Under these 

conditions, molds and bacteria will 

proliferate unless the pan is cleaned 

frequently. 

It is important to verify that condensate 

lines have been properly trapped and are 

charged with liquid. An improperly 

trapped line can be a source of contamination, depending on where the line terminates. A properly installed trap could also 

be a source, if the water in the trap 

evaporates and allows air to flow through 

the trap into the conditioned air. 

During the heating mode, problems can 

occur if the hot water temperature in the 

heating coil has been set too low in art 

attempt to reduce energy consumption. If 

enough outdoor air to provide sufficient 

ventilation is brought in, that air may not 

be heated sufficiently to maintain thermal 

comfort or, in order to adequately condition the outdoor air, the amount of outdoor 

air may be reduced so that there is insufficient outdoor air to meet ventilation needs. 
Humidification and 

Dehumidification Equipment 

fu some buildings (or zones within 

buildings), there are special needs that 

warrant the strict control of humidity (e.g., 

operating rooms, computer rooms). This 

control is most often accomplished by 

adding humidification or dehumidification 

equipment and controls. fu office facilities, it is generally preferable to keep 

relative humidities above 20% or 30% 

during the heating season and below 60% 

during the cooling season. ASHRAE 

Standard 55-1981 provides guidance on 

acceptable temperature and humidity 

conditions. (See also the discussion of 

humidity levels in Section 6.) 

The use of a properly designed and 

operated air conditioning system will 

generally keep relative humidities below 

60% RH during the cooling season, in 

office facilities with normal densities and 

loads. (See the previous discussion of the 

cooling coil.) 

Office buildings in cool climates that 

have high interior heat gains, thermally 

efficient envelopes (e.g., insulation), and 

economizer cooling may require humidification to maintain relative humidity 

within the comfort zone. When humidification is needed, it must be added in a 

manner that prevents the growth of microbiologicals within the ductwork and air 

handlers. 

Steam humidifiers should utilize clean 

steam, rather than treated boiler water, so 

that occupants will not be exposed to 

chemicals. Systems using media other 

than clean steam must be rigorously 

maintained in accordance with the 

manufacturer's recommended procedures 

to reduce the likelihood of microbiological 

growth. 

Mold growth problems are more likely 

if the humidistat setpoint located in the 

occupied space is above 45%. The high 

limit humidistat, typically located in the 

ductwork downstream of the point at 

Above: Occupants of this building 

complained of an intermittent fish tank 

odor. An investigation showed that this 

water spray humidification system is 

regularly maintained. The coils are 

washed roughly every two weeks using 

fresh tap water, eliminating the need for 

any use of algacides. Below: Further 

investigation identified the fact that the 

maintenance practice was causing the 

odor problem. Thispicture.ofthe . 

downstream side of the .coils was taken 

one day after the washing. A high 

pressure stream of water caused algae ' 

in the water to foam and float for several 

dews, coinciding with the occupant 

complaints. 

HV AC Systems and Indoor Air Quality 129 
DUCT LEAKAGE 

Lea~age of air from ducts can cause or exacerbate air quality problems, in addition to wasting energy. In general, sealed duct systems 

specified with a leakage rate of less than 3% will have a superior life 

cycle cost analysis and reduc.e the likelihood of problems associated · with leaky ductwork. Examples of excessive duct leakage leading to ~.problems include: 

llllealiage oflighftroffer.:tYpe. diffuseriafthe~diffu.ser/llght. fixture . ~ ·· fnterfac~ when they are Installed in a return plenum. Such leakage 

has b~~~ ~l)ownt!;) caus.~ gross short-circuiting between supply and 

return, wasting much of the conditioned air. If the "room" t!lermostat fs located in the return plenum, the room can be very uncomfortable while the temperature in the plenum is operating at the . controf setpolnt. · · · . . 

"··leakage of supply ductwork due to\loose~fitii~~:j~ints a~d connec~ tions or "blow outs" of il'Tl.Pr()p,erly fa!:>rica~e.d s7a!TI~. . , 

• leakage of return ducts located in crawl spacesor below slabs, . •flowing soil gases and molds to enter the ductwork 

which water vapor is added, is generally 

set at 70% to avoid condensation (with a 

potential for subsequent mold growth) in 

the ductwork. Adding water vapor to a 

building that was not designed for 

humidification can have a negative impact 

on the building structure and the 

occupants' health, if condensation occurs 

on cold surfaces or in wall or roof cavities. 

Supply Fans 

After passing through the coil section 

where heat is either added or extracted, air 

moves through the supply fan chamber and 

the distribution system. Air distribution 

systems commonly use ducts that are 

constructed to be relatively airtight. 

Elements of the building construction can 

also serve as part of the air distribution 

system (e.g., pressurized supply plenums 

or return air plenums located in the cavity 

space above the ceiling tiles and below the 

deck of the floor above). Proper coordination of fan selection and duct layout during 

the building design and construction phase 

and ongoing maintenance of mechanical 

components, filters, and controls are all 

necessary for effective air delivery. 

130 Appendix B 

Fan performance is expressed as the 

ability to move a given quantity of air 

(cubic feet per minute or cfm) at a given 

resistance or static pressure (measured in 

inches of water column). Airflow in 

ductwork is determined by the size of the 

duct opening, the resistance of the duct 

configuration, and the velocity of the air 

through the duct. The static pressure in a 

system is calculated using factors for duct 

length, speed of air movement and changes 

in the direction of air movement. 

It is common to find some differences 

between the original design and the final 

installation, as ductwork must share 

limited space with structural members and 

other "hidden" elements of the building 

system (e.g., electrical conduit, plumbing 

pipes). Air distribution problems can 

occur, particularly at the end of duct runs, 

if departures from the original design 

increase the friction in the system to a 

point that approaches the limit of fan 

performance. Inappropriate use of long 

runs of flexible ducts with sharp bends also 

causes excessive friction. Poor system 

balancing (adjustment) is another common 

cause of air distribution problems. 

Dampers are used as controls to 

restrict airflow. Damper positions may be 

relatively fixed (e.g., set manually during 

system testing and balancing) or may 

change in response to signals from the 

control system. Fire and smoke dampers 

can be triggered to respond to indicators 

such as high temperatures or signals from 

smoke detectors. If a damper is designed 

to modulate, it should be checked during 

inspections to see that it is at the proper 

setting. ASHRAE and the Associated Air 

Balance Council both provide guidance on 

proper intervals for testing and balancing. 

Ducts 

The same HV AC system that distributes 

conditioned air throughout a building can 

distribute dust and other pollutants, 

including biological contaminants. Dirt or 
dust accumulation on any components of 

an air handling system its cooling coils, 

plenums, ducts, and equipment housingmay lead to contamination of the air 

supply. 

There is widespread agt'eement that 

building owners and managers should take 

gt'eat precautions to prevent dirt, high 

humidity, or moisture from entering the 

ductwork; there is less agt'eement at 

present about when measures to clean up 

are appropriate or how effective cleaning 

techniques are at making long-term 

improvements to the air supply or at 

reducing occupant complaints. 

The presence of dust in ductwork does 

not necessarily indicate a current microbiological problem. A small amount of dust 

on duct surfaces is normal and to be 

expected. Special attention should be 

given to trying to fmd out if ducts are 

contaminated only where specific problems are present, such as: water damage or 

biological gt'OWth observed in ducts, debris 

in ducts that restricts airflow, or dust 

·discharging from supply diffusers. 

Problems with dust and other contamination in the ductwork are a function of 

filtration efficiency, regular HV AC system 

maintenance, the rate of airflow, and good 

housekeeping practices in the occupied 

space. Problems with biological pollutants 

can be prevented by minimizing dust and 

dirt build-up, promptly repairing leaks and 

water damage, preventing moisture 

accumulation in the components that are 

supposed to be dry, and cleaning the 

components such as the drip pans that 

collect and drain water. 

In cases where sheet metal ductwork 

has become damaged or water-soaked, 

building owners will need to undertake 

clean-up or repair procedures. For 

example, in cases where the thermal liner 'j 

or fiberboard has become water-soaked, 

building managers will need to replace the 

affected areas. These procedures should 

be scheduled and performed in a way that 

does not expose building occupants to 

increased levels of pollutants and should 

be carried out by experienced workers. 

Correcting problems that allowed the 

ductwork to become contaminated in the 

first place is important. Otherwise, the 

corrective action will only be temporary. 

The porous surface of fibrous glass duct 

liner presents more surface area (which 

can trap dirt and subsequently collect 

water) than sheet metal ductwork. It is 

therefore particularly important to pay 

attention to the proper design, installation, 

filtration, humidity, and maintenance of 

ducts that contain porous materials. In 

addition, techniques developed for 

cleaning unlined metal ducts often are not 

suitable for use with fibrous glass thermal 

liner or fiberboard. Such ducts may 

require a special type of cleaning to 

maintain the integrity of the duct (i.e., no 

heavy brushing tools that might fray the 

inner lining) while removing dirt and 

debris. 

More research on both the efficacy and 

the potential for unintended exposures to 

building occupants from various cleaning 

techniques is needed before firm guidance 

can be provided regarding duct cleaning. 

Pay attention to worker safety when 

working with air handling systems 

including during duct cleaning. Any 

worker who may potentially breathe duct 

contaminants or biocides should wear 

suitable protective breathing apparatus. 

Workers who are doing the duct cleaning 

should be encouraged to also look for 

other types of problems, such as holes or 

gaps in the ducts that could allow contaminants to enter the ventilation airstream. 

Building managers can obtain more 

information on the issue of HV AC 

contamination and cleaning from the 

professional standards developed by some 

trade associations (See Guidelines of Care 

Developed by Professional and Trade . 

Associations in Section 5 and refer to 

Appendix G for a list of organizations 

with expertise and materials on these 

issues.) 

HVAC Systems and Indoor Air Quality 131 
PRELIMINARY RECOMMENDATIONS ON DUCT CL~A~ING. ' ' \ • ' I '' "' n 

. • 1. Any duct cleaning should be 

scheduled during periods when 

the bultding Is unoccupied to 

·· pt'tfvent exposure to chemicals and 

·loosenfJ(l particles. 

The air handling unit should not be 

used during the cleaning or as an 

air movement device for the 

cleaning process. The National Air 

Duct Cleaning Association recommends that the system should be 

run to allow at least eight air 

changes in the occupied space 

when duct cleaning has been 

completed. 

2. NegatiVlt air pressure that will 

draw pollutants to 11 vacuum 

collection system should be 

~ maintained at 11/l times in the duct 

_ cleanfng artttl to prevent migration 

of dust, dirt, and contaminants 

Into occupied areas. 

. Where possible, use vacuum 

equipment or fans during cleaning 

and sanitizing to make sure that 

cleaning vapors are exhausted to 

the outside and do not enter the 

occupied space. 

3. ff it is determined that the 

ductwork should be cleaned, 

careful attention must be given to 

protecting the ductwork. 

When gaining access to sheet 

metal ducts for cleaning purposes, 

it is essential to seal the ac<;:ess 

hole properly in order to maintain 

the integrity of the HVAC system. 

Access doors are recomm~nded if 

the system is to be cleaned 

periodically, and all access holes 

should be identified on the 

building's mechanical plans. 

Particular attention is warranted 

_ when cutting fibrous glass ducts, 

and manufacturers' recommended 

procedures for sealing should be 

followed stringently. Use existing 

~ duct system openings where 

possible because it is difficult to 

repair the damage caused by 

cutting new access entries into the 

ductwork, Large, high volume 

vacuum equipment should only be 

used with extreme care because high 

negative pressur~ together with 

limited airflow can collapse ducts. 

4. Duct cleaning performed with high 

velocity airflow {i.e., greater than 

6,000 cfm} should include gentle, 

well-controlled brushing of duct 

surfaces or other methods to 

dislodge dust and other particles. 

Duct cleaning that relies only on a 

high velocity airflow through the 

ducts is not likely to achieve satisfactory results because the flow rate at 

the duct surf<,~~e remains.tqo IO)IV ~o 

remove many particles. 

5. Only HEPA filtered {high-efficiency 

particle a"estor) vacuuming equip· 

ment should be used if the vacuum 

collection unit is inside the occupied 

space. 

Conventional vacuuming equipment 

may discharge extremely fine 

particulate matter back into the 

atmosphere, rather than collecting it. 

Duct cleaning equipment that draws 

the dust and dirt into a collection unit 

outside the building is also available. 

People should not be allowed to 

remain in the immediate vicinity of 

these collection units. 

6. If biocides are to be used, then 

select only products registered by 

EPA for such use, use the products 

according to the manufacturer's 

directions, and pay careful attention 

to the method of application. 

At present, EPA accepts claims and 

therefore registers antimicrobials for 

use only as sanitizers, not disinfectants or sterilizers in HVAC systems. 

(See Appendix F for definitions of 

antimicrobials.) There is some 

question about whether there are 

any application techniques that 

will deposit a sufficient amount of 

the biocide to kill bacteria, germs, 

or other biologicals that may be 

present. Materials such as deodorizers that temporarily eliminate odors 

caused by microorganisms provide 

132 Appendix B 

only a fresh smell, and are not 

intended to provide real control of 

microbiological contaminants. 

7. Use of sealants to cover interior 

ductwork surfaces is not recommended. 

No application techniques have 

been demonstrated to provide a 

complete or long-term barrier to 

microbiological growth, nor have 

such materials been evaluated for 

their potential health effects on 

occupants. In addition, using 

sealants alters the surface burning 

characteristics of the duct material 

and may void the fire safety rating _ 

of the ductwork. 

8. Careful cleaning and sanitizing of 

any parts of coils and drip pans can 

reduce microbiological pollutants. 

Prior to using sanitizers, deodorizers, or any cleansing agents, 

carefully read the directions on the 

product label. Once cleaned, these 

components should be thoroughly 

rinsed and dried to prevent exposure of building occupants to the 

cleaning chemicals. 

9. Water-damaged or contaminated 

porous mate•·ials in the ductwork 

or other air handling system 

components .should be removed 

and replaced. 

Even when such materials are 

thoroughly dried, there is no way to 

guarantee that all microbial growth 

has been eliminated. 

10. After the duct system has been 

cleaned and restored to use, a 

preventive maintenance program 

will prevent the recurrence of 

problems. 

Such a program should include 

particular attention to the use and 

maintenance of adequate filters, 

control of moisture in the HVAC 

system, and periodic inspection and 

cleaning of HVAC system components. (See discussion of Preventive Maintenance on page 36 in 

Section 5.) 
Terminal Devices 

Thermal comfort and effective contaminant removal demand that air delivered 

into a conditioned space be properly 

distributed within that space. Terminal 

devices are the supply diffusers, return and 

exhaust grilles, and associated dampers 

and controls that are designed to distribute 

air within a space and collect it from that 

space. The number, design, and location 

(ceiling, wall, floor) of terminal devices 

are very important.· They can cause a 

HV AC system with adequate capacity to 

produce unsatisfactory results, such as 

drafts, odor transport, stagnant areas, or 

short ~circuiting. 

Occupants who are uncomfortable 

because of distribution deficiencies (drafts, 

odor transport, stagnant air, or: uneven 

temperatures) often try to compensate by 

adjusting or blocking the flow of air from 

supply outlets. Adjusting system flows 

without any knowledge of the proper 

design frequently disrupts the proper 

supply of air to adjacent areas. Distribution problems can also be produced if the 

arrangement of movable partitions, 

shelving, or other furnishings interferes 

with airflow. Such problems often occur if 

walls are moved or added without evaluating the expected impact on airflows. 

Return Air Systems 

In many modem buildings the aboveceiling space is utilized for the unducted 

passage of return air. This type of system 

approach often reduces initial HV AC 

system costs, but requires that the designer, 

maintenance personnel, and contractors 

obey strict guidelines related to health and 

safety codes (e.g., building codes) that 

must be followed for materials and devices 

that are located in the plenum. In addition, 

if a ceiling plenum is used for the collection of return air, openings into the ceiling 

plenum created by the removal of ceiling 

tiles will disrupt airflow patterns. It is 

particularly important to maintain the 

integrity of the ceiling and adjacent walls 

in areas that are designed to be exhausted, 

such as supply closets, bathrooms, and 

chemical storage areas. 

After rerum air enters either a ducted 

return air grille or a ceiling plenum, it is 

. returned to the air handlers. Some systems 

utilize return fans in addition to supply 

fans in order to properly control the 

distribution of air. When a supply and 

return fan are utilized, especially in a VA V 

system, their operation must be coordinated in order to prevent under- or overpressurization of the occupied space or 

overpressurization of the mixing plenum in 

the air handler. 

Exhausts, Exhaust Fans, and 

Pressure Relief 

Most buildings are required by law (e.g., 

building or plumbing codes) to provide for 

exhaust of areas where contaminant 

sources are strong, such as toilet facilities, 

janitorial closets, cooking facilities, and 

parking garages. Other areas where 

exhaust is frequently recommended but 

HV AC Systems and Indoor Air Quality 133 

Return air is frequently carried through non-ducted 

plenums. It is more difficult 

to control leakage of pollutants into or out of this type 

of return air system than a 

ducted system. 
may not be legally required include: 

reprographics areas, graphic arts facilities, 

beauty salons, smoking lounges, shops, 

and any area where contaminants are 

known to originate. 

For successful confinement and exhaust 

of identifiable sources, the exhausted area 

must be maintained at a lower overall 

pressure than surrounding areas. Any area 

that is designed to be exhausted must also 

be isolated (disconnected) from the return 

air system so that contaminants are not 

transported to another area of the building. 

In order to exhaust air from the building, make-up air from outdoors must be 

brought into the HV AC system to keep the 

building from being run under negative 

pressure. This make-up air is typically 

drawn in at the mixed air plenum as 

described earlier and distributed within the 

building. For exhaust systems to function 

properly, the make-up air must have a clear 

path to the area that is being exhausted. 

It is useful to compare the total cfm of 

powered exhaust to the minimum quantity 

of mechanically-introduced outdoor air. 

To prevent operating the building under 

negative pressures (and limit the amount of 

unconditioned air brought into the building 

by infiltration), the amount of make-up air 

drawn in at the air handler should always 

be slightly greater than the total amount of 

relief air, exhaust air, and air exfiltrating 

through the building shell. Excess makeup air is generally relieved at an exhaust or 

relief outlet in the HV AC system, especially in air economizer systems. In 

addition to reducing the effects of unwanted infiltration, designing and operating a building at slightly positive or neutral 

pressures will reduce the rate of entry of 

soil gases when the systems are operating. 

For a building to actually operate at a 

slight positive pressure, it must be tightly 

constructed (e.g., specified at less than 

one-half air change per hour at 0.25 

pascals). Otherwise unwanted exfiltration 

will prevent the building from ever 

134 Appendix B 

achieving a neutral or slightly positive 

pressure. 

Self-Contained Units 

In some designs, small decentralized units 

are used to provide cooling or heating to 

interior or perimeter zones. With the 

exception of induction units, units of this 

type seldom supply outdoor air. They are 

typically considered a low priority maintenance item. If self-contained units are 

overlooked during maintenance, it is not 

unusual for them to become a significant 

source of contaminants, especially for the 

occupants located nearby. 

Controls 

HV AC systems can be controlled manually 

or automatically. Most systems are controlled by some combination of manual and 

automatic controls. The control system can 

be used to switch fans on and off, regulate 

the temperature of air within the conditioned 

space, or modulate airflow and pressures by 

controlling fan speed and damper settings. 

Most large buildings use automatic controls, 

and many have very complex and sophisticated systems. Regular maintenance and 

calibration are required to keep controls in 

good operating order. All programmable 

timers and switches should have "battery 

backup" to reset the controls in the event of a 

power failure. 

Local controls such as room thermostats 

must be properly located in order to 

maintain thermal comfort. Problems can 

result from: 

• thermostats located outside of the 

occupied space (e.g., in return plenum) 

• poorly designed temperature control 

zones (e.g., single zones that combine 

areas with very different heating or 

cooling loads) 

• thermostat locations subject to drafts or 

to radiant heat gain or loss (e.g., exposed 

to direct sunlight) 
• thermostat locations affected by heat 

from nearby equipment 

To test whether or not a thermostat is 

functioning properly, try setting it to an 

extreme temperature. This experiment will 

show whether or not the system is responding to the signal in the thermostat, and 

also provides information about how the 

HV AC system may perform under extreme 

conditions. 

Boilers 

Like any other part of the HV AC system, a 

boiler must be adequately maintained to 

operate properly. However, it is particularly important that combustion equipment 

operate properly to avoid hazardous 

conditions such as explosions or carbon 

monoxide leaks, as well as to provide good 

energy efficiency. Codes in most parts of 

.the country require boiler operators to be 

properly trained and licensed. 

Both ASME and ASHRAE have made 

recommendations of how much combustion air is needed for fuel burning appliances. 

Elements of boiler operation that are 

particularly important to indoor air quality 

and thermal comfort include: 

• Operation of the boiler and distribution 

loops at a high enough temperature to 

supply adequate heat in cold weather. 

• Maintenance of gaskets and breeching to 

prevent carbon monoxide from escaping 

into the building. 

• Maintenance of fuel lines to prevent any 

leaks that could emit odors into the 

building. . 

• Provision of adequate outdoor air for 

combustion. 

• Design of the boiler combustion exhaust 

to prevent re-entrainment (especially 

from short boiler stacks or into multistory buildings that were added after the 

boiler plant was installed). 

Modern office buildings tend to have 

much smaller capacity boilers than older 

buildings because of advances in energy 

efficiency. In some buildings, the primary 

heat source is waste heat recovered from 

the chiller (which operates year-round to 

cool the core of the building). 

