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International Sympos/Water supply and dr QC100 .U57 N0.553, 1979 C.1 NBS-PUB-C 19

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NBS Special Publication 553
NATIONAL BUREAU OF STANDARDS

The National Bureau of Standards' was established by an act of Congress on iMarch 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology

and facilitate their effective application for public benefit. To this end, the Bureau conducts

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provides engineering measurement traceability services; develops test methods and proposes

engineering standards and code changes; develops and proposes new engineering practices;

and develops and improves mechanisms to transfer results of its research to the ultimate user. The Laboratory consists of the following centers:

Applied Mathematics — Electronics and Electrical Engineering2 — Mechanical

Engineering and Process Technology 2 — Building Technology — Fire Research —

Consumer Product Technology — Field Methods.

THE INSTITUTE FOR COMPUTER SCIENCES AND TECHNOLOGY conducts

research and provides scientific and technical services to aid Federal agencies in the selection, acquisition, application, and use of computer technology to improve effectiveness and

economy in Government operations in accordance with Public Law 89-306 (40 U.S.C. 759), relevant Executive Orders, and other directives; carries out this mission by managing the Federal Information Processing Standards Program, developing Federal ADP standards

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; Some divisions within the center are located at Boulder, CO 80303.
AU6 17 1979

Water Supply and Drainage

in Buildings

no ^53

Proceedings of an International Symposium

September 28-30, 1976

National Academy of Sciences

Washington, D.C.

Editors

Lawrence S. Galowin

JoAnne R. Debelius

Center for Building Technology

National Engineering Laboratory

National Bureau of Standards

Washington, D.C. 20234

In cooperation with:

Counterpart Commission W-62

U.S. National Committee for the International Council

for Building Research, Studies and Documentation

Building Research Advisory Board Commission on Sociotechnical Systems

National Research Council

U.S. DEPARTMENT OF COMMERCE, Juanita M. Kreps, Secretary

Luther H. Hodges, Jr., Under Secretary

Jordan J. Baruch, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

Issued August 1979
Library of Congress Catalog Card Number: 79-600105

National Bureau of Standards Special Publication 553

Nat. Bur. Stand. (U.S.), Spec. Publ. 553, 232 pages (Aug. 1979)

CODEN: XNBSAV

U.S. GOVERNMENT PRINTING OFFICE

WASHINGTON: 1979

For sale by the Superintendent of Documents. U.S. Government Printing Office, Washington, D.C. 20402

Stock No. 003-003-02101-6 Price $6

(Add 25 percent additional for other than U.S. mailing).
PREFACE

In the United States, the process by which plumbing systems are

planned, designed, constructed, and operated is highly regulated by

prescriptive (as contrasted with performance) codes and standards and

largely comprises the specification, assembly, installation, and operation of materials and equipment offered by a diversity of manufacturers.

Because the process revolves about products—fixtures, fittings, or trim

(often referred to as brass), specialty items, and pipe—technological

developments that have been and continue to be made are mainly productoriented and the result of proprietary research and development activities of manufacturers. These proprietary activities benefit from and

are constrained by research performed in furtherance of the development

of plumbing codes and standards. The broader and more basic research

has traditionally been centered at the National Bureau of Standards and

augmented by programs at a limited number of universities such as the

Stevens Institute of Technology, the University of Iowa, the University

of Illinois, Pennsylvania State University, Massachusetts Institute of

Technology, Johns Hopkins University and Virginia Polytechnic Institute.

With each new product or product-oriented advance or systems integration in a building there is growing awareness by those involved in

plumbing (and by informed outsiders) that the current process of planning, designing, constructing, and operating plumbing systems does not

(a) engage the expertise of all the scientific areas that, in actuality,

comprise the basis of plumbing, (b) provide a valid basis for comparing

objectives and economics of competitive development, (c) focus innovative

efforts on potentially exploitable developments, and (d) facilitate

exploitation of developments. This awareness is being heightened by

recent drought experiences and broadened concerns of the availability

of water and energy and the complexity and cost of waste water or by-product disposal.

Given this widening interest in, and national need not only for

improving the state of the art of- plumbing but also for improving the

integration of considerations relating to plumbing with those relating

to other building and utility concerns, the Counterpart Commission, in

cooperation with the CIB W-62, decided that it would be useful to convene

an international symposium. The meeting theme was directed at improving

the description of plumbing research needs defined earlier by the

Counterpart Commission , to place those needs in perspective ¥is-a-vis

other building and utility research needs, and to suggest a general plan

of action for research activity. In preparation for the symposium, the

Counterpart Commission had a series of theme papers prepared by subcommittees of its members and other knowledgable specialists which could

provide the framework for discussion at the symposium.

iii
The topics of primary concern identified from the United States

perspective were submitted in the following position papers:

1 . Water Requirements and the Procedures for Estimating the Demand for

Water in Buildings

The most widely used procedure for estimating the demand for water

within buildings is the probabilistic method developed by Dr. Roy

Hunter while at the National Bureau of Standards. The Hunter method

provides an estimate of the number of fixtures most likely to be

operating simultaneously as a function of the total number of fixtures in the design. In developing this technique for real systems,

Hunter departed from a rigorous probabilistic approach and substituted equivalency factors (fixture units). It is believed that the

computational complexity of the true probabilistic approach was one

of the reasons why Hunter developed the fixture unit concept. The

advent of the modern digital computer removes this restraint.

The Hunter technique and values assigned to the parameters have

changed little since their establishment 35 years ago, and in view

of their recent experiences in large-scale building projects,

engineers have begun questioning the accuracy of this method. The

results of several studies indicate that significant potential

savings, in both initial costs and operating costs, can be achieved

with an accurate knowledge of the demand for water within buildings.

This position paper discusses alternative mathematical models, the

nature and extent of a field data acquisition program, the human

factor element, and the preparation of a design guide. Accurate

knowledge of water usage patterns is required to establish a national policy in water related energy conservation.

2. Water and Water -Related Energy Conservation in Buildings

In its final report, Water Policies for the Future , the National

Water Commission concludes that the present water quantity situation is good except in the Rio Grande, Lower Colorado, and Great

Basin regions, where consumption exceeds the man annual run-off.

The shortage, as high as 36 percent in one area, is offset by

mining groundwater or by bringing water in from other regions.

Looking ahead, the Commission recommends future outlooks be based

on several possible outcomes, in contrast to earlier studies which

based projects on extensions of past trends. Our current concern

for energy, for example, may influence water withdrawals and con- sumptions far beyond our expectations.

It is against this background that water conservation in buildings

must be evaluated. With existing technology, approximately 30

percent of the water consumed in residences can be saved; yet

little progress is being made. Major research programs considering

recycling of waste water are under way, and there may be areas where

iv
the implementation of these techniques should be accelerated.

Needed are cost-benefit analysis at local, state, and federal

levels and cost effectiveness analysis at the consumer level and

particularly for large consumers. The impact of conservation

practices on the health and welfare of residents also needs to be

evaluated further.

This position paper examines water conservation practices and

water-related energy conservation practices on a very broad scope.

The interaction of water conservation with energy conservation and

other sayings (waste water treatment, regional and odd lot) may be

far more important than the conservation of water itself.

Protecting Water Quality in Buildings

Much research has been done to provide a base for the setting of

limits for organic and inorganic contaminants in our drinking

water. Additional research has been undertaken to provide guidelines and technical manuals for health, engineering, and water

supply associations so that treatment processes can be upgraded

to meet the requirement of the Safe Drinking Water Act.

A determination of the extent to which contaminants enter the

water within the building needs to be made. Inorganic materials

have been known to come from the material used in the distribution

network. Cross-connections with process equipment and sewer lines

have been identified as sources of organic contaminants. The reuse

of water will increase the potential for hazardous cross-connections

and the buildup of heavy metals.

This position paper gives detailed consideration to the possible

source of contamination within buildings and suggests a research

program to produce answers to offset this health hazard.

Hydraulics and Pneumatics of Gravity Drainage Systems

Renewed interest in the hydraulics and pneumatics of gravity drainage systems has been stimulated in the United States by reports on

the wide-spread acceptance of single-stack (self -vented) drainage

systems in Britain and Europe and by the results of U.S. laboratory

research and field trials with single-stack drainage, reduced-size

venting, and other innovative designs. Some of the contemporary

model codes are beginning to incorporate or at least to consider

evaluation guidelines for innovative approaches to drainage system

design. These innovative approaches probably offer significant

potential savings in cost and materials, and some provide for

simplified configurations that could be attractive from architectural and construction standpoints, particularly in manufactured

modular construction.

v
This position paper assesses the status of current evaluation

methodology, discusses the principal problems, and describes the

potential impact of improved methodology, and includes a plan

for stimulating needed research activity that should be useful

both to researchers in the proposal of meaningful research and

to potential funding organizations in evaluating the proposals

and in allocating funds to selected programs showing significant

potential.

5. Alternate Concepts for Transporting and Treating Wastes

Thirty to forty percent of the water consumed in the home is used

by the water closet. The primary purpose of this waste water is

to carry solids through the network of drainage pipes without

clogging. The use of this highly processed clear potable water

to carry away waste is questioned, and alternatives are sought.

Interim solutions such as the separation of wastes, black water

vs. grey water, must be examined and placed in perspective. Longrange solutions considering sewage treatment, energy, transport

costs, etc., must be researched.

This position paper examines water supply and drainage for buildings in its broadest sense and suggests new concepts.

6. Performance Concepts for Water Supply and Drainage Systems

Difficulties have been encountered in the evaluation of innovative

approaches in water supply and drainage under the provisions of

contemporary American plumbing codes. These difficulties are largely attributable to the characteristics prescriptive nature

of the codes and to the lack of an adequate evaluation methodology

for predicting or testing the essential performance (i.e. , those

attributes that determine health, safety, and essential sanitary

and physiological functions).

The philosophy of the performance approach in this field is that

the traditional prescriptive standards, which are adequate for

proven solutions, are not suited to the evaluation needs of innovative approaches. Thus, supplemental performance standards are needed to facilitate the acceptance of innovations.

This position paper describes the current status of performance

evaluation methodology in relation to water supply and drainage

for buildings, discuss the principal problems, and indicate the

potential impact of improved methdology. A plan for stimulating

needed research activity is included that will be useful to

researchers in the proposal of meaningful research and to potential funding organizations in evaluating the proposals and in

allocating funds to selected programs showing significant

potential.

vi
FOREWORD

This report contains the papers presented at the International

Symposium on Water Supply and Drainage convened on September 28-30,

1976 at the National Academy of Sciences, Washington, D.C, conducted by

the U.S. National Committee for the International Council for Building

Research, Studies and Documentation (CIB) Counterpart Commission W-62.

The meeting provided the opportunity to exchange information and identify general needs and common perspectives of plumbing in on-going

research applications and practices in the United States and other

countries.

The objective of the U.S. National Committee for the International

Council for Building Research, Studies and Documentation (USNCCIB)

Counterpart Commission W-62 is the enhancement of the efforts of those

who seek to improve and apply the sciences and technologies used to

provide potable water to, distribute the water within, and remove the

liquid waste from buildings. To this end, the Counterpart Commission

function is to:

1. Serve as a liaison between U.S. interests and the CIB and thereby

provide a mechanism through which the ready exchange of plumbing

research data generated by U.S. public and private. organizations

and other CIB members is encouraged.

2. Stimulate the generation of research studies and information on

the state of the art and improvement in the field of plumbing

research and technology.

3. Motivate organizations to take positive action in furthering

plumbing research studies and documentation, and in improving

practice.

This document was published by the National Bureau of Standards

in collaboration with the National Academy of Sciences. The Counterpart Commission gratefully acknowledges the financial support provided

by the National Science Foundation for the actual convening of

the symposium, and the generosity of the National Bureau of Standards

in publishing these proceedings; it sincerely appreciates the contribution of the participants at the symposium and of the authors of the

papers incorporated in these proceedings.

vii
The project which is the subject of this report was approved by

the Governing Board of the National Research Council, acting in behalf

of the National Academy of Sciences. Such approval reflects the Board's

judgment that the project is of national importance and appropriate with

respect to both the purposes and resources of the National Research

Council.

The members of the Committee selected to undertake this project and

prepare this report were chosen for recognized scholarly competence and

with due consideration for the balance of disciplines appropriate to

the project. Responsibility for the detailed aspects of this report

rests with that committee.

Each report issuing from a study committee of the National Research

Council is reviewed by an independent group of qualified individuals

according to procedures established and monitored by the Report Review

Committee of the National Academy of Sciences. Distribution of the

report is approved by the President of the Academy, upon satisfactory

completion of the review process.

The National Bureau of Standards assisted in the organization of

the meeting and with staff participants in developing several of the

contributed papers. The proceedings are published by the National

Bureau of Standards to provide the document as a reference available

to the public.

This is a report of work under Task Order No. 345, Contract Number

NSF-C310 between the National Science Foundation and the National

Academy of Sciences. Reproduction in whole or in part is permitted

for any purpose fey the United States Government.

Inquiries concerning this publication should be addressed to

either 1) the Executive Director, Building Research Advisory Board,

National Research Council, 2101 Constitution Avenue, NW, Washington,

D.C. 20418, or 2) the National Bureau of Standards, Center for Building Technology, Washington, D.C. 20234.

The Editors

viii
CONTENTS

Page

Preface iii

Foreword _. . . . . . . . . . . . ! • • • •_ vii

Abstract , xi

WATER SUPPLY AND CONSERVATION

Water Requirements and Procedures for Estimating

the Demand for Water in Buildings

by R. V. Benazzi, L. Guss, R. Orend, R. S. Wyly,

and T. P. Konen 3

Protecting Water Quality in Buildings

by G. Williams, T. P. Konen, F. Liposki, J. R. Myers,

L. Nielsen, W. Mikucki and W. Staton 15

Water and Water-Related Conservation in Buildings

by A. J. Fowell, A. Bransdorfer, P. Fletcher,

R. J. Orend, H. J. Pavel and G. H. Williams 21

HYDRAULIC ANALYSIS AND PERFORMANCE CONCEPTS FOR WATER

SUPPLY AND DRAINAGE SYSTEMS

Hydraulics of Gravity Drainage Systems

by R. S. Wyly, R. V. Benazzi, T. P. Konen,

R. R. Manfredi and L. S. Nielsen 35

Performance Concepts for Water Supply and Drainage

Systems in Buildings

by L. S. Galowin, W. J. Downing, L. S. Nielsen,

M. J. Orloski and R. S. Wyly 53

Alternative Concepts for Transporting and Treating

Wastes Within Buildings

by T. P. Konen, R. S. Bevans, W. J. Boegly,

D. Savitsky and C. Cole 71

INTERNATIONAL PERSPECTIVES

CIB W-62 Purpose, Methodology and Fields of Work

by K. Ovesen, Danish Building Research Institute 8]

ix
Standardization Structure in Europe

by F. Perrier, CSTB, France . . . 89

Certification and Agreement System in Europe

by D. Trinkier, Germany 101

Research Laboratories with CIB Interest

by R. Hanslin, C. D. J. Webster and V. Nielsen,

Denmark 109

CONTRIBUTED PAPERS

Cost Benefit of Plumbing: Large Fringe Benefits for

Sanitary Installations by Thorough Analysis of System

by T. Rosrud, Norwegian Building Research Institute .... 131

Economic Water Supply Design Based on Performance

Requirements

by E. Olsson, National Swedish Building Research

Institute 137

Production, Transport and Use of Hot Water

by F. Perrier, CSTB, France 161

Performance Requirements for Taps: A Consensus from

Scandinavia

by V. Nielsen, Denmark 175

Code Structure and Standardization in the United

States

by M. Snyder, United States 193

Potential Savings from Using Reduced-Size Venting in

the United States

by H. Marshall, R. Ruegg and R. Wyly, United States .... 207

USNCCIB W-62 Members 227

Contributors to the Proceedings 229

USNCCIB Officers and Members 1975-1976 231

BRAB Officers and Members 235

x
ABSTRACT

This report contains the papers presented at the International Symposium

n Water Supply and Drainage convened on September 28-30, 1976 at the National

cademy of Sciences, Washington, D.C. and conducted by the U.S. National

ommittee for the International Council for Building Research, Studies and

ocumentation (CIB) Counterpart Commission W-62. The meeting provided the

pportunity to exchange information and identify general needs and common

erspectives of plumbing in on-going research applications and practices

n the United States and other countries.

ey Words: Building water systems; CIB; international plumbing research;

lumbing and drainage; U.S. research in plumbing.

xi

WATER SUPPLY AND CONSERVATION

WATER REQUIREMENTS AND PROCEDURES FOR ESTIMATING

THE DEMAND FOR WATER IN BUILDINGS

by

Robert V. Benazzi, Lawrence Guss,

Richard J. Orend, Robert S. Wyly, and Thomas P. Konen

The need to conserve all natural resources has led researchers to investigate methods for conserving both water and energy in today's plrmblng

systems, and one startling fact has become increasingly more evident;

that is, within the plumbing industry very little is known about water

requirements and the procedure for estimating the demand for water.

Methods used today in the design and sizing of water supply systems are

based upon guidelines that were established many years ago, and few

changes have been made. On the basis of experience, engineers have tried

to modify existing sizing techniques, but they have met with only limited success even though recent studies indicate that most supply systems are oversized by a large margin—a waste of valuable time, labor, and materials.

Unfortunately, however, insufficient quantitative and qualitative data are available to permit development of the improved general computation procedures required if a meaningful policy on conservation of materials and

water-related energy is to be established.

This paper seeks to describe current methodology, both domestic and foreign,

and the problems associated with it. Also discussed are the merits and

potential impact of improved methodology.

Background

The most widely used method for estimating the demand for the water supply

system is that developed by Dr. Roy B. Hunter of the National Bureau of

Standards. 1 Hunter realized that the most difficult task in determining

the conditions of flow in a plumbing system Is to predict the number of

fixtures most likely to be operating simultaneously out of the total number

of fixtures in the design. Knowing that the fixtures in a plumbing system

are used Intermittently, Hunter theorized that the actual loading effect

of a single fixture was dependent upon the frequency of use of the

fixture, the length of time that the fixture was In use» and the average

flow rate of the fixture.

3
The method established by Hunter assumes that there are many fixtures

and that the operation of each fixture Is a random event. This method

requires knowledge of the frequency of use (the time Interval between

fixture usage), the operating time, and the flow rate of each fixture.

The values assumed by Hunter are given In Table 1.

TABLE 1 Characteristics of Selected Plumbina Fixture

Fixture

Frequency of Use

T (sec.)

Operating Time

t (sec.)

Flow Rate

Q 0/sec.) (gpm)

Water closet,

valve 300 9 1,7 (27)

Water closet,

tank 300 60 .25 W

Bathtub 900 60 .5 (8)

To determine the number of fixtures that could be in operation, Hunter

made use of the binomial probability theory and developed the following

general expression for a system consisting of the same type of fixture:

r n /. \n-r r pr = (1-p)

n r r

p

Where p

f= probability of r fixtures out of a total of n fixtures operating

n simultaneously, = the number of ways r fixtures can be selected

from a collection of n fixtures, (1-p) » probability of (n-r)

fixtures operating at any given instant, and p = probability or r fixtures operating at any instant.

In converting this relationship into a useful tool, Dr. Hunter established

the criterion that, for an adequate system, the demand should not exceed

the design value more than 1 percent of the time. Thus, It can readily be seen that the demand load Q, is equal to:

Q = q

- m,

Where q = the volume rate of consumption of a single fixture, and m = the

maximum number of fixtures that probably will not operate simultaneously more than 1 percent of the time.

Because of the computation limits at the time Hunter developed his methodology, he did not generalize the expression given above to encompass several

fixture types. Alternatively, Hunter developed the fixture unit concept

which provided an empirical computation procedure for estimating the demand of

mixed systems. This concept utilizes the assumption that the ratio of the design factor for different fixtures is independent of the demand. However,
because no rigorous study has been made, this fixture unit approach has

led to gross errors resulting in overdesign. Also, because of the

paucity of field measurements of the input data for Hunter's technique,

practicing engineers have used desiqn guides generally based upon judgment of usage parameters. Many of these judgments were in gross error.

While the Hunter method has been in general use in both the United States

and the United Kingdom since its presentation, Wise and Croft 2 recently

obtained data for the frequency of use of water closets, lavatories, baths,

and kitchen sinks in 108 British homes with average water needs. Using an analysis similar to Hunter's, but with their own field data, these investigators found they could nearly double their values for frequency of use without changing their design load calculations. If used in the design of

a plumbing system, Wise and Croft's lower probabilities could result in

smaller-diameter pipe sizes as compared to those determined from Hunter's

values.

T. W. Maver 3 has investigated the frequency distribution method of demand

in lieu of considering fixture types. The Maver approach requires the

construction of frequency plots and the determination of distributional

form. Upon acceptance of the hypothesis for a particular distribution,

a demand may be specified that will be exceeded not more than a prespecified portion of time. Maver also considered the effects of various factors

on maximum daily consumption through regression techniques.

Marchetti

1* has proposed a method that utilizes a radical formula equating

a design factor to the square root of the number of homogeneous outlets.

This approach utilizes one fixture type under limited circumstances of

evaluation.

in 1972, Webster 5 challenged Hunter's basic assumption that each fixture

has an equal probability of use. His theoretical treatment and analysis

of the problem were based on a generalized Poisson distribution that assumes an equal probability of use of the various fixture types. Like

Hunter, he assumed fixed flow rate requirements by fixture. By evaluation

of the frequency of flow for all combinations of fixtures in a London

apartment building study, Webster obtained a distribution of .outlet fixture

demand. He then compared this demand to the theoretical model. Webster

found that his analysis yielded results which were in better agreement

with his field data than the results predicted by Hunter's model.

With the advent of large, tall buildings, engineers began to take a serious

look at the sizing techniques they employed. The advent of "tankless"

pumping systems —systems utilizing either constant-speed or variable-speed

pumps to maintain constant system pressure—also was instrumental in indicating overdesign. It was found that pumping plants seldom operated above

70 percent of their capacity. Heating plants for the production of domestic

hot water also were found operating at substantially lower ratings than

their capacities.

5
In 1959 a group of practicing engineers in Detroit brought this problem to

the attention of the American Society of Sanitary Engineers (ASSE) at its

national convention. A task force was organized and a test program was

initiated on apartment buildings ranging in size from 20 to 292 units.

The test results indicated that the overdesign of the cold water system

ranged from 80 to 300 percent and the overdesign for the hot water ranged

from 270 to 620 percent. 6

A permanent group was formed under the auspices of the American Society

of Mechanical Engineers (ASME) to undertake a national testing program

to determine actual usage of hot and cold water in buildings of various

types. In order to gain experience, a pilot program was undertaken by

The Engineers Collaborative at a site owned and operated by the Chicago

Housing Authority. Although data gathering was not the principal objective, sufficient information was collected to permit development of a curve (Figure 1.) that indicates demand predictions are in excess of 100

percent of those observed. 7

Standard Probability Design Curve

Ll

Medium and High Income

Apartment Buildings

Plumbing Fixture Units

FIGURE 1. GENERAL COMPARISON BETWEEN TEST DATA AND THE

STANDARD PROBABILITY CURVE FOR APARTMENT BUILDINGS

TOTAL COLD WATER SUPPLY

6
In 197^, the impact of excessive demand estimates in piping networks was

investigated by Monihan and Konen. 8 In cooperation with the consulting

engineering firm of Jaros, Baum 6 Bolles, an existing 30-story apartment

building was studied, and comparisons of demand estimate were made utilizing Hunter's method, the engineers' proprietary method, and a modified

Hunter's curve. The parameters utilized by Hunter (i.e., frequency of

use, operating time, and flow) were modified to new assumed values. This

study indicated possible savings from the improved knowledge of demand as 15 to 20 percent in labor and 10 to *»0 percent In material, depending upon

the particular design and demand load.

For the most part, building codes in the United States recommend Hunter's

method for estimating the demand of water in buildings, but engineers

usually are allowed to vary from this method and substitute their own methods. For drainage systems, however, the codes differ slightly from

one another. Data gathered from various research programs plus the

experience of the members of the code committees are used to establish

tables on drainage and vent systems. This has led to the establishment

of several model plumbing codes which, while different from one another,

all lead to overdesign.

In most cases, the need for newer research is indicated when one speaks

of high-rise structures, because today's codes generally have been written

for the smaller and lower-rise buildings. In almost all cases high-rise

buildings fall outside the limits of the codes, and existing charts are just extrapolated. Thus, if a 50-story structure required 200-mm (8-inch)

pipe, a 75-story structure would require a 250-mm (10-inch) pipe.

NEEDED RESEARCH AND ANTICIPATED BENEFITS

What is required today is a computation method that can be adopted both

nationally and internationally and that would give the design engineers

the ability to design a piping system for the needs of the structure, and

the local officials the ability to check the design. Thus, all individuals

on the building team would work from the same data base. Only then can economical design be realized. The establishment of a comprehensive

computation method requires the following:

1 . Development of a Mathematical Model

The generation of a mathematical model or models describing the water

supply distribution system in a building is essential to any program

seeking to develop a new method for estimating demand. The development and confirmation of a mathematical model is the first step in the

development of an analytical procedure. Since buildings vary in size,

shape and function, it is anticipated that no one model will satisfy

all applications. It is the responsibility of the research team not

only to develop a useful model, but also to indicate the areas where

the model will be applicable.

7
Establishment of User Needs

In line with the above research and possibly before final models have

been established, much research is required into user needs. The

primary prerequisite for determining the demand for water Is to

establish how the water will be used. Basically, user needs may

be broken down Into two categories: CO biological needs, and

(2) psychological needs.

Within each category three water usage characteristics may be defined.

These correspond to Hunter's model and Include: (1) frequency of

usage; (2) duration of usage; and (3) flow rates. The characteristics

overlap biological and psychological categories as do the specific

functions such as flushing toilets, taking baths, washing dishes,

cleaning, performed in using water. The principle objectives of

research in this area must be: (1) to identify those water usage

needs which are biological necessities (by category) and separate them

from individually generated psychological demands; and (2) to determine

how to conform to the biological needs and reduce the psychological (i.e.,

not "objectively" required) needs.

The biological needs for which water is used in buildings are eastly

identifiable (e.g., toilet, washing, cleaning, drinking and cooking)

and (conceptually) are relatively easy to measure. The information

required includes the absolute amount of water usage and the distribution of usage (by function) over time. From empirically derived models

It wtll be possible to determine current need by function and across building types. Using available or new technology, It will be possible

to reduce the need and demand for water by Imposing rules or restrictions

on water usage which fall within specified biological need limitations.

Thus, If flush toilets are biological necessities, it is technically

possible to design them so they consume less fresh water or use recycled

water, thereby reducing demand and/or need. If we understand the usage

of toilets over time it will be possible to design appropriate flow rates

or to modify the usage pattern (frequencies).

The above discussion addresses the areas of Identifying biological needs

and current usage, and matching available technology to the needs In a manner which can reduce water usage and system demands. The resultant human

factors difficulties arising from these efforts are what we shall define

as psychological needs. The ability to meet a minimal biological requirement does not mean the solution achieved by technologists will be accepted

by users.

As used here, psychological needs refer to individual requirements for

water usage which are not biologically determined or which extend beyond

the minimum biological requirements. Such needs are not less strongly

felt, but it may be argued that they are "objectively" less necessary and are therefore subject to modification, I.e., reduction. In building this

factor Into design models or conservation efforts it is necessary to

consider the establishment of minimum biological requirements and methods

8
for gaining compl iance (either voluntarily or by force) with those

standards. For example, a shower nozzle may be designed which provides

enough flow for adequate rinsing, but which restricts the water flow

to considerably lower levels than are currently acceptable to most

known users. The problem becomes one of. imposing the new standard

on a potentially non-receptive public. Similar problems exist with

the amount of water needed to flush a toilet, the use of recycled water

for certain functions, scheduling large scale water uses, etc.

In terms of Information requirements the first step is to determine

currently acceptable levels of change for each of the usage characteristics

(flow, frequency, and duration) across all functional areas. It may then

be possible to design down to these limits. if this does not reduce

demand sufficiently it may be necessary to impose a more restrictive

solution or change attitudes of users in the appropriate areas. Both

of these activities require extensive future investigation.

The potential for change must be evaluated carefully since it is not

practical to design fixtures or systems that never will be used. It must be determined how strong user habits are and whether water-saving

fixtures will be accepted.

Improvement of Fixture and Fitting Design

An obvious contributor to the demand of water in the building is the

plumbing fixture itself. The conservationists have argued for watersaving fixtures, and from the point of view of saving gallons of water,

this is important. However, it is even more Important if the goal is

to lower the demand rate for water In a building.

Brady and Konen have Investigated the influence of changes in the

frequency of use, the duration of use and the volume of discharge of

a water closet. These influences are shown In Figures 2, 3» and A.

It Is seen that the frequency of use factor Is the most influential

parameter. It Is also seen that changes in the volume of water consumed by the water closet can reduce the demand where a large numder

of fixtures are Involved.

9
FIGURE /». DEMAND VS NO. OF FIXTURES V=17.0 liters

-t— . r 50 100 150

Number of Fixtures

10

200 250
Thus, we can see the Impact that fixture and fitting design have

upon the demand curve for a building. Research must be continued

on better methods of designing fixtures in the future.

k. Understanding the People/Fixture Ratio

Practicing engineers have observed a phenomenon about which very

little is written—the people/fixture ratio. This term refers to

the number of people a particular fixture is to handle during a given

time span.

As mentioned earlier, one of the parameters that Hunter used In developing his method was the time between use of a fixture. It is

obvious that if a fixture is to be used by 20 people, the time between uses will be considerably less than if a fixture is to be used

by only one person. Practicing engineers have seen the effect of

this ratio when des igni ng stadiums or theaters, facilities in which

the demand for water is increased greatly due to the increased usage

of each fixture and the lessening of the time between usage. This

phenomenon must occur, however, in all buildings. The effect that

the time between use functions has on the denand curve can be seen

in Figure k. Thus, research is required into this area to determine,

first, the proper number of people to be served by a fixture and,

second, to provide a method that will allow the designer the opportunity to vary his demand formula based upon the variance In this ratio.

Anticipated Benefits

Billions of dollars are spent on the collection, storage, purification,

and distribution of water in buildings; therefore, the benefits of the

proposed research program are clear. Recent estimates of cost savings

indicate the potential for:

1 . A 25 percent reduction in residential water use through follow-up

on programs based on reliable Information establishing minimum and

maximum flow rates for fixtures.

2. Savings in material costs of as much as 5 percent on the supply

side and 20 percent on the drainage side through the use of smaller

pipes, boilers, and pumps.

10

3. Labor savings of 25 percent or more. The program would benefit

consumers by lowering costs and bettering performance, manufacturers

by permitting more effective use of materials and a more reliable

basis for the standardization and improvements in quality of performance, contractors by Improving their competitive position

through the application of better design procedures that would

permit more economical installation and more effective utilization

of manpower and materials, engineers by providing a method with

which they could design with confidence, eliminating the need for

11
large factors of safety, and the general public by conserving water

(through the use of better-designed fixtures resulting from a better

definition of use requirements).

*k Energy conservation through the use of better-designed systems based

upon the establishment of more accurate water supply requirements.

To achieve these ends, it is believed that a new research program must

be started and supported. The foregoing areas for research are those

that can be envisioned now as areas requiring more and greater knowledge.

As research continues, new areas requiring attention will very likely

appear. The most important need in research today, however, is the ex- change of ideas between the researchers. A concurrent and cooperating

research effort both in this country and abroad Is essential.

12
REFERENCES

1. Hunter, Roy B., Methods of Estimating Loads in Plumbing Systems,

National Bureau of Standards, BMS, 65 (19^0).

2. Wise, A. F. E., Croft, J., Investigation of Single Stock Drainage for

Multi-story Flats. Journal Royal Sanitary Institute, Ik (9) 195^,

pp. 797-826.

3. Maver, T. W. , Water Storage and Power Requirement', Analytical Methods

and Design Duplications in Hazardous Wards. Proceedings CIB on Water

Demand, September , 1972, Garston, England.

k, Marchetti, M., Impianti Interni De D i str i but i one D'Aqun 19^8, Giorande

Del Genio Cib i le No. 69.

5. Webster, C. J., An Investigation of the Use of Water Outlets in Multistory Flats, Proceedings CIB on Water Demand, 1972, Garston, England.

6. Guss, L. , Water Usage Studies and Research Programs. Proceeding of

Seminar on Mechanical and Electrical Systems for High-Rise Buildings,

May 1973, Chicago.

7. Tremari', Albert, Plumbing Systems Design Procedures, Proceeding of

Semlraar on Mechanical and Electrical Systems for High-Rise Buildings,

May 1973, Chicago.

8. Monihan, David M., and Konen, Thomas P., The Significance of Innovations in the Design of Water Supply Systems in High-Rise MultiFamily Dwellings.. Davidson Laboratory Report 7^-1775, Stevens

Institute of Technology, Hoboken, N. J.

9. Konen, Thomas P. and Brady, Peter M., Jr., A Review of The Parameters

in the Hunter Model for Estimating the Demand for Water Supply and

Drainage, presented at CIB W-62 Symposium on Drainage and Water

Supply for Buildings, 11 September 197^, Horsholm, Denmark.

10. Konen, Thomas P., Jackson T., Fowell, A. J., The Evaluation of

Several Sanitary Drainage, Waste and Vent Systems. Davidson Laboratory

Report SIT-DL-7^-1 176. Stevens Institute of Technology, Hoboken, N.J.,

1974.

13

PROTECTING WATER QUALITY IN BUILDINGS

by

George Williams, Thomas P. Konen, Frank Liposky,

James R. Myers, Louis Nielsen, Walter Mikucki, and Walter Staton

During the period 1971-1974 there were 99 reported outbreaks of disease

associated with water used for drinking or domestic purposes, a significant increase over earlier periods. The reasons for this apparent in- crease are not known but it may be the result of an increase in surveillance. Approximately one-third of the waterborne disease outbreaks in-

/olved municipal water systems, these, however, were responsible for 67

Dercent of the 17,000 cases of illnesses. Thirty-two percent of the

outbreaks were the result of deficiencies in the distribution systems.

)ther causes are inadequate treatment, 29 percent, and use of untreated

surface water, 19 percent. These facts 1 indicate that disease caused by

drinking contaminated water continues to occur.

rhe Safe Water Drinking Act of 1974 establishes as a national goal safe

drinking water for all Americans. Faced with this enormous task, the

Environmental Protection Agency (EPA) has developed a strategy that

recognizes it is not possible to correct all problems in a year or two

and that success will come in small increments. During the past year,

the U.S. Environmental Protection Agency has promulgated National Interim

Primary Drinking Water Regulations 2 which establish maximum contaminant

levels for organic and inorganic chemicals, turbidity, and microbiological

contaminants. These regulations apply to community and noncommunity water

supply systems. The estimated annual costs to the 40,000 community water

systems that provide water to 1 78 million Americans to conform to these

regulations have been determined to be: $17 million to $36 million above

the present expenditures for routine monitoring, $146 million to $247 million

for capital expenditures for new treatment plants and $259 million for

operating and maintenance expenditures. 3

The major accomplishment by the EPA In promulgating interim drinking water

standards and the review of the costs to achieve them mandates that the

building Industry examine its role In protecting the safe drinking water

that will be delivered to the site.

15
Background

Traditionally the protection of water quality In buildings has been

limited to a continuing program to monitor connections to the potable

water system that could cause contamination from back pressure or back

syphonage.

A cross connection is any actual or potential physical connection between

a potable water supply and any waste pipe, soil pipe, sewer, drain, or any unapproved source through which it is possible for contaminated or polluted water to enter the potable system. Furthermore, it is any

potable water supply outlet which is submerged or can be submerged in

waste water or any other source of contamination. Cross connections may

be regarded as direct or indirect. A direct connection is an arrangement

whereby a safe water system is physically joined to a system containing

unsafe water, sewage, of other waste. An indirect connection is an arrangement whereby unsafe water in a system may be blown, sucked, or otherwise diverted into a safe water system.

Concern for the protection of the water supply became evident with the

introduction of pressure tanks. With the pressure tank system, more

uses were found for water (e.g., fire protection, cooling, heating).

Accompanying this increase in water usage was the need to prevent the

backflow of water from the pressure tank Into the water main.

At that time the house tank and most of the fixtures, such as water closets,

bathtubs, laundry tubs, and sinks, had the fill pipes below the flood rim.

The problem which arose from this design was that during times of low

pressure in the public water system, water could syphon back into the

system and cause contamination. In order to overcome this problem, New

York City, in 1883, put into effect a regulation that all water supply

connections made to fixtures below the flood rim had to be removed. The

most hazardous of these connections was the direct water supply valve for

flushing water closets. Regulation of this particular connection was not

enforced, and inevitably fell by the wayside. About 1903, the double check

valve assembly came into use when it was found that a single check that

had been in use would not give positive protection.

As more complex systems such as, industrial process piping and heating and

cooling systems come into being, a more positive means of protection was needed to protect the potable water system. In 19^2, the reduced pressure

principle backflow preventer was introduced. This was designed to have a minimum of two independently acting, approved check valves, together with

an automatically operated differential pressure relief valve located

between the two check valves. During normal flow, and at the cessation of

normal flow, the pressure between these two checks must be less than the

upstream (supply) pressure. In case of leakage of either check valve, the

differential pressure relief valve, by discharging to the atmosphere, must

operate to maintain the pressure between the checks at less than the supply

pressure. The unit must Include tightly closing shutoff valves located at

each end of the device and each device must be fitted with properly located

test cocks.

16
Prdbl ems

Many effective products are commercially available to prevent contamination of the potable water system from back flow and back, slphonage.

Yet numerous cross connections occur each and every day. With all the

technical knowledge and understanding of the hazards which can and do

exist, there is still a long way to go in protecting the drinking water.

Who knows what happened in Philadelphia just this year? Unconfirmed

reports indicate 22 unprotected cross connections were found In an inspection of those facilities. Was it the water? In Aiken County,

South Carolina, the town's water supply was contaminated by a chemical

from an industrial building in 1975. In Chattanooga, Tennessee, i nsec- ticide poison was found in water of ^5 homes in March 1976. 6 There are many more such cases on record. Investigators estimate at least 1,000 cross connections are made per day In the United States alone. It Is believed that cross connections continue because of lack of awareness

on the part of the general public, the absence of specific detailed

knowledge by plant maintenance workers and inadequate training of plumbing inspectors. Most manufacturers of . protect ion devices will assist

localities in initiating water protection programs and some manufacturers

have held seminars. 7

However, cross connections are not the only way in which water in the

distribution systems within can become contaminated. The Danish Corrosion

Center, following the lead of their Norwegian counterparts, have conducted

laboratory experiments to determine if plumbing fittings manufactured in

their country were subject to dissolution of metals In the water. 8 Their

findings are shown and compared to the tolerance limits of the World

Health Organization and the U.S. Environmental Protection Agency below.

Cadmium and Lead Concentrations Found In Fittings

Contami nant Findings Tolerance WHO and EPA

Cadmi urn Lead

0.027 mg/i

0.1 mg/£**

0.01 mg/£

0.05 mg/i

one fitting others had concentrations of 0.01 mg/fl,

three fittings others had concentrations less than 0.05 mg/£

These results are based on tests of 10 fittings that were exposed to

synthetic water, soft and acidic, for a period of 10 days. Short-term

experiments with exposures of less than 2k hours showed, with a one-hour

exposure, metal pick-up was of the same order of magnitude as with an exposure of 12 or 2k hours. These findings suggest further study to ensure

the safe drinking water remains safe as it travels through the water distribution system within the building.

17
Research Needs

Bacterial and chemical contamination of water has been known to occur

in the distribution systems within buildings. The contamination of

the water supplies has often been through cross connections. Recent

research has suggested that contamination may result by the release of

heavy metals from common materials used in these systems. These findings

mandate that further studies and investigations be initiated to safeguard

the publ i c heal th.

1. A comprehensive study of the potential for the contamination

of the water supply by cross connections within buildings

should be undertaken. With a better definition of the cross connection problem, it is envisioned that improved regulations,

which may consider the degree of the hazard for various types

of interconnections, will evolve. The degree of the hazard

should be determined after an evaluation of the potential

for contamination is made considering the probability of

failures and whether they are detected or undetected.

The concept of containment--isolation of the building from the community

water system—should be considered. Investigation should study the concept

for single-family dwellings, multifamlly dwellings, and industrial buildings, separately and together.

2. The reporting of the contamination of water within buildings

should be included as a part of regulations governing safe

drinking water so that effective corrective action may be

taken where required.

3. Unprotected cross connections in boilers and converters for

providing domestic hot water should be investigated to determine

the level of risk incurred. Solar energy systems have a similar

problem,

k. A public awareness program should be considered as this may be

the most effective method of reducing the multiplicity of cross connections that presently exist and aid in reducing

the growth of potentially hazardous situations.

5. Consideration should be given to the extension of regulations

that require protective devices on manufactured equipment that

is connected to the water system. Many industrial, medical

and home appliances tie into the distribution system as a matter of routine.

6. The contamination of the water supply system by heavy metals

dissolving from conduits, joints and fittings must be investigated

further. The corrosion engineer must now consider deterioration

of the quality of the water in addition to the deterioration of

the material carrying it.

18
References

1. Waterborne Disease Outbreaks in the U.S. - 1971-1972*. Gunther F.

Craun, Leland J. McCabe, James M. Hughes, Journal-American Water

Works Association, August 1976. pg. k2Q-h2k.

2. National Interim Primary Drinking Water Regulations, Federal

Register, Vol. 40, No. 2^8, Wednesday, December 2k, 1975.

3. Economic Evaluation of the Promulgated Interim Primary Drinking

Water Regulations. U.S. Environmental Protection Agency Report

No. EPA 570/9-75-003, U.S. Environmental Protection Agency, Washington,

D.C.

k. Standard Plumbing Engineering Design. Nielsen, Louis S., McGraw-Hill,

Inc., New York, 1 963

5. South Carolina Town Gets Water Brought In. The Greenville News,

Greenville, S.C., October 14, 1975-

6. Poison Found in Water of Homes in East Lake, The Chattanooga Times,

Chattanooga, Tennessee, March 26, 1976.

7. A Backflow Prevention Program, What it is and How to Put It into

Effect. Walter Staton, Watts Regulator Company, Lawrence, Massachusetts.