Cooling Towers 

Maintenance of a cooling tower ensures 

proper operation and keeps the cooling 

tower from becoming. a niche for breeding 

pathogenic bacteria, such as Legionella 

organisms. Cooling tower water quality 

must be properly monitored and chemical 

treatments used as necessary to minimize 

conditions that could support the growth of 

significant amounts of pathogens. Proper 

maintenance may also entail physical 

cleaning (by individuals using proper 

protection) to prevent sediment accumulation and installing drift eliminators. 

HV AC Systems and Indoor Air Quality 135 

It is important to determine 

periodically whether the 

HV~C controls are correctly 

caltbrated. In addition, time 

clocks must be checked to 

see if they are properly set 

and running. Power 

failures frequently caus~ 

time clocks to be out of 

adjustment. 
~, - ···F1Guntfa~2=· s&t~ct&ii"Vfi..a:t'il&1:iCiil' R~co~menil&tio~s 

Application 

: Food aJ~d Beverage :s-...vtco · , , · ., 

; Offices 

Public Spaces 

ltotall Stores, Sales 

floors, Showroom 

Floors 

'Sports and 

Amusement 

Theaters 

Education 

Hotels, Motels, - ltesorts, 

= Dormitories 

Dining rooms 

---- C~fete"fla~ fast food 

_ Bars, cocktaill()unges 

Kitchen (cooking) 

Offtce .space 

Reception areas 

Conference rooms 

Smoking lounge 

Elevators 

· Basement and street 

Upper floors 

Malls and arcades 

- Smoking lounge 

Spectator areas 

Game rooms 

Playing floors 

· BaUrooms and djscos 

.· ·· Lol:l~ies 

:: Auditor.ium 

Classro()m 

···· Music rooms 

Libraries 

Al!ditori1.1ms 

Bedrooms 

Living rooms 

Lobbies 

Conference rooms 

Assembly rooms 

O~upancy 

(people/1000 ft2) 

70 

100 

100 

20 

7 

60 

50 

70 

30 

20 

20 

70 

150 

70 

30 

100 

150 

150 

50 

50 

20 

150 

30 

50 

120 

SOURCE: ASHRAE Standard 62-1989, Ventilation for Acceptable Air Quality 

136 Appendix B 

Cfm/person Cfm/ft2 'I 

20 

~0 

30 

15 

20 

15 

20 

60 

1.00 .I 

I 

0.30 

0.20 

0.20 

60 

15 

25 

20 

25 ~ 

.. I 

~ 

20 

15 

15 

15 

15 

15 

i 'I(' I 30cfm/room 

30cfni/room .. 15 

20 

15 
Water Chillers 

Water chillers are frequently found in large 

building air conditioning systems because 

of the superior performance they offer. A 

water chiller must be maintained in proper 

working condition to perform its function 

of removing the heat from the building. 

Chilled water supply temperatures should 

operate in the range of 45°F or colder in 

order to provide proper moisture removal 

during humid weather. Piping should be 

insulated to prevent condensation. 

Other than thermal comfort, IAQ 

concerns associated with water chillers 

involve potential release of the working 

fluids from the chiller system. The rupture 

disk (safety release) of the system should 

be piped to the outdoors, and refrigerant 

leaks should be located and repaired. 

Waste oils and spent refrigerant should be 

disposed ,0f properly. 

ASHRAE STANDARDS AND 

GUIDELINES 

Standard 62-1989, "Ventilation 

for Acceptable Air Quality" j 

ASHRAE 62-1989 is intended to assist 

professionals in the proper design of 

ventilation systems for buildings. The 

standard presents two procedures for 

ventilation design: a "Ventilation Rate" 

procedure and an "Air Quality" procedure. 

With the Ventilation Rate procedure, 

acceptable air quality is achieved by 

specifying a given quantity and quality of 

outdoor air based upon occupant density 

and space usage. Examples of the tables 

listing the prescrip~ve amounts of outdoor 

air for the Ventilation Rate procedure are 

presented at the end of this section. 

The Air Quality procedure is a performance specification that allows acceptable 

air quality to be achieved within a space by 

controlling for known and specifiable 

contaminants. This procedure is seldom 

used because source strength is usually not 

known. 

Whichever procedure is utilized in the 

design, the standard states that the design 

criteria and assumptions shall be documented and made available to those 

responsible for the operation and maintenance of the system. 

Important features of ASHRAE 62-

1989 include: 

• a definition of acceptable air quality · 

• a discussion of ventilation effectiveness 

• the recommendation of the use of source 

control through isolation and local 

exhaust of contaminants 

• recommendations for the use of heat 

recovery ventilation 

• a guideline for allowable carbon dioxide 

levels 

• appendices listing suggested possible 

guidelines for common indoor pollutants 

Standard 55-1981, ''Thermal 

Environmental Conditions for 

Human Occupancy" 

ASHRAE 55-1981 covers several environmental parameters including: temperature, 

radiation, humidity, and air movement. 

The standard specifies thermal environmental conditions for the comfort of 

healthy people in normal indoor environments for winter and summer conditions. 

It also attempts to introduce limits on the 

temperature variations within a space. In 

addition to specifications for temperature 

and humidity, guidelines are given for air 

movement, temperature cycling, temperature drift, vertical temperature difference, 

radiant asymmetry, and floor temperatures. 

Adjustment factors are described for 

various activity levels of the occupants, 

and different clothing levels. 

Important features of this standard 

include: 

• a definition of acceptable thermal 

comfort 

HV AC Systems and Indoor Air Quality 137 
This air washer is used to 

remove particles and 

water-soluble gaseous 

contaminants and may also 

control temperature and 

humidity in the airstream. 

Such systems are subject 

to severe bacterial 

contamination. 

• a discussion of the additional 

environmental parameters that must 

be considered 

• recommendations for summer and winter 

comfort zones for both temperature and 

·relative humidity 

• a guideline for making adjustment for 

activity levels 

• guidelines for making measurements 

It should be noted that space temperatures above 76°F but within the summer 

comfort envelope have nevertheless been 

associated with IAQ complaints in offices. 

Note: As of summer 1991, a revised 

Standard 55 was nearly ready. 

Standard 52-76, "Method of 

Testing Air-Cleaning Devices 

Used in General Ventilation for 

Removing Particulate Matter" 

This standard is intended to assist professionals in the evaluation of air cleaning 

systems for particle removal. Two test 

methods are described: the weight 

arrestance test and the atmospheric dust 

spot test. The standard discusses differences in results from the weight arrestance 

138 Appendix B 

test and the atmospheric dust spot test. 

The atmospheric dust spot test is the test 

used to determine the "efficiency " of an 

air cleaner. The values obtained with 

these two tests are not comparable. For 

example, a filter with a weight arrestance 

of 90% may have an efficiency by the 

atmospheric dust spot test below 40%. 

The weight arrestance test is generally 

used to evaluate low efficiency filters 

designed to remove the largest and 

heaviest particles; these filters are commonly used in residential furnaces and/or 

air-conditioning systems or as upstream 

filters for other air cleaning devices. For 

the test, a standard synthetic dust is fed 

into the air cleaner and the proportion (by 

weight) of the dust trapped on the filter is 

determined. Because the particles in the 

standard dust are relatively large, the 

weight arrestance test is of limited value in 

assessing the removal of smaller, respirable-size particles from indoor air. 

The atmospheric dust spot test is 

usually used to rate medium efficiency air 

cleaners. The removal rate is based on the 

cleaner's ability to reduce soiling of a 

clean paper target, an ability dependent on 

the cleaner removing very fine particles 

from the air. However, it should be noted 

that this test addresses the overall efficiency of removal of a complex mixture of 

dust, and that removal efficiencies for 

different size particles may vary widely. 

Recent studies by EPA, comparing 

ASHRAE ratings to filter efficiencies for 

particles by size, have shown that efficiencies for particles in the size range of 0.1 to 

1 microgram are much lower than the 

ASHRAE rating. 

Important features of this ASHRAE 

standard include: 

• definitions of arrestance and efficiency 

• establishment of a uniform comparative 

testing procedure for evaluating the 

performance of air cleaning devices used 

in ventilation systems 
• establishment of a uniform reporting 

method, for performance 

• methods for ev~uating resistance to 

airflow and dust-holding capacity 

No comparable guidelines or standards 

are currently available for use in assessing 

the ability of air cleaners to remove gaseous pollutants or radon and its progeny. 

Guideline 1-1989 "Guideline for 

the Commissioning of HVAC 

Systems" 

This guideline is intended to assist professionals by providing procedures and methods for documenting .and verifying the 

performanse of HV AC systems so that 

they operate in conformity with the design 

intent. The guideline presents a format for 

documenting the occupancy requir~ments, 

design assumptions, and the design intent 

for the HV AC system. It provides a format for testing the. system for acceptance 

by the owner. In addition, the guideline 

addresses adjustments of the system to 

meet actual occupancy needs within the 

capacity of the system when changes in 

building use are made and 

recommissioning is warranted. 

Important features of this guideline 

include: 

• defmition of the commissioning pr6cess 

• discussion of the process involved'in a 

proper commissioning procedure 

• sample specification and. forms for logging information 

• recommendation for the implementation 

of corrective measures as warranted 

• guidelines for operator training 

• guidelines for periodic maintenance and 

recommissioning as needed 

HV AC Systems and Indoor Air Quality 139 

Appendix C: 

Moisture, Mold and Mildew 

Molds and mildew are fungi that grow 

on the surfaces of objects, within pores, 

and in deteriorated materials. They can 

cause discoloration and odor problems, 

deteriorate building materials, and lead to 

allergic reactions in susceptible individuals, as well as other health problems. 

The following conditions are necessary 

for mold growth to occur on surfaces: 

• temperature range above 40°F and below 

100°F 

• mold spores 

• nutrient base (most surfaces contain 

nutrients) 

• moisture 

Human comfort constraints limit the use 

of temperature control. Spores are almost 

always present in outdoor and indoor air, 

and almost all commonly used construction materials and furnishings can provide 

nutrients to support mold growth. Dirt on 

surfaces provides additional nutrients. 

Cleaning and disinfecting with nonpolluting cleaners and antimicrobial agents 

provides protection against mold growth. 

Other sections of this document have 

discussed the importance of building 

maintenance and proper sanitation in 

preventing IAQ problems. However, it is 

virtually impossible to eliminate all 

nutrients. Moisture control is thus an 

important strategy for reducing mold 

growth. 

Mold growth does not require the 

presence of standing water; it can occur 

when high relative humidity or the 

hygroscopic properties (the tendency to 

absorb and retain moisture) of building 

surfaces allow sufficient moisture to 

accumulate. Relative humidity and the 

factors that govern it are often. misunderstood. This appendix is intended to give 

building managers an understanding of the 

factors that govern relative humidity, and 

to describe common moisture problems 

and their solutions. 

BACKGROUND ON RELATIVE 

HUMIDITY, VAPOR PRESSURE, 

AND CONDENSATION 

Water enters buildings both as a liquid and 

as a gas (water vapor). Water, in its liquid 

form, is introduced intentionally in 

bathrooms, kitchens, and laundries and 

accidentally by way of leaks and spills. 

Some of that water evaporates and joins 

the water vapor that is exhaled by building 

occupants as they breathe or that is 

introduced by humidifiers. Water vapor 

also moves in and out of the building as 

part of the air that is mechanically introduced or that infiltrates and exfiltrates 

through openings in the building shell. A 

Moisture,MoldandMildew 141 

There were complaints of 

visible water damage and 

musty odors in this senior 

citizen housing complex. 

Investigators confirmed that 

the problem was rain entry 

by using an array of hoses 

to spray the walls with 

water, while operating the 

building under negative 

pressure. The test showed 

that rain was entering at the 

joints of the exterior 

cladding, rather than at 

cracks around windows. 
FIGURE C..1: Moisture Gain in a Building 

Air leakage 

(carrying moisture) 

by door openings and 

thru cracks and crevices 

Diffusion through 

doors, walls, partitions 

Liquid water 

thru cracks 

Internal moisture release 

by people, showers, 

wet clothes and towels 

and then evaporated 

Leakage around 

electric plugs and 

cracks in wall 

Moisture Gain - Leakage + Diffusion + Internal 

Courtesy of Dean Wallace 

Shljkun, Clayton State 

Coltege, Morrow, GA 

lesser amount of water vapor diffuses into 

and out of the building through the 

building materials themselves. Figure C~ 1 

illustrates locations of moisture entry. 

The ability of air to hold water vapor 

decreases as the air temperature is lowered. 

If a unit of air contains half of the water 

vapor it can hold, it is s~d to be at 50% 

relative humidity (RH}. As the air cools, 

the relative humidity increases. If the air 

contains all of the water vapor it can hold, 

it is at 100% RH, and the water vapor 

condenses, changing from a gas to a liquid. 

It is possible to reach 100% RH without 

142 Appendix C 

changing the amount of water vapor in the 

air (its "vapor pressure" or "absolute 

humidity"}; all that is required is for the air 

temperature to drop to the "dew point." 

Relative humidity and temperature 

often vary within a room, while the 

absolute humidity in the room air can 

usually be assumed to be uniform. There~ 

fore, if one side of the room is warm and 

the other side cool, the cool side of the 

room has a higher RH than the warm side. 

The highest RH in a room is always 

next to the coldest surface. This is referred 

as the "first condensing surface," as it will 
FIGURE C-2: Relationship of Temperature. Relative Humidity, and Moisture in the Air 

A relative humidity reading taken in a room will only give an 

accurate indication of the actual amount of moisture present if a 

temperature reading is taken at the same time. The chart below 

shows that air at 700 F and 40% RH contains approximately 

0.006 pounds of mo ts · t ure perpo und of d rv a~r · (as m · d. tea t e db y 

ile air that is at 50° F and 40% RH contains 

03 pounds of moisture per pbf.!nd of dry air . 

the bold line), wh 

approximately 0.0 

(as indicated by th 

the 70° Fair conta 

e dashed line). Although both are at 40%RH, 

ins roughly twice as much moisture .as the 

50°F air. 

/· I 

I I 

I I 

;-.;-"'~ •. I c&7 . ~/·. 

/ / r&'~ 

I 

/ / / 

/ / / ~~. '/ / // 7 . .. 

/1 / / / 

I 

I 

,. / 

"/ 

/ 

/ 

// / ... /"' './ / ?,()o/o~ ·~ 

~ // / / ~ 

Relative 

Humidity~~ 

~~ ~ ~ ~ 

(%RH) ' t::::::-,------ . 

:::.---~--~-- ~------- 1---

Temperature ~oF 40°F ( ° Farenheit) --- 70°F at 40% relative humidity 

- '!'- - 50°F at 40% relative humidity 

SOURCE: Adapted from Psychometric Chart fromASHRAE Fundamentals;1981 

be the location where condensation frrst 

occurs, if the relative humidity at the 

surface reaches 100%. It is important to . 

understand this when trying to understand 

why mold is growing on o.ne patch of wall 

or only along the wall-ceiling joint. It is 

likely that the surface of the wall is cooler 

than the room air because there is a void in 

the insulation or because wind is blowing 

through cracks in the exterior of the 

building. 

TAKING STEPS TO .REDU(:E 

MOISTURE 

Mold and mildew growth can be reduced 

where relative humidities near surfaces can 

be maintained below the dew point. This . 

can be accomplished by reducing the 

moisture content (vapor pressure) of the , 

air, increasing air movement at the surface, 

or increasing the air temperature (either the 

.general space temperature or the temperature atbuilding surfaces). 

Moisture, Mold and Mildew 143 

--~ 

I 

I 

I 

/ 

/ 

v 

---

.030 

.028 

.026 "C 

'ii 

.024 ~ 'C 

.022 0 

;020 

'C 

c 

6 

.018 a. 

.. .016 G) 

a. 

.014 ! 

~ .012 o·- ';10 

.010 

caE 

a::o 

.008 ~~ ·- c 

.006 E~ ~0 

.004 :::t:-9-

.003 

.002 
Above: In this building, mold and 

mildew spots appeared on drywall 

joints on the interior walls. When the 

wall was cut open, mold growth was 

visible in the wall cavity and the 

structural steel showed corrosion. The 

problem was caused by construction 

moisture trapped between the interior 

finish and the exterior sheathing. The 

solution was to modify the exterior wall 

so that moisture could vent to the 

outdoors. Below: This is visual 

evidence of air movement through the 

building shell. The water vapor in the 

warm, humid indoor air has condensed 

and frozen on the exterior wall. 

144 Appendix C 

Either surface temperature or vapor 

pressure can be the dominant factor in 

causing a mold problem .. A surface 

temperature-related mold problem may not 

respond very well to increasing ventilation, 

whereas a vapor pressure-related mold 

problem may not respond well to increasing temperatures. Understanding which 

factor dominates will help in selecting an 

effective control strategy. 

Consider an old, leaky, poorly insulated 

building. It is in a heating climate and 

shows evidence, of mold and mildew. 

Since the building is leaky, its high natural 

air exchange rate dilutes interior airborne 

moisture levels, maintaining a low absolute 

humidity during the heating season. 

Providing mechanical ventilation in this 

building in an attempt to control interior 

mold and mildew probably will not be 

effective in this case. Increasing surface 

temperatures by insulating the exterior 

walls, and thereby reducing relative 

humidities next to the wall surfaces, would 

be a better strategy to control mold and 

mildew. 

Reduction of surface temperaturedominated mold and mildew is best 

accomplished by increasing the surface 

temperature through either or both of the 

following approaches: 

• Increase the temperature of the air near 

room surfaces either by raising the 

thermostat setting or by improving air 

circulation so that supply air is more 

effective at heating the room surface. 

• Decrease the heat loss from room 

surfaces either by adding insulation or by 

closing cracks in the exterior wall to 

prevent wind-washing (air that enters a 

wall at one exterior location and exits 

another exterior location without 

penetrating into the building). 

Vapor pressure-dominated mold and 

mildew can be reduced by one or more of 

the following strategies: 
• source control (e.g., direct venting of 

moisture-generating activities such as 

showers) to the .exterior 

• dilutipn of moisture-laden indoor air 

with outdoor air that is at a lower 

absolute humidity 

• dehumidification 

Note that dilution is only useful as a 

control strategy during heating periods, 

when cold outdoor air tends to contain less 

moisture. During cooling periods, outdoor 

air often contains as much moisture as. 

indoor air. 

IDENTIFYING AND CORRECTING 

COMMON PROBLEMS FROM 

MOLD AND MILDEW 

Exterior Corners 

Exterior comers are common locations for 

mold and mildew growth in heating 

climates, and in poorly insulated buildings 

in cooling climates. They tend to be closer 

to the outdoor temperature than other parts 

of the building surface for one or more of 

the following reasons: 

. • poor air circulation (interior) 

• wind-washing (exterior) 

• low insulation levels 

• greater surface area of heat loss 

Sometimes mold and mildew growth 

can be reduced by removing obstructions 

to airflow (e.g., rearranging furniture). 

Buildings with forced air heating systems 

and/or room ceiling fans tend to have 

fewer mold and mildew problems than 

buildings with less air movement, other 

factors being equal. 

"Set Back" Thermostats 

Set back thermostats are commonly used to 

reduce energy consumption during the 

heating season. Mold and mildew growth 

can occur when building temperatures are 

lowered during unoccupied periods. 

(Maintaining a room at too low a temperature can have the same effect as a set back 

thermostat.) Mold and mildew can often 

~-HOW TO n)ENTIFV THE CAUSE OF A MOLD AND 

' MILDEW PROBLEM .. -- . . . 

Mold and mildew are ~::ommonly found on the exterior wall sui-faces of ·. comer rooms in heating climate locations. An exposed comer room is 

. IIkeiy to be significantly colderthanad}oiriing rooms, so that it has a 

' higher relative humidity (RH) than other rooms at the same water -~v1)por pressure. If-mold and mildew growth are found in a corner · 

. mom, then relative humidities next to the room surfaces are above 

."70%. How:ever, is the RH above 70".4 at the surfaces because the room 

' Js too cold or because there is too much moisture present (high water 

_.vapor pressure)?· _ . · . : . ·. . · . . . . ·. . · 

":·.::.The amo!;lnt ofmoisture in the room g.an.be estimated by measur- . · ihg both temperature andRH at the same location and at the same . . 

:· time .. Suppose there are two cases .. In the first case, assume that the 

. RH is 30% and the temperature is 70°F in the middle ofthe room. The 

:, ,l<>w RH atthat temperature indicat~ thattlle yvatervapor pressure (or · absolute humidity) is low. The high surface RH is probably due to 

.. rOOm surfaces that are "too cold." Temperature is the dominating 

:-·. factor, and control strategies should involve increasing the tempera-

: ture atcold room surfaces. · 

· . ·.In the second case, assume that the Rf-1 is 50% and the temperature 

. is 70°F in the middle ofthe room. The higher RH at that temperature 

indicates thatth~:~ water vapor pressure is high and there is a relatively 

c large amount of moisture il') the air .. The high surface RH is probably 

due to air t!"!at is "too moist." Humidity is the dominating factor, and 

: i:;ontrol strategies should involve decreasing the moisture content of 

the indoor air. · · 

be controlled in heating climate locations 

by increasing interior temperatures during 

heating periods. Unfortunately, this also 

increases energy consumption and reduces 

. relative humidity in the breathing zone, 

which can create discomfort. 

Air Conditioned Spaces 

The problems of mold and mildew can be 

as-extensive in cooling climates as in 

heating climates. The same principles 

apply: either surfaces are too cold, 

moisture levels are too high, or both. 

A common example of mold growth in 

cooling climates can be found in rooms 

where conditioned "cold" air blows against 

the interior surface of an exterior wall. 

This condition, which may be due to poor 

duct design, diffuser location, or diffuser 

performance, creates a cold spot at the 

interior fmish surfaces. A moid problem 

can occur within the wall cavity as outdoor 

air comes in contact with the cavity side of 

the cooled interior surface. It is a particu..: 

lar problem in rooms-decorated with low 

Moisture,MoldandMildew 145. 
maintenance interior finishes (e.g., 

impermeable wall coverings such as vinyl 

wallpaper) which can trap moisture 

between the interior finish and the gypsum 

board. Mold growth can be rampant when 

these interior finishes are coupled with 

cold spots and exterior moisture. 

Possible. solutions for this problem 

include: 

• preventing hot, humid exterior air from 

contacting the cold interior finish (i.e., 

controlling the vapor pressure at the 

surface) 

• eliminating the cold spots (i.e., elevating 

the temperature of the surface) by 

relocating ducts and diffusers 

• ensuring that vapor barriers, facing 

sealants, and insulation are properly 

specified, installed, and maintained 

• increasing the room temperature to avoid 

overcooling 

In this case, increasing temperature 

decreases energy consumption, though it 

could cause comfort problems. 

Thermal Bridges 

Localized cooling of surfaces commonly 

occurs as a result of "thermal bridges," 

elements of the building structure that are 

highly conductive of heat (e.g., steel studs 

in exterior frame walls, uninsulated 

window lintels, and the edges of concrete 

floor slabs). Dust particles sometimes 

mark the locations of thermal bridges, 

because dust tends to adhere to cold spots. 

The use of insulating sheathings 

significantly reduces the impact of thermal 

bridges in building envelopes. 

Windows 

In winter, windows are typically the 

coldest surfaces in a room. The interior 

surface of a window is often the first 

condensing surface in a room. 

Condensation on window surfaces has 

historically been controlled by using storm 

windows or "insulated glass" (e.g., doubleglazed windows or selective surface gasfilled windows) to raise interior surface 

146 Appendix C 

temperatures. The advent of higher 

performance glazing systems has led to a 

greater incidence of moisture problems in 

heating climate building enclosures, 

because the buildings can now be operated 

at higher interior vapor pressures (moisture 

lev~ls) without visible surface condensation on windows. In older building 

enclosures with less advanced glazing 

systems, visible condensation on the 

windows often alerted occupants to the 

need for ventilation to flush out interior 

moisture (so they opened the windows). 

Concealed Condensation 

The use of thermal insulation in wall 

cavities increases interior surface temperatures in heating climates, reducing the 

likelihood of interior surface mold, mildew 

and condensation. However, the use of 

thermal insulation also reduces the heat 

loss from the conditioned space into the 

wall cavities, decreasing the temperature in 

' ' the wall caVities and therefore increasing 

the likelihood of concealed condensation. 

The first condensing surface in a wall 

cavity in a heating climate is typically the 

inner surface of the exterior sheathing, the 

"back side" of plywood or fiberboard. As 

the insulation value is increased in the wall 

cavities, so does the potential for hidden 

condensation. 

Concealed condensation can be controlled by either or both of the following 

strategies: 

• Reducing the entry of moisture into the 

wall cavities (e.g., by controlling 

infiltration and/or exflltration of moisture-laden air); and/or 

• Elevating the temperature of the first 

condensing surface. In heating climate 

locations, this change can be made by 

installing exterior insulation (assuming 

that no significant wind-washing is 

occurring). In cooling climate locations, 

this change an be made by installing 

insulating sheathing to the interior of the 

wall framing and between the wall 

framing and the interior gypsum board. 
Appendix D: Asbestos 

IIA sbestos" describes six naturally 

occurring fibrous minerals found in certain 

types of rock formations. When mined 

and processed, asbestos is typically separated into very thin fibers that are normally 

invisible to the naked eye. They may 

remain in the air for many hours if released from asbestos-containing material 

(ACM) and may be inhaled during this 

time. Three specific diseases - asbestosis 

(a fibrous scarring of the lungs), lung 

cancer, and mesothelioma (a cancer of the 

lining of the chest or abdominal cavity) -

have been linked to asbestos exposure. It 

may be 20 years or more after exposure 

before symptoms of these diseases appear; 

however, high levels of exposure can result in respiratory diseases within a shorter 

period of time. 

Most of the health problems resulting 

from asbestos exposure have been experienced by workers whose jobs exposed 

them to asbestos in the air over a prolonged period withoqt the worker protection that is now required. Asbestos fibers 

can be found nearly everywhere in our 

environment, usually at very low levels. 

While the risk to occupants is likely to be 

small, health concerns remain, particularly 

for the custodial and mai.qtenance workers 

in a building. Their jobs are likely to bring 

them into proximity to ACM, and may 

sometimes require them to disturb the 

ACM in the performance of maintenance 

activities. 

EPA estimates that "friable" (easily 

crumbled) ACM, can be found in an estimated 700,000 public and commercial 

buildings. About 500,000 of those buildings are believed to contain at least some 

damaged asbestos. Significantly damaged 

A.CM is found primarily in building areas 

not genemlly accessible to the public, such 

as boiler and mechanical rooms, where 

asbestos exposures generally would be 

limited to service and maintenance workers. However, if friable ACM is pres6nt in 

air plenums, it can be distributed throughout the building, thereby possibly exposing 

building occupants. 

When is asbestos a problem? Intact and 

undisturbed asbestos materials do not 

pose a health risk. The I!lere presenc~ of 

asbestos in a building does not mean that 

the health of building occupants is endangered. ACM which is in good condition, 

and is not damaged or disturbed, is not 

likely to release asbestos fibers into the air. 

When ACM is properly managed, release 

of asbestos fibers into the air is redqced, 

and the risk of asbestos-related disease is 

thereby correspondingly redqced. 

There are a number of guidelines and 

regulations that govern asbestos exposure. 

Occupational standards for preventing 

asbestos-related diseases are recommended 

by N10SH and promulgated by OSHA. 

N10SH guidance contains Recommended 

Exposure Limits (RELs) and OSHA 

standards set Permissible Exposure Limits 

(PELs). The standards also contain many 

other measures, such as surveillance, 

medical screening, analytical methods, and 

tpethods of control. OSHA regulations 

and the EPA Worker Protection Rule also 

provide guidance on day-to-day activities 

that may bring workers in contact with 

ACM. EPA National Emission St!Wdar4s 

for Hazardous Air Pollutants (NESHAP) 

define acceptable practices for renovation 

and demolition activities that involve asbestos-containing materials. In addition, 

many States have set exposure standards 

and other regulations concerning asbestos. 

Asbestos 147 
OSHA requires that signs 

be posted around areas 

where work is being done 

that involves damaged 

asbestos-containing 

materials. These signs 

must communicate specific 

types of information. 

EPA and NIOSH recommend a practical 

approach that protects public health by 

emphasizing that ACM in buildings should 

be identified and appropriately managed, 

and that those workers who might disturb 

it should be properly trained and protected. 

EPA AND NIOSH 

POSITIONS ON ASBESTOS 

In an effort to calm unwarranted fears that 

a number of people seem to have about the 

mere presence of asbestos in their buildings and to discourage the decisions by 

some building owners to remove all ACM 

regardless of its condition, the EPA Administrator issued an Advisory to the Public on Asbestos in Buildings in 1991. This 

advisory summarized EPA's policies for 

asbestos control in the presentation of the 

following "five facts": 

• Although asbestos is hazardous, the risk 

of asbestos-related disease depends upon 

exposure to airborne asbestos fibers. 

• Based upon available data, the average 

airborne asbestos levels in buildings 

seem to be very low. Accordingly, the 

health risk to most building occupants 

also appears to be very low. 

• Removal is often not a building owner's 

Asbestos 

Cancer and Lung Disease Hazard 

Authorized Personnel Only 

Respirators and Protective 

Clothing Are Required in This Area 

148 Appendix D 

best course of action to reduce asbestos 

exposure. In fact, ari improper removal 

can create a dangerous situation where 

none previously existed. 

• EPA only requires asbestos removal in 

order to prevent significant public exposure to airborne asbestos fibers during 

building demolition or renovation 

activities. 

• EPA does recommend a pro-active, inplace management program whenever 

asbestos-containing material is 

discovered. 

NIOSH's position on asbestos exposure 

has been expressed in NIOSH policy statements and internal reports and at OSHA 

public hearings: 

• NIOSH recommends the goal of eliminating asbestos exposure in the workplace. Where exposures cannot be eliminated, exposures should be limited to the 

lowest concentration possible. 

• NIOSH contends that there is no safe 

airborne fiber concentration for asbestos. 

NIOSH therefore believes that any detectable concentration of asbestos in the 

workplace warrants further evaluation 

and, if necessary, the implementation of 

measures to reduce exposures. 

• NIOSH contends that there is no scientific basis to support differentiating 

health risks between types of asbestos 

fibers for regulatory purposes. 

Copies of the EPA and NIOSH policy 

statements and public advisories are available, respectively, from those agencies. 

See the last section in this appendix and 

Appendix G for information on how to 

obtain them. 
PROGRAMS FOR MANAGING 

ASBESTOS IN-PLACE 

In some CaSes, an asbestos operations and 

maintenance program is more appropriate 

than other asbestos control strategies, including removal. Proper asbestos management is neither to rip it all out in a panic nor 

to ignore the problem under the false presumption that asbestos is "risk free." 

Health concerns remain, particularly for 

custodial and maintenance workers. 

In-place management does not mean "do 

nothing." It means having a program to 

ensure that the day-to-day management of 

the building is carried out in a manner that 

minimizes release of asbestos fibers into the 

air, and that ensures that when asbestos 

fibers are released, either accidentally or 

intentionally, proper control and clean-up 

procedures are implemented. Such a program may be all that is .necessary to control 

the release of asbestos fibers until the asbestos-containing material in a building is 

scheduled to be disturbed by renovation or 

demolition activities. 

The first responsibility of a building 

owner or manager is to identify asbestosconta4ling materials, through a buildingwide inventory or oti. a case-by-case basis, 

before suspect materials are disturbed by 

renovations or other actions. The Asbestos 

Hazard Emergency Response Act 

(AHERA) program requires that in schools 

an inventory of asbestos materials be done 

by properly accredited individuals. Starting 

in late 1991 or 1992, there will also be a 

requirement that if an inventory of asbestos 

materials is done in public and commercial 

buildings, the inventory must be done by 

properly, accredited individuals. In public 

and commercial buildings facing major 

renovations or demolition, inspections for 

the presence of ACM are required, according to the 1990 revision of the EPA Asbestos NESHAP. A carefully designed air 

monitoring program can be used as an adjunct to visual and physical evaluations of 

the asbestos-containing materials. 

After the material is identified, the building management and staff can then institute controls to ensure that the day-to-day 

management of the building is carried out 

in a manner that prevents or minimizes the 

release of asbestos fibers into the air. 

These controls will ensure that when asbestos fibers are released, either accidentally or intentionally, proper management 

and clean-up procedures are implemented. 

Another concern of EPA, NIOSH, and 

other Federal, State, and local agencie~ that 

are concerned wiijl asbestos and public 

health is to ensure proper worker training 

and protection. In the course of their daily 

activities, maintenance and service workers in buildings may disturb materials and 

thereby elevate asbestos fiber levels and 

asbestos exposure, especially for themselves, if they are not properly trained and 

protected. For these persons, risk may be 

significantly higher than for other building 

occupants. Proper worker training and 

protection, as part of an active in-place 

management program, can reduce any 

unnecessary asbestos exposure for these 

workers and others. AHERA requires this 

training for school employees whose job 

activities may result in asbestos disturbances. 

In addition to the steps outlined above, 

an in-place management program will· 

usually include notification to workers and 

occupants of the existence of asbestos in 

their building, periodic surveillance of the 

material, and proper recordkeeping. EPA 

requires all of these activities for schools 

and strongly recommends that other building owners also establish comprehensive 

asbestos management programs. Without 

such programs, asbestos materials could be 

damaged or could deteriorate, which might 

result in elevated levels of airborne asbestos fibers.· While the management costs of 

all the above activities will depend upon 

the amount, condition, and location of the 

materials, such a program need not be 

expensive. 

Asbestos 149 
WHERE TO GO FOR 

ADDITIONAL INFORMATION 

For guidance on asbestos, building owners 

and managers are urged to become familiar 

with two EPA documents: Managing 

Asbestos in Place (published in 1990 and 

also known as the "Green Book") and 

Guidance for Controlling Asbestos-Containing Materials in Buildings (published 

in 1985 and also known as the "Purple 

Book"). 

To obtain copies of the guidance publications and other materials mentioned 

above, or to get additional information on 

technical issues, call or write: 

Environmental Assistance Division 

Office of Toxic Substances 

U.S. EPA (TS-799} 

401 M Street SW 

Washington, DC 20460 

Telephone (TSCA Information Hotline): 

202-554-1404 

150 AppendixD 

National Institute for Occupational 

Safety and Health 

Technical Information Branch 

4676 Columbia Parkway 

Cincinnati, OH 45226 

Telephone: 1-800-35-NIOSH or 

1-800-356-4674 

Contact State air pollution control or health 

agencies for information on pertinent State 

activities and regulations. To fmd an asbestos contact in State agencies, consult 

the EPA Directory of State Indoor Air 

Contacts. For a more complete listing of 

publications concerning asbestos, refer to 

Appendix G. 
Appendix E: Radon 

Radon is·a radioactjve gas.produced by 

the decay of radium. It occurs naturally in 

almost all soil and rock. Radon migrates 

through the soil and groundwater and can 

enter buildings through cracks or other . 

openings in their foundations. ·Radon's 

decay products can cause iung cancer, and 

radon is second only to smoking as a cause 

of lung cancer in America. 

Based on early data, the EPA concen:.. 

trated its radon reduction efforts on one- . . 

and two- family homes. Citing results 

from a radon survey conducted jointly 

with 25 States, the EPA arid the Surgeon 

General's office issued a National Health 

Advisory that called for testing most 

homes for the presence of radon. Ex~ 

tensive research and case studies in the 

field have demonstrated practical remediation methods that typically reduce the 

indoor radon concentrations below 4 pCi/L, 

the current EPA action level for all occu~ 

pied buildings. 

Now that EPA technical guidance is 

being successfully used to reduce human 

health risk in homes, the EPA is emphasizing the development of radon measure~ 

ment, mitigation, and prevention tech~ 

niques for schools and large buildings. 

Preliminary data from a nationwide survey 

of Federal buildings indicates that radon 

will probably not be as widespread a prob~ 

lem in large buildings as it is in homes. 

One of the major factors for this difference 

is that multi-story buildings have proportionally less space in direct contact with 

the earth when compared to homes. 

Some of the control technologies utilized 

for homes are being studied for their appropriateness to other building types, ineluding schools and large buildings. In \ , . . 

addition, new m,ethods and technologies are 

being developed to ensure a practical and 

cost-effective reduction of radon in these 

buildings. As a result, published documents on ~uidance and protocols for measurement and remediation of radon in large 

buildings are not currently available. 

This publication provides an overview of 

radon issues, and should be used only as 

background information. For more information, refer to other sources of information that are specific to radon in indoor air. 

BUILDING MEASUREMENT, 

DIAGNOSIS, AND REMEDIATION 

Protocols specific to the measurement of 

radon and radon progeny in large buildings 

are tentatively scheduled to be published by 

EPA in early 1992. These large building 

measurement protocols can assist skilled 

building owners or facility personnel in 

making initial screening tests for the 

presence of radon. A new protocol specific 

to large buildings is necessary due to the 

major differences in building dynamics, 

HV AC systems, and occupancy patterns 

between large buildings and homes, and 

how these impact radon. 

As part of its effort to develop widespread State and private sector capabilities, 

the EPA established a voluntary proficiency 

program (Radon Measurement Proficiency 

Program) for radon laboratories and commercial measurement firms. A State Proficiency Report (EPA 520/1-91-014), which 

gives information on specific radon measurement frrms in your area, can be obtained from your State radon office or from 

your EPA Regional Office. 

Radon 151 
Three elements must be present for 

radon to be a problem: a radon source, a 

pathway that allows radon to enter the 

building, and a driving force that causes 

the radon to flow through the pathway and 

into the building. Preventing radon from 

entering the building is always desirable 

compared with mitigation after radon has 

entered. The reduction of pathways and 

driving forces are therefore usually the 

focus of attention during diagnostic and 

remediation efforts. 

WHERE TO GO FOR 

ADDITIONAL INFORMATION 

State Radon Offices 

There are several ways to get the name of a 

contact person in your State radon office or 

information about that office. You can call 

the radon contact in the EPA Regional 

Office for your state or you can order the 

Directory of State Indoor Air Contacts 

from the EPA Public Information Center. 

(See list of IAQ and radon contacts and list 

of EPA publications in Appendix G.) 

Regional Radon Training Centers 

As part of its effort to develop State and 

private sector capabilities for radon reduction, the EPA has coordinated the formation of four R.egional Radon Training 

Centers (RRTCs). The RRTCs provide a 

range of radon training and proficiency 

examination courses to the public for a fee. 

Eastern Regional Radon 

Training Center 

Rutgers, The State University 

Livingston Campus, Building 4087 

New Brunswick, NJ 08903-0231 

908-932-2582 

Mid-West Universities 

Radon Consortium 

University of Minnesota 

1985 Buford Avenue (240) 

St. Paul, MN 55108-6136 

612-624-8747 

152 AppendixE 

Due to the diversity and complexity of 

large buildings, and because the research 

and development of appropriate radon 

remediation technologies for these structures are in the early phases, generalized 

building diagnostic and remediation methodologies are not yet available. For assistance, please contact the appropriate organizations on the following list or a professional engineering firm or mitigation company with experience in this matter. 

Western Regional Radon 

Training Center 

Guggenheim Hall 

Colorado State University 

Fort Collins, CO 80523 

1-800-462-7459/303-491-7742 

Southern Regional Radon 

Training Center 

Auburn University 

Housing Research Center 

Harbert Engineeting Center 

Auburn University, AL 36849-5337 

205-844-6261 

EPA Regional Offices 

If you want additional information from 

EPA regarding radon, start with the EPA 

Regional Offices. Telephone numbers 

for radon information contacts are given 

in the list of EPA Regional Offices in 

Appendix G of this publication. 

EPA Radon Division 

If information is unavailable from the 

above sources, please contact the EPA 

Radon Division at: 

Radon Division (ANR-464) 

U.S. EPA 

401 M Street, SW 

Washington, DC 20460 

202-260-9605 
Appendix F: Glossary and Acronyms 

ACGIH- American Conference of 

Governmental Industrial Hygienists. 

ASHRAE American Society of 

Heating, Refrigerating, and Air-Conditioning Engineers. 

ASTM American Society for Testing 

and Materials. 

Air Cleaning-An IAQ control strategy 

to remove various airborne particulates 

and/or gases from the air. The three types 

of air cleaning most commonly used are 

particulate filtration, electrostatic precipitation, and gas sorption. 

Air Exchange Rate-Used in two ways: 

1) the number of times that the outdoor air 

replaces the volume of air in a building per 

unit time, typically expressed as air 

changes per hour, 2) the number of times 

that the ventilation system replaces the air 

within a room or area within the building. 

Antimicrobial- Agent that kills microbial growth. See "disinfectant," "sanitizer," and "sterilizer." 

BRI- See "Building-Related lllness." 

Biological Contaminants- Agents 

derived from or that are living organisms 

(e.g., viruses, bacteria, fungi, andmammal 

and bird antigens) that can be inhaled and 

can cause many types of health effects 

including allergic reactions, respiratory 

disorders, hypersensitivity diseases, and 

infectious diseases. Also referred to as 

"microbiologicals" or "microbials." 

Breathing Zone Area of a room in 

which occupants breathe as they stand, sit, 

or lie down. 

Building Envelope - Elements of the 

building, including all external building 

materials, windows, and walls, that enclose 

the internal space. 

Building-Related Illness Diagnosable 

illness whose symptoms can be identified 

and whose cause can be directly attributed 

to airborne building pollutants (e.g., 

Legionnaire's disease, hypersensitivity 

pneumonitis). 

CFM Cubic feet per minute. 

CO-Carbon monoxide. 

C02 Carbon dioxide. 

Ceiling Plenum- Space below the 

flooring and above the suspended ceiling 

that accommodates the mechanical and 

electrical equipment and that is used as 

part of the air distribution system. The 

space is kept under negative pressure. 

Commissioning - Start-up of a building 

that includes testing and adjusting HV AC, 

electrical, plumbing, and other systems to 

assure proper functioning and adherence to 

design criteria. Commissioning also 

includes the instruction of building 

representatives in the use of the building 

systems. 

Conditioned Air -Air that has been 

heated, cooled, humidified, or dehumidified to maintain an interior space within 

the "comfort zone." (Sometimes referred to 

as "tempered" air.) 

Constant Air Volume System -Air 

handling system that provides a constant 

air flow while varying the temperature to 

meet heating and cooling needs. 

Dampers - Controls that vary airflow 

through an air outlet, inlet, or duct. A 

damper position may be immovable, 

manually adjustable, or part of an automated control system. 

Glossary and Acronyms 153 
Diffusers and Grilles - Components of 

the ventilation system that distribute and 

diffuse air to promote air circulation in the 

occupied space. Diffusers supply air and 

grilles return air. 