8. Pick-Up by Drinking Water of Cadmium and Lead from Fittings, Kate

Nielsen, The Danish Corrosion Center, Report 2111, Proceedings of

The CIB W-62 Symposium, Drainage and Water Supply for Buildings

September 11, 197^. Danish Building Research Institute, Horsholm,

Denmark.

19

WATER AND WATER-RELATED CONSERVATION

IN BUILDINGS

by

Andrew J. Fowell , Arthur Bransdorfer, Peter Fletcher,

Richard J. Orend, Harold J. Pavel, and George H. Williams

Like other nations, the United States is dependent upon precipitation for

its water supply. Although the United States is fortunate in having an

annual overall precipitation of 30 inches, wide regional and seasonal

variations have necessitated extensive measures to supply water where it

is needed; for example, changing the course of rivers to bring water to

arid reg ions; .bui Id ing dams to irrigate vast land areas; and constructing

networks of aqueducts, canals, and pipelines to bring water over mountains

to growing urban centers. The total expenditures for development of water

resources over the years through 1971 are estimated to be $338 billion;

current federal outlays for water resources and related developments are

more than $k billion per year.

In its 1973 report, Water Policies for the Future , the National Water

Commission concluded that the present water quantity situation is good in

all regions except the Rio Grande, Lower Colorado, and Great Basin (Nevada)

regions, where consumption exceeds the mean annual runoff and the shortage

Is offset by mining groundwater or bringing in water from other regions.

Streamflow* and 1970 wi thdrawals** and consumptions*** are compared in

Table 1, and regions are identified. An average of 1^00 million m

3 (370

billion gal) of water is utilized each day in the United States. The bulk

of this water is used for irrigation (35 percent), in steam electric utilities (38 percent), and in industry (17 percent), with less than 10 percent

being consumed in residential and commercial buildings through public water

uti 1 Ities.

The discharge in a surface stream course.

The diversion and removal of water from a natural water course; this

water often is returned with only minor change in quality.

The water withdrawn from a supply and not directly returned to a surface

or groundwater supply because of absorption, transpiration, evaporation,

or incorporation in manufactured products; such water is not immediately

avai labl e for reuse.

21
TABLE 1 - Streamflow Compared with Current Withdrawals and Consumption

(Billion gallons per day)

Annual Flow Available 1 Mean 50% 90% 95% Fresh Water Annual of the of the of the Consumptive Use Withdrawals

Region Run-Off 2 Years Years Years 1970 1 1970 1

North Atlantic 163 163 123 112 1.8 55

South Atlantic-Gulf 197 188 131 116 3.3 35

Great Lakes 63.2 61.4 46.3 42.4 1.2 39

Ohio 19S an g

Tennessee 41.5 41.5 28.2 24.4 .24 7.9 Upper Mississippi 64.6 64.6 36.4 28.5 .8 16 Lower Mississippi 48.4 48.4 29.7 24.6 3.6 13 Souris-Red-Rainy 6.17 5.95 2.6 1.91 .07 3

Missouri 54.1 53.7 29.9 23.9 12.0 24

Arkansas-White-Red 95.8 93.4 44.3 33.4 6.8 12

Texas-Gulf 39.1 37.5 15.8 11.4 6.2 21 Rio Grande 4.9 4.9 2.6 2.1 3.3 6.3 Upper Colorado 13.45 13.45 8.82. 7.50 4.1 8.1 Lower Colorado 3.19 2.51 1.07 0.85 5.0 7.2

Great Basin 5.89 5.82 3.12 2.46 3.2 6.7 Columbia-North Pacific 210 210 154 138 11.0 30

California 65.1 64.1 33.8 25.6 22.0 48

Conterminous

United States 1.201 87 365

Alaska Hawaii

Puerto Rico

580

13.3

.02

.8.17

.2 2.7 3.0

Total United States 1,794 88 371

'MURRAY. C Richard & REEVES. C liodcuc (1972). Estimated UiC of Water in the United States in 1970. Geological

Survey Circular 676. U.S. Geological Survey, Washington, D.C. p. 17. •U.S. WATER RESOURCES COUNCIL (1968). The Nation's Water Resources. U.S. Government Printing Office. Washington. D.C. p. 3-2-6.

22
WATER CONSERVATION AND MUNICIPAL SYSTEMS

Little effort has been expended to Investigate ways to conserve water in

municipal supplies except when regional or local shortages occur and,

even then, conservation usually is promoted only during the crisis while

the recommended solution is increasing the supply through construction

of a major engineering project justified on single-valued projections of

past trends. There are, nevertheless, four major reasons for being concerned about excessive use of treated water: First is the immense problem

of pollution and the effort required to return water to nature in approxinately the same condition it was withdrawn. Second is the enormous cost

of processing water in both input and output phases. Third is the

potential energy savings resulting from decreased water processing and

use. Fourth is the occasional real water shortage, the probability of

tfhich can be decreased by more judicious use of available supplies.

The Water Pollution Control Act amendments of 1972 and the Safe Drinking

«i/ater Act of 197^ are reasons for change in attitudes toward processed

Abater. Municipal sewer systems daily discharge 152 million m

3 (kQ billion

gal) of effluent into the nation's waterways. Much of this effluent receives only primary treatment and some receives no treatment at all. The

rfater Pollution Control Act requires publicly owned waste treatment plants

to provide a minimum of secondary treatment by July 1, 1977. A needs

survey, estimates the investment required to meet the 1977 objectives

through the construction of secondary treatment facilities and interceptor

sewers to be $36.6 billion. 1 The Environmental Protection Agency has

identified the infiltration of groundwater into sewers as a major problem.

<\s infiltration is reduced, the advantages of saving water in homes and

commercial buildings will take on greater significance.

The continuing growth In U.S. water needs is shown in Figure 1. It is expected

that as conformance to the Safe Drinking Water Act of 197^ is achieved,

the cost of water will rise dramatically. For example, Jersey City,

New Jersey, which supplies 265,000 m

3 (70 million gal) of water per day

to several communities, has been advised that a filtration plant for its

system will cost $42 million, and a rate increase of 300 percent has been

suggested to cover the cost of this new plant. In California, pumping

costs are expected to increase by a factor of 10 when the present contract

with the power company expires. It is against this background that water

conservation within buildings must be evaluated.

TECHNOLOGY VS. SOCIOECONOMIC IMPACT OF CONSERVATION

Water conservation research currently being conducted is centered on the

introduction of new devices and techniques into the home or building. Three

factors are particularly important: (1) the economics of water-conserving

devices and techniques, (2) the politics of introducing them into current

codes, and (3) their acceptance by individual users. These interrelated

factors are known to have an impact upon the adoption of many technological

changes, and water conservation In buildings Is no exception.

23
30

0 ,

, 1950 1975 2000 2025

Year

FIGURE 1. PROJECTED CONSUMPTION

MUNICIPAL WATER USE

Water conservation is in itself a challenge for efficient water management.

Many outdated urban distribution systems lose as much as 50 percent of incoming water through leakage, while the overtaxed sewer systems often are required to carry out kO percent more waste than needed due to infiltration

of groundwater.

Considering the staggering costs for the supply and treatment of wastewater,

it is imperative that water be used wisely. In the management of buildings,

utilities conservation is one of the most significant programs carried out

by a building manager. Considerable savings in both tax dollars and natural resources can be made when good management is applied to the use of electricity, heat, and water. The costs for water and sewage average approximately h percent of the total utility costs of normal building operations,

but many indirect savings also result from careful water management. Reducing the amount of water used saves in the cost of heating water and

lowers the electricity costs associated with the operation of pumps. Also,

a reduction in the amount of water handled lowers the life-cycle costs for

maintenance of pumps, fixtures, valves, motors, etc. Thus, an enterprising

building manager who utilizes every means of water conservation at his

command not only provides a service to his community but also can lower

building operating costs without lowering the level of service.

24
Much is known about the direct impact of economics, but the interaction

of economics with the other two ; "social" factors is less well defined

and poses some interesting questions about the adoption of water-saving

changes. The problems experienced with fluoridated water are an example

of how a few people can cause enormous problems by the adoption of

municipal policy changes despite the opinion of a majority of residents. 2 Changing water purity codes probably will be an equally difficult task.

The economic and political issues related to this situation involve a determination of who stands to gain or lose because of such changes,

as well as does the initial cost of converting individual systems.

Finally, one must know what it will take to convince significant numbers

of people that such changes are safe (assuming they are) and that they

should be adopted. One early study on the possibility of reusing water

for various household purposes revealed strong attitudinal barriers to

some uses.

3 Those surveyed in this study found the use of recycled water

for drinking to be most distasteful, and other uses progressively less

distasteful as they moved futher from the body (I.e., bathing was indicated

to be less distasteful than drinking, clothes washing less tha: bathing,

etc.). Such results raise the question of how far water-saving techniques

will be allowed to advance despite obvious conservation advantages. Thus,

research is needed to assess the Impact of conservation in conjunction with

the technology of conservation.

RESIDENTIAL WATER USE AND THE POTENTIAL FOR CONSERVATION

Residential water consumption in the United States is approximately 82

percent higher than in Europe. Average daily consumption in Europe is

132 1/capita (35 gal/capita) while U*.S. daily consumption is 240 1/capita

(64 gal/capita). An analysis of water consumption for a family of foui

two adults and two children in England — is given in Table 2.

TABLE 2 Daily Water Use by a Family of Four

England ** United States 5

Percent Liters (gal) Percent Liters (gal)

Water closet flushing 37 196 (52) 39 378 (100)

Personal bathing 37 196 52 3** 332 88

Laundry 11 56 • 15 14 133 35

Washing up (dishwashing) 11 56 15 6 57 15

Drinking 6 food preparation 4 24 6 5 45 12

Ut i I i ty s i nk k * 2 19 5

Total w 528 140 100 964 255

Data not available for this category.

The most significant difference in water usage involves the water closet (WC)

and is attributed to the higher volume used by U.S. water closets. In England,

WCs that use 9 1/flush (2.4 gal/flush) or 14 1 /flush (3.7 gal/flush) are available; in Europe, the typical WC uses 8 1/flush (2 gal/flush). Residential

25
units in the United States consume approximately 19 1/flush (5 gal/flush).

Most of the low-volume European WCs are of the washout type; a few have

si phonic action. The typical U.S. WC is a vortex siphon unit that provides better scouring action in the inside surfaces of the bowl. In addition, the large water surface area in U.S. siphon bowl wells provides

a cleaner and more hygienic receptacle for waste matter. Reduced-volume

WCs manufactured in the United States using 13 1/flush (3.5 gal/flush)

have attempted to maintain the vortex action to give the good performance

the consumer is accustomed to, while reducing the volume of water. (A

number of chemical [waterless] toilets are available in the United States,

but these units are designed primarily for use In remote locations where

water supply and drainage systems are not available.) The other differences in water consumption between the United States and Europe and

Great Britain are attributed to differences in personal habits and the more widespread use in the United States of appliances such as dishwashers

and automatic washing machines.

While fixture and fitting minimum flow rates based on function have not

yet been researched, the British Code of Practice, CP 310 6

, has established recommended rates of flow at various fittings. These values, along

with information on typical U.S. and European values, are shown in

Table 3.

TABLE 3 Typical Flow Rates for Plumbing Fittings (l[gal]/sec)

United States

Fi xture Eng 1 and 7 Europe7 Early Code8 Current Practice*

Washbas i n 0.15 [2.4] 0.1 [1.6] 0.19 [3.0] 0.1 [1.6]

S ink 0.19 3.0 0.2 3.2 0.28 4.4 0.2 3.2

Bath 0.30 4.8 0.4 6.3 0.38 6.0 0.25 4.0

WC 0.12 1.9 0.1 1.6 0.19 3.0 0.2 3.2

Estimated.

The potential for water saving in various appliances and fixtures may be

estimated on the basis of the following criteria:

1. The amount of water that can be saved utilizing existing technology,

feasible economic transition, and current standards of acceptance.

2. The amount that could ultimately be saved by utilizing future

technology disregarding transition costs and research and development expenditures and assuming performance acceptance standards

can be changed. Table 3 illustrates the potential for water saving

using the foregoing criteria In a typical household of two adults

and two ch i ldren.

26
If the water consumption data presented in Table 3 were typical of all

residential use, they would indicate that a complete nationwide replacement of plumbing fixtures and appliances by their currently available

water-saving counterparts would result In a 34-percent saving (n national

residential water consumption. Similarly, this suggests an ultimate

potential saving of about 78 percent. Assuming the presently estimated

fraction of residential consumption to be 12 percent* of total U.S. water

consumption 9

, these savings would be 4 percent and 9 percent of total

U.S. water consumption.

TABLE 4 Potential for Reduction of Daily Water Consumption by a Typical

Use

Current,

1 (gal)

Cr i ter ion 1 Cr i ter ion 2

l (gal) % Saved 1 (gal) % Saved

Dishwashing 57 (15) 41 (11) 27 19 (5? 66

Cooking/drinking 45 (12) 45 (12) 0 38 (10) 16

Ut i 1 i ty s i nk 19 ( 5) 10 (25) 50 4 ( 1) 20

Laundry 133 (35) 91 (24) 32.5 38 (10) 71

Bathi ng 302 (80) 190 (50) 37.5 75 (20) 75

Bathroom sink 30 ( 8) 15 ( 4) 50 4 ( 1) 87

WC 378 (100) 242 (64) 35 38 (10) 90

Total 964 (255) $34 (190) 34 216 (57) 78

Although water, at least for the present, appears to be abundant In many

parts of the United States, it has been estimated that residential water

heating accounts for an energy consumption of 1.1 million barrels of oil

per day. This represents 15 percent of residential energy consumption

and 3 percent of total U.S. consumpti.on.

Most studies relating to energy conservation recognize the saving that

can result from improved efficiency of water heaters and from reduced

consumption of hot water. In the latter category, which is of interest

here, Muller estimates that 9 percent of energy used for residential

water heating can be saved by the use of flow restrictors in showers

and basin faucets.10

In addition to the energy saving resulting from conservation of domestic

hot water, it should be noted that a reduction in the consumption of cold

water also will save energy since most cold water supplies enter a building at temperatures below the ambient temperature within the building and

leave the building at or new this ambient temperature. In many cases this

represents an 1 1 °C (20 °F) temperature rise and the removal of 4180 kcal

(16,600 Btu) per day from the heat in a typical house by the cold water

used in the toilet alone. Obviously the use of reduced-volume water

Includes individual water supplies.

27
closets wi 11 reduce this energy loss, but research is needed to prove

the performance of such units under conditions simulating those in the

field.

In any study of water-related energy conservation, both the energy used

to heat domestic water and the total energy associated with supply— i.e.,

exploration, facility construction, pumping, purification, and sewage

treatment —must be considered and this will involve the development of

an energy balance sheet. Research is needed to prepare a comprehensive

study of energy use in water supply and wastewater treatment systems.

NEEDED RESEARCH

The following specific research efforts are needed to assist the United

States in meeting its future residential and commercial water supply

needs while preserving energy resources:

1. A comprehensive study of the water source, supply, use, and wastewater treatment for residential and commercial buildings. The main

thrust of this study should be an examination of the economic impact

of conservation in contrast to the technology of conservation. Included should be a careful assessment of the problems of leakage

from the water supply system and infiltration to the wastewater

collection system. The main reason for such a study is to provide

water managers and government officials with the basic economic

information they need to make decisions regarding water supply and

conservation measures.

2. The establishment of the interrelation between the water use by

various fixtures and fittings and their functional performance. An

11 l/min (3 gal/min) shower and the 13 1 (3.5 gal) water closet

appear to have been arbitrarily selected as national goals. Studies

are required to determine safe economic quantities of water required

for acceptable performance of fixtures. Psychological factors (i.e.,

the public acceptance of such changes) must be considered in addition

to the technical aspects of design.

3. A project to determine the comparative performance of fixtures in

general and of water closets in particular under simulated conditions

representative of typical installations in single-family and multifamily dwellings. Empirical test procedures and rating methods to

determine the performance of water closets have been developed and are employed in quality assurance programs and general laboratory

evaluations of new units. However, since performance may be influenced by Installation and field conditions, a more complete evaluation

can be obtained in a plumbing test facility where geometries and

hydraulic conditions expected in a plumbing drainage system can be

simulated. A comprehensive plan for evaluating water closet conformance to acceptable performance standards must consider each of the

28
following areas: (a) geometry of the drainage, waste, and vent system;

(b) piping details immediately adjacent to the closet; (cj location of

the closet in the system; and (d) hydraulic conditions in the stack.

It should be noted that continuation of the sales and promotion of

water-saving water closets and add-on devices without thorough evaluation could result in a health hazard as well as the more likely event

of increased consumption through double flushing.

An assessment of the extent to which recycled water can be used and

the practicality of using gray water for other than human consumption.

The direct reuse of water for human consumption cannot be adopted

until a major research program is completed to demonstrate that

virological and other possible contamination does not present a significant health hazard.

5. Establishment of the energy impact of water conservation through a

careful energy-benefit analysis of the energy associated with water

consumption as well as a determination of the energy impact of various

water-saving measures. For example, inhouse residential recycling

systems may offer substantial net savings in water supply to the

residence but also may result in a wasteful use of energy.

29
REFERENCES

1. Environmental Protection Agency. Economics of Clean V/ater . Washington,

D.C.: U.S. Government Printing Office, 1973.

2. Crain, R. ; Katz, E.; and Rosenthan, D., The PoUtics of Community

Conf 1 ict . Indianapolis, Ind.: Bobbs-Merrel 1 , 1967.

3. Brunold, William H. "Public Attitudes Toward the Reuse of Reclaimed

Water," University of California, Berkeley, School of Public Health,

August, 1972.

b. Ball, E. F. , "Current Measures for Saving Water in the Home." Paper

presented at the C1B W-62 Symposium on Drainage and Water Supply for

Buildings, University of Glasgow, Scotland, October 1975.

5. Bailey, J. R. ; Benoit, R. J.; Dodson, J. L.; Robb, J. M. ; and Wallman,

H. A Study of Flow Reduction and Treatment of Waste Water from Households . Water Pollution Control Research Series 11050 FKE. Cincinnati,

Ohio: Advanced Waste Treatment Research Laboratory, 1967.

6. British Standard Code of Practice . "Water Supply ," CP310: 1965. (The

Council for Codes of Practice, British Standards Institution, 2 Park

Street, London.)

7. Olsson, E. "Water Flow in Dwelling Houses —Some Views on Existing

Conditions and a Glance at the Future." Paper presented at the CIB

Symposium on Water Demand in Buildings, Garston, England, 1972.

8. National Plumbing Code . (American Society of Mechanical Engineers,

New York, New York.)

9. U.S. Water Resources Council. The Nation's Water Resources. Washington,

D.C.: U.S. Government Printing Office, 1968.

10. Muller, John G. "The Potential for Energy Savings Through Reduction

in Hot Water Consumption." In Proceed ings of the 1975 Conference on Water Conservation and Sewage Flow Reduction with Water Saving Devir.es.

pp. 89-116.

11. American Water Works Association, "On the Use of Reclaimed Waste

Waters as a Public Water Supply Source, AWWA Policy Statement."

Journal of the American Water Works Association (October 1971).

12. Bostain, H.E.; Cohen, S.; and Wallman, H. "Water Conservation by the

User." Paper presented at the APWA Meeting, Denver, Colorado, September

1973.

13. Bryson, Samuel G. Water Metering Experiments for the Flat Rate Denver

Residences. Master's thesis, University of Colorado, 1973.
l*t. Chan, M. L., and Heare, S. "The Cost Effectiveness of Pricing Schemes

and Water Saving Devices." In Proceedings of the Conference on Water

Conservation and Sewage Flow Reduction with Water Saving Devices,

PP. 97-189.

15. Coelen, Stephen P. "Water Price—Quantity Relationships and Their

Effect on Water Conservation." In Proceedings of the Conference on Water Conservation and Sewage Flow Reduction with Water Saving Devices,

pp. 15-22. University Park, Pa., The Pennsylvania State University,

July 1975.

16. DeArment, Wallace E. "Impace of Conservation on the Water Industry."

In Proceedings of the Conference on Water Conservation and Sewage

Flow Reducation with Water Saving Devices, pp. 1 97-200 , University

Park, Pa., The Pennsylvania State University,

17. McLaughlin, E. R. , "A Recycle System for Conservation of Water in

Residences." In Proceedings of the Conference on Water Conservation

and Sewage Flow Reduction with Water Saving Devices, pp. k

} - 1 33

,

University Park, Pa., The Pennsylvania State University,

18. National Water Commission. Water Policies of the Future: Final

Report to the President and Congress of the United States by the

National Water Commission . Washington, D.C.: U.S. Government Printing

Office, 1973.

19. U.S. National Committee for CIB. National Research Council. Water

Distribution and Supply within Buildings: National Research Needs.

Washington, D.C.: National Academy of Sciences, 197^

31

HYDRAULIC ANALYSIS AND PERFORMANCE CONCEPTS

FOR WATER SUPPLY AND DRAINAGE SYSTEMS

HYDRAULICS OF GRAVITY DRAINAGE SYSTEMS

by

R. S. Wyly, R. V. Benazzi, T. P. Konen, R. R. Manfredi and

L. S. Nielsen, with the assistance of G. E. Mattingly,

E. M. Maybeck and R. C. Schnarr

The function of a plumbing drainage system is to collect and transport

wastewater from the fixtures to the building sewer. In achieving this

function in a safe and efficient manner, water-sealed traps are used to

protect the interior of the building from hazardous or obnoxious gases

that may be produced in the drainage system or sewer. Traps are essentially water seals which permit the passage of water into the drainage

system while blocking the flow of gas out of the system into the

building. The normal depth of a trap seal is 50 mm (2 inches) for

fixtures other than waterclosets , which generally have a seal depth

ranging from 63 mm (2 1/2 inches) to 75 mm (3 inches). The flow of

air and wastewater within the system is complex. It is three-phase,

nonuniform, and unsteady. Over the years, laboratory and field data

have been obtained to provide design loading tables for use in limiting

the flow through the drainage piping to levels which will not threaten

the integrity of the water seal in the traps. A full understanding

of the fluid mechanics of the system has not been developed, due to

the complexity of the hydraulic phenomena within the typical, interconnecting network of pipes. This has necessitated the use of cookbook

designs, prescribed by codes. These prescriptive specifications encourage

oversized systems, stifle innovation, and remove incentives for costeffective approaches vitally needed in the building industry today.

This paper provides a historical perspective of gravity drainage systems in the U.S.A., discusses present design procedures, describes

the hydraulics and pneumatics in some detail, and suggests research

needed to achieve significant benefits.

Historical Perspective

The first plumbing drainage system in the United States were developed

for use in buildings not over three stories in height, and generally

consisted of a 50 mm (2-inch) diameter waste stack for sinks located

in public hallways.* A similar system of 100 mm (4-inch) diameter

collected the wastewater from hopper toilets located in closets with

acess from public hallways. The criteria for the adequacy of the

performance of these systems were rapid drainage of the wastewater

and the absence of odors from sewer gas. These early single-stack

drainage systems were prone to failure of the trap seal by siphonage

and back pressure. About 1874, secondary ventilation through auxiliary,

air pipes was proposed as a means of protecting the water seal in the

trap by maintaining atmospheric pressure on both sides of the seal.

35
The theory was checked empirically and the principle of secondary

venting was established. These continuous waste and vent systems,

which were often modified on a local basis, led to a complex, non- uniform structure of regulations nationally.

The benefits that had been demonstrated through the development and

utilitization of product standards in industrial production, together

with the pressures of the housing needs following World War I, encouraged the standardization of building and plumbing regulations. A

Building Code Committee was established in 1921 under the auspices

of the U.S. Department of Commerce, and laboratory studies were con- ducted by the National Bureau of Standards under the committee's general

supervision. Two significant reports^ »^ were issued, with the final

product known as the "Hoover Code," which was widely utilized by state

and local regulatory bodies, because it provided the first theoretical

and experimental data that could be utilized in semirational design

of plumbing drainage and venting systems. The first report contained

experimental data on the hydraulic and pneumatic performance characteristics of one- and two-story drain, waste, and vent (DWV) systems, and

presented a procedure for estimating peak hydraulic loads for design

purposes involving the "fixture-unit" concept and the theory of probability. The 1932 report benefited from further research stimulated

by the 1924 report.^ These activities produced additional scientific

information on matters such as gas diffusion in drains, terminal

velocities in tall drainage stacks and flow depths in building sewers.

The Hoover Code was the forerunner of the widely accepted American

Standard National Plumbing Code, ASA A40. 8-1955.

Studies ^,6,7,8,9 were ma(j e between 1932 and 1941 to provide additional

scientific basis for DWV system design, in response to needs defined

by the Federal Government agencies concerned with building construction,

and by plumbing installation contractors and code administrators. Perhaps the most significant work^ was that which produced the "Hunter

Curve," a method proposed initially for estimating, for design purposes,

momentary peak hydraulic loads on water-distributing systems. The

method was soon adapted to the prediction of peak loads for sanitary

drainage system, and was utilized to develop pipe-sizing tables for

drainage and vent piping. This was reflected in design manuals and

code recommendations of the late 1940' s and the early 1950' s, and has

10 been carried over into most of the present model codes.

In response to the increasing need for cost-effective design in building

following World War II, renewed attention was turned to investigations

of trap self-siphonage , ^ stack venting, ^ wet venting, and capacities of stacks^ and horizontal drains. * These investigations provided

a basis for some design improvements and better definition of the perfor- mance capabilities and limitations of types of components and systems

with which fairly widespread field experience had already been obtained.

Some of this work is reflected in the present model codes.

36
More recently, starting about the mid-sixties, concern has turned to

the need for effective evaluation methodology for innovative approaches,

e.g. reduced-size venting, single-stack drainage, watersaving fixtures,

etc.

The principal thrust of the present paper is the definition of the

research needed to accomplish greater generalization and precision

in the design of accepted systems, as well as to provide a suitable

technical basis for performance evaluation of innovative systems

(Figure 1). Some technical shortcomings of the existing methodology

are described. .

Present Practice

In actual design work, conformance to the load plumbing code within

the appropriate jurisdiction is required. For a number of years the

local codes have been patterned after the National Plumbing Code^ or

one of the other widely referenced and more recent model codes,

often with modifications based upon experience factors and special

load conditions. The tables of allowable fixture loads on DWV systems

and their components are, in most instances, traceable to early research

on peak load prediction and on the hydraulics and pneumatics of DWV

systems referred to above. These data, with their acknowledged limitations (as indicated below) have been processed conservatively to

produce simple loading tables that specify pipe size directly, according

to the numbers and types of plumbing fixtures and appliances served.

This simple fixture procedure leads to prescriptive engineering methods

that limit the value of the professional designer's contribution and

many instances result in oversized, uneconomical systems.

The principal shortcomings and limitations of the present design and

evaluation methodology can be summarized as follows:

1. Inadequate Data Base

The data base is incomplete, both with respect to time and spatial

distribution of hydraulic loads, and with respect to the hydraulic

and pneumatic effects produced by these loads in representative

systems. Factors contributing to this situation include the

following:

(a) Traditional instrumentation and data processing methods were

not adequate for large masses of essentially dynamic data from

complex systems.

(b) The lack of established scale-modeling techniques and the high

cost of full-scale testing in laboratory and field have led to

experimentation in simplified laboratory systems not adequately

representative of the systems actually installed in modern

buildings, and to the use of very large safety factors in

applying the data to design.

37
2. Imperfect Analytical Procedures

In large part because of the situation described in 1 above, the

simple analytical procedures and mathematical models derived from

the data and used to develop the design tables do not effectively

take into account the inherent dynamic processes, some of the key

parameters that determine service hydraulic load patterns, nor

some of the important design and installation parameters (e.g.

configuration, geometry) that affect hydraulic and pneumatic loadcarrying capacity. Examples include (1) the relationship between

water flow rate, air demand rate, pneumatic pressure fluctuation

and trap-seal retention, and (2) the influence on air demand rate

of length of stack, stack pressure gradient, air circulation in

the piping network, slippage between air and water, and geometry

and size of fittings used for connecting the drainage stack and the

soil and waste branches.

3. Lack of Standard Hydraulic Test Methods

To some degree because of the situation described in 1 and 2 above,

hydraulic test methods used for evaluating component assemblies and

full-scale systems have not been standarized.

The lack of improved specific criteria and design procedures taking into

account 1, 2, and 3 has not been widely recognized, until recently,

as the main cause of overdesign in traditional systems and of difficulty and inordiante delay in determining acceptance of innovative

designs

.

Discussion of Research and Research Benefits

A major reason for renewed interest in the hydraulics and pneumatics

of drainage systems in this country is the widespread acceptance in

other countries of several types of single-stack, self-venting drainage systems. These systems are worthy of consideration for use in the

United States for their potential for cost savings the simplified con- figuration of piping could lead to architectural benefits and simplification in modular construction.

A principal concern is the maintenance of a realistic balance between

continued essential performance and the costs of construction and

operation of the DWV system as modifications to the system are introduced without a methodology for definitive prediction of overall

system. To date, success in implementing proposed innovative costsaving devices, components and systems has varied from reasonably

good to very poor. The present increased interest in water supply

and drainage is attributable, inpart, to the growth in high-rise buildings with their more complex mechanical systems, to the rising costs

of construction, and to the trend toward greater utilization of manu- factured components in building construction requiring standardized

38
plumbing systems. Whether the specific emphasis be the development of

improved performance evaluation methodology, cost reduction, or simply

improved precision in traditional design methodology, the hydraulics

and pneumatics of drainage systems must be studied with modern research

methods and facilities.

Monihan and Konen have suggested the feasibility of using existing technology, with appropriate modification of the values assigned to the various

fixtures and fittings in the Hunter procedure, to achieve a 40-percent

reduction in estimated momentary peak water demand rate. Baker, Bailey,

and Sierka have suggested a 60-percent reduction in consumption with

flow limiters and recycling of gray water. Such reductions in water

usage may reduce the transport velocities in horizontal drains below the

generally accepted velocities of 0.6 m/s(2 ft/s) minimum in drainage

piping and impair the effectiveness of the system. Clearly, the mass media advertisements of chemicals, aerosols, and other means for clearing

of blocked drains indicates a problem exists in the continuing maintenance

of flow of waste-water in drainage systems. DeYoung and Konen-^ have

reported a 25-percent reduction in the velocity of the wastewater in the

piping immediately adjacent to the water closet as the result of changing

from a customary water closet using 19 liters (5 gallons) per operation

(this includes water used to restore the trap seal as well as the excess

that may be wasted by overfill of the trap seal) to a water-saving water

closet using 11 liters (3 gallons) . Cole18 has reported concern about

the use of very low-volume water closets, because they reduce the flow in

sewers, and this might cause increased solids deposition and septicity in sewers under some circumstances, e.g. in new building projects during

early stages of completion and occupancy. Studies in England1 ^ >^0 s howe(j that in multifamily housing the frequency of fixture usage was significantly

less than assumed in the development of the Hunter curve, and that peak water

demand on the systems was significantly less than the estimates obtained

from the traditional British procedure patterned after the Hunter model.

Although the British data alone do not constitute significant evidence

that the American procedure for determining design loads is deficient,

similar American data do suggest strongly that there is a research need

to improve the procedure for estimating peak drainage loads under service

conditions.

The flow in plumbing drainage systems consists of solides, liquids, and

gases. Researchers in the United States and the United Kingdom have

generally believed that the "normal solids in "usual" amounts do not

significantly influence the important hydraulic parameter, pressure, This

has encouraged consideration of the flow as a two-phase system: water

and air. Water enters a drainage system through a trap which provides

a water seal to prevent sewer gases from entering the habitable area of

the building. The wastewater does not generally fill the horizontal branch drains, with the occasional exception of the piping

immediately adjacent to the trap and fixture. Main horizontal drainage lines are sized to run half-full at the expected peak flow rate,

this safety factor being applied to account for multiple

39
uncertainities in design methodology, service loads and installation

detail. The principal driving force is the potential energy resulting

from the slope of the drainage piping. Some kinetic energy contribution

is made through the existence of "shooting" flow (super-critical velocity,

Froude number greater than 1.0) in the immediate reach following the

change in direction from vertical to horizontal. This energy is readily

dissipated in most branch lines but may result in a troublesome hydraulic jump in the building drain at the base of a tall stack. Laboratory

experimentation"'"^ has shown the occurrence of the jump a considerable

distance downstream from the base of the stack (Figure 2). This is

contrary to customary thinking that the jump ordinarily occurs within

10 stack diameters of the base of the stack. However, it has been

2

1

observed in tests with transparent pipe that a washing of the sides

of the building drain with the wastewater occurs for a few feet downstream from the stack as a result of swirling, secondary flow generated

in the vertical to horizontal bend. These washings can cause momentary

blocking of vents taken off the building drain close to the base of

the stack, and this contributes to adverse back pressures in the lower

portion of some systems. Fittings for such vents rolled up to the

customary minimum of 45° would be particularly susceptible to this

phenomenon. The customary design rule of avoiding vent connections to

the building drain within ten stack diameters of the base of the stack

can be justified on the basis of this washing action rather than the

hydraulic jump.

The generally accepted theory for the flow of wastewater in drainage

stacks"*-'^ »^ * depicts two-phase annular flow. The wastewater attaches

itself to the walls of the pipe, forming an annulus. The falling water

drags air with it inside a center core. The thickness of the annulus

at the pipe wall increases with the rate of water discharge to a maximum

allowable value corresponding to an area roughly between one-fourth and

one-third of the cross-sectional area of the pipe. An increase in

thickness beyond this range results in a breakdown of the characteristic

annular flow, accompanied by excessive noise, turbulence and pressure

fluctuations. The hydraulic capacity of drainage stacks with traditional

venting has been defined as that flow rate for which the water occupies

7/24 of the cross-sectional area of the pipe at terminal velocity.

This theory depicts the falling water as acted upon by restraining shear

forces occuring at the wall of the pipe (the restraint at the air-water

interface is ignored) and indicates that these forces limit the water to

a maximum (terminal) velocity ranging from about 3.2 m/s (10 ft/s) to 5.1

m/s (17 ft/s) for (cast-iron) stacks of 75 mm (3 inch) and 150 mm (6 inch)

diameter, respectively. The corresponding terminal velocities are com- puted to develop in approximately 1.7 m (5.6 ft) to 4.4 m (14 ft), respectively, below the point at which water enters the stack. This theory

does not take into account possible effects of inclusions in the flow,

possible effects of inclusions in the flow, e.g. solids or detergents.

Recent investigations have challenged these concepts and the design criteria derived from them as too restrictive and not taking into account

40
some of the important physical parameters that determine the ability of

the systems to service the drainage from the connected load of fixtures,

appliances, and other equipment (Figure 3). In any method for the direct

computation of DWV system performance, the question of possible dynamic

effects should be resolved. While continuous flow experimentation and

static considerations have been emphasized in past research, recent

evaluations of innovative systems using advanced measurement techniques

have shown phenomena (both favorable and unfavorable) apparently due

to the dynamic nature of wastewater discharge. Estimates of the critical

frequency of the common waste fixture trap seal indicate it to be in

the vicinity of the pulsation frequency one would expect in the drainage

system of a high-rise building. If this is correct, resonance may

contribute to excessive trap-seal depletion under some circumstances.

On the other hand, preliminary efforts to correlate vent suction with

trapseal reduction have indicated that some trap forms resist suction

much better than had formerly been supposed. These considerations suggest

a valid case for a study of the dynamic performance characteristics

of flow in a range of representative DWV systems, using both analytical

and experimental techniques with modern instruments and data acquisition

facilities.

Research should take into account the needs for resource conservation and

for associated cost reduction that might be realized in many situations

by the proper sizing of piping to accommodate representative loads.

Estimates of the cost savings from innovative designs such as single-stack

or self-venting drainage, and reduced-size venting have been expressed

in terms such as "up to 40 percent of the DWV piping cost," "potential

savings of the order of $60 per bathroom," and "up to $150 per living

unit." Estimates of the annual national reduction in construction costs

from an across-the-board 10 percent savings in the cost of water supply

and drainage systems, that might be possible from research of loads

alone, have approximated $500 million. Perhaps at least 60 percent

of this, or $300 million could be realized from improved methodology

for DWV systems. It has been estimated that up to $15 million could

be saved annually on the cost of thermoplastic pipe and fitting materials

alone, merely from the widespread use of reduced-size venting.

Although labor savings are often thought not to be significant for a one-or two-pipe-size reduction, analysis of the National Association

of Plumbing, Heating, Cooling Contractors' Labor Calculator 22 shows

that installed costs that reflect labor costs are, in fact, appreciably

affected by pipe size, even by a one-size reduction in some ranges.

Improved design and evaluation methodology would provide energy savings

to the extent that significant reductions in quantities of material

required for construction would provide corresponding savings of energy

for raw material's, manufacture, transportation and handling. For example, even a one-size reduction in all the DWV thermoplastic pipe and fittings

41
sold in the United States would produce a considerable energy savings

in the manufacture of these products and a reduction in the use of

petroleum feedstock for this purpose.

While less tangible than the obvious economic benefits suggested above,

some additional significant and far-reaching benefits can be anticipated

from research. The development of improved design and evaluation

methodology which depends on research would contribute to uniformity

of codes and to interstate acceptance reciprocity, and would facilitate

realistic acceptance of innovative designs with their potential economic

and resource-conserving benefits. This would hasten potential benefits

in becoming real benefits, and would encourage beneficial innovation.

Improved precision, flexibility, and standardization of design and

evaluation methodology would also provide a means to improve the service

to clients by manufacturers, designers, and installers. The system or component providing adequate performance at an acceptable cost could be

specified and its design, acceptance and installation could be completed more efficiently and effectively.

Needed Research

Research is needed in the following areas:

1. Measurement and Definition of Dynamic Flow Characteristics in

Complex Systems .

The limited studies, that have been made with simple test systems, have addressed isolated parts of this general problem,

but these findings need to be brought together in a coordinated

fashion and additional work done to complete the program. Some

of the studies reported since 1972 in the CIB W62 Symposia

provide a start in this direction. Generally accepted methods

are needed for defining or predicting the hydraulic and pneumatic

profiles of the flow from single fixtures and groups of fixtures

distributed by time and space. Then this profile definition

should be applied in a study of trap-seal reaction, a timedependent energy transfer problem. This work would involve

the establishment of adequate correlations between water flow

rate, air flow rate, pneumatic pressure fluctuations, blowback, cross-flow and water rise. System configurations, fitting

geometry and representative additives to waste water (e.g.

suds and solids) should be taken into account in this type of

experimentation.

2 . Carrying Capacities of Horizontal Drains .

Closely related to 1. above, which is largely associated with

phenomena in a vertical system, a need exists for better definition of carrying capacity of both simple and compound horizontal

42
drains. Standing waves combined with hydraulic jumps may initiate undesirable oscillations within idle traps and may significantly alter hydraulic capacities of primary and secondary

building drain branches from the values calculated from

classical continuous-flow formulas. These studies would be

concerned essentially with wave phenomena associated with the

imposition of representative, transient loads.

Analytical Approaches in Predicting Performance .

Mathematical procedures or simulation techniques should be

developed that will predict system performance as a function

of input load. Possibly, the validity of the continuous-flow

approach recommended by Lillywhite and Wise^ for research

purposes will be confirmed by the suggested dynamic studies,

but this will be dependent on the correlations to be defined

and on the extention of the analytical relationships so as to

be applicable to a range of designs that might be encountered

in practice. Again, some of the work reported in the CIB W62

Symposia may provide needed guidance.

Scale Modeling Techniques .

For the purposes of predicting performance of designs not amenable to successful analytical treatment as in 3. above, scale

modeling techniques need to be- developed. Early attempts in

this field were encouraging, but later were abandoned in

favor of full-scale testing. With the present high and rising

cost of testing, it is prudent to reconsider the potential of

scale -mode ling in this field.

Standardization of Full—Scale System Performance Test Methods.

Until suitable scale -mode ling techniques are developed and

general computational capability is further advanced, a need

will remain for full-scale system hydraulic performance tests

(for evaluating innovative systems) that are reproducible

and that can be economically carried out in the field. A

number of different procedures have been tried for this purpose,

but standardization has not been completed nor have all the

technical uncertainties been resolved.

Definition and Modeling of Service Hydraulic Loads .

Hunter's model for momentary peak demand flow rates in large

water service and distribution systems has been utilized also

for the estimating of peak momentary discharge rates and for

the sizing of piping in both small and large drain-waste-vent

systems (Figure 4), for the sizing of water heaters, etc.

43
Some of these applications have required unwarranted extrapolations and probably unrealistic assumptions. Hunter had

cautioned against unwarranted applications of the model and

had pointed out some of its limitations.

The proper sizing of DWV system components depends on muchimproved knowledge of service loads. This need is believed

to be greater than any other single need indicated by 1-5

above. In fact, the full benefits of hydraulics research can- not be realized in practice until design loads definition is

updated and expanded. This work should be a part of the

research on better definition of design load for water service

and distribution systems described in another paper in this

symposium, to avoid duplication of effort. The needed load

data for drainage and water supply systems are rather similar.

44
REFERENCES

1. L. S. Nielsen, Standard Plumbing Engineering Design, McGrawHill, New York, N. Y. (1963).

2. Recommended Minimum Requirements for Plumbing in Dwellings

and Similar Buildings. Report of Subcommittee on Plumbing of

Building Code Committee, National Bureau of Standards BH2 (1924).

3. Recommended Minimum Requirements for Plumbing. Ibid. BH13 (1928,

revised 1931).

4. American Standard National Plumbing Code ASA A40. 8-1955, Minimum

Requirements for Plumbing, American Society of Mechanical Engineers,

New York, N. Y.

5. Methods of Estimating Loads in Plumbing Systems. National Bureau

of Standards BMS 65 (1940). COM 73-10967/LK. R. B. Hunter.

6. Plumbing Manual, Report of Subcommittee on Plumbing. Central

Housing Committee on Research, Design and Construction.

National Bureau of Standards BMS 66 (1940).

7. Water-distributing Systems for Buildings. National Bureau of

Standards BMS 79 (1941). (COM 73-10971/LK) R. B. Hunter.

8. F. M. Dawson and A. A. Kalinske, Report on Hydraulics- and

Pneumatics of Plumbing Drainage Systems - 1, University of Iowa

Studies in Engineering, Bulletin 10 (1937).