Disinfectants -One of three groups ?f · 

antimicrobials registered by EPA for 

public health uses. EPA considers an 

antimicrobial to be a disinfectant when it 

destroys or irreversibly inactivates 

infectious or other undesirable organisms, 

but not necessarily their spores. EPA 

registers three types of disinfectant 

products based upon submitted efficacy 

data: limited, general or broad spectrum, 

and hospital disinfectant. 

EPA- United States Environmental 

Protection Agency. 

ETS -Environmental tobacco smoke. 

Environmental Factors - Conditions 

other than indoor air contaminants that 

cause stress, comfort, and/or health 

problems (e.g., humidity extremes, drafts, 

lack of air circulation, noise, and overcrowding). 

Ergonomics -Applied science that 

investigates the impact of people's 

physical environment on their health and 

comfort (e.g., determining the proper chair 

height for computer operators). 

Exhaust Ventilation- Mechanical 

removal of air from a portion of a building 

(e.g., piece of equipment, room, or general 

area). 

Gas Sorption -Devices used to reduce 

levels of airborne gaseous compounds by 

passing the air through materials that 

extract the gases. The performance of 

solid sorbents is dependent on the airflow 

rate, concentration of the pollutants, 

presence of other gases or vapors, and 

other factors. 

HEPA- High efficiency particulate 

arrestance (fllters). 

HV AC -Heating, ventilation, and airconditioning system. 

154 Appendix F 

Hypersensitivity Diseases - Diseases 

characterized by allergic responses to 

animal antigens. The hypersensitivity 

diseases most clearly associated with 

indoor air quality are asthma, rhinitis, and 

hypersensitivity pneumonitis. Hypersensitivity pneumonitis is a rare but serious 

disease that involves progressive lung 

damage as long as there is exposure to the 

causative agent. 

IAQ-Indoor air quality. 

IPM -Integrated pest management. 

Indicator Compounds - Chemical 

compounds, such as carbon dioxide, whose 

presence at certain concentrations may be 

used to estimate certain building conditions (e.g., airflow, presence of sources). 

MCS -See "Multiple Chemical Sensitivity." 

MSDS -Material Safety Data Sheet. 

Make-up Air -Air brought into a 

building from outdoors through the 

ventilation system and that has not been 

previously circulated through the system. 

Microbiologicals - See "Biological 

Contaminants." 

Multiple Chemical Sensitivity -A term 

used by some people to refer to a condition 

in which a person is considered to be 

sensitive to a number of chemicals at very 

low concentrations. There are a number of 

views about the existence, potential causes, 

and possible remedial actions regarding 

this phenomenon. 

NIOSH- National Institute for Occupational Safety and Health. 

NTIS -National Technical Information 

Service. 

Negative Pressure - Condition that 

exists when less air is supplied to a space 

than is exhausted from the space, so the air 

pressure within that space is less than that 

in surrounding areas. 

OSHA - Occupational Safety and Health 

Administration. 
PELs- Permissible Exposure Limits 

(standards set by OSHA). 

PM- Preventive Maintenance. 

Plenum-Air compartment connected to 

a duct or ducts. 

Positive Pressure - Condition that exists 

when more air is supplied to a space than 

is exhausted, so the air pressure within that 

space is greater than that in surrounding 

areas. 

Psychosocial Factors- Psychological, 

organizational, and personal stressors that 

could produce symptoms similar to poor 

indoor air quality. 

RELs Recommended Exposure Limits 

(recommendations made by NIOSH). 

Radiant Heat Transfer-Radiant heat 

transfer occurs wheri there is a large differ~ 

ence between the temperatures of two 

surfaces that are exposed to each other, but 

~e not touching. 

Re-entrainment --Situation that occurs 

when the air being exhausted from a build~ 

ing is immediately brought back into the 

system through the air intake and other 

openings in the building envelope. 

SBS - See "Sick Building Syndrome." 

Sanitizer One of three groups of antimicrobials registered by EPA for public 

health uses. EPA considers an antimicrobial to be a sanitizer when it reduces but 

does not necessarily eliminate all the microorganisms on a treated surface. To be a 

registered sanitizer, the test results for a 

product must show a reduction of at least 

99.9% in the number of each test microorgan~sm over the parallel control. 

Short-circuiting- Situation that occurs 

when the supply air flows to exhaust registers before entering the breathing zone. To 

avoid short~circuiting, the supply air must 

be delivered at a temperature and velocity 

that results in mixing throughout the space. 

Sick Building Syndrome -Term sometime~ used to describe situations in which 

building occupants experience acute health 

and/or comfort effects that appear to be 

linked to time spent in a particular building, but where no specific illness or cause 

can be identified. The complaints may be 

localized in a particular room or zone, or 

may be spread throughout the building. 

Soil Gases -Gases that enter a building 

from the surrounding ground (e.g., radon, 

volatile organics, pesticides). 

Stack Effect -Pressure-driven airflow 

produced by convection as heated air rises, 

creating a positive pressure area at the top 

of a building and a negative pressure area· 

at the bottom of a building. The stack 

effect can overpower the mechanical system and disrupt ventilation and circulation 

in a building. 

Static Pressure- Condition that exists 

when an equal amount of air is supplied to 

and exhausted from a space. At static 

pressure, equilibrium has been reached. . 

Sterilizer One of three groups of anti- ·· 

microbials registered by EPA for public 

health uses. EPA considers an antimicrobial to be a sterilizer when it destroys or 

eliminates all forms of bacteria, fungi, . 

viruses, and their spores. Because spores 

are considered the most difficult form of a 

microorganism to destroy, EPA considers 

the term sporicide to be synonymous with 

"sterilizer." 

TLVs Threshold Limit Values (guide~ 

lines recommended by ACGIH). 

TVOCs Total volatile organic compounds. 

Tracer Gases- Compounds, such as 

sulfur hexafluoride, which are used to 

identify suspected pollutant pathways and 

to quantify ventilation rates. Tracer gases 

may be detected qualitatively by their odor 

or quantitatively by air monitoring equip-. 

ment. 

VA V Variable air volume system. 

VOCs See "Volatile Organic Compounds." 

Glossary and Acronyms 155 
Variable Air Volume System- Air 

handling system that conditions the air to a 

constant temperature and varies the outside 

airflow to ensure thermal comfort. 

Ventilation Air- Defined as the total air, 

which is a combination of the air brought 

into the system from the outdoors and the 

air that is being recirculated within the 

building. Sometimes, however, used in 

reference only to the air brought into the 

system from the outdoors. 

Volatile Organic Compounds (VOCs) 

Compounds that evaporate from the many 

housekeeping, maintenance, and building 

156 Appendix F 

products made with organic chemicals. 

These compounds are released from 

products that are being used and that are in 

storage. In sufficient quantities, VOCs can 

cause eye, nose, and throat irritations, 

headaches, dizziness, visual disorders, 

memory impairment; some are known to 

cause cancer in animals; some are suspected of causing, or are known to cause, 

cancer in humans. At present, not much is 

known about what health effects occur at 

the levels of VOCs typically found in 

public and commercial buildings. 

WHO World Health Organization. 
Appendix G: Resources 

FEDERAL AGENCIES WITH 

MAJOR INDOOR AIR 

RESPONSIBILITY FOR PUBLIC 

AND COMMERCIAL BUILDINGS 

U.S. Environmental 

Protection Agency 

Conducts a non-regulatory indoor air 

quality program that emphasizes research, 

information dissemination, technical 

guidance, and training. Issues regulations 

and carries out other activities that affect 

indoor air quality under the laws for 

pesticides, toxic substances, and drinking 

water. 

Public Information Center 

(PM-211B) 

401 M Street, SW 

Washington, DC 20460 

202-260-2080 

Distributes indoor air quality 

publications. 

National Pesticides Telecommunications 

Network National toll-free number: 

1-800-858-PEST 

In Texas: 806-743-3091 

Provides information on pesticides. 

TSCA Hotline Service 

202-554-1404 

Provides information on asbestos and 

other toxic substances. 

Occupational Safety and Health 

Administration 

Promulgates safety and health standards, 

facilitates training and consultation, and 

enforces regulations to ensure that 

workers are provided with safe and 

healthfulworking conditions. (For further 

information contact OSHA Regional 

Offices.) 

National Institute for 

Occupational Safety and Health 

Conducts research, recommends standards 

to the U.S. Department of Labor, and 

conducts training on various issues 

including indoor air quality to promote 

safe and healthful workplaces. Undertakes 

investigations at request of employees, 

employers, other federal agencies, and 

state and local agencies to identify and 

mitigate workplace problems. 

Requests for Field Investigations 

NIOSH 

Hazard Evaluations and Technical 

Assistance Branch (R-9) 

4676 Columbia Parkway 

Cincinnati, OH 45226 

513-841-4382 

Requests for Information: 

1-800-35-NIOSH 

or 1-800-356-4674 

Resources 157 
EPA Regional Offices 

Address inquiries to the contacts in the 

EPA Regional Offices at the following 

addresses: 

(CT,ME,MA,NH,RI,VT) 

EPA Region 1 

John F. Kennedy Federal Building 

Boston, MA 02203 

617-565-3232 (indoor air) 

617-565-4502 (radon) 

617-565-3744 (asbestos) 

617-565-3265 (NESHAP) 

(NJ,NY,PR,VI) 

EPARegion2 

26 Federal Plaza 

New York, NY 10278 

212-264-4410 (indoor air) 

212-264-4410 (radon) 

212-264-6671 (asbestos) 

212-264-6770 (NESHAP) 

(DE,DC,MD,PA,VA,WV) 

EPARegion3 

841 Chestnut Building 

Philadelphia, PA 19107 

215-597-8322 (indoor air) 

215-597-4084 (radon) 

215-597-3160 (asbestos) 

215-597-1970 (NESHAP) 

(AL,FL,GA,KY,MS,NC,SC, TN) 

EPARegion4 

345 Courtland Street, NE 

Atlanta, GA 30365 

404-347-2864 (indoor air) 

404-347-3907 (radon) 

404-347-5014 (asbestos) 

404-347-5014 (NESHAP) 

(IL,IN,MI,MN,OH, WI) 

EPARegion5 

230 South Dearborn Street 

Chicago, IL 60604 

Region 5 Environmental Hotline: 

1-800-572-2515 (IL) 

1-800-621-8431 (IN, MI, MN, OH, WI) 

312-886-7930 (outside Region 5) 

158 Appendix G 

(AR,LA,NM,OK,TX) 

EPARegion6 

1445 Ross Avenue 

Dallas, TX 75202-2733 

214-655-7223 (indoor air) 

214-655-7223 (radon) 

214-655-7223 (asbestos) 

214-655-7223 (NESHAP) 

(IA,KS,MO,NE) 

EPA Region 7 

726 Minnesota Avenue 

Kansas City, KS 66101 

913-551-7020 (indoor air) 

913-551-7020 (radon) 

913-551-7020 (asbestos) 

913-551-7020 (NESHAP) 

(CO,MT ,ND,SD,UT,WY) 

EPA RegionS 

999 18th Street Suite 500 

Denver, CO 80202-2405 

303-293-1440 (indoor air) 

303-293-0988 (radon) 

303-293-1442 (asbestos) 

303-294-7611 (NESHAP) 

(AZ,CA,HI,NV,AS,GU) 

EPA Region 9 

75 Hawthorne Street, A-1-1 

San Francisco, CA 94105 

415-744-1133 (indoor air) 

415-744-1045 (radon) 

415-744-1136 (asbestos) 

415-744-1135 (NESHAP) 

(AK,ID,OR,WA} 

EPA Region 10 

1200 Sixth Avenue 

Seattle, WA 98101 

206-553-2589 (indoor air) 

206-553-7299 (radon) 

206-553-4762 (asbestos) 

206-553-1757 (NESHAP) 
OSHA Regional Offices 

(CT,ME,MA,NH,RI,VT) 

OSHA Region 1 

133 Portland Street, 1st Floor 

Boston, MA 02114 

617-565-7164 

(NJ,NY ,PR, VI) 

OSHA Region 2 

210 Varick Street, Room 670 

New York, NY 10014 

212-337-2376 

(DE,DC,MD,PA,VA,WV) 

OSHA Region 3 

Gateway Building, Suite 2100 

3535 Market Street 

Philadelphia, PA 19104 

215-596-1201 

(AL,FL,GA,KY,MS,NC,SC,TN) 

OSHA Region 4 

1375 Peachtree Street, NE, Suite 587 

Atlanta, GA 30367 

404-347-3573 

(IL,IN,MI,MN,OH, WI) 

OSHA Region 5 

230 South Dearborn Street, Room 3244 

Chicago, IL 60604 

312-353-2220 

(AR,LA,NM,OK,TX) 

OSHA Region 6 

525 Griffm Street, Room 602 

Dallas, TX 75202 

214-767-4731 

(IA,KS,MO,NE) 

OSHA Region 7 

911 Walnut Street, Room 406 

Kansas City, MO 64106 

816-426-5861 

(CO,MT,ND,SD,UT,WY) 

OSHA Region 8 

Federal Building, Room 1576 

1961 Stout Street 

Denver, CO 80294 

303-844-3061 

(AZ,CA,ffi,NV,AS,GU) 

OSHA Region 9 

71 Stevenson Street, 4th Floor 

San Francisco, CA 94105 

415-744-6570 

(AK,ID,OR,WA) 

OSHA Region 10 

1111 Third A venue, Suite 715 

Seattle, WA 98101-3212 

206~442-5930 

Resources 159 
OTHER FEDERAL AGENCIES 

WITH INDOOR AIR 

RESPONSIBILITIES 

Bonneville Power Administration 

P.O. Box 3621-RMRD 

Portland, OR 97208 

503-230-5475 

Provides radon-resistant construction 

techniques, source control, and removal 

technology for indoor air pollutants. 

Consumer Product Safety Commission 

5401 Westbard Avenue 

Bethesda, MD 20207 

1-800-638-CPSC 

Reviews complaints regarding the safety of 

consumer products and takes action to 

ensure product safety. 

General Services Administration 

18th and F Streets, NW 

Washington, DC 20405 

202-501-1464 

Writes indoor air quality policy for Federal 

buildings. Provides proactive indoor air 

quality building assessments. Assesses 

complaints and provides remedial action. 

U.S. Department of Energy 

Office of Conservation and Renewable 

Energy 

1000 Independence Avenue, SW, CE-43 

Washington, DC 20585 

202-586-9455 

Quantifies the relationship among reduced 

infiltration, adequate ventilation, and acceptable indoor air quality. 

160 Appendix G 

U.S. Department of Health and Human 

Services 

Office on Smoking and Health 

National Center for Chronic Disease 

Prevention and Health Promotion 

Centers for Disease Control 

1600 Clifton Road, NE 

Mail Stop K50 

Atlanta, GA 30333 

404-488-5705 

Disseminates information about the health 

effects of passive smoking and strategies 

for eliminating exposure to environmental 

tobacco smoke. 

Tennessee Valley Authority 

Occupational Hygiene Department 

328 Multipurpose Building 

Muscle Shoals, AL 35660 

205-386-2314 

Provides building surveys and assessments 

associated with employee indoor air 

quality complaints. 

STATE AND LOCAL AGENCIES 

Your questions and concerns about indoor 

air problems can frequently be answered 

most readily by the government agencies 

in your State or locality. Responsibilities 

for indoor air quality issues are usually 

divided among many different agencies. 

You will often find that calling or writing 

the agencies responsible for health or air 

quality control is the best way to start 

getting information from your State or 

local government. The EPA and Public 

Health Foundation publication, Directory 

of State Indoor Air Contacts, lists State 

agency contacts. (See publications list for 

information on ordering this publication.) 
PRIVATE SECTOR CONTACTS 

The private sector organizations that have 

information for the public on indoor air 

quality issues in commercial and public 

buildings include the following: 

Building Management 

Associations 

Association of Physical Plant Administrators of Universities and Colleges 

1446 Duke Street 

Alexandria, VA 22314-3492 · 

703-684-1446 

Building Owners and Managers 

Association International 

1201 New York Ave., NW, Suite 300 

Washington, DC 20005 

202-408-2684 

Institute of Real Estate Management 

430 North Michigan Avenue 

Chicago,nl 60611 

312-661-1930 

International Council of Shopping 

Centers 

1199 North Fairfax Street, Suite 204 

Alexandria, VA 22314 

703-549-7404 

International Facilities Management 

Association 

Summit Tower, Suite 1710 

11 Greenway Plaza 

Houston, TX 77046 

713-623-4362 

National Apartment Association 

1111 14th Street, NW, Suite 900 

Washington, DC 20005 

202-842-4050 

National Association of Industrial and 

Office Parks 

1215 Jefferson Davis Highway, Suite 100 

Arlington, VA 22202 

703-979-3400 

Professional and Standard 

Setting Organizations 

Air and Waste Management Association 

P.O. Box 2861 

Pittsburgh,PA 15230 

412-232-3444 

Air-Conditioning and Refrigeration 

Institute 

1501 Wilson Blvd., Suite 600 

Arlington, VA 22209 

703-524-8800 

American Conference of Governmental 

Indm;trial Hygienists 

6500 Glen way A venue, Building D-7 

Cincinnati, OH 45211 

513-661-7881 

American Industrial Hygiene 

Association 

P.O. Box 8390 

345 White Pond Drive 

Akron, OH 44320 

216-873-2442 

American Society for Testing and 

Materials 

1916 Race Street 

Philadelphia, PA 19103 

215-299-5571 

American Society of Heating, 

Refrigerating, and Air-Conditioning 

Engineers 

1791 Tullie Circle, NE 

Atlanta, GA 30329 

404-636-8400 

National Conference of States on 

Building Codes and Standards, Inc. 

505 Huntrnar Park Drive, Suite 210 

Herndon, VA 22070 

703-437-0100 

Resources 161 
Product Manufacturers 

Adhesive and Sealant Council 

1627 K Street, NW, Suite 1000 

Washington, DC 20006-1707 

202-452-1500 

Asbestos Information Association 

1745 Jefferson Davis Highway, Room 509 

Arlington, VA 22202 

703-979-1150 

Business Council on Indoor Air Quality 

1225 19th Street, Suite 300 

Washington, DC 20036 

202-775-5887 

Carpet and Rug Institute 

310 Holiday Avenue 

Dalton, GA 30720 

404-278-3176 

Chemical Specialties Manufacturers 

Association 

1913 I Street, NW 

Washington, DC 20006 

202-872-8110 

Electric Power Research Institute 

P.O. Box 10412 

Palo Alto, CA 94303 

415-855-2902 

Formaldehyde Institute, Inc. 

1330 Connecticut Avenue, NW 

Washington, DC 20036 

202-822-6757 

Foundation of Wall and Ceiling 

Industries 

1600 Cameron Street 

Alexandria, VA 22314-2705 

703-548-0374 

Gas Research Institute 

8600 West Bryn Mawr Avenue 

Chicago, IL 60631 

312-399-8304 

National Paint and Coatings Association 

1500 Rhode Island Avenue, NW 

Washington, DC 20005 

202-462-6272 

162 Appendix G 

Thermal Insulation Manufacturers 

Association Technical Services 

Air Handling Committee 

1420 King Street 

Alexandria, VA 22314 

(703) 684-0474 

Building Service Associations 

Air-Conditioning and Refrigeration 

Institute 

1501 Wilson Boulevard, 6th floor 

Arlington, VA 22209 

703-524-8800 

Air-Conditioning Contractors of 

America 

1513 16th Street, NW 

Washington DC 20036 

202-483-9370 

American Consulting Engineers Council 

1015 15th Street, NW, Suite 802 

Washington, DC 20005 

202-347-7474 

Associated Air Balance Council 

1518 K Street, NW 

Washington, DC 20005 

202-737-0202 

Association of Energy Engineers 

4025 Pleasantdale Rd., Suite 420 

Atlanta, GA 30340 

404-447-5083 

Association of Specialists in Cleaning 

and Restoration International 

10830 Annapolis Junction Road, Suite 312 

Annapolis Junction, MD 20701 

301-604-4411 

National Air Duct Cleaners Association 

1518 K Street, NW, Suite 503 

Washington, DC 20005 

202-737-2926 

National Association of Power Engineers 

3436 Haines Way, Suite 101 

Falls Church, VA 22041 

703-845-7055 
National Energy Management Institute 

601 North Fairfax Street, Suite 160 

Alexandria, VA 22314 

703-739-7100 

National Environmental Balancing 

Bureau 

1385 Piccard Drive 

Rockville, MD 20850 

301-977-3698 

National Pest Control Association 

8100 Oak Street 

Dunn Loring, VA 22027 

703-573-8330 

Sheet Metal and Air Conditioning 

Contractors National Association 

4201 LaFayette Center Drive 

Chantilly, VA ~2021 

703-803-2980 

Unions 

AFL-CIO 

Department of Occupational Safety and 

Health 

815 16th Street, NW 

Washington, DC 20006 

202-637-5000 

American Federation of Government 

Employees 

80 F Street, NW 

Washington, DC 20001 

202-737-8700 

American Federation of State, County, 

and Municipal Employees 

1625 L Street, NW 

Washington, DC 20036 

(202) 429-1215 

American Federation of Teachers 

555 New Jersey Avenue, NW 

Washington, DC 20001 

202-879-4400 

Communication Workers of America 

501 3rd Street, NW 

Washington, DC 20001 

202-434-1160 

International Union of Operating 

Engineers 

1125 17th Street, NW 

Washington, DC 20036 · 

202-429-9100 

Service Employees International Union 

1313 L Street, NW 

Washington, DC 20005 

Environmental/Health/ 

Consumer Organizations 

American Academy of Allergy and 

Immunology 

611 East Wells Street 

Milwaukee, WI 53202 

414-272-6071 

American Lung Association 

or your local lung association 

17 40 Broadway 

New York, NY 10019 

Consumer Federation of America 

1424 16th Street, NW, Suite 604 

Washington, DC 20036 

National Center for Environmental 

Health Strategies 

1100 Rural Avenue 

Voorhees, NJ 08043 

609-429-5358 

National Environmental Health 

Association 

720 South Colorado Blvd. 

South Tower, Suite 970 

Denver, CO 80222 

303-756-9090 

National Foundation forthe Chemically 

Hypersensitive 

P.O.Box9 

Wrightsville Beach, NC 28480 

517-697-3989 

Occupational Health Foundation 

112616th Street, NW ' 

Washington, DC 20036 

202-842-7840 

Resources 163 
PUBLICATIONS 

Items marked * are available from EPA 

Public Information Center (PM-211B), 

401 M Street, SW, Washington, DC 

20460. 202-260-2080. 

Items marked ** are available from TSCA 

Assistance Hotline (TS-799), 401 M 

Street, SW, Washington, DC 20460. 

202-554-1404. 

Items marked*** are available from 

NIOSH Pnblications Dissemination, 

4676 Columbia Parkway, Cincinnati, OH 

45202. 513-533-8287. 

General Information 

Cone, James E. and Michael J. Hodgson, 

MD, MPH. Problem Buildings: Building-Associated Illness and the Sick 

Building Syndrome. 1989. From the 

series: "Occupational Medicine: State of 

the Art Reviews." Hanley & Belfus, Inc., 

210 South 13th Street, Philadelphia, PA 

19107. 

Godish, Thad. Indoor Air Pollution 

Control. 1989. Lewis Publishers, 121 

South Main Street, Chelsea, MI 48118. 

Rajhans, G.S., Report of the Interministerial Committee on Indoor Air 

Quality, 1988. Contact: G. Rajhans, 

Health and Safety Support Services 

Branch, Ministry of Labour, 400 Uriiversity Avenue, 7th Floor, Toronto, Ontario, 

Canada M7 A 1 T7. 

Sheet Metal and Air Conditioning 

Contractor's National Association, Inc. 

(SMACNA). Indoor Air Quality. 1988. 

8224 Old Courthouse Road, Vienna, 

Virginia 22180. 

U.S. Environmental Protection Agency 

and the Public Health Foundation. Directory of State Indoor Air Contacts. Updated, 1991. * 

164 Appendix G 

U.S. Environmental Protection Agency. 

Designing for Good Indoor Air Quality: 

An Introduction for Design Professionals. 

(In progress). 

U.S. Environmental Protection Agency. 

1988. Project Summaries: Indoor Air 

Quality in Public Buildings. 1988. 

Contains findings of research on IAQ in 10 

new public and commercial buildings and 

on building material emissions.* 

U.S. Environmental Protection Agency 

and the U.S. Consumer Product Safety 

Commission. The Inside Story: A Guide 

to Indoor Air Quality. 1988. Addresses 

residential indoor air quality primarily, but 

contains a section on offices. * 

U.S. Environmental Protection Agency. 

Sick Building Syndrome. Indoor Air 

Quality Fact Sheet #4. Revised, 1991. * 

U.S. Environmental Protection Agency. 

Ventilation and Air Quality in Offices. 

Indoor Air Quality Fact Sheet #3. 

Revised, 1990. * 

World Health Organization. Air Quality 

Guidelines for Europe. 1987. WHO 

Regional Publications, European Series No. 

23. Available from WHO Publications 

Center USA, 49 Sheridan Avenue, Albany, 

NY 12210. 

Asbestos 

Keyes, Dale L. and Jean Chesson. A Guide 

to Monitoring Airborne Asbestos in 

Buildings. 1989. Environmental Sciences, 

Inc., 105 E. Speedway Blvd., Tucson, 

Arizona 85705. 

U.S. Department of Health and Human 

Services, Public Health Service, U.S. 

Centers for Disease Control, National 

Institute of Occupational Safety and 

Health. Testimony of NIOSH on the 

Occupational Safety and Health 

Administration's Proposed Rule on 

Occupational Exposure to Asbestos, 

Tremolite, Anthophyllite, and Actinolite. 
June 1984, May 1990, and January 1991. 

NIOSH Docket Office, C-34, 4676 Columbia Parkway, Cincinnati, OH 45226. . 

U.S. Environmental Protection Agency. A 

Guide to Respiratory Protection for the 

Asbestos Abatement Industry. 1986. EPA 

560/0TS 86-001.** 

U.S. Environmental Protection Agency. 

Abatement of Asbestos-Containing Pipe 

Insulation. 1986. Technical Bulletin No. 

1986-2. ** 

U.S. Environmental Protection Agency. 

Asbestos Abatement Projects: Worker 

Protection. Final Rule 40 CFR. 763. 

February 1987. ** 

U.S. Environmental Protection Agency. 

Asbestos Ban and PhaseoutRule. 40 CFR 

763.160 to 763.179. Federal Register, July 

12, 1989.** 

U.S. Environmental Protection Agency. 

Asbestos in Buildings: Guidance for 

Service and Maintenance Personnel (in 

English and Spanish). 1985. EPA 560/5-

85-018. ("Custodial Pamphlet"). ** 

U.S. Environmental Protection Agency. 

Asbestos in Buildings: Simplified Sam~ 

pling Scheme for Surfacing Materials. 

1985. 560/5-85-030A. ("Pink Book"). ** 

U.S. Environmental Protection Agency. 

Guidance for Controlling AsbestosContaining Materials in Buildings. 1985. 

EPA 560/5-85-024. ("Purple Book"). ** 

U.S. Environmental Protection Agency. 

Guidelines for Conducting the AHERA 

TEM Clearance Test to Determine 

Completion of an Asbestos Abatement 

Project, EPA 560/5-89-001. ** 

U.S. Environmental Protection Agency. 

Managing Asbestos In Place: A Building 

Owner's Guide to Operations and Maintenance Programs for Asbestos-Containing 

Materials. 1990. ("Green Book").** 

U.S. Environmental Protection Agency. 

Measuring Airborne Asbestos Following 

An Abatement Action. 1985. EPA 600/4-

85-049. ("Silver Book"). ** 

U.S. Environmental Protection Agency.· 

National Emission Standards for Hazardous Air Pollutants. 40 Code of Federal 

Regulation 61. April 1984. ** 

U.S. Environmental Protection Agency. 

Transmission Electron Microscopy 

Asbestos Laboratories: Quality Assurance 

Guidelines. 1989. EPA 560/5-90-002.** 

U.S. Department of Labor. OSHA Regulations. 29 Code of Federal Regulation 

1910.1001. General Industry Asbestos 

Standard. 29 Code of Federal Regulation 

1926.58. Construction Industry Asbestos 

Standard. June 1986; amended September 

1988. DOL-OSHA Docket, 200 Constitution Avenue, NW, Room N 2625, 

Washington, DC 20210. 

U.S. Department of Labor. OSHA Regulations. 29 Code of Federal Regulation 

1910.134. Respiratory Protection Standard. June 1974. DOL-OSHA Docket, 

200 Constitution Avenue, NW, Room 

N 2625, Washington, DC 20210. 

Biologicals 

American Council of Governmental Industrial Hygienists. Guidelines for the Assessment of Bioaerosols in the Indoor Environment. 1989. 6500 Glen way Avenue, 

Building D-7, Cincinnati, OH 45211. 

Morey, P., J. Feeley, and J; Otten. 

Biological Contaminants in Indoor 

Environments. 1990. American Society 

for Testing and Materials. Publications, 

1916 Race Street, Philadelphia, PA 19103. 

Building Management, 

Investigation, and Remediation 

Bazerghi, Rani and Catherine Amoult. 

Practical Manual for Good Indoor Air 

Quality. 1989. Quebec Association for 

Energy Management. 1259 Berri Street, 

Suite 510, Montreal, Quebec, Canada, H2L 

4C7. 

Resources 165 
Hansen, Shirley J., Managing Indoor Air 

Quality. 1991. Fairmont Press, 700 Indian 

Trail, Lilburn, GA 30247. 

U.S. Department of Health and Human 

Services. Public Health Service. Centers 

for Disease Control. National Institute for 

Occupational Safety and Health. Indoor 

Air Quality: Selected References. 

1989.*** 

U.S. Department of Health and Human 

Services. Public Health Service. Centers 

for Disease Control. National Institute for 

Occupational Safety and Health. Guidance 

for Indoor Air Quality Investigations. 

1987.*** 

Weekes, Donald M. and Richard B. 

Gammage. The Practitioner's Approach 

to Indoor Air Quality Investigations. 

Proceedings of the Indoor Air Quality 

International Symposium. 1989. American 

Industrial Hygiene Association, P.O. Box 

8390, Akron Ohio 44320. 

Environmental Tobacco Smoke 

National Research Council. Environmental Tobacco Smoke: Measuring Exposures and Assessing Health Effects. 1986. 

National Academy Press. 2001 Wisconsin 

Avenue, NW, Washington, DC 20418. 

U.S. Department of Health and Human 

Services. Public Health Service. Office 

on Smoking and Health. The Health 

Consequences of Involuntary Smoking, 

A Report of the Surgeon General. 1986. 

1600 Clifton Road, NE (Mail Stop K50) 

Atlanta, GA. 30333. 

U.S. Department of Health and Human 

Services. Public Health Service. Centers 

for Disease Control. National Institute for 

Occupational Safety and Health. Current 

Intelligence Bulletin 54: Environmental 

· Tobacco Smoke in the WorkplaceLung Cancer and Other Health Effects. 

DHHS (NIOSH) Publication No. 91M108. 

1991.*** 

166 Appendix G 

U.S. Department of Health and Human 

Services. National Cancer Institute. 

Office of Cancer Communications. A 

series of one-page information sheets on 

all. aspects of smoking in the workplace. 

For copies, calll-8004-CANCER. 

U.S. Environmental Protection Agency. 

Environmental Tobacco Smoke. Indoor 

Air Quality Fact Sheet #5. 1989.* 

U.S. Environmental Protection Agency. 

Environmental Tobacco Smoke: A Guide 

to the Development of Effective Smoking 

Policies. (In progress.)* 

U.S. Environmental Protection Agency. 

Health Effects of Passive Smoking: 

Assessment of Lung Cancer in Adults and 

Respiratory Disorders in Children. (In 

progress.)* 

PCBs 

U.S. Department of Health and Human 

Services. Public Health Service. Centers 

for Disease Control. National Institute for 

Occupational Safety and Health. Current 

Intelligence Bulletin 45: Polychlorinated 

Biphenyls- Potential Health Hazards 

from Electrical Equipment Fires or 

Failures. DHHS (NIOSH) Publication 

No. 86-111. 1977. Available from the 

National Technical Information Service, 

5285 Port Royal Road, Springfield, VA 

22161. 

U.S. Department of Health and Human 

Services. Public Health Service. Centers 

for Disease Control. National Institute for 

Occupational Safety and Health. A 

Recommended Standard for Occupational 

Exposure to Polychlorinated Biphenyls. 

DHHS (NIOSH) Publication No. 77-225. 

1977. Available from the National 

Technical Information Service, 5285 Port 

Royal Road, Springfield, VA 22161. 

U.S. Environmental Protection Agency. 

Transformers and the Risk of Fire: A 

Guide for Building Owners. 1986. OPA/ 

86-001. ** 
Radon 

U.S. Environmental Protection Agency. 

State Proficiency Report. 1991. EPA 

520/1-91-014. Available from State 

radon offices. List of laboratories that 

have demonstrated competence in radon 

measurement analysis. 

Standards and Guidelines 

American Conference of Government 

Industrial Hygienists. Threshold Limit 

Values and Biological Exposure Indices. 

1990-1991. 6500 Glenway Avenue, 

Building D-7, Cincinnati, OH 45211. 

U.S. Department of Health and Human 

Services. PUblic Health Service. Centers 

for Disease Control. National Institute for 

Occupational Safety and Health. NIOSH 

Recommendations for Occupational 

Safety and Health. Compendium of 

Policy Documents and Statements. 

DHHS (NIOSH) Publications 91-109. 

1991.*** 

U.S. Department of Labor. OSHA 

Regulations. 29 CFRPart 1910.1000. 

OSHA Standards for Air Contaminants. 

Available from the U.S. Government 

Printing Office, Washington, DC 20402. 

202-783-3238. Additional health 

standardsfor some specific air contaminants are also available in Subpart Z. 

Ventilation/fhermal Comfort 

Brief descriptions of the ASHRAE 

standards listed below are included in 

Appendix B. ASHRAE materials are 

available from their Publication Sales 

Department, 1791 Tullie Circle, NE, 

Atlanta, GA 30329. 404-636-8400. 

ASHRAE Guideline 1-1989. Guideline 

for the Commissioning of HV AC 

Systems. 1989. 

ASHRAE Journal. October 1989 issue. 

Several articles describing ASHRAE 

Standard 62-1989. · 

ASHRAE Standard 52-76. Method of 

Testing Air-Cleaning Devices Used in 

General Ventilation for Removing 

Particulate Matter. 1976. 

ASHRAE Standard 55-1981. Thermal 

Environmental Conditions for Human· 

Occupancy. 1981. 

ASHRAE Standard 62-1989. Ventilt;t:-

tionfor Acceptable Indoor Air Quality. 

1989. 

National Conference of States on Building·. 

Codes and Standards, Inc. The Ventilation 

Directory. 505 Huntmar Park Drive, ~uite 

210, Herndon, VA 22070. 703-481-2020. 

Summarizes natural, mechanical, and 

exhaust ventilation requirements of the 

model codes, ASHRAE standards, and 

unique State codes. 

TRAINING 

American Industrial Hygiene .Association (AIHA). P.O. Box 8390, 345 White 

Pond Drive, Akron, OH 44320. 216-873-

2442. Sponsors indoor air quality courses 

in conjunction with meetings for AIHA 

members only. 

American Society of Heating, Refrigerating, and Air~Conditioning Engineer~ 

(ASHRAE). 1791 Tullie Circle NE, 

Atlanta, GA 30329. 404-636-8400. 

Sponsors professional development 

seminars on indoor air quality. 

NIOSH Division of Training and 

Manpower Development and NIOSHfunded Educational Resource Centers. 

4676 Columbia Parkway, Cincinnati, OH 

45226. 513-8221. Provide training to 

occupational safety and health professionals and paraprofessionals. 

OSHA Training Institute. 155 Times 

Drive, Des Plaines, IL 60018. 708-297-

4913. Provides courses to assist health 

and safety professionals in evaluating 

indoor air quality. 

Resources 167 

Indoor Air Quality Forms 

This section of the document is a collection of the forms that appear or are mentioned in the text. Consider making copies 

of the forms, blocking out the page infor-. 

mation·at the· bottom of the copies, and then 

reproduc;ing these copies for .use in your 

building. Some or all of them may require 

adaptation to meet your specific needs. . 

Blank formatted sheets "are included for 

preparing your own HV AC Checklist and 

Pollutant and Source Inventory. 

The forms appear in the following 

sequence: 

IAQ Management Checklist (4 pages): for 

keeping track of the elements of the IAQ 

profile and IAQ management plan · 

Pollutant Pathway Record For IAQ 

Profiles: for identifying areas in which 

negative or positive pressures should be 

maintained 

Zone/Room Record: for recording information on a room-by-room basis on the 

topics of room use, ventilation, and occupant population. 

Ventilation Worksheet: to be used in conjunction with the Zone/Room Record when 

calculating quantities of outdoor air that are 

being supplied to individual zones or rooms 

IAQ Complaint Form: to be filled out by 

the complainant or by a staff person who 

receives information from the complainant 

Incident Log: for keeping track of each 

IAQ complaint or problem and how it is 

handled 

Occupant Interview (2 pages): for recording the observations of building occupants 

in relation to their symptoms and conditions in the building 

Occupant Diary: for recording incidents 

of symptoms and associated observations 

as they occur 

Log of Activities and System Operation: 

for recording activities and equipment 

operating schedules as they occur 

HVAC.Checklist- Short Form (4 pages): 

· to be used as a short. form for investigating 

an IAQ problem, or for periodic inspections of the HV AC system. Duplicate 

pages 2 through 4 for each large air handling unit. 

HVAC. Checklist- Long Form (14 pages, 

followed by one blank formatted sheet): 

to be used for detailed inspections of the 

HY AC system or as a long form for investigating an IAQ problem. Duplicate pages 

1 through 11 for each large air handling 

unit. 

Pollutant Pathway Form For 

Investigations: to be used in conjunction 

with a floor plan of the building. 

Pollutant and Source Inventory (6 pages, 

followed by one blank formatted sheet): 

to be used as a general checklist of potential indoor and outdoor pollutant sources. 

Chemical Inventory: for recording 

information about chemicals stored or 

used within the building 

Hypothesis Form: to be used for 

summarizing what has been learned during 

the building investigation; a tool to help 

the investigator collect his or her thoughts. 

Indoor Air Quality Forms 169 

·. r 

IAQ Management Checklist Page 1 of4 

Building Name:-------------------------- Date:--------,-~-~~ 

Address:-------------------------------------------

Completed by (name/title):-------------------------------~-

Use this checklist to make sure that you have included all necessary elements in your IAQ profile and, 

IAQ management plan. Sections 4 and 5 discuss the development of the IAQ profile and IAQ managf3ment plan. 

Date begun Ltocation ,, 

or completed Responsible person ("NA" i~ the item is not 

Item las applicable} (name, telephone) applicable to this building) 

lAO PROFILE 

Collect and Review EJ(isting r: 

Records ,' { , . . : ' .. 

HVAC design data, operating I 

instructions, and manuals 

HVAC maintenance and calibration '' 

records, testing and balancing reports 

Inventory of locations where occupancy, equipment, or building use 

has changed 

Inventory of complaint locations 

Conduct a Walkthrough : Inspection of the Building ~,' 

List of responsible staff and/or 

contractors, evidence of training, 

and job descriptions 

Identification of areas where 

positive or negative pressure I 

should be maintained 

Record of locations that need 

monitoring or correction "' 

Collect Detailed Information 

Inventory of HVAC system 

components needing repair, 

adjustment, or replacement 

Record of control settings and 

operating schedules 

Indoor Air Quality Forms 171 
IAQ ~"'anagement Checklist Page2 of4. 

Date begun Location 

or completed Responsible person ("NA" if the item is not 

~~m (as applicable) (name, telephone) applicable to this building) 

Plan showing ahrflow directions or 

pressure differentials in significant 

areas 

Inventory of slgnifi'cant pollutant 

sources and their lc,cations 

MSDSs for supplies rmd 

hazardous substance~~ that are stored 

or used in the buildinst 

Zone/Room Record 

IAQ MANAGEMENT PLAN .. 

Select IAQ Manager 

I f Review IAQ Profile 

Aaaign Staff Responsibilrtiest ~ Train Staff 

" 

Facilities Operation and Mair.1tenance 

• confirm that equipment operating 

schedules are appropriate 

• confirm appropriate pressure 

relationships between building 

usage areas 

• compare ventilation quantities to 

design, codes, and ASHRAE 62-1989 

• schedule equipment inspections 

per preventive maintenance plan or 

recommended maintenance schedule 

• modify and use HVAC Checklist(s); 

update as equipment is added, 

removed, or replaced 

• schedule maintenance activities. to 

avoid creating lAO problems 

172 Indoor Air Quality Forms 
IAQ Management Checklist Page3of4 

Date begun Location 

or completed Responsible person ("NA" if the item is not 

Item (as applicable) (name, telephone) applicable to this building) 

• review MSDSs for supplies; request 

additional information as needed 

• consider using alarms or other 

devices to signal need for HVAC 

maintenance (e.g., clogged filters) 

Housekeeping 

• evaluate cleaning schedules and 

procedures; modify if necessary 

• review MSDSs for products in use; 

buy different products if necessary 

• confirm proper use and storage of 

materials 

• review trash disposal procedures; 

modify if necessary 

Shipping and Receiving 

• review loading dock procedures 

(Note: If air intake is located nearby, 

take precautions to prevent intake of 

exhaust fumes.) 

• check pressure relationships around 

loading dock 

Pest Control 

• consider adopting IPM methods 

• obtain and review MSDSs; review 

handling and storage 

• review pest control schedules and 

procedures 

• review ventilation used during 

pesticide application 

Indoor Air Quality Forms 173 
IAQ Management Checklist Page 4 of4 

Date begun Location 

or completed Responsible person ("NA" if the item is not 

Item (as applicable) (name, telephone) applicable to this building) 

Occupant Relations 

a establish health and safety 

committee or joint tenant/ 

management IAQ task force 

a review procedures for responding 

to complaints; mo~ify if necessary 

a review lease provisions; modify 

if necessary 

Renovation, Redecorating, 

Remodeling 

a discuss IAQ concerns with 

architects, engineers, contractors, 

and other professionals 

a obtain MSDSs; use materials 

and procedures that minimize 

IAQ problems 

a schedule work to minimize 

IAQ problems 

a arrange ventilation to isolate 

work areas 

• use installation procedures 

that minimize emissions from 

new furnishings 

Smoking 

a eliminate smoking in the building 

a if smoking areas are designated, 

provide adequate ventilation and 

maintain under negative pressure 

a work with occupants to develop 

appropriate non-smoking policies, 

including implementation 

of smoking cessation programs 

174 Indoor Air Quality Forms 
Pollutant Pathway Record For 

IAQ Profiles 

This form should be used in combination with a floor plan such as a fire evacuation plan. 