9. F. M. Dawson and A. A. Kalinske, Report on the Hydraulics and Pneumatics of the Plumbing Drainage System, Technical Bulletin 2 of the

National Association of Master Plumbers, Washington, D. C. (1937).

10. American Model Plumbing Codes:

Basic Plumbing Code (1975), Building Officials & Code Administrators International, Chicago, Illinois.

Standard Plumbing Code (1975), Southern Building Code Congress

International, Birmingham, Alabama.

Uniform Plumbing Code (1976), International Association of Plumbing

and Mechanical Officials, Los Angeles, California.

National Standard Plumbing Code (1975), National Association of

Plumbing, Heating & Cooling Contractors, and American Society of

Plumbing Engineers, Washington, D. C.

11. Self-siphonage of Fixture Traps. National Bureau of Standards

BMS 126 (1951). COM 73-11052/LK. J. L. French and H. N. Eaton.

45
12. Stack Venting of Plumbing Fixtures National Bureau of Standards

BMS 118 (1950). COM 73-11014/LK. J. L. French.

13. Wet Venting of Plumbing Fixtures. National Bureau of Standards

BMS 119 (1950). COM 73-11016 J. L. French, H. N. Eaton and

R. S. Wyly.

14. Capacities of Stacks in Sanitary Drainage Systems for Buildings.

National Bureau of Standards Monograph 31 (1961). COM 75-10045/LK

R. S. Wyly and H. N. Eaton.

15. Investigation of Hydraulics of Horizontal Drains in Plumbing Systems.

National Bureau of Standards Monograph 86 (1964). COM 75-10046/LK.

R. S. Wyly.

16. Household Water Conservation Effects on Water, Energy and Waste-Water

Management, by Larry K. Baker, Harold E. Bailey and Raymond A.

Sierka. Conference on Water Conservation and Sewage Flow Reduction

with Water-Saving Devices, April 8-10, 1975, J. 0. Keller Conference

Center, The Penn State U., University Park, Pa.

17. An Investigation of the Performance and the Effects of Reduced

Volume Water Closets on Sanitary Drainage, Sewers, and Sewage

Treatment Plants, by Thomas P. Konen and Raymond DeYong. Conference

on Water Conservation and Sewage Flow Reduction with Water-Saving

Devices, April 8-10, 1975, J. 0. Keller Conferences Center, The

Penn State U., University Park, Pa.

18. Impact of Home Water Saving Devices on Collection Systems and Waste

Treatment, by Charles A. Cole. Conference on Water Conservation

and Sewage Flow Reduction with Water-Saving Devices, April 8-10,

1975, J. 0. Keller Conference Center, The Penn State U., University

Park, Pa.

19. Wise, A. F. E. and Croft, J., Investigation of Single-Stack Drainage

for Multistory Flats, J. R. San. Inst. 74, No. 9, Page 160 (1954).

20. An Investigation of the Use of Water Outlets in Multi-Story Flats,

by C. J. D. Webster. Proceedings, CIB W62 Symposium on Water Demand

in Buildings, Building Research Establishment, Garston, England

(1972).

21. Konen, T. P., Jackson, T. and Fowell, A. J., "The Evaluation of

Several Plumbing Drainage Waste and Vent Systems," Davidson

Laboratory, Stevens Institute of Technology, Report SIT-DL-74-1776

(December 1974).

22. NAPHCC Labor Calculator II, National Association of Plumbing-HeatingCooling Contractors, Washington, D. C. (1971-Revised 1975).

46
23. Lillywhite, M. S. T., and Wise, A. F. E., "Towards a General Method

for the Design of Drainage Systems in Large Buildings," Building

Research Station (England), Current Paper 27/69 (1969).

24. Wise, A. F. E., Drainage Pipework in Dwellings: Hydraulic Design

and Performance, DSIR, Bldg. Res. Station, London, England (1957).

25. Model-Prototype Study of a Plumbing Drainage System, D. A. Gyrog,

F. M. Dawson, and E. C. Lundquist, No. 2019 HY5, pp. 67-75,

Journal of Hydraulics Division, Vol. 85, Proceedings of the

American Society of Civil Engineers, (May, 1959).

47
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50


PERFORMANCE CONCEPTS FOR WATER SUPPLY AND DRAINAGE

SYSTEMS IN BUILDINGS

by

L. S. Galowin, W. J. Downing

L. S. Nielsen, M. J. Orloski and R. S. Wyly

The performance concept is described in relation to water

supply and drainage for buildings, its present status examined

and the needs for research and implementation aids explored.

Difficulties in determining acceptance of innovations under

traditional plumbing codes and product standards are discussed,

and the advantages offered by performance evaluation methodology are pointed out.

The paper describes some of the research needs and other

impediments to early development and widespread implementation

of viable performance evaluation methodology, and suggests means

of overcome impediments. A current activity is described that

is intended to develop a consensus performance standard for

plumbing systems as a complement to the traditional prescriptive code.

INTRODUCTION

Difficulties have been encountered in the acceptance of innovative,

performance-oriented to problems in water supply and drainage under the

provisions of comtemporary American plumbing codes. These difficulties

are due largely to the characteristic prescriptive nature of the existing

codes and of the standards referenced by these codes, and to the absence

of adequate methodologies for predicting or testing the essential performance, i.e., methodologies for determining the satisfaction of the

requirements for health, safety and essential sanitary and physiological

functions as deemed necessary to fulfill user needs and public welfare.

The reliance upon traditional codes which specify allowable configurations

and designs, pipe sizes and materials inhibits implementation of innovative solutions for water supply and drainage systems and for water con- servation practices, and limits materials resource conservation and

energy conservation opportunities. The consequences are overdesign of

traditional systems and delay or difficulty in gaining acceptance of

innovative approaches. The interest in the performance approach results

from a recognition of the opportunities that it can provide for fulfilling the essential needs for building services in terms of user requirements through unencumbered engineering design to suit the particular

circumstances.

In order to facilitate the development and utilization of performance

standards, adequate performance evaluation methodology must be provided

53
as a substitute for the slower service history evaluation approach of

the prescriptive codes. The prescriptive specifications for materials,

products and systems with which considerable service experience has

been gained have usually served their purpose well. But with the development or proposal of new materials, components and systems, and of new

uses for existing materials it is essential that performance evaluation

techniques be developed which are applicable as systematic and organized

procedures for predicting service performance.

Traditionally, specification writers attempted to identify and specify

the materials and products that were known from service trials to provide

satisfactory performance under normal usage conditions over a period of

time. The concept of the performance approach, however, is based upon

short-term measurements that signify the degree to which user requirements are fulfilled without imposing limitations on any particular com- bination of physical and chemical properties, on the design or on the

method of manufacture or construction. For further background on the

performance concept the reader is referred to bibliographies included

in recent papers [1, 2].^'

It is necessary to distinguish between systems and materials in discussing the performance concept. System performance relates to the functional and safety adequacy; materials performance relates mainly to the

durability aspect of sustaining the essential functions and safety of

the system in which the materials are utilized. The problem of perfor- mance evaluation for a component made from an innovative material poses

considerable difficulty because of uncertainty in the ability to simulate

the effects of the service environment in tests for durability. (See

Figure 1). This problem is also the predominant one in the traditional

specification-type approach where the difficulty is the long period of

service history required to permit a meaningful evaluation. Under either

approach, findings may fall somewhere between the "clearly satisfactory"

and "clearly intolerable" categories. In this area, the acceptance

decision may require additional data and/or informed judgment based on

a consideration of functional adequacy and realistic performance levels

for the satisfaction of user requirements.

Considering the example of an innovative piping material, a number of the

properties of materials may be involved in the development of performance

evaluation methodology. In this approach, the particular requirements

to be emphasized and the measures of performance that are critical will

depend on conditions of the service application and on the physical and

chemical properties of the material that determine the relevant performance characteristics. For example, fire spread might be a significant

measure for an assembly of materials that are subject to burning or pyrolysis such as wood or thermoplastics, but probably not for an assembly of materials generally considered non-combustible such as masonry,

Numbers in brackets refer to the list of references at the end of

this paper.

54
steel or cast iron. On the other hand, some of the important measures

for metals, e.g., electrolytic corrosion, may be of little or no consequence for a non-metal.

The issues of current interest considered here are related primarily to

problems in the development and implementation of performance standards

for water supply and drainage for buildings. The key technical needs

related to the identification of significant criteria to characterize

the essential performance, and to the establishment of the methodologies

and techniques for measurement on the basis of these criteria. Research

and other actions should be directed to the resolution of technical problems associated with prediction of future service performance, and with

the development of protocols for acceptance. The solution of these

problems requires better definition of relevant physical and chemical

processes and environments, and of the effects of installation detail

on performance.

PRESENT STATUS OF PERFORMANCE EVALUATION METHODOLOGY

A. Existing, Stated or Implied Performance Statements

The present status of performance evaluation methodology in the USA is

deficient. A few well developed elements of performance evaluation

methods already exist as statements in codes or generally recognized

standards. Other elements are implied in existing documents, but not

actually stated in performance language. Still other elements have not

been effectively defined or developed, and it is in these areas that the

most important research needs can be identified.

In reviewing existing standards or other technical documents, one occasionally finds a complete or nearly complete performance statement,

presented in a format approximately as follows:

Requirement (qualitative)

Criterion (quantitative)

Test (a definitive and reproducible measurement technique)

Commentary (rationale or explanation) — optional

The familiar leak test requirements of the plumbing codes are usually

presented in this format, approximately. But, unfortunately, not all

statements in the present generally accepted standards and codes are complete or follow this logical arranagement.

Nevertheless, a number of existing implied performance statements can

be identified and sometimes these can be restated in performance terms,

wholly or in part. For example, a restatement can be made of the apparent performance intent of some of the familiar specifications in American

plumbing codes relating to sanitary drain-waste-vent systems. The significant performance measures (criteria) may be expressed as follows, based

on findings in recent research studies [3, 4]:

55
1. Adequate trap-seal retention with suction ( > 50%)

2/ 2. No emissions with back pressure (back pressure < 38 mm WG-'

3. Minimum water rise or flow interference from hydro dynamic

or hydrostatic effects (water rise < 1.0 D; interfixture

discharge retardation < 10%) —

While these criteria seem to be implied in qualitative terms by the

codes, systematic definition and quantification is largely lacking. For

standardization of the suggested performance statements, a consensus on quantification and test procedures is required.

The main problem with implied performance statements is that standard

test procedures or other suitable evaluation techniques do not now exist

in a number of instances . It appears, however, from a review of various

recent documents describing test procedures for sanitary drainage system

hydraulic performance evaluation, that early standardization of some of

the procedures may be possible. Similarly, standard tests may be possible in other areas in the near future, such as tests for measuring the

hydraulic and waste removal performance characteristics of plumbing

fixtures and appliances.

B . Some Technical Impediments to Performance Evaluation

The principal technical impediments to a viable performance evaluation

approach in the field of water supply and drainage in buildings can be

categorized as follows:

1. Incomplete definition of the physical and chemical processes

involved in the representative operation of the various

components and systems that might be utilized in innovative

approaches

.

2. Inadequate information on the service environment, particularly with respect to load patterns involving:

(a) hydraulic and pneumatic demands

(b) forces, both transient and continuous

(c) temperatures of fluids transported

(d) chemical composition of fluids transported

3. Poor correlation between short-term test results and longterm performance in service.

For example, the mathematical models for gravity drainage systems

2' WG-water gage . A measure of pressure, with reference to atmospheric

pressure, expressed in terms of equivalent height of water column.

56
are inadequately defined for the purposes of performance evaluation.

Knowledge of the laws of air circulation, air-water "slippage", and air

demand is incomplete and partly for this reason large "safety" factors

are used in the design of traditional systems [5].

The inadequacy of existing information on the service environment is

exemplified by recent reports on the deficiencies of the Hunter model

for design hydraulic loads; yet the Hunter model remains the principal

basis of the generally accepted U.S. practice. There is general, worldwide acknowledgement of the need for a comprehensive program to update

or replace this mode [5, 6],

The problem of correlation between performance in short-term tests and

that in the service environment has been exemplified by the difficulties

and long period involved in establishing acceptance of thermoplastics

piping in appropriate applications in the U.S.A. Significant elements

of the problem have related to insufficient definition of temperature

and chemical composition of fluids transported in service, and of the

poor correlation between accelerated test results and long-term service

performance [7].

C. ANSI A40 Performance Standard Program

It was against this background that initiation of the development of a complementary performance standard was recently authorized by the Sponsors and the Standards Committee of the A40 project Minimum Requirements

for Plumbing, under the procedures of the American National Standards

Institute (ANSI). The performance standard is expected to. be complementary to the updated specification-type model code that is being developed, not in competition with it. In fact, the expectation is that

a performance standard would be a useful aid in the administration of

specification-type codes by establishing a methodology for acceptance of

innovations, an area in which traditional codes are deficient. Conceivably, as familiarity and experience are gained in the concept and use of

the performance standard, the specification-type code would gradually

adopt more and more of the performance language and format.

The initial activity has been to begin the development of a consensus on

the specific steps to be taken, on the sequence in which they are to be

taken on the identification of feasible means for carrying the work to

a suitable conclusion. This has been described in some detail in

reference [1]. Once format, terminology and basic philosophy are agreed

upon, the first major task is to index existing codes and standards for

actual or implied performance statements in the agreed-upon format.

It is expected this exercise will be quite informative in identifying

several technical and administrative impediments to a current limited

application of the performance approach, but at the same time will identify those areas in which early success is possible.

57
RESEARCH NEEDS AND ACTION REQUIREMENTS

A. General Needs

References [5, 6, 8, 9, 10] provide some detailed definition of a number

of specific research needs in hydraulics and pneumatics of plumbing systems, alternative methods of waste disposal, water quality, water conser- vation and other technical areas. It is not the primary purpose of this

paper to dwell on these details, but rather to suggest meaningful actions

needed to facilitate broad implementation of performance evaluation

methodology in the technical areas addressed by the referenced papers.

The performance approach can be beneficial because it enables us to think

in a rational and systematic way about the entire building process, from

the fabrication through the installation in buildings. However, it

appears that the performance approach is going to be in a continuous

state of development for some time because of the need for new information. There exists, then, the requirement for a deliberate and uniform

process of development relying upon existing technical data and sound

professional judgment for some time, but with the transition to improved

quantitative evaluation methodologies as our knowledge expands. The gaps

of technology require sufficient basic knowledge of the relevant physical

and chemical phenomena, supplemented by analytical modeling methods or testing methods to provide definitive and meaningful bases for reproducible evaluative techniques. The simplest method of performance evaluation could comprise a mere visual inspection, possibly supplemented by

the use of a ruler or a level. A higher-order method might take the form

of a full scale test of a component or of the complete system, requiring

the use of instruments suitable for measuring changing discharge rates,

pressures, etc. The most sophisticated method is the utilization of a valid mathematical model that permits the computation of the performance,

given the input values that represent the service conditions and the

relevant properties or technical characteristics of the innovative

system, component or material.

The broad topics of technical research and other activity which are identifiable can be categorized as follows:

1. Cataloging and analysis of the requirements of a variety of

users, in a suitable performance format.

2. The identification of the essential measures (criteria) for

performance and the establishment of realistic levels of

performance of the installed system that will satisfy the

users' essential requirements. These measures and perfor- mance levels must relate the functions and properties of

the system and its components to the essential characteristics of the services delivered to the user.

3. The development of reproducible, reliabe test procedures,

model laws and mathematical models involving the key

58
measures in (2) and including guidelines for interpretation

of results to determine conformance with the requirements

in (1).

4. The establishment of a consensus performance standard

derived in accordance with the above steps and its acceptance by appropriate regulatory bodies. However, this should

be supplemented by steps (5) - (8) for the desired impact.

5. The development of protocols for submission of supporting

data to approval authorities and for its processing to

determine acceptance.

6. The establishment of viable, accredited testing laboratories

to fulfill the need for conducting tests called for in the

performance standard.

7. The provision of inspection procedures and installation

standards suitable for innovations.

8. The establishment of training and education programs to

facilitate performance specifications interpretation and for

examination of designs and installations represented as in

accord with performance specification.

These general needs may be seen in perspective by considering Figure 2,

which is a conceptual model for the evaluation of innovations.

B . Users and User Needs

The definition and satisfaction of user needs can be addressed in terms

of qualitative requirements and quantitative measures that characterize

the functions of water supply and drainage systems in terms of user

awareness. It is necessary to establish the definition of the users in

the framework of the building construction process through delivery to

the ultimate occupant.

Perhaps the first user (of standards and evaluation methodology) in this

chain is the plumbing or mechanical systems designer, who endeavors to

specify safe, economic solutions whithin the multiple constraints established by the financier, by the regulatory authority, and sometimes by

other members of the building team such as general contractor, architects

and structural engineers. Barriers to optimum engineering design and

cost effectiveness often occur at one or more of these links. A barrier

frequently cited is the code or other regulatory document; yet the regulatory body is another important user, because public health, safety and

occupant welfare are dependent on adequate standards and acceptance procedures administrated by the regulatory authority. Another important

user is the installing contractor, who must preserve the essential attributes of the design to maintain adequacy of performance after installation. Standards must take into account the needs of the installer,

59
particularly since installation can have very significant effects on costs and continuity of functional adequacy of the system.

Finally, the occupant, the ultimate consumer is the user of the final

product, the building with its water supply and drainage services. This user is at the end of the chain, and has somewhat different needs from

the previous users. His key needs are health/safety, functional adequacy

sufficient to satisfy daily requirements for drinking water, culinary

activities, bathing, cleaning, and removal of body wastes in a safe,

sanitary and aesthetically acceptable manner. Other important needs of

this user are cost effectiveness and durability (continuity of essential

safety and functional capability). Thus, the performance standard must

address parameters that can assure, with optimum cost and convenience,

the satisfaction of this user's needs for adequate performance over a realistic time period such as the mortgage period or the period until

planned retrofit or obsolescence occurs.

Research is needed to better define user requirements and user response

to changes in the characteristics of familiar services. Data should be

obtained, analyzed and indexed according to category of user and type

of requirement. The analysis should endeavor to identify those user requirements that might be subject to quantification and measurement in

terms of safety, function of some other attribute. The "measures"

(criteria) involved in such quantification provide the cornerstones of

definitive performance evaluation methods.

C . Measures of Performance and Performance Levels

If the users are first identified and their qualitative needs defined,

as suggested in (B), then it becomes necessary to determine the parameters that can be utilized as quantitative measures (criteria) in procedures to measure the extent to which the qualitative user needs are satisfied.

In anticipation of the advent of new materials, new applications of

traditional materials, hydraulic systems for innovative types of service

and innovative hydraulic designs for traditional services, many questions

arise concerning performance capability in terms of health/safety, functional adequacy and durability.

Examples include:

1. Corrosion resistance and leaching as related to the selection of new materials for potable water conforming to

current regulations.

2. Backflow resistance of hydraulic systems comprising some components transporting potable and others nonpotable

water.

60
3. Fouling and clogging resistance of hydraulic systems transporting water or other fluids having a high concentration of

solid matter and a low rate of discharge.

4. Acoustic acceptability, pressure-shock resistance and erosion

resistance of hydraulic systems utilizing innovative materials

and designed for high velocity, intermittent flow.

5. Surface fouling, odor and sewer gas emission resistance,

flushing effectiveness and water-use efficiency of watersaving fixtures and appliances.

6. Dimensional and strength stability of piping materials for

solar heating systems utilizing different fluids.

7. Resistance to sewer emissions of drainage systems that violate the venting specifications of traditional codes of

practice.

It is evident that these questions indicate the need for research to

better define the physical or chemical parameters that can be used as reliable and meaningful measures of the adequacy of performance, as well as to determine the minimum levels of performance that should be

provided by a performance standard.

D . Test Methods and Evaluation Techniques

Reasonably accurate and reproducible test methods or other systematic

evaluation techniques are essential to the implementation of the performance approach. These procedures must be designed to employ definitive

measures (criteria) as indicated in (C).

Perhaps the greatest need is for methodology suitable for predicting

performance in service over a period of time.

Overdesign practices and prohibitions against innovative approaches tend

to continue without suitable performance test methods that address user requirements and employ appropriate performance measures. Performance

limits must be set, either in the performance standard or in the acceptance protocol.

In the utilization of performance test procedures, it will be helpful

to include commentary or guidelines to aid in the interpretation and

reporting of test results.

Certainly there is a need for considerable research in developing the

systematic, reproducible evaluation methods that are needed. Recent

experience gained in several exploratory performance studies has supported this view [3, 4, 11, 12, 13].

61
E. Consensus Performance Standard

The establishment of a consensus performance standard that includes the

relevant performance statements is necessary for relating the provision

of the services and the utility of such services to provide the

attributes required by the user.

The performance statements must provide definitive guidance for evaluation of unqiue methods and materials, emphasizing systematic methodologies for determining satisfaction of an evaluation protocol for a generic

class

.

It is anticipated that the performance "standard" would actually comprise

a number of parts, e.g., water supply and distribution, sanitary drainage,

storm drainage, etc.; somewhat as is now the fashion in the prescriptive

codes. Coordination in format, terminology and basic concept for the

different parts would be essential, and should be so planned at the outset. The evaluation methods required to support the performance standard

might be incorporated by reference if they themselves were promulgated by a recognized standards organization. Until this occurs, the evaluation

methods should be included in the performance standard.

F . Implementation Aids

In order to achieve widespread implementation of a performance standard,

approval protocols must be established. This requires the establishment

of procedures and formats for submitting supporting data and interpreting

test results to the end that a definitive acceptance decision can be

obtained. For this purpose the important attributes and requirements

must be clearly defined and related specifically to quantification by

measurement through easily understood test methods. Guidelines are required to assist innovators in submitting the appropriate data in a suitable format.

Among the more important implementation aids are the following:

1. Laboratory Accreditation Program

There is a need for accreditation of testing laboratories to

provide for the use of uniform methods of evaluation and for

uniform capability for generating reliable, reproducible test

results.

Testing laboratory accreditation fills a gap which is compatible

with the American system of building code administration. In

Europe acceptance protocols and certification testing are widely

provided under centralized governmental direction. By contrast,

in the U.S.A. this authority is vested in the fifty states or

in the much larger number of smaller political divisions. This

has contributed to delay in the development of a generally

accepted laboratory accreditation program as well as to dealy

in achieving uniformity among the various plumbing codes.

62
In order to fulfill the requirements for establishing test

credibility for materials, elements and systems for water supply

and drainage, a testing laboratory accreditation program on a national scale is required, but should not be unduly influenced

by the national government. Advances in the utilization of the

performance approach may be expected to increase through a comprehensive, generally accepted laboratory accreditation

procedure. Possibly this need could be satisfied through the

National Voluntary Laboratory Accreditation Program which was initiated by the promulgation of procedures published in the

Federal Register on February 25, 1976, as part of part 7 of

Title 15 in Commerce and Foreign Trade. There, it was stated

that the goal of the program is to provide in cooperation with

the private sector a national voluntary system. It has the

stated purpose to examine upon request the professional and

technical competence of private and public testing laboratories

that serve regulatory and nonregulatory product and certification needs. The program also is intended to accredit those

laboratories that meet the qualifications which will be established under these procedures. It is required that the participating laboratories that are accredited maintain their

qualification status through suitable checks and examinations.

It is readily recognized that there is a close link established

between the research necessary to formulate the required test

methods and acceptance protocols and the determination of the

adequacy of resources and expertise for suitable testing services. The detailed criteria for accreditation of laboratories

in this field remains to be established. Not only are the technical expertise of staff and the quality of equipment important

items, but also important are the methods for obtaining data,

recording and keeping of records, as well as the ability to

report results in a meaningful and useful manner.

The intent of the program is to serve in a timely manner the

needs of industry, consumers, and the Government. The orientation of the program is such as to assure that accredited testing

laboratories can render services of evaluation regarding a product or system to ascertain whether the requirements of applicable standards are satisfied. Requests to the Secretary of

Commerce to determine if there is a need to accredit testing

laboratories are required to include the text of an applicable

standard and the text of a test method if not included in the

standard. In setting forth the basis of a preliminary finding

of need for accredited testing laboratories, consideration must

be given to: the benefit to the public interest; whether it is

necessary to extend beyond existing laboratory accreditation

programs in the public or private sector; whether there is in

existence a standard deemed as being of importance to commerce,

consumer well being, or the public health and safety; whether

there exists a valid testing methodology for ascertaining

63
conformity to the standard for the specific product involved.

At the present time, the vehicle for administering the laboratory accreditation program has not been effectively defined.

Plans Examination and Inspection of Instal lations

In demonstrating performance acceptability through function satisfaction in accordance with a standard and its test methodology,

it is necessary to account for the possibility of degradation

of the anticipated quality of performance as a consequence of

the normal installation/construction process. Techniques must

be developed and translated into practical application in the

field which provide acceptance inspection procedures and installation standards for the purposes of the approval authorities.

Inspection and field testing procedures are needed to detect

and limit the occurrence and consequences of imperfect practices

in the field. To implement the performance standard, there is

a need for training and education of examiners who may review

designs and inspect installations (in the factory or in the

field). These tasks can be more difficult under a performance

standard since more sophisticated expertise and interpretative

capability may be required to establish compliance. The departure from reliance upon "cookbook" prescriptive specifications

greatly modifies the procedures for plans review and installation inspection. Greater freedom to develop more truly engineered solutions becomes possible, but uniformity of acceptance

requires trained, specialized staff to interpret and understand.

Reliance upon gradually obtained experience, on-the-job training, and formal engineering education appears to provide the

current hope for growth toward acceptance of the performance

approach in plans review and installation inspection. Continuing efforts will be required to promote professional educational

orientation toward performance evaluation for water supply

drainage systems. Also, installation standards should be initiated by the proponents of innovations working with the appropriate consensus standard body and regulatory authorities con- cerned with the performance standard. Conformance with these

installation standards probably should be a part of the

approval protocol.

Illustrated Manual of Acceptable Methods and Temporary Approvals

A useful guideline document would be a cumulative manual showing

solutions that have been found acceptable under a performance

standard. For situations where the evaluative art is not at

hand for rigorous determination of conformance, a resource base

(such as a technical council of a duly constitued evaluation

group) with a laboratory arm established by the sponsors of a performance document under the auspices of a nationally recognized standards body, should be available to determine a

64
consensvis on the technological problems and to provide important

guidance in the needed test development and data interpretation

service. Such a Council might find it purposeful to administer

a temporary approvals program for generally promising innovations for which generally recognized standards do not exist.

In some ways, this might serve the function in the U.S. that

the Agreement approvals system serves in Europe.

The Agreement System, used in several of the Western European

countries, comprises explicit administrative and technical procedures for the evaluation of innovations, pending the development of generally recognized standards. Agreement certificates

are valid for a stated period only, but often they provide a basis for interim acceptance by the regulatory authorities.

This system has been described further by Trinkler [14].

Summary of Key Points

In the foregoing discussion of the performance approach, we have used

the terminology: attribute, requirement, criterion and method of

evaluation. These together with a commentary (optional) , comprise a "performance statement." The universal attributes of function,

health/safety and durability (continuity of essential functional capability and health/safety attributes) have been suggested. The term

"requirement" is adopted to signify a meaningful, qualitative indicator

of conscious user need related to the relevant universal attribute. The

"criterion" is a quantitative measure that can be used as the basis of

a "method of evaluation" (a test) to determine the extent .to which the

requirement has been satisfied. (See Figure 3.)

Since performance evaluation methodology does not address specific

details of hardware nor is it concerned with just which particular engineering solution is employed, capability must be provided to predict or test for adequacy of any proposed solution through measurement. To

satisfy such needs a systematic and reproducible methodology must be

provided. That methodology may be either of a basic computational type,

or of an empirical type utilizing a definitive reproducible test or sytematic inspection procedure. Due to the difficulties and high costs

of field verification tests or demonstrations, suitable laboratory tests

and computational procedures are needed. This need dictates efforts to

develop suitable procedures for scale model testing and component assembly testing with non dimensional applicability to full-size systems.

The utlimate evaluation technique is a mathematical model that predicts

specific performance levels in terms of agreed upon physical or chemical

criteria, provided the appropriate inputs are furnished with respect to

representative loads, specific dimensions and configuration, and relevant

properties of the materials. (See Figure 4.) This approach also leads

to a recognition of the need to incorporate the principles of economic

modeling and lifecycle concepts.

65
It is possible through a viable performance approach to reduce overdesign

which has characterized prescriptive solutions. This is because the

essential performance would be measured according to relevant criteria

instead of inferred from a specification of the properties of particular

solutions already found satisfactory (often actually much better than

satisfactory) from a lengthy period of service experience. The prescriptive approach tends to produce over-design in traditional solutions and

offers little help in attempting to evaluate innovative methods and

materials in a reasonable time frame.

The performance approach requires a systematic methodology for evaluation

especially applicable to innovative methods and materials, but yielding

results compatible with service history when applied to traditional solutions. This requires the development of reproducible, reliable test procedures for measurement with guidelines for interpretation of test

results to determine conformance. The formulation of standard test procedures accompanied by accepted interpretative techniques is essential to

a viable, consensus performance standard. To be effective the research

results must be supplemented by the development of an acceptance protocol

through which regulatory bodies will recognize the basic evaluation methods derived from the research. This protocol would require also a means

for accreditation of testing laboratories recognized for capability to

conduct tests and evaluate the test results in accordance with a performance standard. (See Figure 4.)

CONCLUSIONS

A. Principal Technical Research and Standards Development Needs

From the foregoing it is concluded that many of the key technical needs can be satisfied by organized, aggressive research with a performance

orientation. These needs can be categorized under the following headings.

1. Definition of user needs (requirements) and suitable measures

(criteria) for determining the extent to which the requirements are satisfied.

2. Development of evaluative techniques through which systematic,

reproducible quantitative determinations of adequacy of performance can be made using the criteria defined in (1). This

will require new knowledge of the fundamental physical and

chemical processes that determine adequacy of performance,

better information on the service environment, the development of mathematical models, and the formulation and standardization of test methods with a performance orientation.

B . The Need for Acceptance Protocols and Laboratory Acc reditation

A consensus of the building community and regulatory systems must be

developed defining the elements of acceptance protocols, if the results

of research are to be utilized optimally in the furtherance of the

66
performance approach. A uniform approval methodology needs to be defined

in some detail, and acceptable vehicles for promulgation of consensus

performance standards need to be identified. Suitable mechanisms for

laboratory accreditation and certification of new methods and materials

must be defined that will be compatible with the objectives of performance evaluation.

C . Educational and Training Need s

Because of the new concepts, new terminology and special complexities of

the performance approach for water supply and drainage, there is a significant need for education and special training, not only for potential

users of performance evaluation methodology but also for the specialists

who may participate in its development.

D. Recommendations on Activity Priorities and

Establishment of Program

1. An important first step in the educational area has already been

undertaken—i.e., authorization for initiating the drafting of an ANSI A40 performance standard for plumbing. This type of

activity needs to be broadened to emcompass a greater range of

building services so that familiarity with the performance

approach can be obtained by workers in a different areas of

expertise related to the design, standardization and regulation

of building services.

2. A most important, second step is the consensus definition of

research needs that can be obtained from the results of the

pilot activity in (1). Encouraging developments in definition

of various types of research needs are already occurring in the

CIB W62 Commission program, particularly as reflected in the

present symposium, and these data should be reviewed from the

standpoint of performance evaluation needs. Because to date a considerable emphasis on empirical and prescriptive design

criteria has characterized the research, it is anticipated that

the suggested exercise will define special technical research

needs for performance evaluation.

3. The third step requiring concentrated activity is the establishment of a consensus on the means for implementation of potentially valuable research findings. Planning for this program

should be started before the work defined in step (2) is widely

initiated. Suitable approaches relating to needs such as laboratory accreditation, regulatory acceptance protocol, accreditation of plans examiners and inspectors, installation standards

and format for submittal of innovative proposals should be

resolved. Only through successful implementation can the benefits of research be realized.

67
4. Following a reasonable consensus and the formulation of con- crete recommendations from the studies indicated in (1) through

(3) above, these recommendations should then be brought to the

attention of potential funding agencies, regulatory agencies,

the design and installation disciplines, and the manufacturers

as an aid in the simulation and evaluation of proposals for

specific, needed research.

E . Impact

A planned coordinated program along the general lines indicated above

could provide the needed supplmentary and complementary methodology for

viable performance evaluation of water supply and drainage for buildings.

This could have important impact on cost reduction, on the conservation

of resources and on stimulation of productive capacity through innovative

methods and material. It could also provide benefits to the administrators of prescriptive codes in facilitating acceptance decisions in a uniform and organized fashion.

o

/ The present standard program within the ANSI A40 Project-' offers a significant opportunity to begin the systematic development and implementation of the performance approach in plumbing. The A40 Committee and its

sponsors deserve widespread support in their program to emphasize this

activity during the next several years.

ACKNOWLEDGEMENT

The contributions of Mr. K. T. Stringer, P.E., Mobile Homes Manufacturer's Association to the determination of specific scope and emphasis

of the paper is acknowledged. Mr. C. T. Mahaffey, Building Codes Analyst,

Center for Building Technology, National Bureau of Standards contributed

a number of beneficial ideas concerning aids to implementation of performance evaluation methodology and clarity in the presentation of performance concepts.

REFERENCES

1 . Approach to Performance Evaluation for Water Supply and Drainage

for Buildings . Paper 12, Proceedings of the CIB Commission W62

Symposium on Drainage and Water Supply for Buildings, Glasgow,

September, 1975. Building Services Research Unit, Dept. of

Mechanical Engineering, University of Glasgow, 3 Lilybank Gradens,

Glasgow W2, Scotland. R. S. Wyly and L. S. Galowin.

Subcommittee 17, Plumbing Performance, Standards Committee A40, Minimum Requirements for Plumbing, sponsored by The American Society of

Mechanical Engineers and the American Public Health Association under

procedures of The American National Standards Institute.

68
2. The Evolution of the Performance Approach in Plumbing. Proceedings

of NBS-NCSBCS Joint Conference on Research and Innovation in the

Building Regulatory Process. National Bureau of Standards Special

Publication SP 473 (In press). R. S. Wyly, L. S. Galowin and

M. J. Orloski.

3. Performance Criteria and Plumbing System Design . National Bureau

of Standards Technical Note (In review). M. J. Orloski, and

R. S. Wyly.

4 . Hydraulic Performance of a Full-Scale Townhouse System with ReducedSize Vents . National Bureau of Standards Building Science Series

BSS 60 (August, 1975). S.D. Catalog No. C13. 29:2/60. M. J. Orloski

and R. S. Wyly.

5. Hydraulics of Gravity Drainge Systems . Paper II - 1. Proceedings

of the CIB Commission W62 Symposium on Drainage and Water Supply for

Buildings, Washington, September, 1976. USNCCIB, National Academy

of Sciences, 2101 Constitution Ave., N.W. , Washington, D.C. 20415.

R. S. Wyly, R. V. Benazzi, T. P. Konen, R. R. Manfredi, and

L. S. Nielsen.

6 . Water Requirements and Procedures for Estimating the Demand for

Water in Buildings . Paper I - 1. Ibid. R. V. Benazzi, L. Guss,

T. P. Konen, R. J. Orend and R. S. Wyly.

7 . Investigation of Standards, Performance Characteristics and Evaluation Criteria for Thermoplastic Piping in Residential Plumbing

Systems . National Bureau of Standards Building Science Series (In

review). R. S. Wyly, W. J. Parker, E. T. Pierce, D. E. Rorrer,

G. C. Sherlin and M. Tryon.

8. Protecting Water Quality in Buildings . Paper 1-2. Proceedings

of the CIB Commission W62 Symposium on Drainage and Water Supply

for Buildings, Washington, September, 1976. USNCCIB, National

Academy of Sciences, 2101 Constitution Ave., N.W. Washington, D.C.

20418. G. H. Williams, T. P. Konen, W. Mikucki, J. R. Myers,

L. S. Nielsen and W. Staton.

9. Water and Water-Related Conservation in Buildings . Paper 1-3.

Ibid. A. J. Fowell, A. Bransdorfer, P. Fletcher, R. J. Orend,

H. J. Pavel and G. H. Williams.

10 . Alternate Concepts for Transporting and Treating Wastes Within Buildings . Paper III. Ibid. T. P. Konen, R. S. Bevans,

W. J. Boegly, C. E. Cole and D. Savitsky.

1 1 • An Investigation of the Adequacy of Performance of Reduced-Size Vents Installed on a Ten Story Drain, Waste and V ent System . Davidson Laboratory, Stevens Institute of Technology Report

SIT-DL-73-1708 (July, 1973). T. Jackson and T. P. Konen.

69
12 . The Evaluation of Several Plumbing Drainage Waste and Vent Systems . Davidson Laboratory, Stevens Institute of Technology Report

SIT-DL-74-1776 (December, 1974). T. P. Konen, T. Jackson and

A. J. Powell.

13. The Effect of Water Closet Type on Drainage System Capacity . Plumbing Engineer (July-August and September-October, 1974).

T. P. Konen.

14. Certification and Agreement System in Europe . Paper IV - 3.

Proceedings of the CIB Commission W62 Symposium on Drainage and

Water Supply for Buildings, Washington, September, 1976. USNCCIB,

National Academy of Sciences, 2101 Constitution Ave., N.W.,

Washington, D.C. 20418. D. Trinkler.

70
ALTERNATE CONCEPTS FOR TRANSPORTING AND

TREATING WASTES WITHIN BUILDINGS

by

T. P. Konen, R. S. Bevans, W.J. Boegly

D. Savitsky, and C. Cole

Twelve years after the first sanitary sewer system was constructed in 18^ in

Hamburg, Germany, the United States began building public sewage facilities.

In the early days, efforts were limited to the collection system; 100 years

ago, only an occasional sewage treatment plant was built. Today 163 million

people, 76 percent of our population, are served by sewers. Ninety-seven

percent of these citizens are served by some type of treatment facility.

It has been estimated that the gross investment in public sewage facilities

during the period 1856-1971 has been $58. billion. The result of this seemingly huge effort has been a disappointment. The construction of treatment

plants has just about offset the increase in BOD load resulting from the in- creases in sewered population. The BOD' discharged to our waterways by treatment plants today is just slightly less than that discharged in 1957. See

Table 1.

TABLE 1

Year

EFFECT OF SANITARY SEWAGE TREATMENT

Col lected by

Sani tary

Sewers

Reduced by

Treatment

Discharged by

Treatment

Plants

1957

1962

1968

1973

(millions of pounds of BOD per day)

16. k 7-7

19.8 10.8

23.3 15.0

27.1 18.5

8.7

9.0

8.3

8.6

Of greater concern are the results of the 1973 Needs Survey prepared by the

Environmental Protection Agency, wherein the estimated costs for constructing

needed public sewage facilities for communities to meet the requirements set

forth In the Federal Water Pollution Contract Act Amendments of 1972 are

$60.1 billion, an amount equal to the total current Investment. These costs

were reported for five categories, as shown in Table 2.

71
TABLE 2

PROJECTED COSTS TO MEET REQUIREMENTS OF 197^ FWPCA

2

(bill ions of dol 1 ars)

Category I Secondary Treatment Facilities $16.6

Category I I Treatment More Stringent than Secondary 5.6

Category I I Rehabilitation to Correct Infiltration

and Inflow

0.7

Category IV New Sewers 2k.k

Category V Correction of Overflows from Combined

Sewers

12.7

$60.1

Throughout the 1 960 1 s and early 1970's, the federal government encouraged thi

design and construction of larger and larger sewage treatment plants for the

obvious lower unit costs. In communities where public officials favored

growth, little time has been lost in applying for and receiving significant

federal aid to build new sewer and treatment plants. In most cases, the

federal government contributes 75 percent of the costs for these facilities.

As a result, new sewers and sewage treatment plants have become the prime

determinant in land use. The oversizing of interceptors to ensure adequate

future capacity has accelerated growth. The regional i zat ion of plants has

hastened urban sprawl. Little attention was given to the cost of the collection system as most of the engineering experience was in high density areas where the per capita costs for collection are generally low.

An example of the total cost of sewage collection and treatment is shown in

Table 3. It is interesting to note that two-thirds of the total costs are forthe amortization of capital expenditures with more than half of these

costs attributed to the collection system. Not only is the collection syster

expensive, it is also inefficient. Wastewater Is comprised of the spent

water from residences, industrial wastes, and ground water infiltration. A

typical makeup is forty percent residential, forty percent industrial, and

twenty percent infiltration. The actual pollutants are only a very small

fraction of the total flow. It is a burden on the treatment plant to handle

the high volume of water used to convey the small amount of waste matter to

the plant.

There are additional disadvantages to large regional sewage treatment and

collection systems. Among these are:

1) Point discharge - Enormous volumes of effluent and sludge are concentrated at one location which often poses additional

environmental problems with the ultimate disposal of the waste.

72
2) Water where water is not required - Regional plants with advanced wastewater treatment produce an effluent whose quality

is sufficiently high so as to permit its immediate reuse for

purposes other than human consumption. Often the industrial

and commercial uses are far from the treatment plant which

results in high costs making reuse unattractive.

in additional concern that encourages change is the extensive building moraoriums that have been enacted in many locations as the result of overloaded

reatment plants.

AN OPPORTUNITY FOR CHANGE

he 1972 Amendments to the Federal Water Pollution Control Act mandate that

11 municipalities provide secondary treatment for their wastewater by 1977.

n achieving this objective, municipalities and others may use a wide variety

I secondary treatment methods and sludge disposal plans. The Environmental

rotation Agency has gathered and distributed basic information for the

reliminary evaluation of 11 alternative treatment technologies and 12

Iternative sludge disposal methods. The treatment technologies include

iological, chemical, and land treatment approaches. The sludge handling

nd disposal methods include landfill, incineration, land spreading, and

cean dumping. The study recognizes that conditions vary in different parts

if the country and that optimum waste treatment systems are dependent on

ocal and regional conditions.

"he practicing engineer encounters numerous situations in designing buildings

ind building complexes. At one time he may be involved in new construction

n a rural area where sewers and treatment plants are nonexistent; at another

:ime he may be involved in the renovation of a major inner city complex where

iewers are at their design capacity and the treatment plant overloaded. He

lay be faced with any combination of the factors shown in Figure 1.

ly treating water supply, drainage and waste disposal as a building system,

:he -engineer can devise a design that will be cost effective and environmentally

iound. There is often little incentive for innovation in the subsystems bemuse the improvements taken by themselves are often small.

n related papers at this symposium, the research needs and benefits of improved

inowledge of the demand for water, the influence of water savings, and advancelents in the hydraulics of drainage have been given. Similar advances in

/astewater treatment should be possible.