Building Name: -.,--------------.,.--------,---- File Number: ----------

Address: _____________________________________________ _ 

Completed by:---------------------- Title:----------- Date: --------

Sections 2, 4 and 6 discuss pollutant pathways and driving forces. 

Building areas that contain contaminant sources (e.g., bathrooms, food preparation areas, smoking lounges, print 

rooms, and art rooms) should be maintained under negative pressure relative to surrounding areas. Building areas 

that need to be protected from the infiltration of contaminants (e.g..., hallways in multi-family dwellings, computer 

rooms, and lobbies) should be maintained under positive pressure relative to the outdoors and relative to surrounding 

areas. 

List the building areas in which pr~ssure relationships should be controlled. As you inspect the building, put a Y or N 

in the "Needs Attention" column to show whether the desired air pressure relationship is present. Mark the floor plan 

with arrows, plus signs (+) and minus signs (-)to show the airflow patterns you observe using chemical smoke or a 

micromanometer. 

Building areas that appear isolated from each other may be connected by airflow passages such as air distribution 

zones, utility tunnels or chases, party walls, spaces above suspended ceilings (whether or not those spaces are 

serving as air plenums), elevator shafts, and crawlspaces. If you are aware of pathways connecting the room to 

identified pollutant sources (e.g.; items of equipment, chemical storage areas; bathrooms), it may be helpful to record 

them in the "Comments" column, on the floor plan, or both. 

Intended Pressure Needs 

Building Area Use Positive Negative Attention? Comments 

(zone, room} (+) (-) IV/N) 

Indoor Air Quality Forms 175 

Zone/Room Record 

Building Name:-------------------- File Number: ------------- Date:----------

Address: --------------------------- Completed by:------------Title:---------

This form is to be used differently depending on whether the goal is to prevent or to diagnose IAQ problems. During the development of a profile, this form 

should be used to record more general information about the entire building; during an investigation, the form should be used to record more detailed 

information about the complaint area and areas surrounding the complaint area or connected to it by pathways. 

Use the last three columns when underventilation is suspected. Use the Ventilation Worksheet and Appendix A to estimate outdoor air quantities. 

Compare results to the design specifications, applicable building codes, or ventilation guidelines such as ASHRAE 62-1989. (See Appendix A for some outdoor 

air quantities required by ASHRAE 62-1989.) Note: For VAV systems, minimum outdoor air under reduced flow conditions must be considered. 

PROFILE AND DIAGNOSIS INFORMATION DIAGNOSIS INFORMATION ONLY 

Build!:1g Area Use** Source of Mechanical Comments Peak Number of Total Air Outdoor Air Supplied 

(Zone/Room) Outdoor Air* Exhaust? Occupants or Supplied per Person or 

(Write "No" Sq. Ft. Floor Area** lin cfm)*** per 150 Sq. Ft. Area 

or estimate (in cfm)**** 

cfm airflow) 

* Sources might include air handling unit (e.g., AHU-4), operable windows, transfer from corridors 

** Underline the information in this column if current use or number of occupants is different from design specifications 

*** Mark the information with a P if it comes from the mechanical plans or an M if it comes from the actual measurements, such as 

recent test and balance reports. 

**** ASHRAE 62-1989 gives ventilation guidance per 150 sq. ft. 

i 

Ventilation Worksheet 

Building Name: ----------------------- File Number: ----------

Address: ________________________________________ _ 

Completed by (name): ---------------------- Date: ----------

This worksheet is designed for use with the Zone/Room Record. Appendix A provides guidance on methods of 

estimating the amount of ventilation (outdoor) air being introduced by a particular air handling unit. Appendix B 

discusses the ventilation recommendations of ASHRAE Standard 62-1989, which was developed for the purpose of 

preventing indoor air quality problems. Formulas are given below for calculating outdoor air quantities using thermal 

or C02 information. · 

The equation for calculating outdoor air quantities using thermal measurements is: 

Outdoor air (in percent) = T return air - T mixed air 

=-----:::---- X 100 

T return air - T outdoor air 

Where: T =temperature in degrees Fahrenheit 

The equation for calculating outdoor quantities using carbon dioxide measurements is: 

Outdoor air (in percent) = C5 - Cr 

--c- x 1oo 

Co- r 

Where: c.= ppm of carbon dioxide in the supply air (if measured in a room), or 

C.= ppm of carbon dioxide in the mixed air (if measured at an air handler) 

C,= ppm of carbon dioxide in the return air 

C0= ppm of carbon dioxide in the outdoor air 

Use the table below to estimate the ventilation rate in any room or zone. Note: ASHRAE 62-1989 generally states 

ventilation (outdoor air) requirements on an occupancy basis; for a few types of spaces, however, requirements are 

given on a floor area basis. Therefore, this table provides a process of calculating ventilation (outdoor air) on either 

an occupan~y or floor area basis. 

Zone/Room Percent of Total Air Peak Occupancy D:.!.. E = (Ax100) X D 

Outdoor Air Supplied to (number of people) c Outdoor air 

Zone/Room or Total Air Supplied Per Person 

(cfml Floor Area Supplied Per Person (or per square foot area) 

(square feet) .(or per square foot areal 

A B c D E 

Indoor Air Quality Forms 179 

Indoor Air Quality Complaint Form 

This form can be filled out by the building occupant or by a member of the building staff. 

Occupant Name: ________________________________________________ __ Date: 

Department/Location in Building: ------------------------------------- Phone:--------------------

Completed by: ---------------------------- Title: -------------------.Phone: ________________ _ 

This form should be used if your complaint may be related to indoor air quality. Indoor air quality problems include 

concerns with temperature control, ventilation, and air pollutants. Your observations can help to resolve the problem 

as quickly as possible. Please use the space below to describe the nature of the complaint and any potential causes. 

We may need to contact you to discuss your complaint. What is the best time to reach you? __________________ _ 

So that we can respond promptly, please return this form to: ------------------------------------------

IAQ Manager or Contact Person 

. Room; Building, Mail• Code 

OFFICE USE ONL V 

File Number: ---------------------- Received By:----------------------------- Date Received:---------

Indoor Air Quality Forms 181 

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Indoor Air Quality Forms 183 

Occupant Interview Page 1 of2 

Building Name:---------------------- File Number: ----------

Address: ____________________________ ~-------------

Occupant Name:------~---------- Work Location:----------------

Completed by:---------------Title:-----------Date:--------

Section 4 discusses collecting and interpreting information from occupants. 

SYMPTOM PAlTERNS 

What kind of symptoms or discomfort are you experiencing? 

Are you aware of other people with similar symptoms or concerns? Yes· ___ _ No ___ _ 

If so, what are their names and locations?-------------.,.-----.,.---------------

Do you have any health conditions that may make you particularly susceptible to environmental problems? 

Cl contact lenses Cl chronic cardiovascular disease 

Cl allergies Cl chronic respiratory disease 

Cl chronic neurological problems 

TIMING PATTERNS 

When did your symptoms start? 

When are they generally worst? 

Do they go away? If so, when? 

Cl undergoing chemotherapy or radiation therapy 

Cl immune system suppressed by disease or 

other causes 

Have you noticed any other events (such as weather events, temperature or humidity changes, or activities in the 

building) that tend to occur around the same time as your symptoms? 

Indoor Air Quality Forms 185 
Occupant Interview Page2of2 

SPATIAL PA1TERNS 

Where are you when you experience symptoms or discomfort? 

Where do you spend most of your time in the building? 

ADDITIONAL INFORMATION 

Do you have any observations about building conditions that might need attention or might help explain your· 

symptoms (e.g., temperature, humidity, drafts, stagnant air, odors)? 

Have you sought medical attention for your symptoms? 

Do you have any other comments? 

186 Indoor Air Quality Forms 
Occupant Diary 

Occupant Name:------------Title:------------ Phone:----------

location:------------------------ File Number:. ____________ _ 

On the form below, please record each occasion when you experience a symptom of ill-health or discomfort that you 

think may be linked to an environmental condition in this building. 

It is important that you record the time and date and your location within the building as accurately as possible, 

because that will help to identify conditions (e.g., equipment operation) that may be associated with your problem. 

Also, please try to describe the severity of your symptoms (e.g., mild, severe) and their duration (the length of time that 

they persist). Any other observations that you think may help in identifying the cause of the problem should be noted 

in the "Comments" column. Feel free to attach additional pages or use more than one line for each event if you need 

more room to record your observations. 

Section 6 discusses collecting and interpreting occupant information. 

Time/Date Location Symptom Severity/Duration Comments 

Indoor Air Quality Forms 187 

Log of Activities and System Operation 

Building Name:-------.,.------ Address:------------ File Number: ______ _ 

Completed by:--------------Title:----------- Phone:---------

On the form below, please record your observations of the HVAC system operation, maintenance activities, and any 

other information that you think might be helpful in identifying the cause of IAQ complaints in this building. Please 

report any other observations (e.g., weather, other associated events) that you think may be important as well. 

Feel free to attach additional pages or use more than one line for each event. 

Equipment and activities of particular interest: 

Air Handler(s): ---------------------------------------

Exhaust Fan(s): --------------------------------------

Other Equipment or Activities:----------------------------------

Date/Time. Day of Week Equipment Item/ Activity Observations/Comments 

Indoor Air Quality Forms 189 

HVAC Checklist - Short Form Page 1 of4 

Building Name: -------------,,---------Address:----.,...--------------

Completed by:-----------------'-----Date: ______ File Number:--------

Sections 2, 4 and 6 and Appendix 8 discuss the relationships between the HVAC system and indoor air quality. 

• Clean and dry? ------------- Stored refuse or chemicals?--------------

• Describe items in need of attention -------------------------------

~inAJOR MECH~;;~~t:E~~;p.,;~~~------ ~ ~=- . ~ .· 

• Preventive maintenance (PM) plan in use? ------------------------,--------

Control System 

• Type 

• System operation 

• Date of last calibration ------------------------------------

Boiler 

• Rated Btu input ------Condition ----------------------------

• Combustion air: is there at least one square inch free area per 2,000 Btu input? ----------------

• Fuel or combustion odors --------,--------,----------------,--------

Cooling Tower 

• Clean? no leaks or overflow?----------- Slime or algae growth?--------------

• Eliminator performance ----------------------------------,----

• Biocide treatment working? (list type of biocide)---------------------------

• Spill containment plan implemented?----------- Dirt separator working?----------

Chillers 

• Refrigerant leaks?--------------------------------------

• Evidence of condensation problems? -------------------------------

• Waste oil and refrigerant properly stored and disposed of?----------------~-----

191 Indoor Air Quality Forms 
HVAC Checklist - Short Form Page2of4 

Building Name: _________________ Address: -----------------

Completed by:-----------------Date: ______ File Number: _______ _ 

AIR HANDLING UNIT 

• Unit Identification Area served -----------------

Outdoor Air Intake, Mixing Plenum, ~nd Dampers 

• Outdoor air intake location.---------------------------------

• Nearby contaminant sources? (describel-----------------------------

• Bird screen In place and unobstructed?-----------------------------

• Design total cfm ----- outdoor air (O.A.) cfm ----- date last tested and balanced-------

• Minimum% O.A. (damper setting)----- Minimum cfm O.A. (total cfm x minimum% O.A.) 

100 

• Current O.A. damper setting (date, time, and HVAC operating mode)-------------------

• Damper control sequence (describe)------------------------------

• Condition of dampers and controls (note date) --------------------------

Fans 

• Control sequence -------------------------------------

• Condition (note date) ----------------------------------

• Indicated temperatures supply air ---- mixed air ----return air ____ outdoor air -----

• Actual temperatures supply air ---- mixed air ---- return air ____ outdoor air -----

Colts 

• Heating fluid discharge temperature ___ _ ~T --- cooling fluid discharge temperature ___ ~T __ _ 

• Controls (describe) 

• Condition (note date) 

Humtdffier 

aType --------------If biocide is used, note type ---------------

• Condition (no overflow, drains trapped, all nozzles working?)---------------------

• No slime, visible growth, or mineral deposits?--------------------------

Indoor Air Quality Forms 192 
HVAC Checklist- Short Form Page3of4 

Building Name: Address:-----------------

Completed by:------.,.-------'----.;.,_ __ Date:------File Number:--------

- - --- ~-

,_;,,,.,,,,: 

Supply Air Return Air Power Exhaust · 

Zone/ System ducted/ cfm ducted/ cfm cfm control serves 

Room Type unducted unducted (e.g. toilet) 

,, 

Condition of distribution system and terminal equipment (note locations of problems) 

• Adequate access for maintenance? ______________________________ _ 

• Ducts and coils clean and obstructed? -----------------------------

• Air paths unobstructed? supplY--- return ---transfer--- exhaust --- make-up ----

• Note locations of blocked air paths, diffusers, or grilles -----------------------

• Any unintentional openings into plenums?----------------------------

• Controls operating properly? ________________________________ _ 

• Air volume correct?------------------------------------

• Drain pans clean? Any visible growth or odors? --------------------------

Filters 

Location Type/Rating Size . Date Last Changed Condition (give date) 

193 Indoor Air,Quality Forms 
HVAC Checklist - Short Form .. ' 

~· 

Page 4of4 

Building Name:-----------------Address: _____________ .;.___ __ _ 

. Completed by: ________________ Date: ______ File Number:-------

OCCUPIED SPACE 

ThMmo~at~es-----------------------------------------------

i Zone/ Thermostat What Does Setpolnts Measured Day/ 

Room Location Thermostat Temperature Time 

Control? Summer Winter· 

(e.g., radiator, 

AHU-3) 

Humidi~at/Dehumidistattypes---------------------------------------

Zone/ Humidistat/ WhatDoeslt Setpoints Measured Day/ 

Room Dehumidistat Ccmtrol? {%RH) Temperature Time 

Location 

• Potential problems (note location)---------------------------------------

• Thermal comfort or air circulation problems (drafts, obstructed airflow, stagnant air, overcrowding, poor 

thermostat location) 

• Malfunctioning equipment---------------------------------

• Major sources of odors or contaminants (e.g., poor sanitation, incompatible uses of space) 

Indoor Air Quality Forms 194 
HVAC Checklist - Long Form Page 1 of14 

Building:----------------------- File Number:------------

Completed by:---~--------- Title:------------ Date Checked: ____ _ 

Appendix B discusses HVACsystem components in relation to indoor air quality. 

Needs Not 

Component OK Attention Applicable Comments 

•· OU.s~d~t·~irln~k:~~ , , '':c . ···:::·. " ' ·;:,· ': .~·z .7:c: .·::.•::.::• .·•·. . • i ' .. ,; . + . ... . . ·. ·.·•· ·.•. <·" '... : ,. '',:.: '· '·; ·. ~-.l ·,, .:-.. '• .• ;:. ,· .... • • .. >: " . .•• .< '.:.. .• ·, ,' ; ··. ·, ·. 

Location 

Open during occupied hours? 

U riobstructed? 

Standing water, bird droppings 

in vicinity? 

Odors from outdoors? 

(describe) 

Carryover of exhaust heat? 

Cooling tower within 25 feet? 

Exhaust outlet within 25 feet? 

Trash compactor within 25feet? 

Near parking facility, busy road, 

loading dock? 

. ; " ., .. 

.... ' ····· ' 

·,· . : > '' 

· · Bi111 Screen '·.·. ' ·: ... · .'-" ',, .· .. ' .: : :: ... : . ': ' ' .. ·:. : ' 

:.,. :· ':·:~ ·. , .. ~ ' ' 

Unobstructed? 

General condition? 

Size of mesh? (1/2'' minimum) 

"' ' :.· ·.· '" .·· ,, ·: :': :' : ' ... ,.. : ,. : ·:•. ·.' '~:: •'= 

'OUtside Air Dampens . . •, ' ,; ' ., ~-. " •. :. •,,; ,'. ··. ::; :. '· :: .. , ; ! .···. _· ' . .'. . ' ' ·.. . ... . ' 

" 

Operation acceptable? 

Seal when closed? 

Indoor Air Quality Forms 195 
HVAC Checklist - Long Form Page2of14 

Building: ______________________ File Number:------------

Completed by:-------------Title:----'--------- Date Checked: ____ _ 

Needs Not 

Component OK Attention Applicable Comments 

Actuators operational? 

"' "~ .,....,,,,.,."'" 

·::.o!if~ .... ~!~ (~~~~• ~!''1!~ ...................... ~k ~Inn appliublt'l coda 111 "•"11'•'1"11 '

111 11111" 

,'l!ll!lll~li:C:I":ABI~tl!ti;t":o;:z:;:;:i89~i""lllll" '""·I"''"'' I""""""""''''' ' '' "'I 

Minimum% O.A. 

Measured % O.A. 

Note day, time, HVAC operating 

mode under "Comments" 

Maximum% O.A. 

Is minimum O.A. a separate damper? 

ForVAV systems: is O.A. increased 

as total system air-flow is reduced? 

·····.JVIIxlng Planum :::i·i·" ,,···: ···.:: ...... ·.::· "•:::· ::· .. i' 

II ! ~ ' ' " I II ' " ' ,., .. :: ..... :.:····. .. ' .. : .. ·.::.: ,, ·.·' ,' ,.> • 

Clean? 

Floor drain trapped? 

Airtightness 

• of outside air dampers 

• of return air dampers 

• of exhaust air dampers 

All damper motors connected? 

All damper motors operational? 

Air mixers or opposed blades? 

196 Indoor Air Quality Forms 
HVAC Checklist - Long Form Page3of 14 

Building:----------------------- File Number:------------

Completed by:-------------Title:------------ Date Checked; ____ _ 

Needs Not 

Component OK Attention Applicable Comments 

Mixed air temperature control 

setting. OF 

7reeze stat setting OF 

Is mixing plenum under negative 

pressure? Note: If it is under 

positive pressure, outdoor air 

may not be entering. 

. Filters ~ ·. . .. 

·. .' : .. ' ...... ·· ·.: : ..... 

Type 

Complete coverage? '. 

(i.e., no bypassing) 

Correct pressure drop? (Compare to 

manufacturer's recommendations.} 

Contaminants visible? 

Odor noticeable? 

.·· 

Spray Humidifier$ or 

Air Washers .•.. · . . . • . ..... 

Humidifier type 

All nozzles working? 

Complete coil coverage? 

Pans clean, no overflow? 

Drains trapped? 

Biocide treatment working? 

Note: Is MSDS on file? 

Spill contaminant system in place? 

Indoor Air Quality Forms 197 
HVAC Checklist - Long Form Page4of14 

Building: _____________________ File Number:-----------

Completed by:-------------Title:------------ Date Checked: ____ _ 

Needs Not 

Component OK Attention Applicable Comments 

F•c• .. •ll~ 1;1~~ D~m~M!~, """"' '"' '"'"'''"' '·''""""'""''' "'"'!": '""'''"'''; "' ... :""'"'' '.'' .. ''; "•' 

Damper operation correct? 

Damper motors operational? 

Cooling Coil ,, 

''""iliii, " ,,·,· ,,,,' . :; ,;• ,; " ,,,.,,, '•" '"!, ~ 

Inspection access? 

Clean? 

Supply water temp. __ °F 

Water carryover? 

Any indication of condensation 

problems? 

1 

Conden~te Drip Pana ' 

Accessible to inspeCt and clean? 

Clean, no residue? 

No standing water, no leaks? 

Noticeable odor? 

Visible growth (e.g., slime)? 

Drains and traps clear, working? 

Trapped to air gap? 

Water overflow? 

198 Indoor Air Quality Forms 
HVAC Checklist- Long Form Page 5 of14 

Building: __ ____,------------------ File Number:-----------

Completed by:-------------Title:----------- Date Checked: ____ _ 

Needs Not 

Component OK Attention Applicable Comments 

Clean, straight, no carryover? 

' .· :· .· . .... · '.· : 

·:• : .:. ..';. -• ;,•> , r , •: ';,; .. , . : ...•• :·: ·: 

Clean? 

No trash or storage? 

Floor drain traps are wet or sealed~ 

No air leaks? 

Doors close tightly? 

····<' .. }' .:. .•.:. ·: ....... · ·'< .. : .. ">· .•.· . : . <:···.·. 

·: · .. :. <: ·'>·~··:,. "' :.;.•./<:' ,::;:·:'.-· •,,, ·:.··: ._;;: ...•.. . •. ·,: . -_._ :. ·:· :'-, - ,: '' '' •.-. 

Location---------

Fan blades clean? 

Belt guards installed? · 

Proper belt tension? 

Excess vibration 7 

Corrosion problems? 

Controls operational, calibrated? 

Indoor Air Quality Forms 199 
HVAC Checklist - Long Form Page6of14 

Building: ______________________ File Number:_· __________ _ 

Completed by:------------- Title:----------~- Dat•e Checked: ____ _ 

Needs Not 

Component OK Attention Applicable Comm.ants 

Control sequence conforms 

to design/specifications? 

(describe changes) 

No pneumatic leaks? 

:!!i"~·nq'ii~f'''""'''·'' ·· .. : : ... .. ,,.,,.;,ii:: •• , ..,;,., ·, .. , .. ,;.;, ... ,i.,,.,.::.:::t•; '""'" i'll,,;,, ·""' •,:,.,,,,,,,,,,,,,,,..,,,, .. ; ,,,., .. ·'·' ii , ,.li•' I"'''"'·' '

1

,ti,,i!i,,t,l ii!,itti';, •!il•'~<,:ll" · :i:,1''i!i,i'•ili•i!i·iit'Jt, "'•"iiil,,i! •l,,!l ;!,! 'i' '""·''·"''il'tl,ii•'i\i•!l~••'' ', '' 1,{•'V't ,,;:: ·,,:,· 1 · ,l;::•:,,.!,f":l;:::,,\,;!,;1: 

"'"" ,,,,, "'""''' ,· •''•' " ''"""'' ",:•. ' .. ,' "' ,, ' ''~" ' ' ' .,,, ',\11'.'\"' 'I' 

Inspection access? 

Clean? 

Contra•! sequence conforms to 

design/specifications? 

(describe changes) 

Supply water temp. --°F 

Discharge thermostat? 

(air temp. setting Of) 

.,. :11'" ','_' .. ... ,, " ,.,, . 

····Reheat Coil• "" '!!''::'''"'" ,,,, .. ,, .. '"' .,. , .. ,,.,,,,,., ,.,,,' ,,,. '"·'· ·' '''" . :"' ·'', '""'·'. " ,, ... ,,,,,, .,,,,.,,.,, :· ":, ... '·'··""' . ''"·· .:• .. :,:· ~, ·' : ,,, : .. ·, r. ,,,,,,,, ,,''''"' ', ·,,,'•: , .. ',,., 1 "' ", .... , .. ,.,, ....... ,,,,, .... ,, ,,., ,,.,.,,,, 

Clean? 

Obstructed? 

Operational? 

:: ate.m Uumidit'.er '" ·,;, ,'! 

" :; .·;:, "' ' ;: . ·.;'·· ..... ', I 

Humidifier type 

Treated boiler water? 

Standing water? 

200 Indoor Air Quality Forms 
HVAC Checklist - Long Form Page 7of14 

Building:---------------------- File Number. ___________ _ 

Completed by:-------------Title:------------ Date Checked: ____ _ 

Needs Not 

Component. OK Attention Applicable Comments 

Visible growth? 

Mineral deposits? 

Control setpoint Of 

I . 

High limit setpoint ---°F 

Duct liner within 12 feet? (If so, 

check for dirt, mold growth.} 

Sup_pl~ Ductvv~~k -... ·.····· .. : .. · > ... \; ':· .·• · •. '·. · .:, , .• >/;,.A; .. ' , · .,, .. ··.··••·· \'; ",· }·>:.·:. .. ·~··········· .:·<·:·· ·· 

.' 

·.·· .... ::,., .'•' 

Clean? 

Sealed, no leaks, tight connections? 

Fire dampers open? 

Access doors closed? 

Lined ducts? 

Flex duct connected, no tears? 

Light troffer supply? 

Balanced within 3-5 years? -·. 

Balanced after recent renovations? 

Short circuiting or other air 

distribution problems? Note 

location(s) 

Pressuri~ca•liau .. ·· .·. '.:. ,·, ... · .... '·:· . ·.• .. ·· ·. ?'· ,< ' ': , •. :: :/: ·,· ···.: . · .. ': .. 

. SupplyPienum: ·· · .. ·" ....• 

.'· :· ... ' . . . ·:. ·. ·• ·•.· ..... : '· .;:- · ..... ···: ··.:·:::> .. •• ·;_ ·::, ... ·. · ... :' . ....... ·.·. -. ''i 

No unintentional openings? 

All ceiling tiles in place? 

Indoor Air Quality Forms 201 
HVAC Checklist - Long Form Page8of14 

Building: _____________________ File Number: __________ _ 

Completed by:-------------Title:----------- Date Checked:-----

Needs Not 

Component OK Attention Applicable Comments 

Barrier paper correctly placed and 

In good condition? 

Proper layout for air distribution 7 

Supply diffusers open? 

Supply diffusers balanced? 

Balancing capability? 

Noticeable flow of air? 

Short circuiting or other air 

distribution problems? Note 

locstlon(sJ ln"Comments" 

· .. TermfMI EfJulpment (supp~y) 

Housing Interiors clean and 

unobstructed? 

Controls working? 

Delivering rated volume? 

Balanced within 3-5 years? 

Filters in place? 

Condensate pans clean, drain 

freely? 

~- :·: • .•.. •,en;',';"•:'•·> c: . !·" ~.~tj:':•";"::.I~J!iF """~'"F(!: ... ":• :•·n•,i:j 

~~·· ,. " '""""'*"~·· ,. • .0 ::~ .•••••. ,·:,··•.:!:'''''!':.:::· •. < ··-•~!dG·:;.·,. ·::~ ·~:~::\',·'·: • •.c<':• : .. :\:.<1•.1 

Minimum stops % 

Minimum outside air_% 

(from page 2 ofthis form} 

Minimum airflow cfm 

Minimum outside air __ cfm 

202 Indoor Air Quality Forms 
HVAC Checklist - Long Form Page9of14 

Building:------------.,..---------- File Number:--~--------

Completed by:---....,----------Title:----------- Date Checked: ____ _ 

Needs Not 

Component OK Attention Applicable Comments 

Supply setpoint __ °F (summer) 

__ °F (winter) 

> ..• :. ··, .. >~·-·~·:< •, ·:··· ::·. . ' ... .·.·:·)·::"'"' : ,: ·'', ·:... -,. ·.' .. ' · Thermostats . • ''" •:,:·.. '• :;~r·;:{,·•> .. ··;::.,:··,:,.:,···,, ' ;·:'·,··,>: " : >} . ,'.,.'. :.· ' ., -_- ·: :·,. _· "":! ·.' 

Type 

Properly located? 

Working? 

Setpoints ____ °F (summer) 

__ . °F (winter) 

Space temperature __ °F 

HumiditY Sensor .- ·:., .··'· . < '/',, :> .-• ··::_.· ..... :-·: >;,,_-- . ' ) : ... '';, ,'_._- ···-. - :--,·-: 

,• .... •' -.< (: :;· ·~:·:~:):. : ·> >'· -·•· •. -.·.···-. -·- ·--.·- :'; '- : ' : 

Humidistat setpoints %RH 

Dehumidistat setpoints __ % RH 

Actual RH __ % 

. - - - ·'·· -·~·' ·_ ·: - -·-;-· .!•· <._ '; .:(•.-• .• ;: ,_.. ;- / .. y:,,;:_,.;; .: .. -• ... ,_. . ···:· ····:· ;_, - :' ·'·. ----_ .•- -- ' . Room Part1t1ons _ . _. ,• ..... ·. · · :: : ; 

,·· '. ' .. ··.. .i: ,· - ;:, -.. --: :., ·>''-· ., ____ 

··: --- - _- ; --_ .. -

Gap allowing airflow at top? 

Gap allowing airflow at bottom? 

Supply and return _each room? 

Indoor Air Quality Forms_ 203 
HVAC Checklist - Long Form Page 10of14 

Building: _____________________ File Number:-----------

Completed by: _____________ Title: ___________ Date Checls:ed: ____ _ 

Needs Not 

Component OK Attention Applicable Comments 

' 

, • bllrwella 

Doors close and latch? 

No openings allowing 

uncontrolled airflow? 

Clean~ dry? 

No noticeable odors? 

f"''''''~··.' ,·· ' :: ',. ',; ' ' 

~u~ Air P~enum ; ,.,,, '"' ,, :, ':' illii.•. ' 'l::' : ,,,: ' ,, ,:·, ''' ' ' 

Tiles In place? 

No unintentional openings? 

Return grilles? 

Balancing capability? 

Noticeable flow of air? 

Transfer grilles? 

Fire dampers open? 

·.: .::::::: ),, \: ~ 

" ,, : 

, .Du~ed rr.tums 

Balanced within 3·5 years? 

Unobstructed grilles? I 

Unobstructed return air path? 

.. -·-·· :. •:Rtitum Fan Chambers ' li::::!l~% ' ,, ,, ':';. .L ': .!• . ,\ " ~ . ,' ,_; .. 

Clean and no trash or storage? 

No standing water? 

Floor drain traps are wet or sealed? 

204 Indoor Air Quality Forms 
HV AC Checklist - Long Form Page 11 of ?J. 

Building:---------------------- File Number:-------------'-

Completed by:........_ ____________ Title:------------ Date Checked: ____ _ 

Needs Not 

Component OK Attention Applicable Comments 

No air leaks? 

Doors close tightly, kept closed? 

.. , . :Return FJ~nt~ . . ·····.· ;, . . .. . . ·., '• < ( ) ' .• , • ·'· • . • ··:t .... ·.· . ··.'• .···, .. · .. ·· . .. • ~ •.. >• ,· . .. . • ·'··· ·::: •!·;::':::· :•. ·' · .. ·• >i .... ·.) .. • ;:;, ;, ... ·r •·· .· ... ·.·. . , .. ~· <• ., .·1 •,: ....... . ,'· . . .... · 

Location 

Fan blades clean 7 

Belt guards installed? 

Proper belt tension? 

Excess vibration 7 

Corrosion problems? 

Controls working, calibrated? 

Control sequence conforms to 

design/specifications 7 

(describe changes) 

· ... ' . ' : .. '• ·.·· .·:, ',, .... •. ·" ::::·: .. ·<·: ........ ,,. ·: ,., •.• 'i··•c. '• . ·,· .•. ;:·, '·. ;·, •.. .... :·. .·. 

, .. Exha~ J:•n•· ·· ... : ·> >>~:·. ::·•Y•.·'·~··~··.,:;i· :<:·~~ ,/! :'·· .. ·:. · ... ·· •• ·. · ... ... . . . . 

Central? 

Distributed (locations) 

Operational? -

Controls operational? 

Toilet exhaust only? 

Gravity relief? 

Indoor Air Quality Farms 205 
HVAC Checklist - Long Form Page 12of14 

Building: ______________________ File Number:------------

Completed by:-------------Title:----------- Date Checked:-----

Needs Not 

Component OK Attention Applicable Comments 

Total powered exhaust __ cfm 

Make-up air sufficient? 

p_wi;;llf -:- :--· ~;.; :;,1::1:,,·., .• :MZ&stt\J.IIII;Iillrt,,,u~Jiitt*'IGI '"':r·· :

1

.:,···, 

. 1"ollet Exhausts .. , . . ..,} ...... ,.,,. .. .,, 

. ~'· ., ;,,,- '· .. ,' .... . ,, . ' ·~· ,, >•· ..<'•,!', •. ' 

Fans working occupied hours? 

Rogfsters open, clear? 

Make-up air path adequate? 

Volume according to code? 

Floor drain traps wet or sealable? 

Bathrooms run slightly negative 

relative to building? 

F. . · :•'""', .: ·. · :~'l!c ,,~.,::.:~·i'l~~· ::l::i::::::·::··· ,. •< ~% ''·· ,; •

1

1. ''''"' :: •• t':jt~~¥;,~:·; '<•:·~·~~· ·. 'l'i: "" ,r·, ::::J Smoking Lounge.EXhaust ... ' ..... . . . ······· ... """ .... -·· ~· . ., ... , .. , ... -_ ..... ···---.,. ..,,.. ···--· ,_., e ·<'•"'' 

Room runs negative relative to 

building? 

F ·:;;-.. . '· .,.,;,.,.: '·· ..... :;::i!il!l!:i::::··. ..:,,·:~;:::::;,·: '"·'c"%'"' .; , ... ;;,:;; :::;;; :;:::;;;,;;•,;;,;;:: ·:~t;:;;' ,, Prlnt ·.·•. 

- •.,: . ., ... -:·:·~ '· : · ·;: -:·c:;:• c;-'·-"' · . , ....... •'' .. :"' .,~··· . ··' •· '. 

Room runs negative relative 

to building? 

..•. ·, '. . .... '•" • ·' ·~·"""" ... , .. '" '~*"~"'"''~~""'"" ,.,,,.,.,, Garage 1/antilation ' '!'""'''· '7.',' '"''"''' ''"'""' .. :•·;c ,: .. ,,," " ,?{~ "" ,.,, 

Operates according to codes? 

Fans, controls, dampers all operate? 

206 Indoor Air Quality Forms 
HVAC Checklist - Long Form Page 13of14 

Building:--~----------,--'---~--,-..,..----...,..-- File Numbef: ,...------------~ 

Completed by:-~---~------- Title:--------...,.-...,.--- Date Checked: ____ _ 

Needs Not 

Component , OK Attention Applicable Comments 

Garage slightly negative relative 

to building? 

Doors to building close tightly? 

Vestibule entrance to building 

from garage? 

"" 

.. ' : ·:.. .. > ~;,: ·• :: ·:c "" :· ... -:·•;:;· ' i: • ·:,,• '· .. ·.•·: . < • ·~ • ·,·, 

. M.echanical. Room$ ... ·. · .":' < ~', :- ,. .. ..• ; .. : ... '> .·= X.· .. , ... , .· .... ·· .• _.·. " .. · :· :·. ·: . :· 

General condition? 

Controls operational? 

Pneumatic controls: 

• compressor operational? 

• air dryer operational? 

Electric controls? Operational? · 

EMS (Energy Management System) 

or DOC (Direct Digital Control): 

• operator on site? 

• controlled off-site? ., . 

• are fans cycled "off" while 

building is occupied? 

• is chiller reset to shed load? 

.. . . " . ·•·.· . ~·:. . . : :· .··.: .:'·':::• . : . . ,,:,·.•;;_ .:··. :•, ·: ·,.:• :,., ?·· < .•: :.;.c.. ::.::. • . _.: '·: /. . ·.:.· ' ·~ i 

Preventive Maintenance· · •. . .. :<··· .<" • ·• ••. :; . ,·.··"·:;<;;.,•.::":: • ., ••'"'·',:• .•.•.. :~:f.<:I' ..• ·•:·.,.··•···~t •·c .. \ •·•.•.· :, '·· ... ;'j " .. ,· .. '· ; . 

Spare parts inventoried? 

r;pare air filters? 

Control drawing posted? 

Indoor Air Quality Forms 207 
HVAC Checklist - Long Form Page 14of14 

Building: ______________________ File Number:------------

Completed by:-------------Title:----------- Date Checked:-----

Needs Not 

Component OK Attention Applicable Comments 

PM (Preventive Maintenance) 

schedule available? 

PM followed? 

~ .. .. ·, .·' "• '');i,;;'' ,:, '' :,lklih 

·:, ::::~::::::•,., ' '2·,'-' .·~~~ :'::"'": ::·::::•::·:::' ,'',, ·, :' :: ;Y"' ':" ,,~ :' "' '"'"'.:: : '. ~:" ·." : : ':, ·'·:" 

Flues, breaching tight? 

Purge cycle working? 

Door gaskets tight? 

Fuel system tight, no leaks? 

Combustion air: at least 1 square 

Inch free area per 2000 Btu input? 

~¢aounu.tower·'·"·· .. ;~ .·.:. ,,,;,.:,, ' il:. '==i·.o·,;,,,, :,•, ·' "=?""""~~"'"•, ··i:··J,,,:,,' ... :: .. ~·;~ ·~;::,;:•:::::' /::.;;;, ~ ,\ l.'ic.: . ·: .. .:: " ;i 

~·,:" ' ,;,, .. "" · .. ' ·, ,,,::,1,11'' ,:, 

""'""' . .:. :,;::; '•::: .. : ..··"''' if.:L ,, '·'>! '' 

Sump clean? 

No leaks, no overflow? 

Eliminators working, no carryover? 

No slime or algae? 

Biocide treatment working? 

Dirt separator working? 

~chlllena"'. "" ' '""' "··' ""' ,'"""''"'"' """"' ··:··~~··· "''"'""'" "::" ·: ,, """,'""·'· c "· '" '" "" , .. ·-:"',"'' ,, " " ,·,:; 

'·;'' ,; ' "•'' " ' '::!:¥; 

No refrigerant leaks? 

Purge cycle normal? 

Waste oil, refrigerant properly 

disposed of and spare refrigerant 

properly stored? 

Condensation problems? 

208 Indoor Air Quality Forms 
HVAC Checklist - Long Form Page_ of_· 

Building:-------------'------------ File Number:..,.-----~-------

Completed by:----'----------- Title:--"'----'--------- Date Checked: ____ _ 

Needs Not 

Component OK Attention .Applicable Comments 

" 

.. 

Indoor Air Quality Forms 209 

Pollutant Pathway Form For Investigations 

Building Name: --------------------- File Number: ____________ _ 

Address:-------------------- Completed by: ______________ _ 

This form should be used in combination with a floor plan such as a fire evacuation plan. 

Building areas that appear isolated from each other may be connected by airflow passages such as air distribution zones, 

utility tunnels or chases, party walls, spaces above suspended ceilings (whether or not those spaces are serving as air 

plenul)1s), elevator shafts, and crawl spaces. 

Describe the complaint area in the space below and mark it on your floor plan. Then list rooms or zones connected to the 

complaint area by airflow pathways. Use the form to record the direction of air flow between the complaint area and the 

connected rooms/zones, including the date and time. (Airflow patterns generally change over time). Mark the floor plan 

with arrows or plus (+) and minus (-) signs to map out the airflow patterns you observe, using chemical smoke or a 

micromanometer. The "Comments" column can be used to note pollutant sources that merit further attention. 

Rooms or zones included in the complaint area:----------------------------

Sections 2, 4 and 6 discuss pollutant pathways and driving forces. 

Rooms or Zones Pressure Relative to 

Connected to the Complaint Area 

Complaint Area Use Comments (e.g., potential pollutant sources) 

By Pathways +I- date/time 

Indoor Air Quality Forms 211 

Pollutant and Source Inventory Page 1 of6 

Building Name: ___________________ Address:----------------

Completed by:---------------- Date: _______ File Number:---------

Using the list of potential source categories below, record any indications of contamination or suspected pollutants 

that may require further investigation or treatment. ·sources of contamination may be constant or intermittent or may 

be linked to single, unrepeated events. For intermittent sources, try to indicate the time of peak activity or contaminant production, including correlations with weather (e.g., wind direction). 

Sections 2, 4 and 6 discuss pollutant sources. Appendix A provides guidance on common measurements. 

Needs 

Source Cptegory Checked Attention location Comments ,. '.< ;; ., . .., .. :'::: :/ '>· _:. : 

.·.·.······· 

., ... ·~······ :.:·.· . 

.. .. / ·.::·;< 

. $()URCESOUTSIDE BUILDlNQ' .. ' 

' ·' .··'' ::.. ·.'.'· :·' . ·· .. · ·~: ' ...... '', , .. ' ;, 

._.contami~pt~d.p~~Jd~or /dr ··• . •:. ,,>' F ..... · ::,. .· ·< ··.•·· . .. ' . ' ; ·. ;· . ·> 

' . '' .• .. ·, ;' ,• · .•••.... · •. {··· ' ..•• : .. ''' :; :),, ' ... > •··.·· •. : ' .. ·. .·.· 

' ' 

Pollen, dust 

Industrial contaminants 

General vehicular contaminants 

' ' ' . . , .. · ' . "'/' ,", ·.:;,, ,' 

. :,; '", ·y.' ·. ' :,, < :: .:·:.··. ' ' ' . 

· · Em!ss,on$ from Nearby ·S"ui:Ce,$ '··': 

·:, ' .... :. .. < 

Vehicle exhaust (parking areas, 

loading docks, roads) 

Dumpsters 

Re-entrained exhaust 

Debris near outside air intake 

. " ; . ·:J,' ·· . . ·:.': J , .. ·:' . ·.• :,·:· :·:> .. '· 

··.Soil Ga$ ·.: ' ' 

'' 

. < ., ·, ., ' ,.:. ' .. /. · . : . 

'' ',, ··'' : .,> ' .. ·· ' . .:· ,' :' . '-.•. > ..•' '·. ·,, " 

Radon 

Leaking underground tanks 

Sewage smells 

Pesticides 

Indoor Air Quality Forms 213 
Pollutant and Source Inventory Page2of6 

Building Name: ____________ ;__ ____ Address: ---------------

Completed by:--------------- Date:------File Number:---------

Using the list of potential source categories below, record any indications of contamination or suspected pollutants 

that may require further investigation or treatment. Sources of contamination may be constant or intermittent or may 

be linked to single, unrepeated events. For intermittent sources, try to indicate the time of peak activity or contaminant production, including correlations with weather (e.g., wind direction). 

Needs 

Source Category Checked Attention Location Comments 

·~q ,.,, ·~·.-·.·;;-;:c.:c. " ;;;;;; :;;;; . "'""' . ;;·:;l;~.: r ;;,;:;;; '·v ;;;;:, !.'.~~:.; . :. ,.· .....•. · .. 