'here are at present several comprehensive reports on the collection, treatlent, and disposal of liquid wastes. The first of these was prepared by the

'ederal Water Quality Administration,^ now a part of the Environmental

'rotection Agency. This report examines in detail opportunities for reducing

:he effluent from individual homes, the present technology in treating these

/astes, and possible techniques for improving the treatment process. One

tundred and eight references are cited in the text. Fifty-five additional

'eferences are included. Nineteen manufacturers of waste treatment equipment

tre identified, fourteen of these were making home treatment units or contemplated

taking them.

73
The second major report was prepared by the Oak Ridge National Laboratory for

the Department of Housing and Urban Development in 1 974 . 3 A specific objective of this study mentioned earlier In this paper was an evaluation of the

current and future technology of waste water collection and treatment so that it could be incorporated into Modular Integrated Utility Systems. One

hundred and ninety references are cited. If a weakness exists in this report,

it is its failure to suggest research needs.

It is evident from these studies that extensive research has been done in this

field. It appears that many major corporations are actively pursuing this

potential market.

Building Project

1

New Construct! on

L

1 Re nova t ion

i

1 1 Existing Collection System No Collection System

or System at Capacity

i I

i i

Existing Treatment Plant No Treatment Plant or Plant at Capacity

FIGURE 1

Looking Ahead

The percentage of the population living In the standard metropolitan statistical areas is continually increasing; it is expected to do so in the years to come, see Figure 2. In our central cities, urban renewal has resulted in a change in

the use of the land, single-family homes, and small multifamily dwellings are being replaced by larger buildings. Some of these are apartment houses, some are office complexes, others are combinations. The growth of these multidwellin

projects is shown in Figure 3» New types of residential projects such as condominiums and planned unit developments are coming into being. In a special

edition, "Probing the Future," the editors of Engineering News-Record report

74
the single-family detached housing's share of the market will fall from the

55 to 60 percent level of today to perhaps 30 percent by the end of this

century. Apartments (five or more units) will account for 50 percent. The

balance will be townhouses, duplexes and fourplexes. It is expected that

by the year 2000, 80 percent of the population will live in or around our

cities. Building complexes housing 20,000 people may be commonplace. We

must prepare now to meet the needs of these new structures.

Research Needs

It is easy to state and comprehend that minimizing the water input requirements

to a building is a good idea and that there is a rippie effect on the entire

water cycle. What is difficult to judge is the significance of this idea.

Where no collection or waste water treatment facilities exist, the impact of

minimizing water consumption may be much more significant. The following

programs are suggested to provide the building engineer with the tools to

meet the requirements that are rapidly approaching our nation.

1. Earlier studies on waste treatment systems have not considered

the relationship that exists between the building water supply

and drainage systems and the treatment process. It is envisioned

that the significant reduction in the waste water will influence

the approach to on-site treatment. There have been many developments and a number of important field trials of new concepts.

Detailed performance and operating experience data must be gathered

on these developments and made available to the building engineer.

Indications are that restraints, other than technical ones, are impeding the implementation of existing technology. Typical

concerns to be explored are the reluctance of health authorities

to grant approvals and the concern of building owners over the

level of skills required and the adequacy of maintenance programs.

Additional specific questions should be addressed to manufacturers.

Among these are: What is the current annual production rate of

package units? What is the manufacturer's estimate for these

products in the years to come? The 1 969 report prepared by the

FWQA listed 19 firms in the package waste water treatment business.

It will be interesting to determine how many are in this field

today.

2. The design and installation of water supply and drainage systems are governed by plumbing codes developed on experimental data . obtained in the 1930's. While numerous editions of these codes

have been issued, the basic hydraulic information has not changed.

A design and full scale laboratory model of a water supply and

drainage system, based solely on the functional need, such that

the demand rate and per capita consumption are a minimum, Is a primary objective. European practices and field trials here In the

U.S. have indicated that lavatory fitting flow rates of 1/2 gpm

and less are acceptable. Water closets, compatible with gravity

75
FIGURE 2

Populat ion

FIGURE 3

New Hous ing Units

50,000 -

25,000 -

0

1950

S inqle-fami ly structures

/ /

/ / Multi-family structures

/ /

/ /

/

i960 I9V0

Year

T9S0

76
drainage systems, are known to operate on volumes as low as 2 quarts. Additional studies Indicate short duration of use factors for kitchens. Incorporating parameters applicable to

the advanced system will reduce the expected peak flow

approximately k0%. This, in turn, should yield a significant

savings in material and labor.

The design of the supply piping will be based on the most

advantageous use of materials and consider both energy cost

and life-cycle cost. Gravity supply systems, fed from storage

tanks, may regain favor over continuous pumping systems in view

of energy considerations. Numerous changes in the vent system

are expected.

3. An economic study of wastewater discharge, its treatment, and

its influence on the environment for several combinations of

conditions that have been known to occur in the field is required.

Examples are: 1) installation where there is adequate water

supply, no collection system, and good treatment facilities,

2) installation where there is an inadequate water supply,

acceptable collection system, but an overtaxed treatment facility.

Following this overall view of the water supply, wastewater

drainage and sewage treatment study, full scale demonstration

programs reflecting Improved systems and their advantages

should be built on a regional basis so that the building water

supply and output effluent have a minimum dependency on the

surrounding environment.

References

1. Environmental Quality, Fifth Annual Report of the Council on Environmental Quality, U.S. Government Printing Office, Washington,

D.C., 197*+.

2. The Economics of Clean Water - 1973, U.S. Environmental Protection

Agency, Washington, D.C. 20^0, 1973.

3. Ml US Technology Evaluation - Collection, Treatment and Disposal of

Liquid Wastes, W.J. Boegly and others, Oak Ridge National Laboratory,

Oak Ridge, Tennessee, 197^.

h. A Study of Flow Reduction and Treatment of Waste Water from Households.

J. R. Bailey and others. General Dynamics, Electric Boat Division,

Groton, Connecticut. FWQA Program 11050 FKW, December I969.

77

INTERNATIONAL PERSPECTIVES

CIB W-62 PURPOSE, METHODOLOGY AND FIELDS OF WORK

by

Kaj Ovesen

Danish Building Research Institute

CIB W-62 is one of the Working Commissions within CIB and furthermore it is one of the younger commissions. No. 70 has not yet been reached. Out of

these numbers around 30 are in use.

W-62 has the working field: Water Supply and Drainage for Buildings, and for

professionals within that field it must be surprising that our number is as

high as 62. According to the importance of Water Supply and Drainage a much

lower number--say k or 5

_ -could be expected. We will try to find the reason

for that later on, but first a few words about our mother organization.

CIB, The International Council for Building Research, Studies and Documentation

T he International Council for Building Research, Studies and Documentation has

the abbreviation CIB because of the French name: Conseil International du

Batiment pour la recherche, 1 'etude et la documentation. CIB is a nongovernmental organization having members in more than 50 countries throughout

the world.

The Establishment of CIB

The first members—and the founders—of CIB were the large building research

institutes. Today also other public and private institutes working with

building research and information are members and so are a number of individual

experts. The members fall in four categories, namely: Public Full Members,

Industrial Full Members, Associate Members and Unattached Members. It may look

a little complicated but in the daily work in the commission we never worry

about that.

The idea of making such an organization goes back to the end of the second

World War. During the war a large number of buildings were destroyed and it was necessary to increase the effort of building new houses by all possible

means. In many countries building research institutes were established and for

the new institutes international cooperation was a natural way of starting the

work.

81
The first to take care of was the building information and documentation,

and an organization covering this field--CIDB—was created in 19^9. The

present organization and the name CIB goes back to 1953. The international

cooperation on buildings was started with the full support of the United

Nations Organization.

Working Methods of CIB

CIB applies a number of different working methods. The most imposing one is

the big public congress held every three years. The purpose of these congres

ses is first of all to inform of scientific progress. The last one took

place in Budapest in Hungary in 1975 and treated the theme: The Impact of Research of the Built Environment. The next one will be in Edinburgh in 1977

and there for the first time we shall have contributions from most of the

working commissions--incl uding W-62. Furthermore several specialized confer- ences and symposia are to be arranged. As an example we had in 1972 a joint

symposium on Performance Concept in Buildings in Philadelphia. It was arranged by RILEM, ASTM and CIB.

The Working Commissions

The research work is taking place in the working commissions among which the

W-62 also is found. The commissions are quite different in their way of

working. Some of them are concentrating on information of the research ac- tivities of their members. Some of them have coordinated research programs

and others have integrated their work in order to produce common CIB publications .

W-62: Water Supply and Drainage for Buildings

W-62 was established as CIB commission in 1971 after some informal discussions between representatives of Great Britain, Czekoslovakia and the

Scandinavian countries. All these countries had a wish and a need for

international cooperation.

As terms of reference it was decided that the commission should:

report on research in progress in water supply and drainage systems,

encourage and coordinate further research aimed at providing information

on the characteristics and performance of such systems and data for their

design, and

arrange discussion meetings and conferences.

This program gave us members from \k different countries who sent about 50

delegates to the first annual meeting and symposium in Garston at the British

Building Research Establishment.

Since then we have increased the number of member countries up to about 25

representing almost all parts of the world. The very number of members is

not the most important thing. It is far more interesting that most of our

82
members are highly active within the research field of water supply and

drainage. I suppose that the majority of laboratory facilities used for

this purpose belong to our members. It is our duty to use these possibilities in the right way.

A great number of members will not necessarily result in many coordinated

projects. Therefore we have never tried just to expand the number of members —but we have very often asked individual institutes or experts to

join us.

The Past Work of W-62

I will try to summarize the work carried out in the commission from the beginning and until today.

Already at the first official meeting in 1972 we had a symposium. The theme

of the symposium was "Water Demand in Buildings". We had the opportunity to

present a number of new research reports from different countries and from

different views. The symposium was a very fruitful one —especially for the

research workers being active within this field.

The idea was to continue this way, that is to find a limited research field

and a number of scientists being ready for presenting and discussing new

papers. However, it proved to be difficult to structure the symposia in that

way--our members were too active and had too many results, so at the symposium in Stockholm in 1973 we had papers from the whole field of drainage.

This was a good meeting too and the greater variations in the subjects seemed

to be popular among the members.

For the following year, 197*», we had decided not to have a symposium, but we

had to change our minds. A large number of members asked for a possibility

to present their work and to have a qualified discussion. Because of the

change of decision this symposium—which took place in Copenhagen —was un- structured and covered drainage as well as water supply but in spite of

that some good results were achieved.

During the first years we started working groups under the following head1 ines

:

Experimental Techniques in Research on Drainage Systems

Performance Concept Related to Water Closets

Performance Criteria for Piping Materials as a Function of Use

Water Demand

Problems in International Cooperation on Water Supply and Drainage

At that time we felt in the commission that we had to decide whether we

wanted to be just a forum of information or we rather should try to make

planning for the future—to follow or to govern the development.

83
International cooperation is difficult because our goals —at least our short-term goals —are different. It is extremely difficult in an area as drainage and water supply because we have old and very strong traditions

all of us —first of all the traditions called codes.

Codes must be based —at least partly—on the traditions. It is quite

natural that we within the field of water supply and drainage have codes

being very traditional and very restrictive. We will find the same pattern

within all fields where a risk of life may occur, i.e., fire, combustion or electricity. In those cases you will find codes being based on detailed

requirements for materials and design —non-performance requirements.

Non- performance requirements are used when it is too dangerous to make

experiments —and water supply and drainage has been dangerous, indeed, and

killed much more people than fires and explosions. This fear is reflected

in today's code of practice, but we have forgotten the reason.

The way of making codes has changed, at least in some countries. The

performance-based code will become a reality sooner or later, but we still

have the existing installations which will be in use for many years and

thereby influence the design of new systems. That's why our commission was number 62 instead of number 2, and that's why the international cooperation

is extremely difficult.

The old traditions will also be a barrier for the cooperation in the future,

but this barrier must in some way be perforated.

i At one hand we have to face the fact that our member countries are different

and in some way will maintain a difference. On the other hand, we must co- operate in such a way that all of us will benefit; it is difficult.

Building Up Guidelines for Future Work

In the planning group we saw the results of the differences among the member

j countries. The working groups mentioned earlier did not meet our expectations. The more remote from each other", the more different, the less the

work.

At the same time we noticed an increasing interest in presenting papers at

the symposia.

From these facts we draw the lesson that the research activity among our

members was high but that it was hardly possible to change the direction of

this activity. The only way was to avoid seeking for members being interested

in a certain research problem, but rather take starting point in the actual

work in the member institutes.

81 As a foundation for the planning we have to know what is going on in the mem- ber countries and member institutes. We must have data on projects and programs and we have to up-date these data regularly.

84
On this basis it must be possible to find ways of organized cooperation and

information. On this basis we can find subjects for symposia, make contact

among a small or a big number of persons, establish one-man groups for collection and combining data from other members and so forth.

We are at the beginning of this process. We have already pretty good information about the capacity of all member laboratories. We know the persons

being involved and we have a broad view of the work going on.

At our last meeting in September 1975 in Scotland, we used our knowledge to

structure the symposium. We called for papers on the following subjects:

Water Economy

Standards and Regulations

National Research Needs

Many of the papers were invited but the subjects were open to non- invited

papers too.

We got papers of fairly good quality and most of the papers were valuable to

a majority of members —and not only to the author and his national reputation.

With only four papers we got a fairly broad view of the problems of the water

economy. Papers from England, Japan and India showed clearly three different categories: a country with rather small problems and good technology, a country with big problems and a good technology, and a country with big

problems and a poor technology.

This year we have chosen subjects within the performance concept for our

symposium, namely, Performance Requirements and Performance Test i ng. We

have chosen this field for two main reasons. Firstly, many of our members

are working very hard on this subject, so we have results as well as an audience being prepared for the discussion. Furthermore, we need the discussion because the use and the understanding of the performance concept

seems to differ from one country to another.

The second reason for discussing the performance concept at this meeting is

that we—especially on this subject—expect qualified contributions to the

discussions from our American counterpart. We know that the U.S. has far the

greatest experience in this field.

The Goals and the Future Work of W-62

I have been asked to tell about the goals of CIB W-62 and I should be glad

to do that. We have not yet made an official long-range program but we have

some ideas and wishes for the future. What I can give you now is my personal conception of the future of W-62, but other members present at this meeting are welcome to add, or to protest.

A few years ago I am sure that I could have given you a detailed and

ambitious program. Today the answer will be a little different. Not less

85
ambitious but the strict details have been replaced by the hope and the

knowledge of the difficulties.

1 . Mutual Understanding

The most important goal at the moment must be to bring the research

workers together, to give them an opportunity to speak and, first of

all, to teach them to listen to each other and to understand each other.

The understanding is important because differences in patterns and traditions have a heavy influence on the research —often we don't notice

it.

In Scandinavia we normally use 6-8 litres of water to flush a water

closet. Consequently, I find that our system is better than for instance the American system using about 20 litres per flush. We are working with water closets with reduced flush quantities down to

3 litres or less, but nevertheless I am fully convinced that our systems are much better than systems from abroad using no water at all.

How to make the best systems!

We have built up an understanding of the different functional requirements to be met.

The best tool for common, technical understanding is the performance

concept. Using that, we can bridge the differences among our ways to

make water supply and drainage. In that way we may understand that

systems in other countries are not necessarily bad —but they are made

to fulfill other performance requirements.

2. Research for Use in Practice

I am sure we could have a nice club for mathematical and physical games —we have had some of it now and then. We must never forget that

science is not the purpose itself but one of our means. That is why

we have to join the work with legislation, standardization, codes and

the like, and bring the results of our scientific work into the rules of

the society.

We must do that as well on the international stage as in the individual

countries. We must prevent that national codes just are made as prolongation of old traditions because this will prevent research and

development and exchange of products and ideas across the borders.

We must prevent that standardization is nothing but a fight among the

biggest producers supported by their own countries. This can only be

done on a basis of international research.

86
3. Making a World Model Code

From Scandinavia I can tell about our experience in making a supranational

code covering five different countries. Eight years ago the hard work was

finished and we had a performance-based model code covering drainage and

water supply. Today all the countries have their national codes in function and the small differences among them are hardly to be noticed. When

we started the work, some of the countries involved had nothing but a lot

of different local rules.

New systems and components can be introduced by passing adequate approval

tests. Test methods have been developed by the different Scandinavian

building research institutes and related institutes. A component being

approved in one of the Scandinavian countries will normally be approved

in the other countries without difficulty and using the same test results.

This is because all of the test methods have been worked out within the

frame of a Scandinavian cooperation and because authorities, and test and

research institutes from the different countries have regular meetings.

Work like that is difficult and the more different the countries are in

geography and way of living, the more difficult it is. In the European

Standard Organ izat ion--the CEN--they have established a group working

with something like a European model code. Some of our members have

joined the group and inform us regularly.

A worthy task for CIB W-62 would be to make a world model code, a code

based on the fact that human beings all over the world are like each

othei—but also taking into account that needs, wishes and resources

may vary from country to country.

h. To Give Priority to the Right Jobs

The W-62 should make a planning which could be a support for our members

in giving priority to their research works.

We do that by inspiration —not by force (which anyhow is impossible).

We must try to prevent fighting against the details and forgetting the

main issues. It must be wrong that some of the best laboratories are using their strength in making a perfect system a little better while

other member countries are not able to bring clean water to the user.

Neither must we forget that water and water systems are just one of the

possible solutions —except for the drinking water. I was a little afraid

when we took the name "Water Supply and Drainage" as the name for our

commission. However, it was too difficult to find a short name explaining that we want to handle all functions which today are carried out by means of water and waste water systems.

We may expect a change in systems. In many countries we have a lack of

water for many different reasons. We find it in poor countries and rich

87
countries. We have to consider this problem very careful. Do we need

to use water for the same purposes and to the same extent as we do today? Could we improve the efficiency of our systems in order to save water?

To Be a Link

In the leaflet telling about USNC/CIB I found a little drawing represent

ing this organization as a link between CIB and United States Building

Community. I like that symbol and I want the W-62 to be a link too--in

more than one respect.

We shall be a link from one member to another. From the rich member to

the poor membet—from the small member countries to the big ones. We

shall link the developed technology and the undeveloped one, and as a non- governmental organization we should also be a link between authorities and the practice.

I hope that our commission will grow up to a good and a strong link.

88
STANDARDIZATION STRUCTURE IN EUROPE

by

Francois Perrier

C.S.T.B., Station de Recherche de Champs, France

This document consists of three parts:

1. Review on the organization of European Committee for Standardization (CEN) and on its functioning rules.

2. Review on the organization of International Organization for Standardization (ISO) and on its functioning rules.

3. Summary on present works in CEN and ISO within the field of CIB W62. • Questions studied,

• Who studies them, • State of progress.

THE EUROPEAN COMMITTEE FOR STANDARDIZATION

1 . Compos i t ion

T!<e European Committee for Standardization (CEN) , which has been created

in Paris in May 1961, is an association of national standards bodies of

European Community (EC) and European Free Trade Association (EFTA) countries.

The members of CEN are: Austria, Belgium, Denmark, Finland, France, Germany, Italy, the Netherlands, Norway, Portugal, Sweden, Switzerland, and

the United Kingdom, and the national standards bodies of any other European country which would accede to the Treaty of Rome or would become a member of EFTA. Further membership is open to any country of Western

Europe whose economy is closely entwined with those of the EEC and EFTA

countries, and whose ultimate adherence to one of these economic communities could be anticipated.

2. Scope of CEN

The aim of CEN is to promote the development of trade and exchange of

services by eliminating obstacles caused by provisions of a technical

89
nature and to free trade exchanges between all the member countries by

the following means:

- Harmonization of members' standards to create European Standards, and

the creation of European Standards "de novo" based on the requirements of the situation in any case where other appropriate and valid

standards do not exist.

- Cooperation with political, economic and scientific European organizations in the field of standardization.

Support of worldwide standardization, and particularly in the International Organization for Standards (ISO) and International Electrotechnical Commission (IEC).

Ensuring an uniform implementation of ISO Standards and relevant IEC

publications in Europe.

Preparation of reports on the state of harmonization of standards of

CEN members.

- Provision of certification services on the basis of European Standards.

- Making available to the Commission of the European Communities and

other governmental organizations European Standards to which they can refer in their directives or other instruments.

Electrotechnical questions are not the concern of CEN.

Organ izat ion

The organizational structure of CEN consists of:

a Steering Committee,

- a Central Secretariet,

- Working Groups (WG) , with their secretariets

,

- Such councils and committees as the Steering Committee may set up to

further its aims.

Steering Committee

The Steering Committee consists of representatives of the members.

Each member represented at meetings has one vote. The Chairman and

the Vice-Chairman of the Steering Committee are elected by the members of CEN. (Present Chairman: Mr. Jan Ollner, Sweden.) The Steering Committee shall meet whenever necessary and at least once a year.

Central Secretariat

The CEN Central Secretariat is headed by a Secretary-General who is

appointed by, and responsible to, the Steering Committee. The Secretary

General prepares the meetings of the Steering Committee. He is responsible for the implementation of the decisions of the Steering Committee.

90
Working Groups

The technical work of CEN is normally the responsibility of CEN working groups. The creation of a working group and allocation of its

secretariat to a CEN member are decided by the Steering Committee.

The Steering Committee also decides on the disbandment of a working

group.

At the moment, there are k~l working groups.

The Chairman of the working group is elected by the members of the

working group.

k. Technical Works

Choice of Subjects

Any member of CEN may take the initiative for asking for the study

of a new question. Proposals for new work may also be received from

international organizations.

A proposal will be considered as eligible if, in the field in question,

differences between national standards or regulations cause obstacles

to the exchange of knowledge, goods or services, or hamper mass production .

Subjects proposed by scientific or trade organizations will also be

eligible, when the organizations are prepared to contribute to their

study.

If work exists in ISO in the field selected, any CEN activity will be

directed to complementing and implementing this ISO work.

Participation in the Work

Each member of CEN shall inform the Secretariat of the working group,

as well as the CEN Central Secretariat, whether or not it wishes to be

a member of the working group, or if it later modifies its participation.

Conduct of the Works

Working groups are expected to produce draft European Standards for

CEN ballot by the agreed target date. For this purpose the scope of

each project should be suitably restricted.

If it appears unlikely than an European Standard can be produced by

the target date, the working group should aim at the issue of an Un ification Report . The acceptance of an Unification Report, however,

should not imply that further attempts to reach an agreement on an European Standard should be abandoned.

91
The working group is entirely free to conduct its work as it seems appropriate, establishing liaison with other organizations if necessary. It is responsible for the project up to, and including, the

adoption of the working group's final draft.

Adoption

When a draft proposal has received substantial support from the mem- bers of a working group, it is sent to the Central Secretariat.

A. CEN member ballot

The final draft proposal is registered at the Central Secretariat

and circulated as a Draft European Standard (pr EN) to all CEN

members with the ballot form. This form should be returned within six months to the Central Secretariat.

B. Scruting of votes

At the end of the voting period, the Central Secretariat, in con- sultation with the working group secretariat, analyzes the

results of the voting and prepare a ballot report for submission

to the Steering Committee.

It also decides whether in the light of the voting criteria given

in the CEN Constitution, a recommendation for acceptance should

be made to the Steering Committee.

If the pr EN is not approved by the majority of the members voting, it cannot go forward, and the matter is referred back to the

secretariat of the working group. A new draft may be prepared for

submission to members.

C. Final ballot

The final text of the pr EN is submitted to the members of the

Steering Committee. The voting period is two months. Following

adoption by the CEN Steering Committee, the versions in English,

French and German are forwarded to the Central Secretariat by the

working group's secretariat. The Central Secretariat circulates

them to all CEN members.

Publ ication

CEN members who have approved the European Standard are required to

publish it as soon as possible and without change as a national Standard .

Refe rences

The above-mentioned indications are extracted from two documents of CEN:

92
CEN/N 337 - CEN Constitution

CEN/N *»20 - Directives for the technical work of CEN.

THE INTERNATIONAL ORGANIZATION FOR STANDARDIZATION (ISO)

1 . Compos i t ion

The International Organization for Standardization (ISO) has been created

in 1947. It was a continuation of the International Federation of the

National Standardizing Associations - ISA - created in 1926. The ISO incl udes

:

• Member bodies: National Standards bodies (6k member bodies),

• Correspondent members: generally, governmental organizations (16

correspondent members)

on the whole, 80 countries.

2. Scope of ISO

The scope of ISO is aimed at worldwide agreement on International Standards with a view to the expansion of trade, the improvement of quality,

the increase of productivity and the lowering of prices. ISO work covers virtually every area of technology, with the exception of electrotechnical questions which are the responsibility of ISO's affiliated organization the International Electrotechnical Commission (IEC).

3. Organ izat ion

The organizational structure of ISO consists of:

- a President (Mr. Ake T. Vrethem, Sweden)

- a Vice-President (Mr. Ral f Hennessy, Canada)

- a Secretary-General (Mr. 01 le Sturen)

a Council which consists of the President and \k representatives of

member bodies.

an Executive Committee (EXCO)

. a Planning Committee (PLACO)

Some Technicals Committees (TC)

subcommittees (SC)

working groups (WG)

.

The preparation and formulation of ISO International Standards is the

responsibility of ISO technical committees.

93
Technical Works

Choice of Subjects

The initiative for the study of a new question belongs to:

- one of several member bodies,

- a Technical Committee,

- a Technical Division,

a committee of Council,

the Secretary-General

,

- an external organization.

The demand is submitted at the Central Secretariat and circulated to

all members committee. After the ballot (four months), the report

established by the Central Secretariat is circulated to PLACO, and

then to the Council which decide. (Creation of new Technical Committee.)

Participation in the Work

The technical committees consist of members committees which have ex- pressed the wish to take part actively in works (P members) or want

to know the state of progress (0 members)

.

Conduct of the Works

The main work of each Technical Committee is to ensure the drawing up

of International Standards . If no agreement can be obtained in order

to submit a draft proposal, the Technical Committee can ask that the

draft be publ ished as a Technical Report . The works are carried out

by members of the Technical Committee, which can also decide the creation of subcommittees and working groups. It can cooperate with other

ISO technical committees or with other international organizations.

Adopt ion

When a draft proposal has obtained a large agreement from members of

a Technical Committee or a subcommittee, it is dispatched to the

secretartiat of the Committee or subcommittee.

The draft proposal is submitted for ballot to P members. When a large

agreement is obtained, it is dispatched to the Central Secretariat.

The Central Secretariat records the draft proposal as a Draft International Standard (DIS) and circulates it to all the member-commi ttees

for approval

.

94
Note : There is a procedure that said: "combined voting procedure"

which allows just one ballot (P members and members committees together).

When a Draft International Standard has been adopted, it is dispatched to the Central Secretariat which submits it to the Council.

The Council decides if the DIS can be agreed or no, in order to be

published as an International Standard.

Publ icat ion

After agreement by the Council, the Central Secretariat publishes

the International Standard.

The members committees should circulate the International Standard

in their respective countries.

5. References

The above-mentioned indications are extracted from the following documents of ISO:

Directives for the technical work in ISO,

ISO Memento,

ISO Catalogue,

- Guide for the presentation of International Standards and Technical

Reports

.

EUROPEAN AND INTERNATIONAL STANDARDIZATION IN THE FIELD OF CIB W-62

1 . Technical Committees - Subcommittees - Working Groups

The Figure 1 shows a simplified water supply and waste system, on which

are given the questions studied now, either by CEN or ISO.

In a more detailed way, the works are carried out by the following institutes:

- Valves, taps and miscellaneous devices for water supply in buildings

• CEN/WG 36 : "Valves and taps for water supply in buildings"

This working group studies particularly:

stop-valves,

- draw-of taps,

95
Water meters

I SO/TC 30: "Measurement of fluid flow in closed conduits"

- SC 7: "Water meters".

Pumps

. I SO/TC 115 : "Pumps".

Pipes for water supply

. Metal lie: I SO/TC 5 : "Metal pipes and fittings"

- SC 1: "Steel tubes"

SC 3: "Non-ferrous metal pipes"

- SC 5: "Fittings (6ther than cast iron)".

. Plastics: ISO/TC 138 : "Plastics pipes, fittings and valves for the

transport of fluids"

- WG 2: "Plastics pipes and fittings for water supplies".

- WG 5: "Methods of test and general properties of pipes, fittings

and valves in pastic materials".

WG 7: "Valves and auxiliary equipment of plastics materials".

Taps and fittings for sanitary appliance

CEN/WG 3^ : "Water fittings and waste fittings for sanitary appliances" - Dimensions - Quality.

This working group studies particularly:

- Taps (single, mixing tap and mixers)

- Waste fittings (emptying, siphon ...)

dimensional, mechanical, hydraulic, physical and chemical,

acoustic characteristics.

Sanitary appliance

CEN/WG 7 : "Connecting dimensions of the sanitary appliances"

Waste and soil pipes

. metal 1 tc: ISO/TC 5 : "Metal pipes and fittings"

- SC 1 : "Steel tubes"

SC 2: "Cast iron pipes, fittings and their joints"

SC 3: "Non-ferrous metal pipes"

- SC 5: "Fittings (other than cast iron)".

96
plastics: ISO/TC 138 : "Plastics pipes, fittings and valves for the

transport of fluids"

- WG 1 : "Plastics pipes and fittings for soil, waste and drainage".

- WG 5: "Methods of test and gener properties of pipes, fittings

and valves in plastic materials".

- WG 6: "Reinforced plastics pipes and fittings for all applications".

. mineral : ISO/TC 77 : "Asbestos fibres and products in asbestos-cement"

- WG 20: Revision of ISO/R 391 and 392.

- Drainage equipment

CEN/WG 77 : "Drainage equipment"

(The scope of working of this working group is not yet completely

defined)

.

Other technical committees interesting the CIB W-62:

ISO/TC 21: "Equipment for fire protection and fire fighting".

- ISO/TC 59: "Building construction"

/SC 7 - WG 2 - "Bathroom and toilets"

- WG k - "Accomodation ducts".

ISO/TC 92: "Fire tests on building materials and structures".

- ISO/TC 147: "Water quality".

- ISO/TC 156: "Corrosion of metals".

2. Results of Work

The different ISO technical committees mentioned have already established

a number of International Standards (or specifications). These are given

in ISO Catalogue (classified in technical committee order).

Concerning CEN, there is not yet European standards, but draft standards

which are or which are going to be at inquiry.

- CEN/WG Zk

:

Pr EN 27 - Mixing taps with concealed body for mounting on horizontal surfaces - Part I - Dimensional characteristics.

Pr EN 28 - Mixing taps with combined visible body known as "single

hole" for mounting on horizontal surfaces - Part I - Dimensional characteristics.

Pr EN 29 - Simple taps for mounting on a vertical surface - Part I - Dimensional characteristics.

97
Pr EN .. - Mixing taps with visible cross-connected body for mounting on vertical surfaces - Part I - Dimensional characteristics.

CEN/WG 36:

. Pr EN 6k - Stop valves

strength.

. Pr EN 6^ - Stop valves

. Pr EN 66 - Stop valves

- Test for watert ightness and mechanical

- Mechanical endurance test for moving parts

- Measurement of flow rate and head loss

Stop valves: dimensional characteristics:

. Pr EN ..: Dimensions for the interchangeabi 1 i ty of

headwork on bodies of stop valves type

. Pr EN ..: Dimensions for the i nterchangeab i 1 i ty of

headwork on bodies of stop valves type Q_ DD

. Pr EN ..: Dimensions for the interchangeabi 1 i ty of

headwork on bodies of stap valves type

. Pr EN ..: Dimensions of the different types of ends

for connecting to pipework.

CEN/GT 7:

. Pr EN 31

. Pr EN 32

. Pr EN 33

. Pr EN 3k

. Pr EN 35

. Pr EN 36

. Pr EN 37

Pedestal wash basins - connecting dimensions.

Wall hung wash basins - connecting dimensions.

Pedestal washdown WC pan with close coupled cistern,

visible or concealed trap with vertical outlet - Connecting dimensions.

Pedestal washdown WC pan with close coupled cistern - connecting dimensions.

Pedestal bidets over rim supply only - connecting dimensions.

Wall hung bidets over rim supply only - connecting dimensions.

Pedestal washdown WC pan with direct flush, visible or

concealed traip with horizontal or vertical outlet —

connecting dimensions.

Pr EN 38 - Wall hung WC pan with independent water supply - con- necting dimensions.

CEN/GT 77:

This working group, lately set up, has not yet established European

draft standards. Two experts' groups have been set up:

GE 1: Drainage equipment for streets.

98
GE 2: Drainage equipment for houses.

At the moment, the GE 1 studies a document relating to "gully tops and

manhole covers".

The GE 2 studies a document relating to floor gully.

99

CERTIFICATION AND AGREEMENT SYSTEM IN EUROPE

by

D. Trinkler

(Translated by Madison Brown)

Certification in Europe

Construction regulation in the U.S.A. is probably similar to that in Europe

with the obvious difference that seven different languages are spoken in the

European Commun i ty--Dan i sh , Dutch, English, Flemish, French, German, and

Italian. The American situation may also be comparable to what existed in

Germany until some 30 years ago--namely, the decision as to whether or not a building material or a construction design was suitable for a specific intended use was made at the site itself and consequently these decisions frequently differed from site to site, region to region, or state to state,

sometimes to the point that decisions contradicted each other. This state of

affairs became more and more unsatisfactory as the exchange of goods and services grows more common and does so beyond the authority with which the

decisions on suitability lie.

What seems generally true is that public authorities, namely the communities

or states, consider it their responsibility to protect the public against all

kinds of dangers. For example, because dangers for the individual or the

general public can arise from the erection or use of buildings, various instruments were developed to protect against hazards in construction. Historically these instruments developed differently among the individual states and

even within the states themselves.

According to the information collected by the Construction Engineering Institute (Institut fur Bautechnik), the conditions in the European Community

countries are as follows:

Bel gi um

Here we find technical certificates (agrements techniques) granted by the

Belgian Association for Technical Certification in Construction (Union Beige

pour 1 'Agrement Technique dans la Construction; UBAtc) . This is a private

association of the National Housing Institute (Institut National du Logement)

,

the Scientific and Technical Construction Center (Centre Scientifique et

Technique de la Construction), and the insurance companies (Bureau SECO)

.

Such a certificate constitutes a qualitative, descriptive rating of building

procedures, materials, elements, and facilities. The standardization is not

101
ratings take into account safety, habitabi 1 ity

,

furthermore contains economic aspects. Thus the

certificate is not a matter of governmental authoIn general, regulations issued under public law do not require a certificate, j Such a certificate is, however, mandatory for construction commissioned by

public authorities, under conditions of insurability (insurance is mandatory), and to some extent in building contracts.

Denmark

The Housing Ministry (Bol igministeriet) through its department the State Construction Research Institute (Statens Byggeforskn ing Institut) grants

certificates (Godkendel se) . This is a confirmation under public law either

that specific new building materials and construction designs comply with the

requirements stipulated in the laws governing construction or that other new building materials and construction designs satisfy the requirements laid

down by the Housing Ministry, if such are not covered by the construction

laws or the standards.

Precondition for the granting of a building permit is the presentation of an approval certificate (Godkendel se) provided it is required, i.e. prescribed

under publ ic 1 aw.

Apart from this kind of certificate, there are others similar to the test

certificates granted by special committees for sanitary equipment, gas appliances, electric household appliances, underground oil and fuel tanks, and

el evators

.

The Federal Republ ic of Germany

The Construction Engineering Institute (Institut fur Bautechnik) in Berlin

grants the general construction supervision certificate and the test certificates on behalf of the higher construction supervisory boards of the federal

states (Lander)

.

These approval certificates attest to the intended serviceability of building

materials not in common use, structural members, or construction designs

from the standpoint of public safety with special emphasis on life and health.

An obligation exists under public law to apply for such a certificate unless

evidence of serviceability has been produced in some other manner.

Test certificates are granted for specific manufactured building materials

which have been designated in statuatory orders, structural members, and

facilities, if, because of their special nature or intended use, their com- pliance with the safety requirements depends in considerable degree on their

superior qual ity.

In the area of site drainage, testing is obligatory for:

very comprehensive. These

and durability; the rating

granting of this technical

r i ty

.

102
- pipes for the discharge of sewage and storm water (with the exception

of outside storm water drains and water supply pipes), their fittings

and sealing materials (except the customary packings of white rope and

1 ead)

;

- overhead drain pipes for storm water, urinals, air traps, basins, and

j drains with built-in air traps;

- flushing tanks and plug-type basin flushing devices;

shut-off devices in sewage and storm water plants (with the exception

of water supply pipes);

- waste water pumps and check valves and preventers;

sewage treatment devices;

- gasoline separators; and

fuel oil separators and fuel oil check valves.

| As far as water supply is concerned, the German Gas and Hydraulic Engineers'

Association (Deutscher Verin von Gas- und Wasserfachmannern ; DVGW) regulates

the approval of materials.

France

The situation in France is the most complicated. There is legally no binding approval system. Various governmental, semi-governmental, and private

bodies grant so-called technical opinions (avis techniques) or approval cer- tificates (agrements) upon request. These are technical recommendations

regarding the suitability of construction procedures, materials, elements, or appliances whenever their newness or their use does not yet permit standardization. The most important office issuing such technical opinions is

the Scientific and Technical Building Center (Centre Scientifique et Technique du Batiment; CSTB) in Paris. It issues technical opinions on the basis

of the decisions of an inter-ministerial committee backed by experts'from

other organizations.

As a general principle, there is no obligation to apply for such a technical

opinion. The regional (departmental) authorities are, however, entitled —as the lower echelon building authori t ies--to require information about the

materials to be utilized in multi-storied buildings, special purpose buildings (e.g., those open to the public and places of work), as well as public

housing apartment buildings; that is to say, demand proof of serviceability

in the form of technical opinions. In this context, one should take into

account that in France one half of all the apartments being built are public

housing projects. As far as government buildings are concerned, the individual ministerial departments grant their own approval certificates within

their spheres of competence —partly on the basis of their own tests —for

103
new building materials, structural members, and designs.

Since all architects and building contractors are insured to meet a 10-year

warranty obligation, the insurance companies, too, have a certain influence

on construction activities. For this reason they also grant their own approvals for new building materials, structural members, and construction designs

and do this through a special organization, the Construction Risks Management

Division (Groupement par la Gastion des Risques de la Construction; GECO) . I these cases, however, the existing technical opinions of the Scientific and

Technical Building Center or the approval certificates of the ministeries are

not necessarily always accepted as they stand, since the insurance companies

often increase or modify the requirements.

Thus, under certain circumstances the manufacturer of a certain non-standardized material will have to apply for a technical opinion at the Scientific

and Technical Building Center, an approval certificate at one of the ministries, and an approval certificate at Construction Risks Management Division

--all three at the same time.

Normally the Construction Risks Management Division is informed of the use of new products, since otherwise there is no insurance coverage.

Great Britain

In Great Britain there is no binding approval procedure for new building

materials. At present every lower-echelon construction supervisory board,

the District Council, can decide at its own descretion whether or not a new building material is suitable. An approval, however, can be applied for on

a voluntary basis at the Approval Board--a private institution with government cooperation. In this case, we are dealing with the descriptive rating

of suitability for conventional, standardized, or new building materials and

designs, a rating that goes beyond safety. Even if these approval s--wh i ch

have merely the effect of recommendat ions--are not binding on the construction supervisory authorities, they are nonetheless recognized by lower

authorities as evidence of suitability.

In the future the ministry responsible for construction will be able to grant

so-called type approvals itself or entrust other agencies with this responsibility. These type approvals are comparable to the general construction

supervisory certificate in the Federal Republic of Germany. The lower authorities will be bound by the decision rendered in the type approval. Nonetheless, there will still be no obligation to apply for such an approval.

I re! and

In Ireland also there exists no binding approval procedure. The lowerechelon construction supervisory authorities, the Counties or the County

Boroughs, can decide on their own whether a specific building material is

suited or not.

However, for standardized building materials, structural members, and

104
construction designs there is a mandatory quality control process, the Irish

Standard Mark Licensing Scheme, enforced by the Institute for Industrial Research and Standards (MRS), the Irish standardization organization.

Italy

Here as well the local authorities charged with the granting of building permits, the commune authorities or, in small communities, the mayor and the

building committee, in granting building permits implicitly decide upon the

admissibility of new building materials, structural members, and construction

desi gns

.

Every second year, however, a special governmental body does issue technical

directives regarding the requirements for specific building materials,

structural members, and construction designs. Manufacturers of reinforced

concrete, prefabricated concrete, and metal components have to notify the

responsible ministry about the manufacturing process, the results of their

own in-plant monitoring, and the like. In addition, before the start of con- struction, they must submit to the state department of construction-*

independent of the usual procedure followed in securing a building permit--

data regarding properties, quality, mixing ratios, etc.

In other cases the private Central Institute for Industrialization and Building Technology (Instituto Centrale per 1

1 Industrial izzazione e la Technologia

Edifizia) in Milan grants approval for new building materials, structural

members, and construction designs. The preponderance of certification is in

the field of plastic products.

Luxemburg

The lower-echelon construction supervisory authorities decide upon the admissibility of new building materials during the granting of building permits.

The Netherlands

A central approval committee (CCA) which is composed of the Building Center

(Bouwcentrum) , which is the executive member, KOMO and KIWA, and other organizations issues certificates (atteste) . These are descriptive suitability

ratings for new building materials, structural members, and construction designs, a rating which extends beyond concerns for safety alone.

Basically there is no obligation under public law to apply for a certificate

except in some instances of government (or government- financed) buildings;

similarly, the 900- some communities are entitled, through their own building

regulations, to demand the presentation of a certificate at the time application is made for a building permit.

UEAtc Procedure

The European Union for Technical Approval of Construction, the UEAtc (Union

Europeene pour 1 'Agrement technique dans la Construction) is composed of the

105
responsible agencies in Austria, Belgium, Denmark, the Federal Republic of

Germany, France, Great Britain, Italy, the Netherlands, Portugal, and Spain.

These agencies are obliged to recognize by conf i rmat ion--wi th restrictions or amendments where necessary—an approval granted by a competent domestic

authori ty

.