··············· ·: ' ,,,, :•·. ..· .. ,.·;~·::'; . . : . ''"' '' hdc"q' -~. " ..,,( .,,. ,, ~0!.. ., ";!II(~'!;/·: :.:.::;Ji·l:,;:"'''''' .. : :::•:,: ... :li.: •. !l.i'""'"'"'l::•,• : . :· -·~·~"t':e·., ·, "~ I :,:,.. ·: .. \~''· 

Rooftop 

Crawlspace 

uiPAi~N-t ........... ·.... , · :: .. ':'"·· · ············ ::I -:;.;;,t:~:i i •. ·;::::,., : ''l: i';:;;;·. ·"f -~ ,:;-~::-:::·;;~ • t~:l:;: . f :.; 

. '''''' ···.·········· ,,:, ,;,:,;:·: '' ·:.,:.,:·:::.,v:-.,-.,: :r<.~ '<"· " . , ,,,: :: .. ::::, .L; ·. ;·;.;: 't, .. Z·ll"'\ l4 -~ -~:; , .'!Y:~' :.•::;!;; .•. :.:··, · .. , ' ' ,: 

...... , .... ' '''. ''"""'''"'' '"""""'''" ,,,,,,,,, .. ,, ''' .. ,,:;;;,:;; .. : ... : : , .. :···· "" :··:·:· . •'' .. , -~ \. ,.::,."; 

AC $ystem Equipment ,, /,:,. '' ·:·:·:·:·:·:·:':',•:';'i'''''i!i'':,!l'i'· ,, ·'lllll,:ll•: .. li"li'''"''l::,.,,,,,,,,,,,,,:.,,;,·,;.;.: ..... .:.:.:,''.~ ,.,..,,,.,. · .. .,,.,,.,,,.,, '' ,, '' 

Combustion gases 

Dust. dirt, or microbial growth 

In ducts 

Microbial growth in drip pans, 

chillers, humidifiers 

Leaks of treated boiler water 

~~i~l:lif±:\J •l#~~jW! '~ -~~~:i'i! lii!,:i'!l, .. .!' ,:z::: ;:. C,l:il"'jf,i.;'f'.~)~ !' . ",' •• 

: ':',.-. : .. ).-' ·,'' ""' ... ""'.. ·····•·• '''" '""'"" ''" ' .... """· ·,,,, ' . , ... ·. ,.-., ' '. '•'•' ., .. ; .. ''"' : ' '.,\ 

Office Equipment 

Supplies for Equipment 

Laboratory Equipment 

Indoor Air Quality Forms 214 
Pollutant and Source Inventory Page3of6 

·auilding Name: ___________________ Address: ~---------------

Completed by:--------------- Date: ______ File Number:---------

Using the list of potential source categories below, record any indications of contamination or suspected pollutants 

that may require further investigation or treatment. Sources of contamination may be constant or intermittent or may 

be linked to single, unrepeated events. For.intermittent sources, try to indicate the time of peak activity or contaminant production, including correlations with weather (e.g., wind direction). 

Source Category 

Smoking 

Cosmetics (odors) 

Cleaning materials 

Cleaning procedures (e.g., dust 

from sweeping, vacuuming) 

Stored S!Jpplies 

Stored refus~ 

compounds (e.g., paint, caulk, 

adhesives) 

Stored supplies with volatile 

compounds 

Use of pesticides 

Needs 

Checked Attention Location 

lndoorAir Quality Forms 215 

Comments 
Pollutant and Source Inventory Page 4 of6 

Building Name: __________________ Address: ----------------

Completed by: _______________ Date: ______ File Number:---------

Using the list of potential source categories below, record any indications of contamination or suspected pollutants 

that may require further investigation or treatment. Sources of contamination may be constant or intermittent or may 

be linked to single, unrepealed events. For intermittent sources, try to indicate the time of peak activity or contaminant production, including correlations with weather (e.g., wind direction). 

Needs 

Source Category Checked Attention Location Comments 

" '''"':""'~" ~ '" ,.,,.,,..;.',;-~ ·. ! '". "···> ;•'\:":.",:".~.'': ·. "'. BUiLDING CoMPONE.NTS FURNISHINGS . ... .. " ... " . ·,,,,,, /.,,., .. ~ •. .:, ?""~"'" ·, ... :., .. :•,,,,,,,.·:;.:.,:,,,,,,,, . ·, '· ; ""' "··'~,;~:~, , "~.'J,:.;.d ,,, ,: : '"" 'co .... ·, !·"' ,.,, '· ;, ', ..... ·,' 

'~··-·lllr''"'~'•'''i" 'I """'"'"• >o1iW l.~-'L ,..,,...,_, ib"'"''M 

''"""'"''"'""''''''"'''""'"''''·'' ·.· .. · ·'·: ;n@"i;v-.",0.M''-~''"""'·"' ',~;:,;,::;;;;; ;·; '"" /!/" ,,,, ... ·,~". 

.to~ttonl. Asaoclat&d with'b'USi"orfib&ri ',,' " " 

"" 

Oust-catching area 

(e.g., open shelving) 

Deteriorated furnishings 

Asbestos-containing materials 

" ",, ,;,,,, ·!·'"" ,, . •' ,:~,, ,,;,., .:,·.;; .',.; Unsanftarv Conditions/W~ter.Darrlage '\_• . " 

.··· '"' '" '" 

Microbial growth in or on soiled 

or water-damaged furnishings 

' 

Indoor Air Quality Forms 216 
Pollutant and Source Inventory Page5of6 

Building Name: ~~--------~;.__ _______ Address:------------'------'--

Completed by:-------'----------· Date:-------File Number:---------

Using the list of potential source categories below, record ;:my indications of contamination or suspected pollutants 

that may require further investigation or treatment. Sources of contamination may be constant or intermittent or may 

be linked to single, unrepeated events. For intermittent SO!Jrces, try to indicate the time of peak activity or contaminant production, including correlations with weather (e.g.; wind direction). 

Source Category 

Volatile compounds 

Needs 

Checked Attention 

:·. <· . ;. ·:,., . .. ·:,. . ,-,., ....... . . . : .·.~ .. 

~idental Events · ; · ..•. ; 

Spills (e.g., water, chemicals, 

beverages) 

Water leaks orflooding. 

Fire damage 

:··: ' . : · .. 

'· ·>· ,·'·· ' 

Location 

',; 

... ' 

·.· 

•, : 

Comments 

:. ··. . . : .•·.•... ., .... , .

. ::...:.• · .... :: ... ·, .. ···::·(··,·. ·:·. . .. ' . ;, ,· . ,::: 

. • .. • < • '·'.· .: ':•, .. '. '· .. · 

. : ... ··:.\ •'• :· .. '•. : ·.··., : ·' . ·I 

: ·', " .. : .·· 

>. .: ·;, ;' ' j 

Indoor Ait Quality Forms 217 
Pollutant and Source Inventory Page 6of6 

Building Name: __________________ Address: ---------------

Completed by:--------------- Date: ______ File Number:---------

Using the Jist of potential source categories below, record any indications of contamination or suspected pollutants 

that may require further investigation or treatment. Sources of contamination may be constant or intermittent or may 

be linked to single, unrepeated events. For intermittent sources, try to indicate the time of peak activity or contamimmt production, including correlations with weather {e.g., wind direction). 

Needs 

Source Category Checked Attention Location Comments 

f ... -••1 Use/Mixed U11e k~s ~' r .• '• ', "'"·\':' .;•.': '' ""~.:·,:: :;: ··;.~:;.:, ,,,,., '•',.,. 

roc~ '' '.~· .... ,..' .,,. " " 

Smoking lounges 

Food preparation areas 

Underground or attached 

parking garages 

Laboratories 

Print shops, art rooms 

Exercise rooms 

Beauty salons 

f&~~9i!tl~oJReilai~,Remo<~eri'n9 .~., ' '·: .. '"' ',,,, ..... ,_,,,,., ¥:~::::~ ···,·:··.· .. ,, ·;; :::::::::::,'!":.::.·:· ' :::· ""' " ·" ,. 

'41. ;, ~h.',/, , , ,,,,,-,,;,;;. '\% ,','/ ~~~t:r ,,,f!h~~~\:l~-1":i,lt I'WJf.J(;;&,l:F\ '''""''"'"'"·"':··· """""~··'····'''''"''''''"''''''''' ," ,4, 

Emissions from new furnishings 

Dust, fibers from demolition 

Odors, volatile compounds 

Indoor Air Quality Forms 218 

" 
Pollutant and Source Inventory· Page_ot_·. 

Building Name: ___________________ AddrE!SS: ----------------

Completed by:---------------- Date: _______ Fjle Nl!mber: ---------

Using the list of potential source categories below, record any indications of contamination or suspected pollutants 

that may require further investigation or treatment. Sources of contamination may be constant or intermittent or may 

be linked to single, unrepeated events. For intermittent sources, try to indicate the time of peak activity or contaminant production, including correlations with weather (e.g., wind direction). 

Sections 2, 4 and 6 discuss pollutant sources. Appendix A provides guidance on common measurements. 

Source Category Checked 

Needs 

Location Comments Attention 

. 

. ., 

Indoor Air Quality Forms 219 

Chemical Inventory 

Building Name:-------------------- File Number:-....,------------

Address: _______________________________________________ _ 

Completed by:---------------------------- Phone:---------------------

The inventory should include chemicals stored or used in the building for cleaning, maintenance, operations, and pest 

control. If you have an MSDS (Material Safety Data Sheet) for the chemical, put a check mark in the right-hand column. 

If not, ask the chemical supplier to provide the MSDS, if one is available. 

Sections 2,4 and 6 discuss pollutant sources. Section 4 discusses MSDSs. 

Date Chemical/Brand Name Use Storage Location(s) MSDS on file? 

Indoor Air Quality Forms 221 

Hypothesis Form Page 1 of2 

Building Name: _____________________ File Number:-------------

Address: ______________________________________ __ 

Compl~edby: ____________________________________ _ 

Complaint Area (may be revised as the investigation progresses): 

Complaints (e.g., summarize patterns of timing, location, number of people affected): 

HVAC: Does the ventilation system appear to provide adequate outdoor air, efficiently distributed to me~ occupant 

needs in the complaint area? If not, what problems do you see? 

Is there any apparent pattern connecting the location and timing of complaints with the HVAC system layout, condition 

or operating schedule? 

Pathways: What pathways and driving forces connect the complaint area to locations of potential sources? 

Are the flows opposite to those intended in the design? ------------------------

Sources: What potential sources have been identified in the complaint area or in locations associated with the complaint 

area (connected by pathways)? 

Is the pattern of complaints consistent with any of these sources?---------------------

Indoor Air Quality Forms 223 
Hypothesis Form Page2of2 

Hypothesis: Using the information you have gathered, what is your best explanation for the problem? 

Hypothesis testing: How can this hypothesis be tested? 

If measurements have been taken, are the measurement results consistent with this hypothesis? 

Results of Hypothesis Testing: 

Additional Information Needed: 

224 Indoor Air Quality Forms 
Index 

Arr distribution, see also HV AC system, Ventilation 7-8,24-27, 35, 38,57-71, 82-84, 88,92-93, 111-115, 121-135, 146, 

177, 193, 201-206 

Air handling units, see also HV AC system 124-130, 177, 192, 199 _ 

Air pressure, see HV AC system, Pressure relationships, and Ventilation 

Airflow, see also Pressure relationships and Ventilation 24, 26, 64, 71, 99, 104, 114, 121-122, 125 

Asbestos 63, 147-150, 164-165 

ASHRAE, see also Standards, guidelines, and advisories 121, 167 

Guideline 1-1989 139 

Standard 52-1976 126, 138 

Standard 55-1981 57,66, 129, 137 

Standard 62-1989 8, 14, 28, 34-35, 41, 60,64-66, 82-87, 115, 126, 136-137 

Bioaerosols, see Biological contaminants 

Biocides 5, 73, 91, 94-95, 132 

Biological contaminants 5, 24, 35-36,40,48, 56, 63, 76, 82, 86, 91-95, 102-105, 117-118, 125, 127, 129, 131-132, 135, 

138, 141-146, 165 

measuring 105, 117 

Boilers, see also HV AC system 87-88, 113, 124, 135 

Building-related illness (BRI) 11, 86, 101, 105 

Carbon dioxide (C02) 36, 49,57-58,60-61,74-76,87, 110-115 

Carbon monoxide (CO} 10, 37, 56, 58, 75-77, 100, 113, 118, 135 

Chemical Inventory 23, 26,72-73, 169,221 

Chemical smoke 22,60-61,68,75, 77, 110-112 

Chillers, see also HV AC system 124, 135, 137 

Cleaning materials 32, 36, 73, 97 

Combustion gases 29, 56, 75, 86, 89, 100, 113 

Complaint area 49, 53-54, 65, 68-69, 76 

Complaints 10-11, 27, 32, 46, 103 

Indoor Air Quality Complaint Form 15, 32, 169, 181 

responding to 14-17 

Control systems, see also HV AC system &; 19-21, 23, 26, 3:i, 34-36,47,57,60, 64-65,76, 82; 92, 

122-126, 128~130, 134-135, 145 

Cooling coils, see also HVAC system , 35, 67, 97, 123-124, 126, 128 

Cooling towers, see also HV AC system 24, 28, 35, 89, 101, 135 

Dampers, see also HV AC system 24, 60, 65, 87, 125, 130, 133 

fire dampers 25, 130 

mixing boxes (mixed air plenums) 124-126 

outdoor air dampers 59-60, 125 

Diffusers, see also HV AC system 58-61, 67, 82-83, 87-88, 113-114, 133 

Index 225 
Ductwork, see also HV AC system 36, 61, 73, 91, 102, 127, 131-132 

cleaning 36, 61, 73, 91, 102, 127, 131-132 

leakage 67, 87, 130 

plenum 24-25,61,67,87,92, 123,125,130,131,133 

return 65, 87, 99, 130, 133 

supply 61, 65, 99-100, 114, 123 

Dust 23,25,32,67, 72-73,118,126,131,138 

Elevators 68- 69, 93 

Environmental stressors 11, 55-56,77-78, 85 

Environmental tobacco smoke (ETS) 6, 9-10, 24-25, 32, 35,40-41, 66, 73, 81-82, 90, 116, 118. 166 

EPA, see Standards, guidelines, and advisories 

Ergonomic stressors 55-56, 78, 85 

Exhaust air, see HVAC system and Ventilation 8-9, 58, 65, 82, 89, 114, 124, 133, 154 

Exhaust fumes 53, 72, 100 

Fans, see also HV AC system 

Filters, see also HV AC system 

22,48,87,89, 124,130,133,145 

2,36,48,60-61,84,91-92,123,126-128,130,138 

Fire codes 27, 58, 83 

Formaldehyde 56, 82, 85, 116-117 

Furnishings 34, 40,72-73,78, 86, 93, 96, 99, 102, 122, 133, 145 

Health and safety 52, 56, 63, 76, 101, 105, 117, 147 

committee 16-17,40,76 

considerations for investigators 52, 56, 63, 76, 101, 105 

Humidification, see also HVAC system 35, 56, 60, 90, 101, 129, 141 

Humidity, see Moisture 24, 49, 56, 67, 60, 82, 89, 94, 110-111, 123, 125, 129 

HVAC Checklist- Long Form 26, 58, 61, 169, 175, 195-209 

HVAC Checklist- Short Form 26, 58, 61- 62, 169, 191-194 

HV AC system 5, 6-9, 57-59, 62, 79, 86, 89, 111, 121, 123, 154 

components 57, 64, 83, 87, 94, 123-137 

design types 7-8, 57-59, 61-62, 64- 65, 121-123 

maintenance 22-23, 62, 67, 91, 122 

operation 6, 25, 52, 55-59, 62, 89, 122, 189 

zones 47, 58, 76, 82, 112, 121-122, 169 

Hypothesis 

developing and testing hypotheses 46, 57, 67, 71, 74-75, 78-79, 223 

Hypothesis Form 57, 67, 71, 74,78-79, 169, 223-224 

IAQ Incident Log 16, 49, 169, 183 

IAQ Management Checklist 42, 169, 171-174 

IAQ management plan flowchart 32 

IAQ manager 32-33 

IAQ profile flowchart 20 

IAQ task force 13, 17, 40 

Indoor Air Quality Complaint Form 15, 169, 181 

Infiltration, see Airflow and Pressure relationships 

Integrated Pest Management (IPM), see Pest control 

226 Index 
Intermittent problems 10, 55, 59, 72, 74,77 

Interview, see Occupant Interview 

Investigation 

collecting additional information 20, 25-29,49-74 

flowchart 45 

forming hypotheses, see Hypothesis, developing and testing 

outside assistance 20, 40, 45, 47, 63, 105-108, 117 

reviewing existing records 20-22, 50, 58 

sampling 74-77, 109-119 

walkthrough 45,47-49 

Legionnaire's disease 11, 56, 101 

Lighting 11,24-25,55,77-78,85-86 

Loading docks 23, 25, 37, 89, 100 

Local exhaust, see also HV AC system and Pressure relationships 9, 22, 40, 65, 82-83, 90, 92, 94, 97, 99-100, 102, 137 

Log of Activities and System Operations 52, 53, 58, 77, 139, 169, 189 

Maintenance 24, 31, 34, 36, 67,97 

preventive 23, 36 

records 22-23 

schedule 23, 34-35, 139 

Manometer 36, 58, 68-69, 110 

Material Safety Data Sheets (MSDS) 20, 28, 32, 35, 38-40, 73 

Measurement 

comparing to standards and guidelines 75- 76, 87 

devices 48, 58, 75, 109-119 

developing measurement strategy 48,74-77 

Microbiological contaminants, see Biological contaminants 

Mildew, see Biological contaminants 

Mitigation 

evaluating approaches 102-103 

judging success 75, 103-104 

managing projects 103 

persistent problems 104 

using air cleaning 81, 84-85, 89,92 

using exposure control 81, 85, 93,96-99 

using source control 81-82, 89-101 

using ventilation 41, 81-84, 87-100 

Mixing boxes, see also HV AC system 61, 124-126 

Moisture 23-24, 95, 128, 131, 141-146 

humidity 24, 60, 120, 122, 137-138, 141-146 

water damage 24, 73, 94, 128, 131-132, 141-142 

Mold, see Biological contaminants 

Multiple chemical sensitivity (MCS) 12 

NrosH, see also Standards, guidelines, and advisories 41, 63, 75, 81, 84, 111, 116, 119, 147~149, 154, 157. 

164-165, 167 

Noise 11, 55, 77-78, 85-86, 127 

Index 227 
C:.ccupan~ 5, 10·11 

complaints 10, 46, 48, 50, 72, 131 

density 24, 66, 73, 78, 87, 122, 136 

Occupant Diary 52, 77,169, 187 

Occupant Interview 50-52, 169, 185 

occupant relations (IAQ management plan) 40 

Odors 8, 24-25, 49, 65 

Outdoor air intake 5, 10, 25, 56, 58, 65, 89,99-100, 121, 124-125 

Outdoor sources of contaminants 5, 25,56-57, 72-74,86, 89, 102, 113, 127 

Peppermint oU 69 

Pestcontrol 23,32,37-38,43,73,84,89 

Integrated Pest Management (IPM) 38 

pesticides 23, 32, 37-38, 76, 85, 96, 116 

Pollutant pathways and driving forces 5, 9-10,50, 54,69-70,79, 82, 84, 89, 97, 100, 115, 152 

Pollutant and Source Inventory 25-26,28,72-74, 169,213 

Pollutant Pathway Form for Investigations 67, 69, 169,211 

Pollutant Pathway Record IAQ Profile 26-27, 33, 169, 175 

Pressure relationships, see also Airflow and HVAC system 8-9,27, 35, 37, 45, 66-68, 71, 82-83, 89, 93, 98, 100-111, 127, 

133-134, 144 

negative/positive 8,26-27,37,70,82-83,89,98,100,110-111,127,132,141,154-155 

Preventive Maintenance, see also Maintenance 36, 132 

Psychrometer 111, 143 

Psychosocial stressors 11,55-56,77-78 

Purchasing 32, 35, 37, 41, 81 

Radon 5, 89, 151-152, 167 

Recirculation, see Ventilation 

Redecorating/Renovation/Remodeling 21, 32, 34, 40, 55, 66, 73, 86,99 

Return air, see HV AC system and Ventilation 

Roofing 23, 85, 89, 99 

Sampling and analysis, see Measurement 

Sick building syndrome (SBS) 11, 155 

Smoking, see Environmental tobacco smoke 

Sources, see also Pollutant and Source Inventory and specific sources (by name) 5, 6, 8-9, 26, 28, 35, 48, 72-74, 76, 

81-82,90 

Special use areas 25, 65, 73, 86, 90, 93, 96, 98, 133-134 

Standards, guidelines, and advisories, see also ASHRAE, NIOSH 43,75-76, 167 

Storage praetices 23, 25, 37, 73,97 

Supply air, see HV AC system and Ventilation 

Surface contamination, see also Biological contaminants 6, 37, 76, 86, 91,94 

Terminal devices, see HV AC system 

Testing and balancing 21, 43, 48, 58, 87, 92, 94,98-99, 103, 123 

Thennal comfort 7, 24,56-57,87,89, 110-111, 121, 133-134, 137, 167 

Thcnnal mass balance 114-115 

Thermostats,seealsoHVACsystem 24,59-60,64-65,67,111,122,134-135,145 

228 Index 
Tools 

for IAQ investigations 45,48-50, 58, 68, 72, 77, 109-119 

for IAQ profiles 20, 22 

Total volatile organic compounds (TVOCs) 115-116 

Tracer gas 58, 69, 77, 112-113, 126 

Trainingm 31, 33, 41, 117~ 139, 167 

Trash disposal 23, 37, 89 

Unit ventilators, see HV AC system 

Unsanitary conditions 24-25,38,65,67, 72, 94, 117 

Ventilation, see also Airflow, ASHRAE 62-1989, HV AC system, Pressure relationships 7, 8-10, 24, 65, 83-84, 110,113, 

122, 126, 130-131, 133, 136, 139, 144, 167 

air distribution 61, 69, 86-87, 95, 104 

outdoor air 24, 65, 82-83, 86-87, 91-92,96, 99-100, 102, 113-115, 121, 122-125, 135, 145 

measuring 87-88 

recirculation 82, 92 

total air 65, 82-83, 95, 99, 104, 113-114 

underventilation 24,56-57,60,66-67,82-83,87-88, 112-113 

Ventilation Worksheet 169, 179 

Vibration 11, 77-78, 85-86 

Volatile organic compounds (VOCs) 6, 82, 96, 99, 102, 115-116 

Walkthrough 

profile 20-25 

investigation 45, 47-49 

Water chillers, see also HV AC system 137 

Water, see Moisture 

Zone/Room Record 28-29,61-62, 169, 177 

*U.S. G.P.0.:1993-752-419:419 Index 229 

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