The UEAtc approval certificate constitutes the positive assessment and description of a "non-traditional" building material, structural member, or

building method. Two shortcomings of this certificate are that the term "nontraditional" is interpreted differently in these countries and that the cer- tificate also covers building accessories and items used by the subcontracting

trades. These items are not relevant as far as construction supervision in

the Federal Republic of Germany is concerned.

The manufacturer of a product applies for an approval certificate at the

UEAtc agency in his own country. On the basis of documentation and its own

tests, this agency grants the approval . In the Federal Republic of Germany,

this approval cannot substitute for the general approval granted by the con- struction supervisory authorities.

The approval certificate (agrement) is considered a "non-paper" only in the

applicant's own country. Validity in other UEAtc countries does not follow

automatically. Application for confirmation must be filed with the UEAtc

agency of the country in which validity is sought. Confirmation results

through the intermediary of the office which first granted the certificate.

If there are no uniform UEAtc directives for the building material in question, confirmation is granted with consideration of any special national con- ditions which may possibly result from deviating technical or legal

requirements or climatic conditions. In the Federal Republic of Germany,

such confirmation can be granted for construction supervision only if the

Construction Engineering Institute (Institut fur Bautechnik) consents.

Concl us ion

The preceding description of the situation in these individual countries re- veals that different solutions are being employed. In this context, one has

to consider that with the generally modest means available, optimal effectiveness is the goal, i.e., safety. For such studies many aspects must be taken

into consideration, e.g., population density, number of training of supervisory staff, legal or non-legal means of enforcement.

In conclusion, I will describe how an approval or test certificate is granted

in the Federal Republic.

A manufacturer or importer files an application for a test certificate with

the Construction Engineering Institute (Institut fur Bautechnik). In doing

so, one must prove that the product satisfies the minimum requirements laid

down by the generally recognized rules of architecture: for example, through measures which are comparable to those examples and principles stated in the

standards; or, as an alternative measure, through accepting restrictions on utilization. In this case, comparative tests between a standardized and a

106
new product under the same conditions constitute an objective method of

I assessment; unfortunately this is not always practicable, especially not in

those cases in which durability is to be rated. The instrument of approval

is not to be misused to by-pass inconvenient minimal requirements prescribed

by the standards in order to sacrifice safety for economic advantages over

competitors who comply with the standards.

j

1 In difficult cases the Construction Engineering Institute (Institut fur

| Bautechnik) calls upon expert committees for assistance in handling applications. According to the bylaws of the Institute, such an expert committee is

composed of at least seven, at most fifteen members. At least three of these

are experts from the top-echelon construction supervisory authorities of the

states (Lander) or of the Federal authorities having a technical interest in

the matter.

The expert committee may call upon further expert individuals to attend as

I guests. The experts work without fee.

The Board of Directors of the Construction Engineering Institute (Institut fur

Bautechnik) appoints the members, the chairman, and the deputy chairmen of the

expert committees on the basis of recommendations from the Administrative

Council. The expert committees may submit suggestions for appointments. The

term of office is five years. It may otherwise expire at the end of the year

in which the member becomes 68. Prior to the expiration of a term, an appointment can be revoked for cause.

The procedure for processing an application is represented in the attached

d iagram.

In the area of site drainage, five expert committees have been set up. They

meet once or twice a year. These are the expert committees for:

sewage pipes and fittings,

sealing materials for sewage systems,

sanitary equipment and fittings,

- waste water pumps and separators, and

- waste water treatment technology.

107
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108
RESEARCH LABORATORIES WITH CIB INTEREST

by

R. Hanslin, C. D. J. Webster and Viggo Nielsen

(A review of research activities and laboratories in Belgium, France, Switzerland [by R. Hanslin], the United Kingdom, South Africa, Australia, Japan

[by C.D.J. Webster], Denmark, Finland, Norway and Sweden [by Viggo Nielsen].)

Bel g ? urn

Code Structure

Every water-undertaking community or city has its own regulations which can

date back to the last century. In the field of water supply, there is only

one statutory law of the Ministry of Health which regulates the quality of

water. Only recently, the Centre Scientifique et Technique de la Construction (CSTC) proposed a uniform regulation (Reglement Sanitaire) for the design of supply and drainage systems. This regulation is the result of many

years of research activities and analytical studies. The Reglement Sanitaire

covers water supply, above- and below-ground drainage, and sewer lines.

To ensure the quality of plumbing materials and equipment, the Institut Beige

de Normalisation ( I BN) issues Belgian standards (NBN) . Other quality standards are published by the Institut National du Logement (INL). These so-called

"Specifications Techniques Unifices" (STS) are established by all organizations

concerned with the specific field and replace the original "cahiers de

charge"

.

Past Research Work

Some outstanding studies have been done by CSTC in the past years, especially

with regard to the investigation of drainage systems. The results have been

presented in many publications and papers.

This research work was started in 1963 in Liege and continued in 1965 partly

at the CSTC Laboratory in a three-story house in Brussels with a 12m-high

stack, in the high-rise building of the Cite Administrative in Brussels and

at the CEBTP test tower in St. Remy, France.

The studies included the investigation of flow patterns in stacks in function

of inlet geometery, of the air flow function of stack length, diameter and

flow rate, and of the pressure fluctuations throughout the whole system. With

analytical methods, correlations of the various parameters were found.

109
Besides examining the hydraulic phenomena in stacks, the performance of traps

and water-closets was determined. An interesting study dealt with the trap

performance under back-pressure conditions together with suds.

Building component parts are also investigated with regard to noise propagation in an acoustical laboratory at the CSTC.

All. tests at the CSTC are run highly systematically. The objects of the investigations are:

improvement of plumbling technology and its performance;

simplification of the installations; and

introduction of prefabricat ion

.

A joint study by the CSTC and the SIB Sweden of the performance of watersaving WCs and flush tanks has just been completed.

Present Research Activities

1 . Water Supply

A two-year research program is under progress to investigate the internal corrosion in galvanized steel pipes for hot water distribution instal 1 at ions

.

2. Drai nage_Systems

The research in the field of drainage is at present directed to a closer

investigation of rain-water drainage. CSTC also participates in the CIB

W-62 group studying the hydraulics of unvented branches.

France

Code Structure

The French Association for Standardization (AFNOR) is responsible for the

preparation of standards when requested by initiators, the Centre Scientifique et Technique du Batiment (CSTB) or itself. The group that deals with

the coordination of technical texts concerned with building materials is the

Groupe Document Technique Unifie (DTU) which is in the hands of CSTB. The

groupe DTU issues "Cahiers de charges", which set down the minimum standards

of products of construction or application of materials. Although only in

governmental contracts are French standard materials and DTU prescriptions

compulsory, they are nevertheless followed quite widely in France today, be- cause architects find it useful to specify these requirements as a safeguard

against bad quality. Manufacturers too have formed their own standard group

and issue the NF (Normes Francaises) standards and mark.

Non-standard materials and products which successfully pass the tests at the

110
building. As an example: the air flow down the stack was found to be a function of various parameters such as the length of the stack. Not only the

sizing and layout of single-stack systems were established and then published

in the recommendations of 1 966 but also a new single-stack system with special fittings for improved performance was developed.

Product Approval

Each official plumbing inspector has the competence to approve or reject a product. As his judgment was in general only based on common sense and ex- perience, it was decided to establish a more scientific way of product

approval. This led to the development of two new laboratories: one run by

the SVGW for the supply and one by the Civil Engineering Department of the

City of Zurich for the drainage side. Although both of these laboratories

do not have federal status, they are recognized widely in Switzerland

today. However, these labs are not geared for research work, but new findings especially in the field of performance characteristics of materials are often a by-product of this product testing.

Present Research Activities

1 . Water Supply ______________

A. Acoustics

In order to increase the quality of life and the standard of living

stringent measures have been enforced by building standards and codes

to limit the acoustical values. In conformity with the German code

DIN 4109 the Federal Institute for Testing Materials (EMPA) and the

Swiss Association of Gas and Water Works (SVGW) have built acoustical

chambers in which mainly valves, faucets, WC tanks, hangers, etc.,

are tested regarding their noise propagation. Especially EMPA has

done fundamental work in this respect, which serves as a guidance

for manufacturers. On a private basis a manufacturer of plastics

drainage material is examining at the moment the noise propagation

of various drainage pipe materials, the effect of their layout and

their interdependencies with other building components.

1

1 B. Water and Energy Conservation

Although water is no rare commodity in Switzerland, its yearly in- crease in use has to be taken under control as the capacities of many sewer treatment plants are exceeded with their polishing performance

therefore deteriorating. Several means are today investigated, such

as two-step WC tank flushing, pressure valves for apartments giving a

j set pressure, reduction in faucet flow rates, investigation of the

actual needs of the public, etc.

In the field of energy conservation studies have been made for the

Federal Government to evaluate district heating and the use of the

thermal waste energy of atomic power plants. At the Vocational

114
CSTB receive an "Avis technique" which is recognized by the Bureaux de Control e.

- AFNOR centralizes and coordinates all work concerned with codes.

Codes can be initiated by everybody.

For buildings the technical code work is submitted to the Groupe de

Coordination des Textes techniques interessant le Batiment (Groupe

DTU) .

- When a code is requested by a member of the group DTU, it is published

in a program and a commission is elected. The members are individuals

from industry, trade, the bureaux de controle, the CSTB, etc. The

draft of the code is submitted by DTU to AFNOR for approval.

- The group DTU has a second function: the issuance of the so-called

"Cahiers des charges" which give details on methods of installation

and calculations.

- Whenever a project is financed by public funds, the codes have to be

followed. In the private sector they are optional. However, the DTUs

are widely followed.

- The industries have no own code organization. However, they work

intensively in the national organizations.

- The mark NF was established in 1938 by AFNOR. It certifies that a product is in conformity with the standard in question.

For all materials and building techniques which are not traditional,

an Avis Technique (requested by a governmental law in 1969) has to be

achieved. The CSTB runs the secretariat of this commission and undertakes most of the tests.

Labo rator ies

The CSTB and the CEBTP (Centre Experimental de recherches et d'etudes du

Batiment et des Travaux Publics) are the two major laboratories in France

for building research. But there exist a number of other technical centers

which do research in the field of building technology.

As examples:

Centre Technique du Bois (CTB) : floors and walls of wood;

Centre Technique des Tuiles & Briques (CTTB)

;

- Centre d'Etudes et de recherches de I'industrie des 1 iants hydraul iques

(CERILH): cement;

- Union Technique de 1 'Electricite (UTE) : all electrical equipment;

- Centre Technique des Industries de la Construction Metal lique (CTICM)

,

and

- Centre d'Etude et de Recherche de 1'lndustrie du Beton (CERIB), etc.

Ill
1 . Centre Scientifique et Technique du Batiment (CSTB)

A. Materials

The CSTB established its laboratories in Champs sur Marne near Paris

in 1950. Here, besides other activities, plumbing products and

materials are investigated and relevant research is made.

Fundamental work including extensive and long-duration experiments

such as hot and cold water cycles, physical and chemical analysis,

water absorption, mechanical stress and pressure tests with plastic

pipes, joints and fittings, enable a better understanding and classification of this rather new material. With these tests, the wall

thickness of various pipe materials and their layout and mounting

techniques could be determined.

The work included both drainage and supply pipes. At present, a study

of pipes and joints is under way investigating such topics as:

- suitability of different materials for supply and drainage pipes;

protection of pipes against damage from outside;

suitability of different glues to join pipes; and

suitability of different elastic joints for pipe connections.

B. Water Supply

Presently the distribution of hot water in supply installations is

being studied with special emphasis on:

loss of energy in pipes and fittings; and

investigation of the water consumption by statistical calculations

and interviews.

C. Valves and Faucets

In several experiments such as endurance and tightness tests, various

aspects of valves and faucets are being investigated. In view of

energy conservation, the effectiveness of mixer taps is being studied.

The products are also examined in an acoustic chamber.

At present, research includes stop valves, flow valves, check valves,

pressure reduction valves, taps and equipment for water treatment.

D. Drainage

Single-stack drainage systems are examined in an eight-story test

tower with ample space allowing two full bathroom layouts per floor

to be joined to the stack. As all supply lines and fixtures are put

in motion by electrical impulses, the tests are operated from a

112
central command post. The pressures developed in the stack or

branches are recorded on an UV-Recorder.

CSTB is also involved in the CIB W-62 examining the performance of

unvented branches. In the field of drainage, CSTB is currently also

investigating the hygienic demands and performance of sanitary appliances .

2. Centre d'Etudes du Batiment et des Travaux Publics (CEBTP)

The highest hydraulic test tower at present in the world is operated by

the Union Nationale des Chambres Syndicales de Couverture et Plomberie

and is situated in the grounds of the CEBTP laboratories in St. Remy near Paris. In this 20-story test tower, supply and drainage systems

are investigated. The pressures in stacks are monitored with electrical sensors placed into the various traps of the fixtures and recorded

on an oscillograph which can be connected to a data processing machine.

At present, the CEBTP, which also operates an acoustic chamber, is

studying with extensive tests roof water drainage, especially with re- gard to surface friction and stack-inlet configurations.

Sw? tzerl and

Code Structure

Due to the federal istic governmental system, each Swiss city or community

has its autonomous building construction authority. More specifically,

plumbing and drainage systems above and below ground are approved by local

inspectors or community engineers. However, plumbing practice is quite uniform in Switzerland as the various bylaws are based on recommendations which

were issued in I960 for water supply installations and 1 966 for drainage systems. Both standards are at present being revised and will receive when

printed the status of a national code.

Early Research Work

In comparison to other countries, coordinated research started rather late,

being originally the domain of companies and individuals. After World War II the Swiss Association of Gas and Water Works (SVGW) established a laboratory

in Zurich. Besides running basic tests and investigating plumbing products, user patterns were established with large-scale inquiries. With these re- sults, and based on the Poisson's probability distribution, a diagram to

determine the design flow rates of supply systems was developed.

In 1959 the tallest test tower for drainage research at that time was built

at the Vocational Training School in Berne. On this 10-story test set-up the.

hydraulic phenomena of the gravity-governed two-phase flow could be studied

in all details. One of the major advantages of this test tower is its height,

which allows the simulation of an actual installation in a high-rise

113
Training School in Berne, the oyeral 1 performance of water-heater

systems are presently investigated.

2. Dra inage

A. Sewer Pipes

At the Federal Institute of Technology in Zurich, large-scale experiments are carried out to investigate the hydraulic characteristics

and to determine the capacity of steep sewer lines. Sewers with

large gradients are fairly common in Switzerland. It is expected

that these results will also give additional information for the design of drain pipes for terrace houses built on steep hillsides.

B. Drainage Systems

Although the hydraulics of drainage stacks and unvented branches have

been thoroughly investigated in the past on the 10-story test tower in

Berne, research activity is still going on. Especially further tests

are run on unvented soil and waste branches serving several fixtures.

This work is coordinated within CIB WG-62 and several laboratories

such as the Centre Scientifique et Technique du Batiment (CSTB) in

France, Centre Scientifique et Technique de la Construction (CSTC) in

Belgium, National Swedish Institute for Building Research (SIB) and

Institut fur Bautechnik (IBT) in Germany are participating.

C. Roof Drainage

In conjunction with the Swiss Association of Master Plumbers and Sheet

Metal Workers, the Vocational Training School in Berne is running an extensive study on the hydraulics of roof drainage, especially with

regard to the capacity of gutters of various shapes, lengths and

grades.

3. Standardization of Plumbing

Economy is not only a function of optimum performance, technical knowledge

and skills of the trade, but also to a large extent of standardized plumbing products and layout techniques. With joint efforts between industry,

trade and architects plumbing products, duct and room dimensions have been

widely standardized. As a consequence, Swiss plumbing has reached a high

level in prefabrication, which has not only increased productivity but

also the technical quality of the system.

United Kingdom

j Building Research Station

Prior to 19^2 there was little organized work related to plumbing and drainage at BRS: the little work that was carried out was confined mainly to an

115
examination of the properties of the materials used. In 19*t2 as part of

national policy a series of committees was set up in the U.K. to study

various aspects of post-war building, and one of these committees appointed

by the Building Research Board was responsible for plumbing. During the

preparation of the committee report, first on plumbing and subsequently on drainage, a considerable amount of experience of current problems was obtained and some of the early trials carried out in the period up to 19^5

incl uded

:

- testing use of plastics for cold water supply in a full-size mock-up;

- appraisals of the labor times required for installation of plumbing

equipment of different materials and the savings that could be

achieved by partial prefabri cat ions ; and some consideration later of soil and underground drainage pipework.

By 19^7 > a more coordinated approach to research in this field was being

adopted at BRE.

Soil and Waste Pipework

A major BRS research project on major above-ground drainage systems started

in 19^9 and further work on the same theme has been carried out intermittent!

up to the present time. This project dealt with the possibilities of simplifying domestic systems currently in use—general ly two pipe systems, one serving soil appliances and the other for waste water, and provided with ex- tensive ventilation pipework in multi-story buildings —by carrying out tests

in the laboratory and in inhibited blocks of flats. The aim was to provide

design data on the Single Stack System, a form of drainage which had already

been installed in a number of buildings in London in the 1930s. The data were primarily for dwellings up to five stories high with a compact bathroom

and kitchen layout, but also covered performance requirements which were applicable to any above-ground drainage system. Designs were based on the use of British Standard pipes, fittings and appliances.

During the next few years field trials on multi-story domestic buildings en- abled the use of the Single Stack System to be extended to 10-story building

using a 100mm stack, and to 25-story buildings using a 150mm stack. Some

work was also done on the application of Single Stack drainage to hospitals,

offices and public buildings and a survey made on drainage systems installed

in new hospital buildings.

Research was then concentrated on the development of a design method for the

sizing of drainage and ventilation stacks for all types of multi-story build

ings, based on information collected from laboratory tests on the flow of air

and water in vertical pipes and the losses at branch inlets to stacks. The

method used a simplified approach to the actual flow conditions and was published in 1969. This was further developed in the early 1970s and more data

collected. All of this work has been consolidated in a new Code of Practice

which ensures that all the results of past BRE work were fully and properly

applied. This Code is due to be published.

116
I Underground Drainage

BRE has also, In the past, been active on the structural design and construction of smal 1 -diameter rigid and non-rigid underground pipelines. In particular, research was on the relationship between pipe strength and the required

bedding and cover for different traffic loadings. The work ceased in 1970. A

project on the hydraulic design of smal 1 -diameter drains serving and close to

domestic buildings is currently being carried out. One of the aims is to de-

; termine the cause of recurring blockages and relating them to size, gradient,

I type of pipework and fittings, and the hydraulic loading of the system. A

! statistical study of the relationship between drain gradient and frequency of

blockage has been carried out. Access requirements are also being examined

along with the possibility of using curved drains without additional access.

Flow depths in installed drains are being measured, and laboratory tests on

the attenuation of flow through near horizontal pipes have been completed,

! which will enable existing design-sizing methods to be assessed.

I Water Economy !

Meanwhile in the field of water supply interest had been focussed by 1955 on water economy. Studies were made of some of the causes of wastage of water.

In dwellings one of the causes was thought to be leaky ball valves installed

in flushing cisterns and storage cisterns and work was carried out to improve

'the durability of the seating surfaces for valves. Another cause of excessive

i water usage was the quantity of water used to flush WCs, and trials were carried out in a number of dwellings to determine the water saved if dual -flush

cisterns were used, i.e., cisterns designed to give the user the choice of

either a one-gallon or two-gallon flush. Studies were made of the water used

for domestic purposes in office buildings resulting in the development of

spray taps for ablutionary purpose which provided economies in the usage of

water and in the use of energy and in some cases in installation costs.

In the last two years work has been revived in these fields and studies are

being made of further economies; studies of ways of implementing early economies in the existing stock of buildings, and studies of the feasibility of

, some waterless appliances.

Protection of Water Supplies

The two main fields of protection involved in the water supply system are protection against backs i phonage and protection against explosion of the hot

water system. Interest in problems of backs i phonage increased in 19^8 after a visit by BRS staff to the U.S.A. where backs i phonage problems were currently

being aired in a film entitled 'The Ominous Arms Case'. At the time work was

devoted to modification of national standards for appliances. In more recent

times, further work has been devoted to appraising and testing the various

backs i phonage devices currently available with a view to possible future modifications of national regulations in this sphere.

With regard to protection against explosion, the U.K. has traditionally used

cistern-fed, and vented, hot water supply systems. However, an appraisal is

117
being made of the protective deyices for mains pressure systems used elsewhere and also an appraisal of the economic assets of such alternatives.

Flow Rates and Flow Velocit ies

Estimation of demand flow rates from the water supply system and estimates of

the flow load applied to drains are similar problems. The first work in this

field at BRS was in 1961 and was inspired by the earlier pioneering work of

Hunter at the NBS in the U.S.A. using fixture units. This work has been followed up at intervals by a series of different approaches to the same problem

backed up by field studies of water use patterns in flats and University

1 aboratories

.

Where high pressures are available in the water pipework, the design flow ve- locities are limited because of noise considerations. For this reason studies

have been made to determine practical limits that should be set to flow velocities.

Level of Provision of Appliances

BRS has recently conducted an investigation into pattern of use and demand

levels for sanitary appliances in offices and schools and from this work re- vised scales of provision have been proposed.

Material

s

A survey of the performance and maintenance costs of metals used in plumbing

has been carried out. This study indicated most problems were already known.

However, the use of stainless steel in plumbing has been studied and some aspects are still under consideration.

In the field of plastics, a study was made of the performance of available

materials for hot water services.

Performance Testing

Work on the development of performance tests has been carried out primarily

for taps and WCs, but also for various valves for protecting water supply systems .

South Africa

National Building Research Institute

1 . History of Past Work

From about I960 to 1965 the work of the then Sanitation Unit was largely

in the field of low-cost sanitation such as night soil systems and eva- poration and oxidation ponds. Work was also begun on the development of

design criteria for sewers based on large-scale flow gauging and sewer photography programmes.

118
Investigations were also carried out in the mid-1960s into the behavior

of the then new materials for sewerage, namely pitch fibre and uPVC.

In the mid-1960s we also began to look at new drainage systems and ma- terials, particularly single-stack and uPVC. The late 1960s saw a revo- lution towards the adoption of flexible construction for sewers with the

consequent introduction of many new forms of joints for clay, concrete,

and asbestos-cement pipes. NBRI played the major role in this revolutionary departure from traditional practice. During this time and right

up to the present, we have continued our work on the field behavior of

flexible pipes, air-testing of sewers, sewer flow data, sewer design

criteria, various types of pipes and joints, maintenance practices and

various aspects of plumbing systems.

2. Present Work

Until now we have not had adequate laboratory facilities to carry out

much research on either drainage of water sypply systems for buildings.

We only entered the water supply field two years ago, but staff shortages

have held back the work. Most of our investigation work has thus been in

the field with actual systems.

Our new plumbing test facility (tower) has however now been completed and we are beginning a test program of evaluating locally available appli- ances and fittings to determine discharge characteristics.

Austral ia

Housing Research Branch of Department of Housing and Construction

Due to Australia's Constitution, each of the Australian States have discrete

autonomous plumbing and drainage authorities. Each State has developed its own codes and bylaws and these vary somewhat in content. Consequently, representatives from each State have come together and have formed a Standing Committee on Plumbing and Drainage, with the object of producing a National

Plumbing Code for Australia.

In conjunction with the Melbourne and Metropolitan Board of Works, a test

program has been commenced:

Performance of sweep junctions,

air entrainment at junctions in graded pipes,

installation of uPVC floor-waste gullies in concrete floors,

- maximum lengths of waste fixture discharge pipes with respect to stranding of non-sol ubl e/syspended matter,

- permissible discharge rates of fully ventilated stacks with respect to

rel ief-vent s Izes

,

- minimum flushing capacities of WC cisterns, and

119
- minimum gradients of drains with guaranteed discharges.

Additional projects will be added pending further development of the National

Plumbing Code.

Meanwhile the MMBW has done a series of tests on basin waste configurations,

and the results of their tests have been included in a Draft National Plumbing Code. This document has been accepted in principle as the basis for

future State regulations. V/e are now in the process of writing a Water Supply Code as a follow-on to the Draft National Plumbing Code.

Japan

Faculty of Engineering, Meij*i University, MUsashi Institute of Technology

1 . Research Activity Developed Before World War II (19^5)

Only within a century, an interest in the field of plumbing has been increasingly paid by scientists as well as general people along with the

remarkable progress in technology for this field.

In Japan, many of the famous contractors and equipment manufacturers in

this field had been established during the years between 1891 and 1920

when various legal regulations on water works, sewerage, disposal treatment, etc., relating to towns and buildings were promulgated. From such

an age, the fundamental research on plumbing was initiated in Japan.

In 193^, the Society of Domestic and Sanitary Engineering (which is presently called the Society of Heating, Ai r-Conditioning and Sanitary Engi- neers of Japan) established a committee to propose regulations for

plumbing based on the consideration that plumbing should no longer be

left without any regulations in spite of the fact that no legal regulations have been proclaimed. In 1939, 'Plumbing Standards and its Explanation 1 was enacted by the committee and published. Thereafter,

investigations and research started to be published in the same Journal.

2. Research Activity After World War II (19^5)

During the 20 years after the War, research on the equipment and material

of plumbing was performed by related manufacturers. With repeated trial

manufacturings and tests, new products were developed. Part of this re- sulted in the enactment of the Standards of the Society of Domestic and

Sanitary Engineering (DSS) and the Society of Heating, Ai r-Cond i t ion ing

and Sanitary Engineers of Japan (HASS) . From these, many important standards have been transfered into the Japan Industrial Standard (JIS) aftei

the establishment of the same by the Industrial Standardization Law en- acted in 19^9.

On the other hand, public research organizations with university laboratories and research organizations for private enterprises are considered

to have been engaged in obtaining the design data which comply with the

120
actual conditions in Japan. The theme relating to water demand of a building

belongs to the said category.

A. Water Supply

Regarding water demand, much research has been performed up until now,

but although research on water demand was made in detail for apartment

houses, in the past no satisfactory research was performed for other

kinds of buildings. However, with the establishment of the Subcommittee on Water Supply in Building in the Plumbing Code Committee, systematic investi gat Tons have been performed on the buildings of the

Telegraph and Telephone Corporation, the Municipally Owned Dwelling

Houses, other office buildings, etc., based on the consideration that

the water demand in application and the peak water demand in a building are important factors employing a new water supply system or a circulating use of water.

In the past, the fixture unit specified in NPC (National Plumbing

Code) which permits easy application was adopted in Japan. By em- ploying the NPC unit, however, only a rough estimate can be obtained

without securing the precise usage factor or ways of usage. Therefore, with the cooperation of the Tokyo Institute of Technology, the

Subcommittee on Water Supply in Buildings specified the unit flow

rate for each fixture after analyzing various experiments and investigations on the characteristics of discharge quantity of each fixture, kinds and combinations of the fixture employed by various

buildings and the way of usage of the fistures.

Referring to the Plumbing Code of the U.S., the value. two times over

that of the inside diameter of a water supply outlet was adopted in

Japan for an air gap. Up until then, the necessity of not contaminating potable water had been stressed.

For the said purpose, the Branch Committee on the Prevention of Water

Contamination was established in the Plumbing Code Committee in order

to set up original standards taking various factors into consideration. Experiments and research proceded with the cooperation of the

Faculty of Engineering of Meiji University. With the maximum load of

*t00 mmHg, an experiment was performed to clarify the conditions of

air gap in relation to the load in piping, the dimension, shape and

structure of a water outlet, the thickness and shape of the top part

of a water outlet, the angle of the top part against the water surface, the effects of accessed wall, and others. As a result of the

study, the experimental results and the proposed values were both

reported to the Branch Committee on the Prevention of Water Contamination in 1973.

Much research and many studies were performed on the required number

of plumbing fixtures in the past. The Subcommittee on the Required

Number of Fixtures in the Plumbing Standard Committee investigated

121
the actual conditions in office buildings, schools and theatres,

and in 1965 recommendations were made.

B. Hot Water Supply

Results of research into hot water supply were announed in I96I

by the Subcommittee on Water and Hot Water Supply Systems in

Apartment Houses established in the Plumbing Code Committee.

C. Drainage

To decide a fixture unit for drainage system, the drain characteristics of a fixture should be obtained as in the case of a fixture unit for water supply systems and research work has been

reported in the past. In connection with this program, the

Branch Committee on Drainage established in the Plumbing Code

Committee proceeded with experiments on the drain characteristics

of a fixture, the allowable gradient of a drain branch pipe with

the cooperation of the Engineering Research Institute of Tokyo

Un i vers ity

.

Since we had no standards for the capacity and structure of a gasoline interceptor for an auto garage or for a kitchen grease

interceptor in the past, manufacturing of the same had been carried out by considering the examples in foreign countries. To

improve this situation, the Branch Committee on Interceptors was established in the Plumbing Code Committee and succeeded in obtaining standards on the optimum capacity for the time being,

backed by actual investigations and experiments carried out with

the cooperation of the Faculty of Engineering of Meiji University.

Reports on treatments of special waste water were announced as early as 1959 in the form of a study or an article.

The materials for piping have been standardized by governmental,

academic and civil organizations such as Japan Industrial Standards (JIS), the Standards of the Scoeity of Heating, Air1 Conditioning and Sanitary Engineers of Japan' (HASS) , the Standards of

the Japan Water Works Association (JWWA) , etc. However, much

attention has been paid to corrosion of piping materials in re- lation with contaminated water.

Merchandise which contains plumbing such as a kitchen unit,

bathroom unit, sanitary unit, etc., have recently been marketed

with a tendancy to increase both in variety and quantity and work

has been done to standardize plumbing systems to facilitate their

instal 1 at ion

.

There are many problems to be solved in the future in the field

of plumbing. In addition, a new problem of 'Water Saving 1 has

122
appeared in front of us. This problem includes the decision of opti- mum flow rate for flushing and of optimum diameter of the drain pipe.

Organization and Research Activity Of the Plumbing Code Committee

In 1951, the Committee on Revision of Standard Specifications, and in

1958, the Plumbing Code Committee were established in the Society of

Domestic and Sanitary Engineering. The former Committee announced

'Plumbing Standard Specifications' from 1955 to 1965. The latter Committee aimed at establishing a Plumbing Code which would fit the Japanese

circumstances by reviewing the fundamental items in the plumbing. At the

initial stage, the following three branch committees were established,

the activities of which succeeded in obtaining a result either through

its own research or research submitted by other organizations:

A. First Branch Committee

Minimum requirements for the number of plumbing fixtures.

B. Second Branch Committee

(1) Conditions of drain at various vent systems and distribution of

the air pressure variation in a drain pipe.

(2) Measurement on experimental values of unit flow rate from fixture

d ra i n

.

C. Third Branch Committee

(1) Optimum flow rate and duration of water supply for important

plumbing fixtures.

(2) Mounting method of an air cushion pipe and the effect of vacuum

breakers for prevention of water hammer.

In 1959, this Committee was submitted the research theme of 'Plumbing System in an Apartment House' by Japan Housing Corporation. In 1961, the

research with the theme of 'Rationalization of Plumbing System in Apartment Houses' was submitted, for which the Subcommittee on Water and Hot

Water Supply System in an Apartment House was established to perform the

fol lowing studies:

- study on idl ing of a water meter;

study on local hot water supply system; and

- study on central hot water supply system in apartment houses.

The results of the above studies were reported to Japan Housing Corporation. In addition to the original studies of the Plumbing Code Committee

and its established branch committees, submitted studies by other organizations were also performed as seen above. From these facts, it can be

123
inferred that an attitude to solve the urgent problems in plumbing by

gathering many experts together for advice in the form of a committee

was establ i shed.

Thereafter, the organizat f on of our Committee was anewed in by es- tablishing the following subcommittees for research and study:

A. Subcommittee on Proposed Plumbing Code

To propose plumbing standards.

B. Subcommittee on Required Number of Fixtures

To investigate and study the required number of plumbing fixtures.

C. Subcommittee on Plumbing Literature

To investigate and classify domestic and overseas literature and

data relating to plumbing.

The results of research activities by the Subcommittees were fully re- ported .

In one of the reports, 'Plumbing Standards', many of the items relating

to numerical values were mentioned as 'to be specified separately 1 . This

backs up our view that satisfactory experimentation and research should

be made in order to obtain a final conclusion which is suitable to the

actual situation in Japan. During the 10 years since that time, systematic research activities have been promoted with many branch committees

established to provide fruitful results.

Denmark

Institutes and Organizations

Research within the field of water supply and drainage for buildings takes

place on the Danish Building Research Institute (SBI) in Hoersholm.

Testing of components to water supply and drainage systems is carried out by

SBI and JTI (Technological Institute of Jutland).

SBI is an independent institution under the management of a board appointed

by the Ministry of Housing. The institution was established in 19**7. The

annual budget is around $3-5 million for the whole institute and about $2

million for work on water supply, drainage, heating and electrical installations .

SBI is financed 90 percent by the Ministry of Housing grants and 10 percent

by research contracts and by sale of publications.

124
Laboratories and Facilities

2

About 270 m of water supply and drainage laboratories with a ceiling height

of 6 m. Gallery in three storeys for drainage experiments and a nine-storey

tower for outdoor experiments.

A noise laboratory is permanently equipped with facilities for noise measurements according to the international standards ISO/DIS 3822/1 and DIN 52218.

The laboratory is made in two storeys with possibilities for other measurements, i kB. , noise from stacks running through two storeys and heating systems .

Past Research Work

1 . Water Supply

- Noise from water supply system (Project No. F-281).

Performance requirements related to taps (Project No. F-392).

2. Drainage

- Unvented drainage stacks.

Drain pipes with small slope.

- Measuring method for discharge characteristics of sanitary appliances.

Design method for unvented parts of a drainage system.

Method for designing, testing, and judgment of the trap (Project No. F243).

- Performance requirements related to water closets (Project No. F-392).

Ongoing and Planned Research Work

1 . Water Supply

Performance requirements related to sanitary components and systems.

Desposition of calcerous substances in taps and other components.

- Water supply systems designed for saving of water.

2. Drainage

- Performance requirements related to drainage components and systems.

Performance of systems with water closets using less than eight litres

per flushing —an investigation in laboratory and in building.

Technological institute of Jutland

JTI is equipped with laboratories equipped for testing water closets, taps,

check valves, vacuum valves, solenoid valves (water hammer), traps, floor

125
gulleys, thermostatic valves, hoses for washing and dish washing machines.

The testings are financed by the manufacturers and the sole agencies of the

components. The testing reports are mainly used for getting the approval of

the Ministry of Housing.

Fin! and

Institutes and Organizations

In the field of water supply and drainage for buildings, Finland has been

without any official research activity until 1975.

Plastic pipe for underground dratnage has been studied for sever years at

the Technical Research Centre of Finland and the Finnish Plastic Industries

Federation and a lot of results from research and testing are published.

In 1975 water supply and drainage was added to the activities of the Technical Research Centre of Finland (STF) . STF is an independent institution

under the management of the Ministry of Industry and Commerce.

Planned Work

The laboratories for water supply and drainage research are not finished yet.

It is planned to start the activities with performance testing of sanitary

components which have to be carried out in connection with the new Sanitary

Code. The testing will be familiar to the testing carried out in other

countries

.

Norway

Institutes and Organizations

The Norwegian Building Research Institute is an independent institute under

the management of a board appointed by the Norwegian Technical Scientific

Council of Building Research. The budget is about $3.5 million for the whole

Institute.

Laboratories and Facilities

The laboratories for water supply and drainage activities are located in a

15 m high building with a floor area of 100 m

2 . The laboratories consist of

a gallery with four storeys for performance test on drainage systems and noise

laboratories for noise measurements according to ISO/DIS 3822/1.

Past Research Work

1 . Water Supply

- Frost prevention of buried pipelines.

126
2. Drainage

- Plastic pipes in buildings.

- Performance of sanitary installations.

Ongoing and Planned Research Work

j 1 . Water Supply

Dimensioning of buried pipelines.

- Performance requirements related to sanitary installations.

2. Drainage

- Drainage systems in the buildings.

Rehabilitation of sanitary systems.

Development of WC drainage with WC using three litres per flush.

Testing Activities

The testing of sanitary components which have to be approved by the authoriI ties at NBI. The testing carried out is very familiar to the testing carried

J out in the other Scandinavian countries, Denmark and Sweden. The test methods and the requirements for approval are made in collaboration within the

group NBS-sanitary.

Sweden

Institutes and Organizations

The National Swedish Institute for Building Research (SIB) is independent

with its own board of directors. The Ministry of Social Affairs grants SIB.

The budget of about $4 million is mainly finance through the Governmental

Council for Building Research.

Laboratories and Facilities

2

j 150 m of indoor laboratories for experiments with water supply and drainage

components

.

Indoor tower facilities for a total height of *t0 m and outdoor tower with a height of 120 m (about k5 storeys). Electronic system for monitoring and

measuring the pressure and flow variations.

Research Work

l The SIB laboratories work 50 percent with contract research, mainly concerning testing of new products.

127
Development of testing methods according to the Building Code which allow

components and systems for which it can be proved in laboratory that they will

work satisfactorily in the building. "Water economy" is a new project planned

to be carried out. The project takes a total view at the water cycle system

and analyzes the possibilities for savings from the borehole to the recipient.

128
CONTRIBUTED PAPERS

COST BENEFIT ON PLUMBING: LARGE FRINGE BENEFITS

FOR SANITARY INSTALLATIONS BY THOROUGH ANALYSIS OF SYSTEM

I by

Tore R(f5srud

Norwegian Building Research Institute

j Some years ago the mechanical industry found a new tool called value analyI sis. The reason for this was that the production tools of this industry

I were very heavily engaged. Work study and production analysis had given

very good results. But in spite of a wel 1 -organ i zed production apparatus,

the result was not satisfactory. Due to this, the industry began a value

analysis of its products and after a short time the economic situation was,

in many cases, considerably improved. How was this achieved?

Value is the lowest total cost for the maintenance of necessary

functions at the right time and with desired quality

Value - ^ unctl0nal properties Attractiveness Cost I or price )

In other words

Value = Good return for money

The producers called together a group of specialists from the departments

of production, buying and selling, in order to assess the properties or

functions of the product and what it cost the firm to develop these functions

in the product. The primary function was first decided upon. Then an attempt was made to find a new product at the lowest possible price which

would fulfil the main function. This could often be a surprisingly cheap product, readily available. The products sometimes lacked the most important

subsidiary functions. Perhaps also these could be obtained reasonably.

! Examples: The same type of valve is used in a motor plant for emptying coolant as is used for draining hot water systems. The primary function is the

stopping of water flow. A plug also does this. The price sank to about 10

percent of that of the value. The disadvantage is that the plug could be

lost in inaccessible places. A chain was attached to the plug and, even

though this doubled the cost, the producer had saved 80 percent of the original cost of the function of emptying coolant.

| In other cases the cost may be the same but the functions have been improved

so that the market and profits will increase.

Value analysis can also, in principle, be applied to sanitary installations.

| These are, however, more complicated than many industrial products and it has

131
been necessary to develop a special procedure to separate the main functions

from the secondary. The possibility of obtaining a better product for the same price is nevertheless present.

^

FUNCTIONAL REQUIREMENT

SAFETY

Up to the present we have lacked the functional analysis, which is the most

important "tool" in the process. However, this "tool" is now being printed

by the Norwegian Building Research Institute. This functional analysis has

produced some remarkable results and led to new techniques and constructions.

Nevertheless, most important is that the work on the developing of functional'

criteria has brought to light properties which increase the usefulness of

sanitary installations and in which component manufacturers are very interested in cooperating. They have obtained a number of new sales possibilities \ and a clearer understanding of the improvements they can make, often at mod- t erate expense. ,

Practical Examples

Previously the noise caused by WC cisterns was very troublesome, especially

when the WC was used at night. It was found that the noise was the result of! water at high pressure being forced through a small outlet into the cistern.

Modification of the small outlet was difficult but the water pressure could

be decreased by increasing friction in the system. This could be achieved by

i

reducing the dimensions of the supply. The supply could thereby have a low

noise level and, at the same time, the cost would be less. The manufacturers

could market a more attractive product and profits be greater.

This procedure can be used for the whole plumbing system. Formerly large dia

meter copper pipe was used and flow was noisy, e.g. when a bath was filled.

i

i

TohminZij Ioaqq. cUame.te.1 coppeA pipe. wai

ttied latfh Cutting high nol&z lzve.1

duA-ing KuntvLYig oq bath

132
The noise function (low noise level), through the analysis, led to increased

friction in the pipe in order to avoid the high water pressure when it was

forced through the faucet.

The small diameters and high rates of flow in the pipe necessary to attain

sufficient friction also resulted in other functional advantages: Hot water

remains in the pipes and cools down between each tapping. The amount of

j water, however, is small in small diameters and the cost of water heating is

! thus less. At the same time water flows rapidly (8-10 metres per second)

from the heater to the bathtub. Waiting time for hot water is thus reduced.

No mJjting ^on. hot woXqa

Another example is the function of leading away drainwater. Formerly, leaders

were of large diameter in order to lead water quickly off flat roofs, to prevent leakage occurring during heavy rainfall.

Le.ak.agn ihoutd not occua

duAtng h&avy kcJji

The dimensioning intensity of rainfall to avoid damage was assessed, based on

the heaviest 10-minute rainfall measured during a 30-year period. This

amounts to 200 litres per second per hectar. Analysis showed that heavy

rainfall is of short duration and seldom occurs during continuous rain. Without any form for drainage, the roof would receive about 1 mm per minute, but

133
this would only result in a water depth of 10 mm during 10 minutes heavy rain

During winter the roof covering is subjected to far greater loading from wet

snow.

DIAGRAM 1

£ rainfall mm or l/m J at Blindtrn SO

0 12 3 4 5 6

The. turn Ofj nainfiall in heavy lain compared with filow in

the, iitonm leaden..

Maximum njj>e in waten level iA given at> the di^enance between

the cuAve fan, thz nain^alt and the waten^low in the t>vu>tem.

Experience has shown that a roof drain becomes blocked by leaves and other

objects, with the result that the water will rise right to the top of the

roof covering. Water will penetrate under the cornice joint and into the

building. Two roof drains are often used to delay blockage by leaves. This,

however, will postpone blockage by only about two weeks. The diameter of the

leader from the roof drain has no influence on the blockage and therefore has

no influence on the run-off rate of rainwater to avoid damage to the roof.

The functional analysis showed that the roof must be fitted with a warning

system to indicate that the roof drain is blocked. The simplest system is an overflow, which may with advantage lead the water on to the head of the caretaker.

The roof drain shall stop all solid matter which can become jammed in the

leader. The roof drain may well allow leaves to pass through if the leader

is of small diameter since the water velocity will be very great and selfcleaning good.

134
Tfie ovzlfilow bkoJUL fimn on to

the. head ofa the aaKetakeh.

Large-d iameter pipe, common today, is not only dear in purchase. The space

it requires in a building is a considerable problem. Planning is often

influenced by it, while at the same time it requires additional construction

to obtain a tasteful concealment of the piping.

Functional analysis does not end here. Rainwater for heavy rainfall is very

expensive for the community. Large-diameter main sewers are used to lead away

the water, so that flooding of low-lying districts can be avoided.

Rainwater is led together with WC and kitchen waste water. Environmental

authorities have plans involving the investment of millions for the transport

and treatment of this water. Our functional analysis deals also with this

aspect. What if we led the' rainwater to the groundwater in the district?

A sinking groundwater level creates problems in some places. It results in

settlement of building foundations. To counteract this we can lead rainwater

! from a roof into a rock-filled trench and allow it to permeate to the groundwater at convenient places.

The same procedure may be adopted for analysis of the entire sanitary installation and with success similar to the examples above. Similar work procedure

has also been formed by the community for those who will use the aids and

tools available. Building specifications and sanitary requirements determine

i functional requirements as criteria in order that the builder can ensure

! health and safety for the user. The requirements may be supplemented by the

I functional analysis which the Building Research Institute is now publishing.

Thereby all links in the production process should be enabled to participate

! in the development of sanitary installations. Thereby they will be more valuable, i.e., the functions relative to the costs will be improved.

135

ECONOMIC WATER SUPPLY DESIGN BASED ON PERFORMANCE REQUIREMENTS

by

Eskil Olsson

National Swedish Building Research Institute

The increased attention being paid to the cost of water and the need for

careful management of our natural resources are two good reasons which justify the development of new water supply and sewerage systems plus the

necessary components for them.

Regulations and other steering instruments must, for a variety of reasons

(energy, environment, economics, technology), be designed so as to limit

unnecessary consumption of water and to stimulate technical progress. Water

supply and sewerage systems for individual houses and for entire municipalities are designed and managed as separate entities. Studies of complete

water supply and drainage systems, ignoring administrative boundaries, and

relationships with the hydrological cycle, should provide new ideas as to

possible approaches.

This paper presents three technical innovations developed in Sweden which

are now in the process of being launched on the market. These are, the flow

regulator, the duct system, and the BPA pipe system. They are all designed

to comply with the Swedish building regulations and would together seem to

engineer a not- i neons i derable decrease in water consumption. This, along

with other trends in Sweden, may have a noticeable influence on the design of

water supply and sewerage networks provided by local authorities. The systems have spotlighted certain deficiencies in the present range of pipe fittings and components, along with the need to discuss certain points contained

in the regulations.

Flow Regulator

A tap—assuming that its flow pressure properties have been taken into account — is designed to produce a regulation flow at a given pressure. If

the pressure is higher, the flow will be correspondingly greater.

However, the pressure in the pipe supplying a tap is often higher than that

allowed for at design stage, one of the reasons being that the pressure in

the municipal mains networks may vary. Water consumption throughout the day

may differ, but the pumps at the waterworks are designed for constant operation. Variations in consumption are allowed for by providing for rises and

falls in water levels in the reservoirs; the actual pressure may be 100-150

kPa higher than pressure guaranteed by the waterworks. Another reason is

137
that the design flow in a branch pipe is, as a rule, an overall flow calculated on the basis of the probability of a number of taps being turned on at

the same time. Since the design flow is always greater than the regulation

flow from individual fittings —and sometimes even much greater—and since it

is not usual to turn on more than one tap at a time, the actual pressure

immediately preceding a tap will almost always be greater than that corres- ponding to the regulation flow. A third reason is that with the present

range of pipes and fittings, it is difficult to design a stack which maintains a balance between differences in height and differences in flow

res i stance.

As we have plentiful supplies of water in Sweden arid strict requirements re- garding the performance of taps, taps in homes and offices almost always

permit unnecessarily large flows of water. This can be eliminated by installing special valves in or immediately behind taps. Such valves, flow

regulators, have been developed in Sweden in the past five years and are now being launched on the market. These help keep the flow more or less constant

at all pressures up to 700 kr^a (Figure 1).

Figure 1 Optimization of flow to regulation flow

138
'The -flow regulator is a new product and is thus still open to improvement.

We may expect to find them incorporated in actual tap fittings or combinations of the same in the future. The authorities responsible for issuing

regulations and standards should make the following general requirements:

- Should a fault occur in the workings of the valve, the device automatically shut off the flow.

- The valve should be difficult to reach in order to prevent interfer- ence by laymen.

- The valve should be approved by the appropriate authority responsible

for issuing regulations.

- The total pressure drop through valve and tap should not exceed 50

kPa.

Efforts should be made to achieve a better balance in the case of flows

I lower than the regulation flow. With the present range of tap fittings,

the scope for adjustment is a rule too narrow. Difficulties encountered

in trying to regulate flow increase with fluctuations in pressure. In general, the torsional angle is between k5° and l80°--in other words, far too

short a moment to be able to balance the flow satisfactorily. This is an

I area in which improvements should be possible.

The next question is whether this technical detail is of any significance

in Sweden. There is, for instance, plenty of water.

However, this is not entirely true for all part of the country and the Swedish plumbing industry exports a considerable amount to countries suffering

from water shortage. Nevertheless, apart from this, useless consumption of

water has a number of obvious disadvantages.

One of these is, of course, that treatment plants, for both supply and waste

water, will be unnecessarily large to the corresponding degree. The economic

effect of this varies greatly from one municipality to another. In places

where there are extensive mains networks and where municipal expansion is

taking place at a slower rate than forecast —something which is fairly common

in Sweden —there is little to be gained from knowing whether water consump-

; tion is rapidly or gradually increasing, or decreasing. On the other hand,

in municipalities where the authorities worry over the possibility of future

deficiencies in capacity, a change of only 1 percent or so in annual consumption can have notable economic effects. The investments under consideration

may concern sums corresponding to thousands of dollars per inhabitant. All

local authorities will, for other reasons, be forced to raise their water

rates, and in most casts by amounts in excess of those corresponding to the

rate of Inflation.

(Another disadvantage, and this applies to all consumers in all Swedish municipalities, is that all water used by households almost always contains a certain amount of hot water. Hot water costs energy and in Sweden there is

total unanimity in political circles as to the fact that unnecessary consumption of energy should be avoided. Measures to this end in other spheres

139
receive substantial state aid. The Swedish Parliament has passed a resolution

whereby all flats in Sweden are to be fitted with their own individual hot

water meters.

There are also certain other tendencies in developments in Sweden which must

be taken into account. Urban izat ion- has at least for the time being entered

a less hectic phase. Housing construction has undergone a marked decline and

is expected to remain at a level corresponding to 75 percent of the volume

constructed over the period 1955-65 in the years ahead. On the other hand, we have a larqe stock of "middle-aged housing" which we shall soon have to do

something about systematically on a large scale. This modernization operation, which will among other things probably involve combining small flats to

form larger ones, will often also mean the installation of entirely new plumbing systems and sanitary facilities.

As far as we can judge, water consumption per capita has stopped rising.

Practically all homes in Sweden now have hot and cold water supply, WC and

bath. Thus, even if improvement continues to be made in the standard of

housing involving more such appliances per person, the total time during

which they are in use will not necessarily increase.

WCs manufactured a few years ago consumed 9 litres every time when flushed.

Those now on the market consume 6 litres and work is progressing on the development of WCs needing only 3 litres. There is also a type of closet known

as Mult rum in which latrine waste and household refuse are converted into

compost and which consumes no water at all. At present, this type is used

only in holiday chalets; there are also certain problems of odor. Various

manufacturers are, however, considering the possibilities of developing variants on this theme, which would be approved for installation in permanent

residential areas.

There are thus good reasons and ample scope for limiting water consumption.

We would seem now to have reached a point at which the grown curve is leveling out. We may even find that water consumption falls. At all events, this

puts many engineers in the municipal water and sewerage field in an entirely

new situation.

In other words, the flow regulator has emerged at a point in time which ren- ders it interesting news.

The Duct System

The duct system involves the installation of water and heating pipes according to the method long in use for electric wiring. Ducts and junction boxes

are built into walls and floors. Soft piping of iron, copper or plastic is

then inserted into the ducts and connected in the junction boxes. Ordinary

metal coil piping with a minimum bore of 75 mm is used for ducting (Figure 2)

J

The duct system has three major advantages compared to conventional systems.

Firstly, installation of plumbing need not be coordinated with erection of

140
141
the load-bearing structure and a clash between two trades as dissimilar as concreting and plumbing is avoided. Secondly, the piping used is easy to

inspect and replace; this facilitates future alterations and may in some cases mean that greater stresses may be permitted on materials, e.g., higher

water velocities in copper pipes. Thirdly, any water leaking from pipes is

filtered off into the drainage system, thus reducing the risk of damage caused

by overflow. In the past few years, the amount of damage caused by water has

increased a great deal, and along with it the insurance premiums.

The duct system requires the use of soft piping. In addition, the diameter of

inner pipe must be considerably less than that of a duct to permit insertion.

There are many reasons for keeping diameters as small as possible—space, fire

safety, acoustic insulation, materials consumption, handling expenses, etc.

Since thick piping is also difficult to bend, it is natural that an effort

should be made to produce the smallest possible bores and the thinnest possible

walls for water pipes.

Experience gained from completed projects has shown that copper piping should

not be of a size in excess of 22x1. When the pressure is low, such a pipe is

capable of supplying a limited number of taps. It is also difficult to con- nect branch pipes inside ducts. It is therefore necessary to work with a large number of rising pipes, a situation from which advantage can be derived.

Two systems connected in parallel involve smaller pressure losses than one system connected in series.

I The smallest possible bore for pipes assumes that we avoid trying to transport unnecessarily large quantities of water and that the velocity of the

water is high. The amounts of water flowing from taps should not exceed the

standard flows. Also, the best possible use should be made of the pressure

avai 1 able.

This brings us back to the need to avoid unnecessary consumption of water.

It is also obvious that it is best to have a high pressure in municipal mains.

The duct system is one which favors pipes and couplings which will stand up

to high pressures and velocities. Copper piping is less suitable than plastic. Development work is in progress with a view to reducing the pressure

drops occurring in bends and coupl ing.

It will be fairly obvious from all this that some of the prerequisites for

the duct system have little in common with the conventional systems of water

supply, e.g., large numbers of small-bore rising pipes. Careful dimensioning

is also essential to ensure that every chance may be taken of producing the

smallest possible bores. The BPA Group, which has developed the duct system,

have therefore also developed a system for standardization and simplified

design of water supply in residential buildings.

The BPA Plumbing System

The BPA plumbing system offers scope for taking advantage of the consequences

of the duct system. If properly exploited, it means lower water consumption

142
I.

and thus lower energy consumption for hot water supply. However, as long as

; there is no noticeable water shortage, it is two other factors which will decide whether the system is to be used or not. One is that it must be possible

to use the system as a standard element of new construction. Development

work has therefore had to take the following points into account:

- The system should comply with the regulations applying for the water

and sanitary engineering field.

. It must be possible to assumble it using pipes and fittings already on the market and to connect it to existing appliances.

It must provide scope for selecting the materials and components which

offer the greatest advantages in each individual project.

, - It must be applicable with all ordinary floor plans.

The second factor is that:

- The system must be competitive in economic terms.

It must have a rationalizing effect on different phases of construction.

This goal is illustrated by the series of sketches in Figure 3.

I However, standardized design inevitably means that certain means of making

savings, which could be taken advantage of through meticulous planning of individual projects, will be bypassed. Further, if this saving potential is

greater than the corresponding design costs, the general standard will not be

applied. Standard designs must therefore have potential for adoption to individual projects.

The difference in prerequisites are of course small in housing construction

where there is large-scale production of similar units. It was therefore

decided to develop the system initially for use in two- and three-storey

blocks of flats, a category of building which represents a large share of

the total construction volume. The unit in question is the stairwell, all

such stairwells being similar in dimension regardless of where they are erected and by whom (Figure h) . But, even given this limitation, two other

forms of variation in prerequisites remain, i.e., the pressure in the municipal mains and the floor plans applying for stairwell sections.

jit was therefore considered best to begin by developing the system as a method requiring standard design of water supply pipes in two- and threestorey blocks of flats with the scope for variation required by pressure in

municipal networks and different floor plans.

Principles of the System and Approach to Calculations

The system can be divided into two main parts—the basic structure and facilities served.

i|The basic structure can, in its turn, be divided into two parts. The first

lof these comprises installations from and including the point of connection

143
When the sanitary engineer receives

the architects drawings, he looks up

the reference number given by the

architect in his standard table and

notes down the data given in the table

No drawings referring to water pipes \ in vertical parts of individual floors, are needed*

BUYER SPECIFIER OF MATERIALS

ON SITE: . SIMPLIFIED CHECKING IN,

CONTROL AND STOCKING

OF MATERIALS,

Since the system consists of standardized components specified in a product catalogue* no special specifications are necessary as regards

materials.

The question of stocks is simplified

thanks to the limited range.

Figure 3 Example of rationalizing effects

144

so
Figure k Floor plans in blocks of flats

in the journal Arkitektur 7.1968. Scale 1:400

in the conventional plumbing system (ground floor in stairwell, TF) and up

to the floor connection (Figure 5). The base slab of each stairwell con- tains a distributor device (Figure 6) which distributes water through pipes

in the floor of the stiarwell (TL) to one or more individual floor distributors (VF) (Figure 6)

f from which a risinq pipe supplies each floor. These

rising pipes (VL) continue into the second part of the basic structure on

the individual floors and are an extension with a maximum length of 2 m of

the rising pipe (FR-VL, Figure 7). The purpose of this particular component

is to make it easier to adapt the system to the prerequisites offered by

floor plans. This extension of the rising pipe may lead to individual appliances or junctions of several pipes connecting a number of appliances;

some examples are given in the figure. One of the major problems in

145
! [VLj

]Vln. 3

I Vln. Z

J (Si

Figure 5 The BPA Plumbing System - Basic Structure

Part 1

.

<a connection to the floor

TF central ground floor distributor

TL branch nipe

VF individual floor distributor

VL rising pipe

146
300

t 50 . 100 , 100 . 50 —

f

1 f— i

75

.4-

Central ground floor distributor (TF)

Ca 100 Bp

Ca 150

tB

4^4

Ca US

Individual floor distributors (VF)

Figure 6 The BPA Plumbing System

Central ground floor distributor (TF)

and individual floor distributor (VF)

Scale 1:5

147
a-

&—aa b

-a

-«

-a-©

-«

-a

B—

B

—S S> —ED €

i

b m

a a

Figure 7 The BPA Plumbing System - Basic Structure

Part 2 - extensions of rising pipes serving

individual floors.

.•mi:

a connection to the floor

1 individual tap

• a junctions for connection of pipes to a number of taps

developing the system has been to establish how these different possibilities

should be classed and described. However, lack of space prevents me from

getting into the details of this dilemma.

Different combinations of tap fittings can be connected to the various con- nection points in Part 2 of the basic structure. These systems of pipes and

fittings together constitute the facilities served and are steered by the

appliances normally found in kitchens, bathrooms, WCs, etc. The systems used

in each type of room can be standardized by definition of a "least favorable

instance" and assignment of pipe dimensions accordingly. An example of this

is given in Figure 8. However, the facilities (bathrooms, kitchens, etc.)

may vary in number and location. Standardized systems for kitchens and bathrooms can therefore offer a large number of different combinations. Each of

these (a total of 30 versions of the facilities in question have been

studied) can, however, be reduced through calculation to two requirements

148
Hn r 1

1

—| J Lt | I +JU-

"I— »

500 -4-

2000 reip. 4000

Figure 8 The BPA Plumbing System - Examples

of "the least favorable instance" for dimensioning of facilities served.

Plan and cross-section through length of pipe.

149
referring to pressure and flow at the end of the rising pipes. These two

values have subseguently been used in making the calculations for the basic

structure of the system.

The height of the basic structure is determined by the standard storey

height (Figure 9)

.

5350

Figure 9

The BPA Plumbing System - Height in basic structure

It has been assumed that the maximum length of the pipe between the central

ground floor distributor (TF) and the individual floor distributor (VF) will

be 12 m, and the system has been designed to accommodate each two-metre

interval

.

The flows to be maintained in fittings in Sweden are governed by the regulations for water and sanitary engineering, which specify regulation flows of

0.*» 1/s for hot and cold water in bath taps, 0.2 1/s for shower and sink fit-f

tings, and 0.1 1/s for taps supplying washbasins. The regulations also spe- * cify the design flows for pipes supplying two or more outlets. The probabl

e

calculated

the

flow is

turned on at

Q on the basis of the probability of more than one tap beingi same time.

The regulations for water and sanitary engineering also contain instructions

regarding the greatest permissible velocity for water in copper pipes.

150
As such systems consist of a multitude of different components, it is also

essential to know the pressure drops involved. When it was found that com- ponents of identical function exhibited different pressure drops, it became

necessary to carry out systematic tests on all components which may be used.

Five hundred components have been examined and some 3,000 measurements have

been taken. Reference curves (pressure- flow) have since been constructed on

the basis of this material for the different component types in question.

A special test rig was used to study pressure and flow in the components.

The values obtained were then fed into a computer for processing and resulted

in regression curves, regression coefficients and standard deviations (Figure

10).

Pressure

i >

Flow

Figure 10

The BPA Plumbing System - Principle governing

choice of reference curves for pipes and components

reference curve

regression curves for variants tested

Dimensioning

Hrst, a summary of the prerequisites for dimensions.

The system consists of a basic structure plus facilities served, a large

number of different arrangements being possible for the latter. A "least

favorable instance" was established for 30 variants and dimensions were fixed

on the basis of flow requirements set out in the water and sanitary engineering regulations and pressure drops recorded during tests carried out at our

laboratory.. In each case, dimensions were fixed in two different ways: a smaller bore requiring higher pressure (H) and a larger bore requiring lower

(L) . In two of the variants, H and L coincide.

Floors are assumed to be identical.

151
Table 1 The BPA Plumbing System

Table for dimensioning (low-pressure alternative) of the basic structure

with facilities served consisting of one bathroom per floor

WORKING PRESSURE ZONES AND DIMENSIONS OF PIPES

Working Branch pipe (TL) Rising pipe

pressure P , (VL) and exin TF inlets, Limit markings: tension (FRexcl . fittings Copper hot water pipes VL) up to

Copper cold water pipes facilities

served

Lengths in meters

M in. bore D : in mm M in D. in mm

i

i

p Meters/Dj D=double pipe Floor

kPa 0-2 2-4 4-6 6-8 8-10 10-12 1 2 3

> 200 16 20 20 20 20 20D 16 16 20

> 210 16 16 20 20 20 20 16 16 20

> 250 16 16 20 20 20 20 13 16 16

> 260 16 16 16 20 20 20 13 16 16 > 280 16 16 16 16 20 20 13 16 16 > 290 13 ! 16 16 16 16 . 20 13 16 16 > 400 13 ! 16 16 16 16 20 13 13 13 > 410 13 ! 16 16 16 16 16 13 13 13 > 430 13

1 13 ! 16 16 16 16 13 13 13

> 460 13 13 13

1

! 16 16 16 13 13 13

> 500 13 13 13 13 ! 16 16 13 13 13 > 530 10 13 13 13 ! 16 16 13 13

> 540 10 13 13 13

j

13 ! 16 13 13 13

< 700 10 13 13 13 13 ! 16 13 13 .3

Sum of regulation flows connected Q = 1.80 1/s in branch pipe
What then remains is to dimension the basic structure for each of the 58 cases (2x30-2). Pressure drops in pipes and fittings are those recorded in

the course of tests at the plumbing laboratory. The lengths of rising pipes

to individual floors are fixed. Branch pipes at ground-floor level, on the

other hand, may be 2, *t

, 6, 8, 10 or 12 m long.

It must be possible to vary the pressure in central ground-floor distributors

depending upon the pressure in the municipal networks. Calculations have

been made for every 10th kPa between 210 and 690 kPa, a total of 50 instances .

This leaves us with a total of 58x6x50 cases for which dimensions must be

fixed. A computer is therefore necessary.

However, the prerequisites already mentioned offer no uniform solution to

the problem of dimensions.

The following series of equations can be used:

Bernoulli's theorem for sections 1 and 2*3

Bernoulli's theorem for sections 1 and 2*2

Bernoulli's theorem for sections 1 and 2*1

Equation of continuity for floor distributor (VF)

The system allows for four unknown quantities, i.e., flows can be determined

if the dimensions are known. However, our position is just the reverse; the

flows are known and we need the pipe dimensions and these may vary. We must

use five dimensions between 8 and 20 mm (bore). In choosing between these,

the main consideration was that the total cost of piping should be as low as possible. An example of the results obtained is given in Table 1.

Separate calculations were made for each version of the facilities to be

served. We began by making calculations based on a 6m-long branch pipe at

ground-floor level. This gives us four unknown bores--for branch pipe and

the three rising pipes. Each one may assume one of the following dimensions:

8. 10, 13, 16 or 20 mm. The computer calculates the necessary working pressure preceding the ground-floor distributor (TF) for all combinations (*tx5 =

20). The combinations are then assembled on the basis of this pressure. Among

those requiring a maximum of 200 kPa, the computer will chose the one involving the lowest total cost of piping and this is subsequently adopted for the

200-210 kPa interval. The computer then chooses from among all combinations

the one which involves the lowest cost of piping at 210 kPa and which can be

used in the 210-220 kPa interval. The computer thus draws up a table

11 VF

,Z2

1 21

153
consisting of 50 lines, one for each interval of 10 kPa between 200 and 700

(<Pa in working pressure preceding the ground-floor distributor.

Data are later added to the table on the dimension of the branch pipe (TL)

when this is 2, k t 8, 10 or 12 m long. The dimension of rising pipes to

individual floors is then for the sake of simplicity assumed to be the same

as when there is a branch pipe (TL) 6 m in length.

In its printout, the computer reproduces only the lines in which changes

occur.

The system can thus by and large be described as 58 such tables for two- and

three-storey blocks of flats along with the accompanying rules and restrictions governing measurement. The most important of these rules is the res- triction of the field of use permitted for copper pipes, shown by the full

black lines and broken lines respectively in the table. Dimensions below

these lines may not be used for copper pipes because the water velocities

involved are too high.

Flow Regulators

A flow regulator is an essential ingredient of the BPA Plumbing System.

Earlier in this paper, I mentioned three reasons why the actual flows often

exceed those calculated for when deciding dimensions. The same course applies in the case of the BPA System. However, in this case, the important

point to bear in mind is that dimensions are small. Larger safety margins

would be necessary in the absence of flow regulators, which would have produced increases in dimensions that might represent a threat to the economy

of the system.

Use

Methods have also been developed to simplify documentation routines and draw

ing operations. All data on dimensions and parts are given in a catalogue.

All the designer has to do is check that installations included in his project fit into the frameworks sketched in the catalogue and to mark the locations of those installations on the architect's plans. This means that there

is no need to provide separate drawings of hot and cold water systems, since

they are identical. To make things still easier, BPA provides ready-printed

transfers which can be stuck onto plans, the only thing required of the

designer being to fill in the appropriate data referring to the basic layout

of the system.

Thus, the main task of the designer will be to decide which of the 30 different combinations of kitchen and bathroom facilities are to be used on his

project, i.e., to judge which of the solutions will prove least expensive. To

do this, all that he needs in addition to details of cost of materials and

labor are the data found in the catalogue and on the plans. The standardized

design also makes it easy to establish unit prices for different parts of the

system. These cost data can of course also be fed into the computer and be

154
coordinated with the program used to produce the dimension tables. It would

also be possible to correct these without delay, should changes occur in the

cost relations between different components.

Admittedly, the system is based on the principle of a duct plus flexible internal pipework. However, the results obtained do not necessarily require

this arrangement. Hard pipes can be used and installed in slots in walls or

made replaceable by some other means. The general version of the system

calls for the use of two special distributors. However, in two-storey buildings, it is better to use T pipes instead of individual floor distributors.

In buildings with basements, the ground-floor distributors (TF) and branch

pipes (TL) can be suspended from basement ceiling and the distributor can be

replaced by a T pipe under certain conditions specified in the catalogue.

The system is thus to all intents and purposes a system for dimensioning and

design. In other words, it is an open system unrestricted by the need to use

special materials and components. Both the distributors can be purchased

separately. As all appliances, with the exception of WCs and washing ma- chines, are assumed to be fitted with flow regulators, it is also possible

to use pipes and fittings offering less resistance to flow than that specified in the dimensioning tables. The same, of course, applies if facilities

served on a given floor are fewer than the number assumed to permit the use of a particular dimensioning table.

The tables assume a maximum pressure drop in tap fittings and flow regulators

of 50 kPa. Anyone requiring a fitting producing a greater pressure drop can make corrections for that difference by reducing the working pressure before

the water reaches the ground-floor distributor by the same difference. Similar

corrections may be made if the storey height is in excess of 2.7 m.

Comments

Tests of components carried out in conjunction with the development work have

shown that there is ample scope of designing cheaper installations. A few

examples are given in Figure 11.

kfia S00- —— ; ;

5 10m 11 15 18 11 IS rum qj o.l Crt Fiqure 11 Pressure in pipes, components and fittings

The diagram illustrates systems of pipes represented by three pipe dimensions.

They are given as equivalent lengths of pipe. The length of pipe can then be

compared to the required pressure and the cost associated with it. Surplus

155
pressure makes it possible to reduce the costs by decreasing the dimensions.

Secondly, we can see that components with the same function have different

requirements regarding pressure and therefore affect costs to differing ex- tents. Smaller pressure drops in components permit a reduction of dimensions.

Thirdly, the pressure requirements refer to fittings in use today. The diagram shows the scatter found at present. Pressures of less than 50 kPa (the

value specified in the regulations) apply for only 22 percent of the fittings

tested. The marked scatter makes it difficult to design installations satisfactorily. Large gains stand to be made here.

Figure 12 illustrates the approach from the technical and economic points of

view. Pressure and costs are parameters used on the x and y axes respectively.

Kroner

1000 -mFigure 12

Principle governing solution from the technical and economic standpoint

The systems represent the dimensions 28, 22, 15, and so on. Cost curves are inserted into this diagram to represent different systems of pipes of equivalent worth. The diagram shows that higher pressures mean smaller dimensions

and a saving of between 100 and 150 Swedish kronor per unit.

Work on the system has thus shown quite clearly that high pressure is of eco- nomic significance. A similar effect would be achieved if the regulation

flows were to be reduced. In Sweden the regulations state that bath fittings

should produce a flow of 0.*» 1/s, while shower fittings need only produce

half of that. The high figure specified for bath fittings can be questioned.

As Table 2 shows, the regulations for bath fittings force the pressure re- quirements up by 200 kPa or more, something which has marked economic conse- quences .

I The BPA system also gives us reason to question the suitability of fixing a regulation flow for each individual fitting. It is this which lies behind
Table 2

The BPA Plumbing System

Necessary working pressure (P) in part of pipe immediately preceding the

central ground-floor distributor (TF) to permit the use of bores of less

than 20 mm in the basic structure of the system installed in three-storey

buildings (low-pressure alternative) when the branch pipe (TL) has a length of 12 m.

Combinat ion of faci 1 it ies P

1 bathroom 410

1 bathroom + 1 separate shower 490

1 bathroom + 1 kitchen 460

1 bathroom + 1 separate WC 460

1 bathroom + 1 kitchen + 1 separate WC 500

1 bathroom + 2 kitchens 530

1 bathroom + 2 separate WCs 510

2 bathrooms 520

2 bathrooms + 2 separate showers 650

2 bathrooms + 2 kitchens 590

2 bathrooms + 2 separate WCs 590

2 bathrooms + 1 kitchen 570

2 bathrooms + 1 separate WC 570

1 shower 210

1 shower + 1 kitchen 240

1 shower + 1 separate WC 240

1 shower + 1 kitchen + 1 separate WC 260

2 showers 300

2 showers + 2 kitchens 350

2 showers + 2 separate WCs 350

1 kitchen 200

1 kitchen + 1 separate WC 210

2 kitchens 210

2 kitchens + 2 separate WCs 300

1 WC 200

2 WCs 200

the 5^ variants found in Table 1. When flats are fitted with their own water

meters for hot water, each home will as a rule also have its own connection

to the rising main. It should be possible to fit this connection with a regulator, just as in the case of tap fittings, etc., to avoid unnecessarily large

flows. It would then be reasonable to instead establish standard values for

pressure and flow at junctions to individual flats. This would reduce the 58

variants to a single table.

157
These measures, and others, would together reduce water consumption and

necessary investment. A development in this direction raises a large num- ber of questions. Would a reduction of water consumption make it possible

to treat waste water in the building itself or at least in the housing area?

Will water volumes become so small that it will be possible to heat water

locally in taps and thus eliminate the need for a separate hot water system?

What will the consequences be in terms of alternations and repairs; are the

existing pipes, if they can be used, too large from the economic standpoint

or can the unnecessarily large flows be neutralized by flow regulators?

Finally, a few words about municipal water mains and sewerage systems. Figure 13 shows a cross-section through the water source and water tower and

Figure 13 From water source to recipient

up to the sewerage treatment plant and recipient. I have included a building

in which incoming water is used and converted into waste water. It is

assumed that the volume of waste water will be identical to that of the fresh

water used in the building; this is also probably true in general, although

few field measurements are available on the subject. If the building consumes

a smaller amount of fresh water, the level in the water tower should remain at

a more stable and higher level, while the amount of water at the treatment

plant should decrease—at least in principle. I have three remarks to make on

this.

Within the systems of water supply found in Sweden today, the authorities are only in a position to 1 imit the amount of water used by households in times of

crisis. The means "avai 1 abl e are far too clumsy to permit application of such

restrictions on a permanent basis.

158
Flow regulators fitted to all taps and water meters in all homes provide administrative and economic means—taxes, rationing, progressive tari ffs--which

can be adjusted according to the size and needs of individual households and

given consumers the opportunity to decide for themselves how and when they

want to save water. Flow regulators and water meters provide the community

or the water authorities with scope for developing civilized means of influencing water consumptions, even when supplies are normal. It is even possible

to say far in advance with the aid of forecasts and expansion plans when or in

what situation the authori ties. expect that cuts will be necessary in water

consumption and what such measures may involve.

The prospects of being able to control water consumption within certain limits

make it worthwhile discussing how a reduction in consumpt ion--at least in re- lation to forecasts —should be made use of. Should the waterworks maintain a higher and more even pressure and perhaps even install pumps for increasing

pressure in situations where this is at present considered unnecessary? Since

higher pressure reduces the cost of pipes in a building, the charge made for

connection to the mains should perhaps be made dependent upon pressure. Or

will studies and experience of measures to cut consumption produce entirely

new solutions to those offered by available methods to guarantee domestic

water supply?

Lower water consumption may entail a risk of blockages in waste water systems,

while at the same time resulting in smaller volumes at treatment plants. The

first of these two possible consequences is undesirable, while the second is

advantageous. However, there is an element of uncertainty in both statements.

We know very little about how much water, and what, runs through the municipal

drainage systems. We do know, on the other hand, that much of the waste water

leaks out of the pipes and that large quantities of groundwater find their way

in. In collaboration with the National Environmental Protection Board, the

plumbing laboratory is planning a series of flow measurements and analyses of

contents of municipal sewage.

Acknowl edgements

The work of preparing this review formed part of the Research Program of the

plumbing laboratory belonging to the National Swedish Institute for Building

Research. The systems and products described have been developed by Swedish

construction companies and industrial concerns. Ingemar Wolff headed the

team responsible for developing the BPA system. Tests carried out at the

plumbing laboratory were directed by Lennart Lindvall.

159

Production, Transport and Use of Hot Water

by

Francois Perrier, C.S.T.B.

Station de Recherche de Champs, France

I ntroduct ion

The sudden rise of oil and other combustibles' prices which had taken place

by the end of the year 1973 led to the so-called "energy crisis".

In order to cope with this crises, a lot of countries have been induced to

undertake studies and research in order to find means of saving energy. As

far as the building is concerned, projects have been waked ou. in three direct ions

:

- thermal isolation;

heating; and

service hot water.

The reader will find in this report some indications about the research which

is now proceding or foreseen in France in the field of service hot water.

Account of the Problem

Two main research lines have been foreseen:

- on about the present techniques, the purpose of which is starting from

a better knowledge of these techniques to improve them, and to bring

about, among other things, energy savings; and

another one about new techniques, the purpose of which is starting from

non- or little-used energy sources, to find new ways of producing ser- vice hot water.

For reach of these two research fields, studies have been worked out in three

di rections:

production of service hot water;

transport and distribution of service hot water; and

use of service hot water.

The studies. must be worked out always keeping in mind the user comfort. Indeed, it would be of no use to bring about highly satisfying solutions as far

161
as energy savings are concerned, without being able to meet adequately the user needs in terms of service hot water.

Present Techri fques

Energies

According to the presently used techniques, the energies to be taken into

account are the "classical" energies such as:

coal ; - oil (fuel )

;

- gas; and

electricity.

Product ion

The study connected with hot water production includes two parts which are related to:

- production means

individual or collective,

with or without storage; and

- hot water production devices.

1 . Product ion Means

A. Individual or collective production

In individual nouses, the hot-water production is itself more often

individual too, i.e., it is operated at a scale of a single-dwelling

house.

In industrial or collective buildings (schools, hotels, barracks,

hospitals, etc.) this production is central and collective.

- On the other hand, both production ways (collective or individual)

may be used for residence buildings or groups of buildings.

The problem which claims our attention in that last case is to know

which are the advantages and drawbacks of each of these solutions, in

order to determine if any one is better than the other and, in the

affirmative, which one?

The choice of any of these solutions is difficult because each one

has got its advantages and drawbacks.

First point to be taken into account is the energy source because,
depending on its kind, the conclusions may be different.

From that point, the problem is to be regarded from three points of

view:

- the financial aspect

installations cost

exploitation cost (consequently the idea of total cost [installation + exploitation])

- the energetical aspect (consumptions) which has itself its financial aspect; and

- the comfort aspect.

The installation cost depends on the chosen device. It will be therefore necessary to check whether, comfort being equal, the installation

of a collective production is more or less expensive than the installation of a great number of individual installations. It will be

necessary to consider the special case of common hot water and heating

product ion

.

The exploitation cost depends on the energy price, on the maintenance

cost (including the cost of replacing material) on the flow-metering

device, and so on. The determination of this cost is very important

because it is probably nearly the same for both means of production

with, maybe, a little bit less expensive for individual production.

The energetical cost depends on the kind of energy and also on the installation: the efficiency of a collective installation is probably

somewhat lower than the efficiency of an individual installation.

The comfort aspect is the most difficult to take into account because,

depending on each person, it is very subjective. Therefore, it will

be necessary to make investigations on the satisfaction of the users

in order to have a better knowledge of their needs. In fact, provided

that they meet these needs, both kinds of installations (collective or

individual) may be used.

Therefore, it can be seen that, depending on the considered aspect, a solution, or the other one *«' f ll be the best one.

To make a choice between these two solutions, it is necessary to draw

up the total balance. This study may be worked out in a certain number of existing installations, the conceptions of which are different:

for each of these installations, the test solutions will be found out,

and starting from these data some general rules will be defined.

With or Without Storage

Among the individual or collective production devices, two main types

163
may be found: , instantaneous heaters-, and

- accumulation heaters.

Tne water heating in instantaneous, heaters is supplied as water is

drawn. The water heating in accumulation heaters does not depend on

j the drawing, for they hold a water reserve more or less important,

which is heated at any moment by a heat-spring. Some other devices

that could be called "semi- instantaneous heaters" are also used,

mainly in case of almost unbroken drawing. Nevertheless, these

heaters hold a small water reserve, the purpose of which is to regularize the hot-water temperature.

The problem that then claims our attention is to know what sort of

device is the more convenient for a given installation.

As before, the first aspect to be considered is the kind of energy.

Indeed, using some kinds of energy (gas, for example) , the choice is

possible, but not when using other kinds (electricity) : an instanta- neous electrical heater Is rarely used except in the case of little

flow rate and little power heaters.

Other aspects to be considered are, as has been said before, energetic, financial, and comfort.

The comfort aspect is here still very important. Indeed, the user

is waiting that his heater give him water at the right temperature

(at a reasonable rate) at the right moment and at a reasonable cost.

This aspect will therefore be considered firstly for the choice of

a heater. Nevertheless, the financial (total cost) and energetical

aspects shall not be ignored.

Studies may be worked out in this field in order to point out—depending on the kind of installation —which type of device is the

most adequate. For that reason, the type of hot-water production

(individual or collective) as well as the user requirements —neces- sary quantities, instant flow rates, optimum frequency, etc. (see

"Use") —must be taken into account.

2 . Hot Water Production Devices

Depending on the production kinds —individual or collective, instantaneous or with storage—different sorts of devices are used.

In France, the following distinctions are made:

Individual production:

instananeous

:

164
- water heater

. gas (P = 125 rath/mi n)

. electrical (P < 10 KW)

bath heater

. gas (125 < P < 400 mth/min)

- distributor

. gas (P > 400 mth/min)

. with accumulation (gas, electricity...):

accumulator (heating body is inside of the tank)

with free flow (not commonly used)

under pressure

preheater (independent tank)

double-purpose devices (heating + hot water).

Collective production

boilers (coal, fuel, gas) coupled with hot-water vessels;

heat exchangers, the heating fluid of which is coming from

outside: hot water, superheated water, steam; and

mixed generators (hot water + heating).

The relevant problem (without speaking of the type of device which choice

results from what has been said above) is the problem of the fitness for

employment of these devices, i.e.:

- mechanical and hydraulic characteristics, materials quality;

consumptions, efficiency;

behavior in service, and especially reliability, scale formation

faci 1 i ty

;

- characteristics of outlying security and regulation devices: safety

unit, thermostate, temperature regulation, etc.

The knowledge of devices' performances will thus allow the setting up of

standards for fitness for employment, and allow the user to choose the

best device connected with a determined use.

ransport and Distribution - Installation

. Individual Production

At the level of individual production, few problems are set by the transport and distribution.

- The heaters providing a single drawing point must be settled as near as possible from this point; and

165
- The heaters providing more than one drawing point must be settled

as near as possible from the point where small and numerous drawings are likely to occur (in order that the cold water volume which

flows at the beginning of the drawing be as little as possible).

The choice of heater location must not therefore require any particular

study.

The distribution pipes should therefore be as short as possible. Their

diameters must be designed so that the hot water comes rapidly to the

user.

The diameters of heating fluid supply canalizations (essentially gas)

must be designed as well in sympathy with pipe lengths and heater kind

(instantaneous or with accumulation).

Studies may be worked out in that direction to design the optimum dimension of pipes in sympathy with the parameters enumerated above.

As far as the installation is concerned, the object of the studies will

be:

installation security;

premises ventilation (gas); and

sizing of flue gases ducts.

Collective Production

The problems of transport, distribution and installation are here much more numerous.

A. Transport

The long-distance transport is required when the hot water or the

heating fluid (case of exchangers) is coming from a central production supplying several buildings.

The problems then depend on the kind of ducted fluid —steam, overheated water, hot water (without speaking of tepid water, which will

be studied later on).

The studies required by these problems concern:

the kind of pipes materials, with account to the ducted fluid

(corrosion, mecanic resistance);

- the pipes' diameter with account to their length, their rates or their speed;

the dilation components;

the pipes working up: overhead, underground, in gutters, etc.

166
the canalizations' insulating: protection of external surfaces

against corrosion;

- the pumping systems, etc.

Distribution

The first relevant problem is the trace of the d i str ibut ion system . Two systems —arterial and ring —may be used:

(1) Arterial System

In this system, the water does not flow through pipes beyond the

drawing periods. Generally, each system supplies a group of

dwellings one above another. The advantages of this system are

the following: the different distributions do not depend on each

other, con cerning pression and rate. The hot water metering

may be operated for each dwelling. The most important drawback

is that the pipework must be cleared of a certain amount of cold

water before the user may get some hot water.

(2) Ring System

In this system, the hot water flows continuously in the canalizations. This system enables the user to get hot water at the very

moment of the drawing, which cust out the wastings.

On the other hand, greater lengths of pipes are needed (hence, some problems during the installation working up), and heat los- ses are more important since the pipes are warm constantly.

The second relevant problem is the distribution systems conception,

and especially the cetermination, for each system (arterial or ring)

of the number of drawing points to be supplied with hot water. This

choice may depend on the building conception and especially on the

opportunity of setting up systems. It may depend too on comfort.

For example, an arterial system allows the use of two distribution

systems for each dwelling —one which supplies the kitchen with 70°C

water, and another one which supplies the bathroom with *tO°C water;

this water is coming from the same distribution, its temperature being pulled down using, for example, a "mixed thermostatic tap".

The third relevant problem is the hot water circulation type . Two

solutions are used:

the thermosiphon circulation which settles itself through the

difference of density (depending themselves on the temperature

drops) between the outward and back pipes; and

the pump-driven circulation, which is a forced circulation.

These different problems put forward the pipe insulating problem , the

importance of which depends on the chosen solution. Taking no account

167
of the insulating stuff quality and efficiency, whose determination

| requires a purpose-made study, it is important to know whether the

savings that result from the heat losses cut down, can make up for

the insulating costs.

The pipe insulating is recommended for arterial systems. In thermosiphon-driven ring systems, the outward pipes may be insulated. On

the other hand, it is not recommended to insulate the back pipes in

order to let the heat losses happen and so embody the water to circulate. The pump-driven installations may have their whole pipes

i nsu 1 ated

.

The last point that must not be forgotten is the water itself (the

kind of which requires a lot of special studies). Indeed, a lot of | disturbances arising from corrosion or scaling, or both, have been

recorded in pipes and devices. Therefore, the kind of ducted water \ must be taken in account when designing and working out an installation, especially as far as pipe materials kind, devices designing,

water treatment installation and pipes blow off are concerned.

To sum up, the installation of hot-water distribution systems sets a ij lot of problems, some of them, badly known, are requiring studies,, \ These studies are intricate because it does not exist a single world- i wide solution, but many depending on: i the building importance;

y its kind (one- or mul t i-storeyed) ; and

the utilization: continuous, intermittent, etc.

In all the cases, the choice of the solution will depend, comfort be- I ing equal, on the balance between the cost of each installation kind

and the connected hot water savings.

Use

I In the present service hot water production and distribution installations,

some inefficiencies are often reported by the user. These inefficiencies

are depending on the above checked-off problems.

5 For instance, according to the distribution kind, an instantaneous production » will induce an unsteadiness of the tapping temperature, a drop in the medium j temperature during peak periods, pressure drops, etc. An accumulating produc-,

tion will induce an important drop in temperature after a tapping period and

temperature fluctuations during daytime,, |i

\-. "i

1 fw no rvv ruo t .' .

' : nc*n(j-»x or*' : - i These drawbacks may be overcome by using overdesigned installations, which

leads of course to higher exploitation and installation costs. This solution

is nevertheless chosen often because of the lack of information about the inhabitants' consumption and the time repartition of these consumptions.

The problem that has to be solved, then, is to know precisely the amount of

I

I 168
hot water requi red by the users. This may be known through a two-step

study:

- Field measurement of hot-water consumption (instantaneous or average)

on different levels: on device (sanitary or domestic), in apartment,

in building and, on occasion, in group of buildings. In order to take

into account the sanitary equipment, the family composition and the

social classes, measurement has to be performed in different classes

of apartments or buildings.

Investigation about the satisfaction of the inhabitants in order to

know their hot-water requirements.

Starting from these data, a statistical-type procedure taking into account

the building characteristics and the foreseen way of living may be laid

down so as to enable the designer to choose more accurately the hot-water

production and distribution types. It will provide too the basis required

for the installation calculation.

The hardness of such studies is due to the subjectivity with which the user requirements are defined. Indeed, a lot of them are satisfied with what they

have, either because they had less before, either because they ignore they

could have more. These investigations must therefore be carefully laid down

and conducted; the resulting data must be cautiously read.

The investigation subject will be mainly threefold:

- the temperature , to point out which values are the most suitable to a defined purpose, and which variations may be allowed;

- the flow rate , in order to give information about the flow rates granted

at teach tapping point (sink, wash basin, bath, shower, etc.); and

- the volume or mass , in order to make it possible to calculate the bestdesigned storage tank volume, particularly in accumulation installations .

Among these notions, the temperature at the drawing point must be especially

taken into account for the installation design. The best value of the water

temperature is, as it has been seen before, related to the utilization type:

it may be, for example, 35°C for a shower or a bath, kO°C for a basin, 70°C

or more for a sink.

Different solutions may therefore be considered:

- A single high-temperature system, the lower of the temperature is obtained through cold water addition or mixing. This solution may not be

reasonable, for example, in the case of a thermos i phon-driven ring

system, because it will give rise to important heat losses;

- A single low- temperature system; an independent heat production will be

169
then required in the kitchen; and

- A low-temperature system and a high-temperature system, which will give

j rise either to a double heat production, or to a single one, the temperature being then lowered on one of the two systems.

On the other hand, the water temperature must be bounded to prevent scaling,

heat losses, etc. This will make it necessary to study temperature controllers

The last point to be taken into account is the hot-water metering problem. Thi

problem has become recently very important, according to new regulations be

prescribed in some countries (with some restraints which will reduce the numbe

of solutions). This will lead to studies on the metering device itself and on

its installation (mainly in the case of collective systems).

Till now the hot water was invoiced either as per contract, either in connection with the number of inhabitants, the housing area ... or with position

water meter readings (without any record of the temperature), etc.

In future, efforts should be directed towards other metering devices such as:

- "calor imetr ic" metering which, by taking into account both the flow rate

and the temperature, makes it possible to know the heat amount delivered

(These devices must be improved because they are presently much too intricate, expensive and unreliable.)

"flow rate" metering, which allows the recording of the quantity of

water used up, but requires, on the other hand, the steadiness of the

hot water temperature (hence, a storage process and an improved regulation). A lot of researches must therefore be performed in that field in

order to perfect accurate, reliable and unexpensive metering devices.

The installation of these devices must be studied as well.

In arterial systems, the problems may be solved while equipping each dwelling

with a flow meter; in the case of a double system, it comes then cheaper to

settle the low-temperature system downstream of the metering device, thus saving a metering device. In ring systems, the solution depends on the system

geometery. In some cases, however, there is nearly no solution. (For example

a flat where different supply pipes start from the same ring system.)

Comments

To sum up, a lot of problems (related to production, distribution and use of

hot water) are still to be solved, even in the standing installations.

These problems are not new, and no care of them had been taken so long because

energy was inexpensive. Now the main thing is to solve these problems because

of the sudden rise in energy prices, and also becuase solving these problems

may help to improve the design and the realization of the installations (in

order to reach, all things considered, to an improvement in user comfort).

170
Jltimately, we must keep in mind that these studies are difficult because

they require the use of a great number of parameters which are all depending one on another.

New Techniques

Energies

Because of the rise in energy prices, the use of unemployed energies till

now has (or is going to) become worthwhile. These new energies are mainly

the so-called "free energies", because they are issued from natural sources —sun, wind, underground, etc., or from an industrial by-product. Among

these energies, the more interesting seem to be:

- solar energy;

- geothermal energy (not sources coming from Earth underground); and

energy recovered from power stations and industries (residual waters).

Other energies may be mentioned too:

energy recovered from building sewage waters, and

- wind energy (for some countries).

Solar Energy

Use of solar energy is advisable only in the districts where solar contribution is important during a great part of the year. The solar collectors'

problem must be examined first. The influence of the collector position on

its efficiency may be studied: orientation (horizontal, vertical, kS° angle),

position referring to the sun, ground nature (more or less reflecting), etc.

The hot water production is the second study to be carried out.

These systems are usually connected with a heat exchanger; it will therefore

be of no use to study anything else than the collector circuit and the

accumulator (tank, etc.) since downstream of the accumulation we come back

to classical solutions.

Because solar energy is not continuously available, it will be reasonable to

plan either a storage mean or a contemporary (classical energies-derived) heat

production. The balance between gross cost (installation and maintence) of

such an equipment and the energy savings (in comparison with a classical system) will allow to calculate the cost of such an apparatus.

Geothermal Energy, "Recovered Energy

Characteristics of such energies are mainly:

171
the temperature of the heat ducting fluid (water, in most cases) is

relatively low: 30°C to 70°C (geotherraal energy) and about 30°C (power

stations recovered energy); and

- the flow rates of this same fluid are very important (up to about 100,

200 m3/h).

Accordingly, the following problems, which are related to transport as well

as to utilization, must be studied:

1 . Product ion

The study of these two energies' production does not take place in this

report. The geothermal energy production concerns mainly the two pits'

(extracting and reinjecting pit) boring. The recovered energy concerns mainly the residual waters which otherwise would be thrown back to the

r i vers

.

2. Transport

The problems to be solved are technical and economical:

On a technical point of view, the transport of huge quantities of

water over very long distances is the main problem; it requires

study on the following points:

pipes: diameters (some meters) and kind of materials;

putting in practice: aerials, buried or in gutter pipes (and,

should the occasion arise, insulating stuff);

expansion joints;

pumping devices, etc.

It must not be forgotten, either, that most of the ducted waters are

often most mineralized.

On an economical point of view, the balance striking will help to fix

the greatest economically speacking distance between the production

and the utilization point.

3. Use

The problems connected to the use are mainly dependent on the water

temperature:

should the temperature be high enough, the hot water utilization is

then directly possible;

- should it not be the case, the hot water utilization is possible after

a reheating (provided by a heat pump, for instance); and

in other cases, it will be necessary either to contrive both the previ ous solutions or (should the tepid water be unable to meet the whole

172
requirements) to plan a complementary classical hot water production.

As noted elsewhere, the strong mineralization of the water must be taken

into account. This will influence the choice of equipment and pipe materials, and will probably require a specific water treatment.

On an economical point of view, as it has already been said, the balance

will be struck by comparison between the great cost of a "classical

energy"-dr i ven installation and a "free energy"-dr iven installation.

pmments

he very kind of energies mentioned in this report prevents the extension of

heir use to a whole country. Indeed, solar energy shall not be used in

oorly sunshined districts. Likewise, geothermal and recovered energies may

nly be utilized in places close to the production points (pits, power staions , plants)

.

ence, it follows that the studies will be the more often about peculiar cases,

ccording to the great number of parameters to be taken into account, it will

e difficult to set up general rules. However, such rules may be set up as far

s some points are concerned. For instance, for geothermal waters, it should

e possible, depending on the various temperatures of the water coming out of

he pits, to set up the greatest distance between the pit and the utilization

oi nt.

inally, the object of the present report is mainly the "service hot water"

se; it must not, however, be forgotten that in most of the cases this water

ill also be used for heating purposes.

Concl us ion

he object of the present report was to point out some problems relevant to

he use of classical and new energies.

t must not be regarded as a comprehensive study. For instance, some aspects

ay have been studied in some countr ies and ignored in this reporto

t is therefore necessary that all the research institutions should acquaint

he CIB W-62 with the nature of these works, and the already obtained results.

n particular, it would be most important to know the conclusions of the inestigations performed about the user's requirements, since the choice of a olution is first dependent on a better satisfaction of these requirements.

173
I

I

I

I
PERFORMANCE REQUIREMENTS

FOR TAPS: A CONSENSUS FROM SCANDINAVIA

by

Viggo Nielsen

Definition and Fiel d of Appl ication

The present performance survey comprises water fittings being connected to

hot- and cold-water supply system which, by order of the consumer, can be

made to attend to one or more of the following functions:

to supply or to cut off the flow of water;

to adjust the water flow to a desired rate;

to supply water of a desired temperature; and/or

to supply a water flow in a specified direction and with a specified

jet characteristic.

Sanitary taps are a very big group of components with different functions,

but also with many common features. This performance survey covers all dif

ferent types of taps and, therefore, all requirements are not relevant for

all taps. In the performance survey it is possible to find the characteris

tics that are relevant to a specific purpose.

This survey is preliminary, for use in connection with water-supply systems

in dwellings, but it can, without essential alteration, be used in other

building categories as well.

Propert i es

1. Tightness against static water pressure.

2. Tightness relating to maneuvering and closing operations.

3. Regulation of water flow.

k. Regulation of water temperature.

5. Suitability of the jet direction.

6. Suitability of the jet character„

175
7. Flow resistance.

8. Stability of flow and temperature.

9. Noise conditions.

10. Cleanabi 1 ity.

11. S impl i ci ty in use.

12. Chemical and physical stability.

13. Susceptibility to bacterial growth.

]k. Surface conditions.

15. Protection against scalding.

16. Heat insulation property.

17. Reliability.

18. Durability, inside resistance.

19. Durability, outside resistance.

20. Mechanical strength, inside.

21. Mechanical strength, outside.

22. Ag i ng durab i 1 i ty

.

23. Compat i b i 1 i ty

.

2k. Working characteristics.

Tightness Against Static Water Pressure

General Requirements

The top and the connection to the water supply system must be tight against

the available water pressure. This should apply for normal use as well as for abnormal, but foreseen circumstances as strokes from outside and variations in the water pressure.,

Proposed Degree of Fulfillment

The tap and the connection to the water supply system must be tight against

a water pressure of 1600 kN/m2, when it is closed by means of a force of 30 N and 1.5 Nm respectively at rotary motions. The water tightness must be maintained during, as well as after, the tests described in "Mechanical strength",

Test i ng

The water fitting is mounted as prescribed by the producer and/or according to

normal practice on the test pipes being relevant to the water fitting in question. The water fitting is fully opened. The pressure in front of the water

fitting is adjusted so that the water flow through the water fitting corresponds to the water flow adequate to the water fitting.

176
The operating device of the water fitting is closed by means of a force of

30 N and 1.5 Nro respectively at rotary motions. Through the water supply

the water fitting is exposed to a pressure of 1600 kN/m2 .

The testing procedure is described in section 7.3.1 in paper (1) in the ref- erence list.

Judgment

No leakage during or after the tests should be found.

Tightness Relating to Maneuver i ng and Closing Operations

General Requirements

The tap must not cause any unintended penetration of water when it is closed

against the available water pressure with a closing force which is in accordance with the possibilities of the user. If the tap has more than one outlet,

the flow of water must only occur through that outlet which is intended for

use. If the tap is equipped with inlets from different water supply systems

(normally cold and hot water), it must be constructed in such a way that

water cannot overflow from one system to another--nei ther when the tap is in use nor when it is closed.

Proposed Degree of Fulfillment

The tap must close tight against a water pressure of 1600 kN/m2 after having

been exposed 100,000 times for opening/closing operations where the closing

has been done by means of a force of 30 N and 1.5 Nm respectively.

If the tap has outlets through a multi-way valve, it must, when drawing off

water from one of the outlets, close tight against a water pressure of 250

kN/m2 for the outlets that are not in use.

Taps designed to be connected to two water supply systems must prevent over- flow from the one system to the other with a pressure difference of 1000 kN/m^

when the tap is closed and a pressure difference of 100 kN/m2 the drawing off

water takes place.

Test i ng

For the tests is used an apparatus being able to open and close the operating

devices of the water fitting about 20 times per minute. The closing mechanism

can be adjusted so that the tap is closed by means of a force of desired value.

The method is described in section 7.^.1 in (1).

The tap is opened to draw off water from one of the outlets, and then this outlet is blocked by a plug or the like just at the outlet opening. After this,

the tap is subjected to a water pressure of 250 kN/m2

, and it is recorded where

there is any water flow from the other outlets. The same procedure is carried

out for all the outlets.

177
Water taps designed to be connected to two water supply systems (hot and cold

water) are mounted so that the hot water inlet is connected to a hot water

supply system (75°C ± 2°C) , and the cold water, inlet is connected to a cold

water supply system (5°C - 20°C).

At a pressure of 50 kN/m2 on the cold as well as the hot water supply system,

the water fitting is fully opened. The temperature of the cold water T^ and

the temperature of the hot water Tv are recorded (within ± 1°C). The pressure;

of the cold water system is increased stepwise by 10 kN/m2 until a pressure ofl 100 kN/m2

. The pressure as well as the temperatures, T|< and Tv , are recorded.,)

The above procedure is repeated at a constant pressure of the cold water supply system and a pressure of the hot water supply system increasing from 50

kN/m2 (0.5 kp/cm2 ) to 100 kN/m2 (1.0 kp/cm2

)

.

During both tests in question, it is examined by means of the temperatures

recorded whether an overflow from one side to another is taking place.

Judgment

Unintended water penetration must not occur. 100,000 opening/closing operations correspond to 10-years use in a dwelling house.

A few drops are permitted.

No overflowing must occur when the tap is closed, and the pressure difference

is less than 1000 kN/m2 .

j]

No overflowing must occur when the tap is opened for water supply from both

systems and the pressure difference is less than 100 kN/m2 .

Regulation of Water Flow

General Requirements

The tap must be constructed in such a way that the user can chose and, within reasonable periods of time, regulate the tap to supply just that flow of

water which is desirable for the purpose with the draw off.

Proposed Degree of Fulfillment

Information which makes it possible to judge the taps' suitability to a certain purpose must be available. For taps with manual regulation of the flow

of water, at least a graph showing the flow as a function of the maneuvering

movement must be available.

Test i ng

The tap is mounted in a test set-up where a constant pressure can be maintained. The pressure is adjusted until the maximum flow through the tap is

equal to the suitable flow for the tap. This flow depends on which purpose

178
the tap is intended for. The suitable flow is indicated in (1) supplementary

sheet D.

The flow through the tap is by means of the operation devices adjusted so that

the flow is about 15, 30, 50, 70 and 100 percent of the suitable flow. The

measured values of the flow are registered on a graph as function of the movement of the operation device. If the maneuvering is a circular movement as well, the angle as distance travelled by the device must be indicated.

Judgment

Subjective judgment.

At the moment no criteria exist on how a suitable regulation characteristic

of a tap for a certain purpose must look alike. It is desireable that the

relation between the value of the waterflow and the movement of the operation device shows linearity.

Taps which have a rotation movement on the operation device must give maximum

50 percent of the suitable flow of water when 50 percent of the movement of

the operation device has been done.

Regulation of Water Temperature

General Requirements

The tap must be constructed in such a way that the user can choose and, within

a reasonable period of time, adjust the tap to supply water with exactly the

temperature that is desirable for the purpose with the draw off.

Proposed Degree of Fulfillment

The tap must, in a simple way and within a reasonable period of time, supply

water with a temperature of deviced value. The accuracy of the temperature

has to be ± 1°C.

Test i ng

The accordance between the temperature scale and the temperature of the water

is checked while the tap is mounted in a test set-up where it is supplied with

water as recommended by the manufacturer. If the tap is not equipped with a temperature scale, it is not possible to test the regulation characteristics

of the tap in a simple way. The testing mentioned below can make a basis for

a relative judgment of the possibilities for adjustment. Taps constructed for

mixing of hot and cold water are mounted in a set-up and supplied with cold

water (20°C) and hot water (60°C) with a pressure on both hot and cold water

of 300 kN/m2. The operation device on the tap is adjusted to a position where

the flow of water is 15, 30, 50, 70° of 100 percent of the flow which is obtained when the hot water supply has maximum values in temperature and flow.

At each of the above-mentioned flow of water the tap is adjusted to supply

water with temperatures of 30°C, k0°C and 50°C.

179
2 2

All measurements are repeated with a pressure of 200 kN/m and 100 kN/m on the hot water system and 300 kN/m2 on the cold water system. For each set

of values for temperature and water flow, the position of the of the operation device is described as mentioned in the previous section. If the position of operation device can be described with two parameters, these are used

as abscissa and ordinate in a graph where waterflow and temperature are described with level curves.

Judgment

Subjective judgment.

Remarks

If the temperature regulation is obtained in another way than mixing two

water flows with different temperatures, other test methods are required.

If the tap is equipped with automatic control device for maintaining the

temperature, it is desireable to know how fast a new temperature on the water

is obtained when the operation device for temperature is moved.

Taps designed for mounting on gas- and electrical-heated water-heaters must

work sufficiently also when the pressure difference between hot and cold wateri

supply is 200 kN/m2 .

Suitability of the Jet Direction

General Requirements

The character of the jet direction must be appropriate as to the application

of the tap.

Proposed Degree of Fulfillment I

l The character of the jet direction is not only dependent on the tap but also

on the placing of the tap. The optimal jet direction depends partly on the

function the tap shall fulfill and partly on the other components that are

used during the fulfillment of the survey function. Information about the jet;

direction described as the angle between a vertical line and the outer line of

the jet with that or those placings for which the tap is constructed.

Taps with adjustable jet direction are described as mentioned above in the

whole range of variability. Taps with more than one jet are characterized

with the angle between the perpendicular and the jet.

Test i ng

The tap is mounted as prescribed by the manufacturer. The angle between the

jet and a vertical line is measured on photos of taps with flows on 70, 100

and 150 percent of the flow suitable for the tap.

180
Judgment

Subjective judgment.

Ninety-five percent of the water from the tap must hit a plate 300 mm from

the tap within a circle with a diameter of 50 mm. None of the water must

hit the plate outside a circle with a diameter of 150 mm.

Suitability of the Jet Character

General Requirements

The character of the jet must be appropriate as to the application of the

tap.

Proposed Degree of Fulfillment

Criteria for the optimal character of the jet to a certain purpose are not

available. The character of the most normal jets can roughly be described

as: (a) heavy, coherent jet; (b) coherent, airy jet, and (c) many separated

jets.

For each of the possibilities, the following information must be available:

(a) the areas of the cross section in the jet and the velocity just after

the outlet.

(b) as (a). The mean velocity in the jet will, in this case, not characterize the velocity of the particles because of the airy water. The

smaller the calculated velocity is, the more airy is the water.

(c) the number of jets, the area, and the mean velocity of the single jets.

Test i ng

The tap is mounted as mentioned in the previous section. The area of the cross section in right angle to the jet direction is determined by measuring on a photo of the tap and jet. The mean velocity is determined by measuring the

j flow. The flow is determined with the pressure adjusted so that the water flow

through the tap is equal to the suitable flow for the tap in question.

Judgment

Subjective judgment.

Flow Resistance

General Requirements

The tap must have a flow resistance of such an extent that a water flow adequate to the purpose is obtained when the tap is fully opened.

181
Proposed Degree of Fulfillment

As the pressure of the supply system where the taps are used may vary within

wide limits, the water flows do not depend on the tap only, and so it is not

possible to prescribe definite numerical requirements to the hydraulic resistance of the tap.

To ensure that when dimensioning the hot and cold water supply systems, the

tap can be chosen correctly as to the pressure of the supply system and the

water flow desired, information must be available of the hydraulic resistance

of the water fitting in fully opened position.

Test i ng

The tap is mounted in s set-up where special tubes for measuring the hydraulic resistance are the most important part. The method is described in (1)

section 7.5.

Judgment

In documents from CEN WG-3^, it is proposed that the water flow from a fully

opened tap must fulfill requirements concerning the flow at a pressure drop

of 300 kN/m2.

Stability of Flow and Temperature

General Requirements

The tap must supply water with the flow and the temperature it is adjusted to

by the user regardless of the temperature and pressure variations in the water

supply to the tap.

Proposed Degree of Fulfillment

Taps with manual regulation devices: Nil.

Taps with automatic regulation devices: The maximum alteration in the adjusted

temperature is 2°C with alteration of the pressure in the cold water supply of

30 kN/m2 .

Testing

The tap is connected to two pressure systems of cold and hot water respectively

The pressure in the cold water system is changed in steps. The pressure and | the temperature are recorded.

I The method is described in (1) section 7.7.

i Judgment

The numerical value of the ration | A t/AP| where At is the alteration in the

182
temperature (°C) of the outflowing water caused by the alteration in the

pressure (kN/m^) in the cold water supply system.

very good unacceptabl

e

! At/AP 0,1 0,15

When the cold water pressure is reduced by 30 kN/m (0,3 kp/cm ) the temperature of the outflowing water must not exceed 43°C until a steady temperature

has been obtained. Ten seconds after the stabilization of the pressure, the

temperature of the outflowing water must not deviate more than ± 2°C from the

value to which it has been adjusted.

I General Requirements

The tap must not cause annoyance due to noise either in the surrounding rooms

or in the room in which it is installed.

In the room where the tap is installed, the noise level must not exceed 50

dB(A) and in the surrounding rooms it must not exceed 30 dB(A).

The noise level caused by the tap does not depend on the tap only, but also

on the water pressure, the design of the piping systems and on the building

design itself. To ensure that the tap can be used in a waywhich prevents

exceeding the noise levels stated, the producer has to give relevant information of the tap's noise level. This information must consist of a statement

of the tap's standard noise level, the so-called "Appliance sound level"

measured according to the terms mentioned in "Testing". The method in question has only in view to judge the part of the noise transferred to the water

supply system and further to the building components and other rooms. No

test methods are developed for the noise caused by the tap in the room in

which it is installed.

The test consists of a comparison between the noise level caused by the tap

in a specified test set-up and the corresponding noise level originated in a standardized source of noise (installation noise-standard). The result of

such a measuring is called the appliance sound level, L/\p, which is the difference between the noise level of the installation noise-standards and that

, of the tap plus a fixed reference value. At the definition of the appliance

sound level a point is made of reaching values being close to the noise levels

obtained in practice for rooms surrounding the one in which the tap is installed. However, it will only be a very rough approach, as the existing con- ditions of building and installation are of great importance. The method is

described in DIN 52218 and IS0/DIS 3822/1.

Noise Conditions

I Proposed Degree of Fulfillment

Testi ng

183
Judgment

2 The tap's appliance sound level L^p at a water pressure of 300 kN/m can be

used for gouping the taps in different classes of quality as to noise.

Class I : LAp

< 20 dB (A)

Class I I : LAp< 30 dB(A)

LAp

is calculated as:

LAp

= k5 - (L

s

- L) dB (A)

where L$ is the noise level caused by the noise standard and L is the noise

caused by the tap in question. Taps in Class I will normally fulfill the r quirement that the noise level in the surrounding rooms not exceed 30 dB(A).

C 1 eanab i 1 i ty

Genera 1 Requ i rements

The surfaces of the tap must be insusceptible to dirt and calcerous deposit.

Alternatively, the tap must be easy to clean mainly by the detergent general ly used.

The tap must be resistant to detergents generally used and to possible special detergents recommended by the manufacturer.

Proposed Degree of Fulfillment

The surface of the tap must be formed in such a way that any part is acces- sible to cleaning without special tools. The surface should not be damaged

by detergents generally used for cleaning and for removing of calcerous deposit. If any of these detergents are deleterious to the tap, it must be

stated by the manufacturer, in which case alternative detergent should be

recommended

.

Test i ng

Ni 1

.

Judgment

Subjective judgment.

Chemical and Physical Stability

General Requirements

The tap must not cause any alteration of the outflowing water concerning

taste and smell or detrimental substances.

184
Proposed Degree of Fulfillment

The tap must not cause any alteration in the chemical composition of the

water.

Test

The water tap is mounted in a testing arrangement, and during one hour the

fitting is subjected to a water flow being in accordance with the flow rate

suitable for the tap in question. After having been demounted and replugged,

the water fitting is flushed out by synthetic water, filled again with synthetic water, and plugged again. The synthetic water is analyzed by atomic

absorption for Cd and Pb. The result is indicated in ug/1, and the total

quantities of Cd and Pb dissolved from the tap are calculated.

The method is described in (2).

Information about the chemical, physical, and biological stability of the

materials employed must be given by the producer.

Judgment

The maximum total quantity of Pb is 15 ug and of Cd is the maximum quantity

2 ug.

Susceptibility to Bacteria Growth

General Requirements

In the tap there must be no possibility of bacteria growth or other biological activities leading to cases of illness or poisoning.

Proposed Degree of Fulfillment

The tap must not contain any materials which may feed or form a basis for

bacteria growth.

Normally the whole part of the tap must be flushed with water each time the

tap is used.

Testi ng

Nil

.

Judgment

Subjective judgment when other tests are carried out.

Remarks

Aerators, showers, etc., must be easy to demount and/or clean.

185
Surface Conditions

General Requirements

The surface of the tap must be formed in such a way that no nuisance or personal injury will occur at normal use, just as cleaning or unintentional

touch must be safe.

Proposed Degree of Fulfillment

The closet must be without sharp edges and rough surfaces.

Test i ng

Nil

.

Judgment

Subjective judgment.

Protection Against Scalding

General Requirements

The tap should be designed in a way which protects the user against scalding

from outflowing water.

Proposed Degree of Fulfillment

The operation devices intended for draw off hot water must be marked carefully. Taps with automatic scalding protection must be designed in such a way

that it is avoided that water of more than 38°C can be drawn off the tap at

direct opening by a single operation. Blocking of the protection must not

take place until the drawing off has been started.

Test i ng

The tap with automatic protection against scalding is subjected to a pressure

of 300 kN/m^ on the cold water side as well as on the hot water side. The

temperature of the water being supplied to the water fitting should be 20°C

and 93°C respectively. The temperature of the water pouring out from the tap

is measured. The same measuring is carried at a pressure of 1000 kN/m^ on tht\

hot water side, and a pressure of 200 kN/m2 on the cold water side.

Heat Insulation Property

General Requirements

The temperature of those parts of the tap which it is necessary to touch when"

operating the tap must not cause any damage to or inconvenience for the user.

f it

£ it

li

su

le

< Ju

186
Proposed Degree of Fulfillment

The temperature of those parts of the tap which it is necessary to touch when

operating the tap must not cause that the temperature of the skin of the user

increases 40°C for the hands and 35°C elsewhere.

Test ? ng

2 The tap is connected to a hot-water supply system and a pressure of 300 kN/m

at a temperature of 75°C (± 2°C) is maintained. The tap is adjusted to the

maximum of the water flow. Taps, the correct functions of which imply the

connection of two or more water supply systems, should be mounted in such a way that the highest possible temperature of the drawn water can be obtained.

The tap should be run through by water during a period of 180 seconds, and

after this the outer surface temperature is measured on those parts of the

water fitting where touching is inevitable when operating the tap in a normal

way. The surface temperature and the places of measuring are registered.

Judgment

The temperature must at no part of the surface in question exceed 41 °C.

Rel iabi 1 ity

General Requirements

The tap must keep its original properties without maintenance for a reason- able term of years.

The expected lifetime should be related to price, ease of replacement and

maintenance of tap.

Proposed Degree of Fulfillment

The producer must give information about maintenance or repair which might be

necessary in the life of the tap. The tap must be easily accessible for the

above repairs (any replacement of components included) when the tap is mounted

as prescribed. The producer must give information of replacement parts being

supplied to the market and stocked.

Test i ng

Visual observations of the possibilities of repair.

Judgment

[subjective judgment.

MComments

It is required that the producer, on account of his own long-range tests,

187
state the expected lifetime of the tap or the number of operations to which

it might be exposed before it will be considered fit for renewal. At such

information the tests in question have to be described in detail.

Durability, Inside Resistance

General Requirements

The tap must not be affected by the water from the water supply system.

Proposed Degree of Fulfillment

The tap must not be affected by the water from the water supply system classified as drinking water systems.

Test i ng

Nil .

Judgment

Subjective judgment based on information from producer.

Durability, Outside Resistance

General Requirements

The tap must be resistant to substances and chemicals which normally are available in a residential house.

Proposed Degree of Fulfillment

The producer must inform about substances and chemicals which can damage the

surface of the tap.

Test i ng

Ni 1

.

Judgment

Subjective judgment.

General Requirements

The tap and its connections to the water supply system must be able to resist

the highest normal water pressure which can occur.

188

Mechanical Strength, Inside
Proposed Degree of Fulfillment

2

The tap must resist a pressure of 1600 kN/m without damage. Taps constructed

for higher working pressure than 1000 kN/m2 must resist pressure + 50 percent.

Test i ng

The testing carried out under "Tightness Relating to Maneuvering and Closing

Operations" will be sufficient also for the present property.

Judgment

The tap must be tight and without visible deformation.

Mechanical Strength, Outside

General Requirements

The tap and its connection to the water supply system must be able to resist

the stresses due to normal use and occasional loads such as punches, kicks,

and strokes.

Proposed Degree of Fulfillment

The tap must in mounted position be able to resist a force of 600 N on parts

under pressure when the tap is closed and 100 N on other parts.

Test i ng

The tap is mounted according to the producer's instructions and/or according

to common practice.

In a number of different places, chosen at random, the tap is subjected to

the single forces mentioned above. The force is transferred to the water fitting by a plunger having a diameter of 25 mm and a plane and surface covered

with rubber of a thickness of 3 mm and a Shore Durometer A Hardness of 55 - 5.

Judgment

The above forces should not involve any permanent deformation or other breakages. No leakiness should be found when the tap is tested as described in

"Tightness Relating to Maneuvering and Closing Operations".

Ag i ng Durab i 1 i ty

General Requirements

The materials forming part of the tap have to show a sufficient degree of

chemical, physical, and biological stability to enable to tap to maintain the

original look and other properties within the expected lifetime.

189
Proposed Degree of Fulfillment

Ni 1

.

Test i ng

Nil

.

Judgment

Subjective judgment

„

Comments

No direct method to determine the durability is available. For some materials, certain methods can be used to judge the influence of some of the aging

factors

.

Compatib? 1 ity

General Requirements

In a simple way, it should be possible to build the tap together with other

relevant components and installation systems.

Proposed Degree of Fulfillment

The producer must give satisfactory information of the overall dimensions, measures relevant to the mounting, joint methods, fastening, and installation

procedure of the tap.

Test i ng

Nil

.

Judgment

Subjective judgment. The measures relevant to mounting must be in accordance

with relevant standards.

Ease of Transport and Handling

General Requirements

Transport, storing and handling should be carried out without difficulties and

in such a way that no risk of injury to health or breakage will ~ccur.

Proposed Degree of Fulfillment

Nil.

190
Test ing

Ni 1

.

Judgment

Subjective judgment.

Comments

The producer ought to give information about the procedure of transport and

handling, and furthermore describe the storage conditions.

191
REFERENCES

The Approval Board of Sanitary Installations of the Danish Ministry of

Housing. "Approval requirements and testing conditions of sanitary taps

for water supply systems". VA 140/DK003 December 1971*.

Contamination of Drinking Water of Cadmium and Lead From Fittings . SB I NOTAT 36. Report on two series of experiments carried out by Kate Niel sen.

192
CODE STRUCTURE AND STANDARDIZATION IN THE UNITED STATES

by

M i 1 ton Snyder

I ntroduct ion

The title for this Symposium is "Water Supply and Drainage for Building" and

this title leads me to believe that, as a third-generation contracting plumber,

I might be in the right place. What else is "plumbing" if it isn't water supply and drainage? As a practical matter, one of the difficult items when discussing plumbing, or plumbing codes, or any legislation or any standards

involving plumbing, is to first agree on a definition of plumbing. This has

been a serious situation for many years —that is, to decide what is and what

is not plumbling—because plumbing is controlled and regulated differently

than what is not plumbing. We will find as we procede further into our discussion today that the definition becomes difficult, complicated, and political and economic because of the many vested interests involved. Some of these

interests want the definition of plumbing to be all-inclusive and believe that

the definition of plumbing should include everything remotely connected with

anything wet, and sometimes even with anything dry, and they believe the

definition of plumbing should include anything that goes through a pipe, or

is even slightly related to anything going through a pipe. On the other

hand, there are interests that believe the definition of plumbing should be

firmly restricted to water in and waste out, and further restricted to include

these items only within the physical confines of a structure, and that if the

water and waste items are outside of a building, they are not plumbing. Certainly somewhere in between these extremes is a sensible definition of plumbing that is objective and does not include or exclude items just because the

interested parties are capable or incapable of performing the extraneous

items, or providing the necessary materials.

For the purposes of our discussion today I submit the following definition of

plumbing taken from one of our widely accepted model codes: "Plumbing is the

practice, materials and fixtures used in the installation, maintenance, ex- tension, alteration and removal of all piping, plumbing fixtures, plumbing

appliances and plumbing appurtenances in connection with any of the following:

sanitary drainage or storm facilities and venting system and the public or

private water supply systems within or adjacent to any building, structure or conveyance; also the practice and materials used in the installation, maintenance, extension, alteration or removal of storm water, refrigeration and air

conditioning drains, liquid waste or sewage, and water supply systems of any

premises to their connection with the public water supply system or to any

acceptable disposal facility. Except for the initial connection to a potable

193
water supply and the final connection that discharges indirectly into a public or private disposal system the following are excluded from this definition: all piping, equipment or material used exclusively for environmental

control, for incorporation of liquids or gases into any product or process

for use in manufacturing or storage of any product, including product development, or for the installation, alteration, repair or removal of automatic sprinkler systems installed for fire protection only or their related

appurtenances or standpipes connected to automatic sprinkler systems or overhead or underground fire lines beginning at a point where water is used

exclusively for fire protection." (NAPHCC - National Standard Plumbing Code1

)

To describe this definition simply, it means that plumbing by definition means water in and waste out for directly connected fixtures intended for personal

sanitation, and that all other uses of water in and waste out are plumbing

only at the points where it is necessary to protect the water supply and to

protect against problems in the drainage connections. We are now back where

we started several minutes ago —that is, we are discussing water supply and

drainage for buildings that we will now call 'plumbing 1 .

It is my intention to discuss with you today "Code Structure and Standardization" concerning the requirements for plumbing installations in the United

States. To do this, I will briefly review the history of plumbing and plumbing codes and standards affecting plumbing, and then go into the present status of these items, and conclude with some personal reflections as to the

status of the important items, and express some opinions.

Background

While the history of the United States tells us that our country is now 200

years old, the health and plumbing histories tell us that we had health and

plumbing problems because of the disposal of human waste matter over 300

years ago. The magnitude of the problem was proportional to the density of

the urban development of any specific area. When local councils were first

formed in the effort to govern, they very quickly recognized the health

problems involved with the habits of depositing human waste in the streets,

or sometimes simply discarding them through an open window. Urban development did not permit many residents the luxury of open ground for the burying

of wastes, or given them the availability of running water courses for the

deposit of these wastes. The original health officers appointed by local

councils did the best they could with what was available, and made sincere

attempts to provide orderly and, to them, sanitary methods of waste disposal.

It is interesting to note that it was the health officers who became involved in these matters because they were truly health matters, and because

there was no one else who would or could become involved. Today, of course,

the trend is away from health officer control over plumbing towards building

inspection personnel control over plumbing, with the health officers being

involved generally only on a peripheral basis, but still, as in all matters

that could involve health, retaining the right to step in when they believe

they should.

Plumbing as we know it today did not evolve until water under pressure

194
became available. In this country, water under pressure first became available for fire fighting, and after the water was available, then water-borne

wastes became the basis for modern plumbing. While all of this development

has taken place in a comparatively short time—approximately 100 years — it

took a lot of effort, planning, and work to provide the street sewerage systems, enlarge and improve the water supply systems, and design and build the

plumbing fixtures and auxiliary equipment so that plumbing installations

could be made. At the same time, small private installations with private

water supplies under pressure and private disposal systems were being designed

and instal led.

Through all these early periods it was indeed health officers who were in control of the situation. Again, because proper disposal of human waste was a health matter, and equally important because these health officers were at the

time the only ones with education and experience who were able to cope with

the problems being generated.

In the last quarter of the 19th century, most of the large urban areas in

this country realized that plumbing was here to stay, and that the proper

installation was important, and they started to develop and implement

plumbing codes. Even with the plumbing codes, the health officers remained

in command.

The early plumbing codes placed the greatest part of their emphasis on the

disposal of human wastes, and very little emphasis on the protection of the

water being applied to make plumbing operative. In addition to controlling

the various physical aspects of a plumbing i nsta 1 lat ion such as ventilation,

room locations, sizes, the fixtures themselves, and other such matters, they

controlled the sizes and materials, and configurations of the piping through

which the disposal of the waste matter took place. The early codes merely

wrote into the laws and regulations what experience up to that time had taught

them would work, and would work satisfactorily for a reasonable period of

t ime.

It is interesting to note that this was the beginning of specification-type

plumbing codes as far as waste matter was concerned, because they were very

careful to detail the various sizes, and loadings, and geometry of the waste

side of the plumbing system so that only what worked yesterday was approved

for installation today. At the same time, there were very few codes that

detailed any information about the water-supply piping, except to say that it

must be there, and it must be adequate, and there was only one mention in a late 19th century plumbing code of protecting the water supply against con- tamination from the waste water, and even this was later ignored by the same

code.

At the very beginning of water-borne wastes and plumbing codes controlling

these wastes, there was knowledge that a liquid trap seal was the most

appropriate method of protecting against the infiltration of filth and disease from the waste side of the system, and there was also the realization

that protecting the integrity of this trap seal would become a major objective of a good plumbing code.

195
An interesting history of plumbing in this country, published some 25 years

ago by our National Association of Plumbing Contractors, 1 points out that

the concept of providing fresh air vents to assist in the protection of these

trap seals was developed by one or more of the plumbing contractors of the

time, and the first approach to the problem was to put small ventilation lines

from the waste lines through to the outside wall. From this small beginning

came all of our modern thinking and modern codes concerning venting. The

past 100 years has created much thinking about this simple problem of protecting the integrity of the trap seal, and even our own National Bureau of

Standards 2 has been involved with what is known as "Reduced-Size Venting" and

it appears that after over 100 years we have come full circle and are right

back where we started. It also appears that while the health officers of

that time might have been in control of the situation, the plumbers of that

time might have been more alert to the basic physical problems of plumbing

installations and how to cope with them.

From the last quarter of the last century to the end of the first quarter of

this century, progress in plumbing codes was continuous but not very meaningful. It was not very meaningful in the sense that there was no genuine new information being sought after by the people writing the plumbing codes, and

plumbing coes were being written and rewritten after the fact, so to speak.

Only the tr i ed-and-true were kept in the code and purely on a specification

basis, and purely on the basis of previously demonstrated practical satisfactory experiences. This approach applied mostly to the sizing, loading, and

geometry of the waste piping systems. Fixtures, appurtenances, and appliances were receiving attention from the manufacturers of these items, and

genuine changes and advances were being made in these items, and these changes

were receiving code approvals. The manufacturers had, and still have, a large

economic stake in advancing the cause of their equipment. There was no equivalent interest group willing to spend the money and the effort to ad- vance the cause of investigating and modernizing the internal piping of a plumbing system, because no economic advantages could accrue to such a group.

Fortunately, in the early 1920s, our Commerce Department under the then Secretary of Commerce Herbert Hoover authorized the then-equivalent of our

National Bureau of Standards to make a genuine investigation into the physics

and hydraulics of plumbing installations, and to make such tests and examinations as they deemed necessary to accomplish this objective. This was done

and after a few years and exhaustive report was issued on July 3, 1923, en- titled "Recommended Minimum Requirements for Plumbing in Dwellings and Similar

Buildings." 3 To my knowledge, this was the first authoritative work in this

country that was based on more than yesterday's experience and in addition

spent a great deal of time and effort on assembling the physical and hydraulic

data applicable to plumbing, and then checked out the data and the theories in

practical tests.

This report included a recommended plumbing code, a report of their investigations, and a discussion of the physics of plumbing systems, as well as other

miscellaneous items such as standardization of materials. Every serious student of plumbing should not only read this report but study it very carefully.

Most of it is still very valid today. Not only is most of it still valid

196
today, but many of the plumbing codes we are still using are exact quotations

from this document. This report on plumbing suggested a minimum plumbing

code, then listed various legal reasons why communities and government were

entitled to have plumbing codes, and as a matter of fact must have plumbing

codes, and then went on to discuss the physics of plumbing systems so that

their suggested codes could be understood and applied, and further listed certain materials for plumbing use.

While the recommended code was purely a specification-type code, there were

general references to the results expected, and reference to the fact that

some of the code provisions should be further studied, and as a matter of

fact the inclusion in the report of the discussions concerning the physics

of plumbing systems leads one to believe that the authors of this report

felt that this was only a beginning and not a conclusive report or code. In spite of this, and because of the general lack of knowledge about what goes on

inside of a plumbing system, and because there were no real efforts to get involved with a performance-type code, from that time on until almost the present

time, the history of plumbing codes in the United States reflects only changes

in the details of plumbing codes and little if any change in the approach to

code writing or in the concept of what a plumbing code should really be.

This report and suggested plumbing code, frequently called the "Hoover Report" 3 or the "Hoover Code" after the then Secretary of Commerce, with its

progress revisions through 1931 was often used as a textbook in the few schools

that taught plumbing at a higher level than the how-to-do-it level, and was one

of the textbooks at the very, very few college-level classes involved with

pi umb i ng

.

In addition to the details of the plumbing installation, the Hoover Report

discussed materials for use in plumbing installations. There is detailed

reference in the report to the various piping materials then in common use

for plumbing installations, and a listing of the specifications of the American Society for Testing Materials (ASTM) 4 for the various pipes and fittings.

It should be pointed out that practically all of the information in the specivications or standards listed for the various pipe and fittings discussed

was involved with the details of the manufacture and testing, as well as the

base materials used in the construction, of the pipes and fittings and practically no listing or discussion of their use or adaptability, or need, in the

installation of plumbing systems. This is today still the preva i 1 i ng s i tuation, with some changes that we will discuss later.

Current Activities

To continue with our history of plumbing codes, in November of 19*t0 our National Bureau of Standards published Report BMS 66 entitled "Plumbing Manual"

which was the result of the work of a committee of only government people.

This "Plumbing Manual" was intended for Federal plumbing work but it was hoped

that it would also be helpful in bringing about greater uniformity and reduction of costs in all plumbing work. Very interesting sections on pressure and

non-pressure drainage and listing different capacities for primary and secondary branches were never picked up by model or local codes. This aggressive

197
forward step was never implemented. BMS 66 also contained the famous "Hunter's Curve" for estimating water-supply demands and pipe sizing information

which were also discussed in BMS 65 and BMS 79. The fact that these 35-yearold reports are still in widespread use should indicate a lack of progress

in plumbing information and code writing. American Standards Association,

now known as the American National Standards Institute (ANSI) 5 appointed a committee, known as the A*tO Committee, to prepare "Minimum Requirements for

Plumbing and Standardization of Plumbing Equipment." This Committee was appointed in 1928 and frankly did little or no productive work, and was dischared in 1939. In 19^1 the A^O Committee was reorganized with a broaderbased membership and did do some real work with various reports to the

extent that in 19^9 they received approval for their work as an American

Standard. Very shortly after the acceptance of the 19^9 report, still an- other A40 Committee was formed with an extremely broad base of membership

to again attempt to prepare an even better, more modern, more acceptable

plumbing code to contain "Minimum Requirements for Plumbing." This Committee's work was completed and published in 1955 and is known as A^O. 8-1955, 6 and for many years in most places—and still in some places—was known as The National Plumbing Code. Again, because of the continuing need for better and more modern plumbing codes, and because of various political frictions in the field of code writing, A^tO. 8-1955 was officially withdrawn as an American Standard on January 20, 1972. There is, at the present time, a current ANSI A*t0 Committee at work on a revision of this plumbing code.

The National Association of Master Plumbers published its "Standard Plumbing

Code" in 1933, and revised it in 19^2. When A^0.8- 1 955 was a viable code,

this national association (now known as the "National Association of

Plumbing-Heating-Cooling Contractors" 1

) did not pursue the publication of

its own code, and accepted the use of A^tO. 8-1955, on which Committee representatives of the Association had served. When the publication of this code

no longer had meaning, and when attempts at revision were so involved as to

stymie any revision, this National Association published its own "National

Standard Plumbing Code" beginning in the spring of 1971, with continuous re- visions through the present time. Shortly after this publication date, the

American Society of Plumbing Engineers 7 joined with the National Association

in sponsorship of their code and in active participation as working members

of the Code Committee.

Another group that served on the A40 Committee was the Western Plumbing Officials Association. At the same time they were serving on this Committee,

they were also busy writing and publishing their own code, which they claim

dates back to 19^5. It is apparent that their greatest interest remained in

their own code; originally used only on our West Coast, they seriously worke

to expand their influence further inland. To assist in this expansion, they

changed the name of their organization to the International Association of

Plumbing and Mechanical Officials (IAPM0). 8 It must be noted that this or- ganization, as well as two more that we will discuss, allow various types of

people in the industry to have an input into their code writing, but only

government officials involved in this type of work can vote.

Another group that served on the A40 Committee was the Building Officials

198
and Code Administrators Internationa], Inc.

9 This organization was one that

did use and accept A40. 8-1955 as the national plumbing code as long as it

remained a viable code. In the last 1960s, BOCA, working as part of the

Committee to revise the 1955 edition of A40.8, recognized that an impasse

had been reached and that the code would not successfully be revised. In 1968 they published their own version of a plumbing code that they still

continue to revise and to publish. Along with IAPM0, the BOCA organization gives voting powers only to government officials.

The Southern Building Congress, 10 an organization of building officials from

the Southeastern States of the United States, never served on the A40 Committee. Starting in 1955, they have published a plumbing code and they are

still revising and publishing this code. Along with IAPM0 and BOCA, the

Southern Building Congress gives voting powers only to government building

officials.

Summary

To quickly review the recent history, the previously most popularly accepted

code as being a truly national code was ANSI 40.8-1955; and after the withdrawal of this code, four organizations entered the competition in order to

have their model codes accepted as a national code. These organizations are

The National Association of Plumbing-Heating-Cooling Contractors jointly

with The American Society of Plumbing Engineers, the International Association of Plumbing and Mechanical Officials, The Building Officials and Code

Administrators International, Inc., and The Southern Building Code Congress.

Every one of these organizations is well-meaning, and a plumbing installation made in accordance with any one of the plumbing codes will be a good

installation. Obviously, they each have their own incentives that prompt

them to pursue the use of their particular plumbing code in the various localities, and hopefully to be recognized as the number one national code.

Our local governments in this country are divided into villages, townships,

cities, counties and states. At every level of these local governments, it

is possible to have individual plumbing codes. In the very few instances

where states have plumbing codes that are intended to be truly statewide,

it is not really possible to prevent the smaller divisions of government

from implementing their own changes in the plumbing code. Our national government has never undertaken to have a mandatory plumbing code at the

national level, and it may not be legally possible for them to do so. However, through the use of their economic programs, the national government

has from time to time attempted to control plumbing codes indirectly. Most

of their efforts toward the economic control of plumbing work and plumbing

codes were directed toward minimizing restrictions as to the use of materials and as to who is permitted to do plumbing work. Needless to say, these

attempts met with great resistance from existing materials manufacturers

and from the people presently licensed to do plumbing work.

We have said many times that while plumbing codes change as you cross city

or county lines, there is no reason why they should, because the laws of

199
physics, the basic pneumatic and hydraulic problems do not change. Obviously, it is the change in people, not the change in the problem, that creates

the change in the plumbing code.

Now that we have reviewed the semi -chaotic history of plumbing codes, let us quickly review the equally semi-chaotic history of materials acceptance and

approvals and standards, and also briefly discuss the slightly less chaotic

story of who does what work and the licensing situation, all of which are an integral part of the code structure.

Starting with our 1923 Hoover Code, we found that there were standards and

specifications for the manufacture of mater ial s -for use in plumbing systems.

Just as with the plumbing codes, many different groups got into the act and

started creating standards bodies and standards, some on a general basis,

and some on a highly specialized basis, and all of them frequently creating

standards specifications for the same items.

With all of these standards, many plumbing codes will and do accept materials

manufactured under them, and in addition reserve the right to accept any

additional materials they deam to be satisfactory for the intended use. Here

again, every village, township, city, county or state can accept anything

they choose to accept. "They" means the particular people in control of the

situation at the time of such acceptance.

An important weakness in the total materials standards situation is that the

standards are truly manufacturing standards, and are not necessarily good or proper standards for various plumbing uses in which the materials eventually

will be used. Occasionally there is a brief mention in the standard of an intended plumbing use, and occasionally there is an appendix with some installation recommendations, but by and large the standards are purely manu- facturing standards.

Other than Federal standards for use by our Federal Government in buildings constructed for their own account, all of the organizations involved in

standards are voluntary organizations, and use of their standards is a voluntary act on the part of an individual manufacturer, and not compulsory. The

only compulsion is economic, in the sense that unless the product conforms

to a standard acceptable in the market intended for the product, sales of the

product becomes more difficult.

To further indicate that these standards are not mandatory on the manufacturers, we quote below a statement issued by one of our prominent plumbing manufacturers at the start of every meeting at which a proposed standard is

being discussed:

"I request that the following written statement be recorded in this

meeting to the effect that each representative in attendance is here

solely for the purpose of assisting in the development of a voluntary

standard through the drafting of language covering such standard; that

no such representative has any authority to agree to accept such

200
standard or its language; that each representative only has authority

to indicate by his vote whether or not he will recommend to his company

the standard as drafted; and that the company of each representative

shall have the exclusive right to determine for itself, independent of

all others, whether or not it will accept such standards."

For assistance to those seeking further information and to demonstrate the

large number of overlapping standards organizations, we list below the names

of those commonly mentioned in our model codes:

- ANSI American National Standards Institute; 5

- ASSE American Society of Sanitary Engineers; 11

- ASTM American Society for Testing and Materials;

1*

- IAPM0 International Association of Plumbing and Mechanical Officials; 8

- AWWA American Water Works Association; 12

- CS Commercial Standards; 13

- FSS Federal Supply Services; 11*

- NSF National Sanitation Foundation; 15

- PDI Plumbing and Drainage Institute; 16

- UL Underwriters' Laboratories, Inc.;

17

- ASME American Society of Mechanical Engineers; 6

- MSS Manufacturers Standardization Society; 18 and

- SPR Simplified Practice Recommendations. 19

The preparation of a plumbing code should involve the use of various groups

of experts —those familiar with the piping details of a plumbing system including the hydraulic and pneumatic problems, those familiar with materials

including ease of installation and life-expectancy problems, those familiar

with consumer needs as to quantity and type of plumbing fixtures, those familiar with the administration of plumbing laws including permits, inspections, and the licensing of people authorized to do the actual installations,

and such other experts as may be needed for specific situations. Most, if

not all, code committees have experts on them—but these experts are only

one or several in each of the required areas, and then jointly decide on all

of the other areas. This does not lend itself to well-balanced plumbing

codes with the interest of the general public and of the consumer coming

f i rst.

When you are discussing the licensing of people to do the plumbing work,

there are many who feel that this is not a proper subject for a technical

plumbing code, and certainly not a subject for a model or national code.

Because of the many types of arrangements and histories in the various localities as to who does what, this certainly seems one part of a code that

should be decided at the local level. This is not a part of the code that

lends itself to the positive reasoning, tests, and calculations represented

by the purely technical aspects of plumbing installations.

201
It might even be possible to also separate the materials approvals and

acceptances from the technical parts of plumbing codes.

These statements about the possible separation of licensing and materials

are made with the full knowledge that these two items —particularly the

materials situation—were the principal causes of the failure of the Committee charged with revising A*tO. 8-1955, and this failure promoted the

current situation of four model codes vying for national recognition,,

At the present time, all four of the organizations with model codes are making determined efforts towards having their particular code accepted on

a wider basis, with the hope that eventually their particular code will be

recognized as "the" national code.

Also at the present time, there is at work an A^O Committee making an heroic

effort to revise and publish a current A40 code which, if accomplished,

might again regain the status of being "the" national code. Strangely

enough, there are representatives of several of the model code organizations

working on this current A40 Committee. Hopefully, all concerned will pur- sue the A^O work at top speed and effort. This seems to be the only

approach to a code that can be accepted by most of the interested parties on

a national basis, and would have great influence on international thinking.

D iscuss ion

At this time I would like to make some personal observations as to which way

I believe codes will become structured in this country and also which way I believe they should be structured.

If the present A^O Committee succeeds in its work, there is an excellent

chance that a revised A^O Code will take over the field that is now confused

by the four model codes and will provide a basis for our many local areas to

have a plumbing code based on the best possible plumbing code, including all

of the latest and best information. If the A^O Committee does not succeed,

it will be because of the diverse interests represented on this Committee,

all which have equal say on matters in which they have little or no expertise, and frequently little or no interest, but use these matters in a political fashion to accomplish their own purposes. In all fairness, they are

entitled to do this under the A^O set up, and further it is quite possible

that this political maneuvering can conclude with a responsible result.

Nevertheless, until a responsible result is accomplished, an objective look

at the process seems to show that a successful revision of A40 cannot be

positively predicted. In the absense of this revision, the present model

code organizations will continue to scramble for localities to adopt their

particular code—and again this might not be all bad, because the competitive spirit engendered by this keeps all of the model codes up-to-date and

aggress i ve.

Another personal observation I want to make is that, concerning materials,

the industry must make up its mind that new materials are being discovered

and manufactured, and that these new materials must be given a chance.

202
As to licensing, I personally believe many of the local licensing structures

are ancient and should be replaced. In this day of new techniques in the

construction industry, various forms of limited licensing should be introduced to include semi-skilled specialists in various phases of the work to

permit the equivalent of production-line work in construction work, while

still reserving the present competency tests for those interested in the

total picture of all plumbing work.

Finally, I must say that an in-depth review should take place concerning the

possibility of performance requirements, and even more important in the direction of generating performance testing at the various levels of design and

installation, so that expected results can be disproven before construction,

or expected results can be guaranteed in advance.

To have and to implement performance-type codes will require better and

more informed designers; much, much better and more informed plans examiners and inspectors; better installers; more responsive financial institutions who will recognize that innovations can be good; and a complete

change of attitudes of manufacturers, installers, contractors and consumers.

Since most of the efforts on plumbing codes have been extended by people

with vested interests, it appears that perhaps a government agency might be

the only place where unbiased information and testing might be available on the technical details of pipe sizing, venting, and geometry that could provide better plumbing at lower costs.

Most of the efforts in the writing of plumbing codes have been spent on the

design and installation of the drainage, waste, and venting system, which

are of course extremely important. Now that most people are completely familiar with the need for the utmost care in the disposal of human waste, but

mostly unfamiliar with the problems that can be created by contamination of

the water supply from an improper installation, it appears that the major

thrust should be along the lines of resolving technical problems involved

with the protection of the water supply, and along the lines of an educational program to alert everybody, those within and those without of the

industry, to the seriousness of the situation.

To paraphrase a recent advertisement, if we are still using codes that are substantially the same as they have been for 20 years or more, and if we

are still using only the same materials, and still using the same construction techniques, then we must be wrong, because in this day and age there

must be something better.

203
REFERENCES

NAPHCC National Association of Plumbing-Heating-Cooling Contractors

1016 20th Street N.W.

Washington, DC 20036

NBS National Bureau of Standards

Washington, DC 20234

RMR Required Minimum Requirements

BH 13 - July - 1923

National Bureau of Standards

Washington, DC 20234

ASTM American Society for Testing and Materials

1916 Race Street

Philadelphia, PA 1 91 03

ANSI American National Standards Institute

1430 Broadway

New York, NY 10018

A40. 8-1955 (ASME)

American Society of Mechanical Engineers

345 E 47th Street

New York, NY 10017

ASPE American Society of Plumbing Engineers

16161 Ventura Boulevard - Suite 105

Encino, CA 91316

IAPM0 International Association of Plumbing. and Mechanical Officials

5032 Alhambra Avenue

Los Angeles, CA 90032

BOCA Building Officials and Code Administrators International, Inc.

1313 E 60th Street

Chicago, IL 60637

SBC Southern Building Congress

1116 Brown Marx Building

Birmingham, AL 35203

ASSE American Society of Sanitary Engineering

228 Standard Bui lding

Cleveland, OH 44 1 1

3

204
American Water Works Association

521 Fifth Avenue

New York, NY 10017

Commercial Standards, Commodity Standards Division

Office of Industry and Commerce

U.S. Department of Commerce

Washington, DC 20230

Federal Supply Service

Standards Division - General Services Administration

Washington, DC 20*t05

National Sanitation Foundation

Ann Arbor, Ml 48106

Plumbing and Drainage Institute

1018 N Austin Boulevard

Oak Park, IL 60302

Underwriters' Laboratory, Inc.

207 E Ohio Street

Chicago, IL 1 5^20

Manufacturers Standardization Society

k20 Lexington Avenue

New York, NY 10017

Simplified Practical Recommendations

U.S. Department of Commerce

Washington, DC 2023*t

205

POTENTIAL SAVINGS FROM USING REDUCED-SIZE

VENTING IN THE UNITED STATES 1

by

Harold E. Marshall, Rosalie T. Ruegg, and Robert S. Wyly

Abstract

Venting is required for sanitary drain-waste-vent systems in buildings to

protect trap seals of plumbing fixtures and thereby block entry of sewer

gases, suds, sewage, and vermin into the buildings. Research has shown that

reduced-size venting (RSV) , an innovative type of venting which utilizes dry

vent pipes substantially smaller in size than those permitted by existing

U.S. plumbing codes, performs satisfactorily in one- and two-story houses.

Builders, contractors, plumbers, consumers, and the research community are

interested in the potential money savings from using RSV. Based on use of

plastic pipe, and depending on other assumptions made, estimates of potential savings in the U.S. per single-family dwelling unit of one- and twostory type are from $*t6 to $125, and for the U.S. as a whole, from $58

million to $1^9 million over the next 11 years. Realization of these potential savings depends on how fast code authorities accept RSV in the plumbing

codes and how fast builders and developers implement RSV technology once it

is authorized in the codes. Although savings are likely to be greater in the

U.S. than other countries due to the more elaborate venting requirements and

the relatively large volume of housing starts, other countries may also find

it cost effective to install RSV.

Key words: Cost savings; drain-waste-vent; economics; life-cycle; perform- ance standards; pipe; plumbing; reduced-size vents; sanitary

drainage systems; venting.

Introduction

In the United States venting is required for sanitary drain-waste-vent (DWV)

systems in buildings to maintain the trap seals of plumbing fixtures. The

venting provides protection by maintaining adequate water seals in the traps,

thereby blocking the entry of sewer gases, suds, sewage and vermin into the

bui Id i ngs

.

Traditional plumbing codes in the U.S. require that venting meet certain

prescriptive standards. In the early 1960s, the National Association of

Homebuilders (NAHB) proposed a laboratory investigation of Reduced-Size Venting (RSV) to test the hypothesis that RSV would be a viable approach to venting. RSV is an innovative type of venting which utilizes dry vent pipes

207
substantially smaller in size than those permitted by existing plumbing codes.

The hypothesis was based on an examination of two premises utilized historical-;

ly in the derivation of the design criteria for standard venting. First, traditional criteria for sizing vent systems were derived from data obtained under

hydraulic test conditions that were more severe than what would be expected in , service, particularly for one- and two-story residential buildings. Prelimi- I nary analysis indicated that air requirements in the vents of the DWV systems j of such buildings are substantially less than that assumed in the prescriptive,

requirements of the codes. Second, traditional criteria were based on the as-

' sumption that a substantial diameter reduction in vent pipes occurred in ser- vice from the accumulation of corrosion products. But with newer materials such

as thermoplastics and some of the corrosion-resistant metals, this assumption

seemed no longer valid.

Studies by the NAHB, 2 the National Bureau of Standards (NBS) 3,lt,s and the SteW

Institute of Technology 5 have since shown that RSV can meet the implied es J sential requirements for performance (adequate trap-seal retention and absense

of sewage and sewer gas emissions) Tmposed on conventional vent systems in one- and two-story houses by the prescriptive requirements of traditional U.S. codes

NBS has published recommended design criteria for RSV 3 and has offered recom- mended code language for RSV in one of the model code organizations (i.e., the

Building Officials and Code Administrators International) and to the American

National Standards Institute (ANSI) Standards Committee AkO Minimum Requirements for Plumbing.

| i

It is not the purpose of this paper to examine the performance characteristics''

nor the research details of RSV, because these have been presented elsewhere. 3,l+,s Rather, our purpose here is to examine the potential cost savings:,

in the U.S. from substituting RSV for standard (conventional) venting in one- ( J and two-story residences. Cost savings are expected from reduced materials

costs, from reduced labor installation costs, and from reduced overhead and

profit charges. No sacrifice in terms of higher maintenance costs, reduced

performance, or reduced durability is expected for properly designed and installed systems. Savings from introducing RSV are estimated for one- and twostory single-family dwellings constructed nationwide over the next decade.

t s Such an analysis of potential savings is of interest to U.S. builders and con-

,a tractors, both of whom are eager to reduce costs and thereby be more competi- ' tive, and to homebuyers, who are eager to minimize their costs for a home. It" is of particular interest to those plumbing contractors who may benefit from

J increased aggregate profits due to their bids being more cost competitive. The 1 analysis also provides useful information to members of the international re- ^\

search community (e.g., NBS) which are concerned about the returns on their

investments in plumbing research.

We recognize that, in this early stage of the development of RSV, predictions [ of cost savings will be limited. Estimates of costs for the different plumbing^0 system designs and some of the other information needed to make precise esti- i

,

e mates of cost savings are without detailed empirical verification. However, we believe that the estimates of savings developed in this analysis give a

Nil

208
reasonably accurate, preliminary indication of the economic viability of RSV,

in that a conceptually logical model is used to evaluate cost savings, and the

underlying assumptions are based on a sampling of expert industry opinion that

appears real isti c.

For prespective, we begin with a background discussion of the installation

requirements and the performance attributes of RSV. We then calculate for one- and two-story residences the estimated cost savings per dwelling and the

aggregate cost savings nationwide. We finish with a discussion of potential

barriers to RSV adoption in the U.S.

RSV Performance Characteristics

The basic configuration of DWV systems utilizing RSV does not differ from standard DWV systems. However, the diameters of the dry vent pipes are smaller

than the standard s i zes--usua 1

1 y from one to four commercial pipe sizes smaller

in the U.S. (Dry vents are pipes through which only air passes; wet vents, in

addition to allowing air to pass, serve intermittently as drains.)

In order to ensure that RSV will meet the performance level now required by

U.S. codes of conventional venting, the following design and installation re- quirements should be considered. Installation should limit RSV to elevations

higher than 6 in. (15 cm) above the flood rim of the fixture(s) served or above

any other points in dry vents which are likely to be intermittently submerged

or subjected to wetting. Vent terminals should be covered with enlarged screen

caps, and vent piping materials should be limited to those that are not subject to substantial scale formation under the prevailing site conditions.

Manufacturers' recommendations should be used for any special fittings, for

joining materials, and for installation procedures that may be required for

size reductions. Finally, the design should be carried out in accordance with

a tested and proven procedure.

Performance characteristics of RSV found in laboratory tests 3 ' 4 ' 5 show adequate

hydraulic and pneumatic performance in one- and two-story residential type DWV

systems. That is, during heavy hydraulic test loads, blow-back or ejection of sewer gases and suds was absent, and an adequate residual trap-seal was recorded for al 1 traps

.

IResidential DWV systems are currently being evaluated by NBS in a field trial

jwith RSV. Pre-occupancy tests using hydraulic loads similar to those described

for the laboratory tests have been completed, and these show satisfactory

hydraulic and pneumatic performance. Post-occupancy data are being obtained

with special sensors and a 100-chanel automatic data acquisition system.

Cost Savings Per Dwelling

Cost savings per dwelling unit are estimated here in 1975 dollars as the difference in the costs of plastic RSV as compared with conventional plastic venting for one- and two-story s i ng 1 e-fam i 1 y houses constructed from 1975 through

,j 1 9 85 in the U.S. It is assumed that the performance of RSV satisfies the minijmum performance requirements implied by plumbing codes for venting, and that the

209
durability and maintainability of RSV are equal to that of conventional systems. If then the costs of RSV are less than those of the conventional venting system called for by plumbing codes, we know that RSV is the more economically efficient technology for venting.-

The cost savings per dwelling unit is calculated for plumbing systems using

thermoplastic piping materials. It is assumed that the plumbing system in

each new house contains two baths, one kitchen, and one laundry room.

Savings from using RSV are influenced by the kind of pipe material used, as well as by the particular venting design that is required by the code in force

This is because pipe materials vary in cost (e.g., copper tube is currently

more expensive than plastic pipe), and because venting designs vary in the

amount of dry vent piping they require. Furthermore, some codes require larger

sizes of vent piping in some applications than do other codes, resulting in

potentially larger pipe size reductions and, therefore, greater cost savings.

The cost savings that are anticipated from substituting RSV for conventional

plastic venting, therefore, increase directly with the price of the convention

al pipe and fitting, the number of units of dry vent pipe and fittings require

and the size reductions made possible by substituting RSV.

The analysis is based on the following three basic types of venting system designs: (1) a fully, individually vented system, referred to here as CI; (2) a | wet vented system, referred to as C2; and (3) a stack vented system, referred

to as C3. Figures 1 through 5 show schematically the details of these designs

starting with the simplest (C3) and ending with the most complicated (CI) for one- and two-story houses. The diagrams are drawn to show the general differences in the designs and to show the measurements of pipe sizes, pipe lengths,;

and number and size of fittings used in calculating savings from substituting

RSV. (The designs are not drawn to scale, and they are not intended to represent any professionally designed, as-built, DWV system.) Discussions indicating the importance of adequate piping schematics in the sizing procedure and

materials take-off are given in BSS 60.

The most elaborate venting system, CI, provides more dry venting that is eligible for RSV than the other two, and thereby provides the largest potential

for RSV savings on a per dwelling unit basis. Because C2 has less eligible dr

venting than CI, it results in somewhat smaller savings, while C3, the least

elaborate of the systems, results in the smallest savings. Tables 1 and 2 sho1 the estimated savings in materials, labor, and overhead and profit that would

result from introducing RSV in a house with each type of venting design. The

estimated savings from using plastic RSV in place of conventional plastic

venting in a one-story home with venting design of type CI, for example, are | $95 in total, comprised of $19 (20 percent) in materials, $56 (59 percent) in

labor, and $20 (21 percent) in overhead and profit. Tables 1 and 2 show that

the cost savings per plumbing system from using RSV are greatest when it is

applied in two-story homes with venting systems of type CI. The cost savings

from RSV are least when applied in one-story residences with venting designs

of type C3. The savings from using RSV range from $125 to $46.

To estimate the savings per system from RSV as shown in Table 1 and 2, the

210

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Table 1 Estimated Savings From RSV Per Plumbing System

In One-Story Residences

System Design

Dollar Sav i ngs

(Percentage Distribution)

riater i a i s Labor Overhead

F Prnf i t

I ota 1

r 1

I o . bi> 56.26 19.85

(20) (59) (21) (100)

C2 17.28 44.34 16.33 77.95

(22) (57) (21) (100)

C3 16.01 20.22 y . ou 45.83

(35) m (21) (100)

Table 2

Estimated Savings From RSV Per Plumbing

In Two-Story Residences

System

System Design

Dollar Savings

(Percentage Distribution)

Mater ia 1

s

Labor Overhead

& Profit

Total

CI 22.73 76.14 26.20 1.25.07

| (18) (61) (21) (100)

6 C2 21.79 34.34 14.87 71.00

(3D (48) (21) (100) I

C3 N.A.t N.A.t N.A.t N.A.t L

t "N.A." means not applicable for purposes of this analysis.

!

1

216 |
costs of RSV were subtracted from the corresponding costs of a conventional

venting system for each design. The total costs of installing RSV and conventional venting systems are calculated according to the following cost formula,

which is based on a cost estimating guidebook7 widely used in the U.S. by the

plumbing industry.

C = (P + F + L) F Q

F

p

, (1)

where

C = Total installed costs of a venting system,

P = Cost of pipe materials,

F = Cost of fitting materials,

L = Cost of labor,

Fq = Contractor's overhead factor (e.g., if overhead charge = 15 percent, then F Q = 1.15), and

F

p = Contractor's profit factor (e.g., if profit = 10 percent, then

F

p = 1.10).

The values for P and F were calculated on the basis of the measurements shown

in the schematics in Figures 1 through 5 and on materials list prices. The system configurations, as well as the sizes and number of units for convent ional

size pipe and fittings, were based on requirements of three prevalent plumbing

codes in the U.S.: The 1975 Basic Plumbing Code (BOCA), 1975 Standard Plumbing

Code (SBCC), and 1976 Uniform Plumbing Code (IAPM0). 8 Unit costs of pipe and

fitting materials, shown in Tables 3 and 4 respectively, were obtained from

plumbing materials and equipment suppliers in the Washington, D.C., area. These

prices reflect a 30 percent reduction in manufacturers' national list prices to

account for contractor discount. By multiplying the number of units times their

respective unit prices, the materials costs for RSV and conventional venting

were obtained for each of the venting designs for one- and two-story residences.

Table 3

Plastic (PVC) Pipe Costs by Sizet

Size in Inches 3 2 1 1/2 1 1/4 1 3/4 1/2

Dollar Costs Per Foot 1.36 .66 .48 .41 .38 .26 .20

The values for labor costs, L, were derived by using the "pipe and fittings"

method of the cost-estimating guidebook7 and an average hourly labor rate of

$20. Based on current practice in the U.S., as indicated by the cost-estimating guidebook and by consultations with industry authorities regarding

t Cost estimates are based on 1976 list prices of a leading brand of thermoplastic (PVC) pipe, reduced by 30 percent for contractor discount. Costs

are for Schedule 40 DWV pipe in sizes 3, 2, 1 1/2 and 1 1/4 inches, and for

Schedule 40 water pipe in sizes 1, 3/4, and 1/2 inches.

217
Plastic

Table 4

Fitting Costs by Sizet

SIZE

Dol lar Costs

Coupl i ng Tee C ross 90°

El 1

45°

Ell

Reduc i ng

Tee

Reduc i ng

Bush ing

•5J • / * 4 53 N11 • Afi • * N A N11 • A~ • N11 r\A m

z 2 77 58 55 11N • A~ • N A

1 1 /Z • zi> 68 1 86 47 37 N A Nii • nA •

1 1 /L 1 1 / H • p.? 42 . 41" i NIN . rvA . N.A.

1

1 70 N A 54 70 N11 • **A • N11 •*»A •

7 /L 51 4

0 1 . Z 1 36 NIN . r\A . 30 62 INN . Ar\ . 11N • /A» •

1

1 /9 / Z

1 C N A ?4 37 M1 * A• " • Nii «,nA »

.3XZ IN . H . IN • r\ . NIN • r\A • N A WIN . r\A . z_? « 00V-/ 78

3X 1 i / z

M A IN . H . INN . ArA . N11 • A~ • N.A. N11 • r\A • 1 85 1 .02

2x1 1/2 N.A. NIN . r\A . Nin • riA • 11N • r%A • N A .80 26

2x1 1/4 N.A. N11 • nA • N A N A Nii • nA • N.A. .54

1 1/2x1 1/4 N.A. iiN • r\A • N A N A N A 96 . 30

1 1/2x3/4 N.A. N.A. N.A. N.A. N.A. 1.21 .56

1 1/2x1/2 N.A. N.A. N.A. N.A. N.A. N.A. .56

1 1/4x3/4 N.A. N.A. N.A. N.A. N.A. .95 .52

1 1/4x1/2 N.A. N.A. N.A. N.A. N.A. .95 .52

3/4x1/2 N.A. N.A. N.A. N.A. N.A. .36 .20

its application, no labor charges were made for "flush" or short-pattern bushings and for couplings for either RSV or conventional venting.

To calculate overhead and profit, values of Fq, = 1.15 and Fp = 1.10 were used,

based on inverviews with contractors. These figures may vary in practice

t Cost estimates are based on 1976 list prices of a leading brand of Thermoplastic (PVC) fittings, reduced by 30 percent for contractor discount. Cost, are for Schedule 40 DWV fittings in sizes 3, 2, 1 1/2 and 1 1/4 inches, and

for Schedule 40 water pipe fittings in sizes 1, 3/4 and 1/2 inches.

* N.A. means not applicable for purposes of this project.

218
depending on the type and size of the project as well as on the size and business procedures of the plumbing contractor. (For further background calculations used in developing Tables 1 and 2, see Reference 9.)

Cost Savings Nationally

So far we have looked at the potential cost savings that would be generated

by substituting RSV for conventional venting of a specific design in an individual one- and two-story house.

To determine the potential total impact of RSV on pVumbing in the U.S., it

would be necessary to look at the aggregated life-cycle cost savings over

time for all types of buildings that might use RSV.

For the aggregate analysis undertaken here, the estimates of cost savings are

limited to an 11-year period from 1975 through 1985, a period for which rea- sonably dependable projections of housing starts are available. The aggregate

analysis is also confined to privately-owned, one-family houses projected for

construction during this 11-year period. A lower-bound estimate results, both

because of the limited time period and because the savings from the possible

use of RSV in multi-family residences and commercial buildings, as well as in new plumbing units retrofitted in existing housing, are not estimated. The

use of conservative projections for construction of new one- and two-story

single-family housing units further lowers the estimates.

The first step in calculating aggregate RSV savings is to estimate the number

of plumbing systems in which RSV will be used. It is assumed that each new

house (one- or two-story) will contain one plumbing system as defined earlier.

The estimated number of new privately-owned, single-family homes to be con- structed yearly, which is assumed to indicate the number of new plumbing systems installed yearly, is based on U.S. Bureau of the Census population

forecasts, 10 U.S. Bureau of the Census Construction Reports ,

1 and U.S. Department of Agriculture housing forecasts. 1 ^ (For a table of these housing

estimates by region, see Reference 9.)

The estimated number of housing units and plumbing systems are approximate

projections of possible housing demand (rather than actual construction), un- der the assumption of continued economic growth, moderate inflation, and no catestrophic events such as war. Cyclical variations are assumed to be offsetting in the long run, and are ignored in the projections.

A breakdown of estimated housing and plumbing systems was made by region be- cause certain venting designs tend to be used more in some regions of the U.S.

than in others, depending upon the codes in effect. It is also necessary to

evaluate the relative incidence of codes in order to estimate cost savings.

Local jurisdictions generally adopt one of the widely recognized model plumbing codes which have been developed by various associations of plumbing and

building officials, or pattern the local code after one of the models. The

IAPM0 Uniform Plumbing Code, one of the model codes, is usually interpreted to

require venting systems of type Cl in most installations. The BOCA Basic

219
Plumbing Code and the SBCC Standard Plumbing Code, two other popular model

codes, are similar to one another in terms of their venting requirements, both

allowing all three types of venting for specified types of construction.

The Uniform Plumbing Code (IAPM0) is the predominant code for the western U.S.

Thus most venting in the West is likely to be type CI. The basic Plumbing Code

(BOCA) is probably the predominant model code for the northeastern U.S., but

the Uniform Plumbing Code and the Standard Plumbing Code (SBCC) are also used

as models in a number of localities in the Northeast. The Standard Plumbing

Code seems to be the predominant model code in the southeastern U.S. A relatively higher proportion of venting installed in the Southeast is likely to be

of the type C3 and a smaller proportion of the types CI and C2 than in the

Northeast, mainly because a greater percentage of houses in the Southeast are

of an architectural design conducive to venting of type C3, the simplest type.

Figure 6 divides the U.S. into three main regions —western, northeastern, and

southeastern—for the purpose of showing the approximate percentage of new

homes which will have venting designs of each of the types CI, C2, and C3. The

estimated percentages of new plumbing systems in each region that will have

each type of venting design are shown in the legend at the bottom of the map.

For example, it is estimated that 20 percent of the new plumbing systems in thej

Northeast will be of the venting design type CI; 20 percent, C2; and 60 percent, C3.

To estimate the future savings of RSV in the U.S., a final piece of information

is needed. It is the "diffusion rate"--the rate at which RSV will be accepted • by code authorities and applied in venting systems. It is unlikely that RSV

will be widely adopted in the beginning, in that it generally takes time in tN<

U.S. for any new building technology to be accepted both by the building regu- j; latory system and by builders, plumbers, and homebuyers. But with demonstrated | ( performance and cost savings, RSV is likely to become widely used.

As a rough proxy for the diffusion rate, we estimated by region the percentage

of new, single-family houses each year in which RSV appears likely to be installed. (See Reference 9 for a listing of these estimates.) To derive these

estimates, the percentage of new houses in which RSV will be used by 1985 was !l first forecasted in consultation with experts in the plumbing industry. The

percentages of new houses in which RSV will be used in each year from 1975

through 1984 were then estimated on the basis of the 1985 forecast by the following formula:

F. =

J

jZ Y.

• F (2)

i=l

J where

F. = calculated percentage

venting ,

of new houses constructed in year j with RSV

220
221
Y. = years from 1975 through 1 985 represented by consecutive numbers from

1 to 11, and

F = preducted percentage of new houses to be constructed in year n (i.e.,

n 1985) utilizing RSV.

This formula was selected for estimating the percentages of new houses from

1975 through 1985 which will utilize RSV because it appeared reasonably descriptive of the patter of acceptance of an innovative building technology;

that is, growing acceptance over time, but at a decreasing rate.

To derive the expected aggregate cost savings from RSV, first the savings for

each region and house type were computed, taking into consideration the plumb- | ing system cost savings from RSV for each of the three types of venting designs

the percentages of houses likely to contain each type of venting design, and

the expected percentage of houses ut i 1 i z i ng RSV. The savings were then summed | across all regions and house types. Table 5 shows the estimated total cost

savings by region and for the U.S. as a whole, based on the stated assumptions.

The projected estimate of aggregate present value savings, discounted with an interest rate of 10 percent, is $106.5 million, based on the use of RSV in an r estimated 3.9 million single-family residences. The largest single part of

these savings is expected to come from the use of RSV in one-story houses in

the Southeast.

An additional cost factor that has not yet been discussed is the cost of re- search and development which is leading to the application of RSV. To ascertain the net benefits of RSV, we need to know the difference between the

present value of cost savings from introducing RSV and the increased cost incurred in its implementation. Taking into account government and private

f laboratory research, field testing, and building trials, we estimate the prej sent value of research and development costs to be approximately $900,000.

Compared with the estimated savings (benefits), the costs are small. The pre- j sent value of the resulting net benefits of RSV is $105.6 million.

Because the cost savings from RSV are sensitive to the assumed levels of ac- ceptance, and because these levels are uncertain, we recalculated our estimatesj

for lower and higher percentages of acceptance than those that were used in the

original estimates. Savings from RSV (not shown in tables here) were still l high —$58 million based on percentages of acceptance half as great, and $1^9

million based on percentages of acceptance 1.5 times as great as those used

initial ly.

9

Impact of RSV in the U.S. and Abroad

s We have demonstrated that RSV has the potential for reducing the cost of housing in the U.S. Estimates of $^6 to $125 in potential savings per singlefamily household, and of $58 million to $1^9 million for the nation as a whole

over the next 11 years, show that the adoption of RSV could result in an important impact on the plumbing and building industry.

Realization of these potential cost savings in the U.S. depends on how fast

code authorities accept RSV in the plumbing codes and how fast builders,

222
Table 5

Estimated Potential Cost Savings From Use of RSV, 1975 through 1985

Region Type of House

Number of RSV

Systems

(1,000)

Present Value

Sav i ngs

($1 ,000,000)

Northeast 1-Story 670 20.5

2-Story 633 12.3

Total 1,303 32.8

Southeast 1-Story 1,557 41.5

2-Story 458 4.4

Total 2,015 45.9

West 1-Story 429 18.7

2-Story 172 9.1

Total 601 27.8

All Regions 1-Story 2,656 80.7

! 2-Story 1,263 25.8

Total 3,919 106.5

developers, contractors, plumbers, and homebuyers implement RSV technology once

it is authorized by the code. Greater use of RSV would be promoted in the U.S.

by demonstrations that RSV meets the performance requirements of venting 3 ' 4 and

223
that RSV will save money. It should be recognized, however, that such factors

as poss ible difficulties in obtaining the smal ler-:sized piping and the special

transition fittings, initial lack of installation experience, lack of familiarity with research findings on the adequacy of performance of RSV, inappropriate code content to facilitate proper design and inspection, and resistance

to change by labor may retard RSV acceptance and reduce the savings to be

realized from RSV over the next decade. However, time will likely reduce many

of these barriers to RSV, and one might expect that the combined thrust of

greater familiarity, better documentation on field trials, and demonstrated

cost savings will soon establish RSV in the U.S. as a viable venting technique

applicable to any type of standard DWV system. The nation stands to benefit

from the provision of plumbing systems with satisfactory performance at considerable dollar savings.

It is probably not justifiable to project the estimated U.S. savings potential

to other countries. Because the U.S. has more elaborate venting requirements

than most other countries, it may have more to gain on a per-hous ing-uni t basis

from adopting RSV than the other countries. However, in those countries where

the government is a major builder, and where codes are centrally imposed, the

transition to a new building innovation such as RSV would probably be much

faster than in the U.S. To arrive at an accurate forecast of the cost savings

impact from the use of RSV in other countries, it would be necessary to make

country-specific analyses similar to this study for the U.S., taking into ac- count current plumbing designs and venting requirements, as well as housing

forecasts and RSV diffusion rates.

ACKNOWLEDGMENTS

This paper is based in part on a report by the Applied Economics Group of

the National Bureau of Standards. 9 A more detailed treatment of these research

findings and the methodology on which they are based appears in "Cost Savings

from Reduced-Size Venting," an article published in Plumbing Engineer . The

authors thank the many readers for their critical reviews of this paper, particularly Dr. John McConnaughey.

224
REFERENCES

This paper is based in part on an article entited, "Cost Savings from Reduced-Sized Venting" by the same authors, Plumbing Engineer , July /August

1977.

National Association of Home Builders Research Foundation, Inc., Performance of Reduced-Sized Venting in Residential DWV Systems , Report LR-210-

17(1971), Rockville, Maryland.

Orloski Mary J. and Robert S. Wyly, Hydraulic Performance of a Full -Scale

Townhouse System with Reduced-Size Vents . National Bureau of Standards

Report, BSS-60, 1975.

Wyly, Robert S. and Mary J. Orloski, Studies of Reduced-Size Venting of

Sanitary Drainage Systems in the U.S.A. , Paper 13, Proceedings of the Commission W-62 Symposium on Drainage Services in Buildings, Stockholm, Sweden, September 1973. Institute for Building Research Document D 1 4 : 1 973

Wyly, Robert S., Grover C. Sherl in, and Robert W. Beausoliel, Laboratory

Studies of the Hydraulic Performance of One-Story and Spl it-Level Residential Plumbing Systems with Reduced-Size Vents . National Bureau of Standards

Report, BSS-49, 197^.

Jackson, T. and T.P. Konen, An Investigation of the Adequacy of Performance

of Reduced-Size Vents Installed on a Ten-Story Drain-Waste and Vent System , Davidson Laboratory, Stevens Institute of Technology Report SIT-DL-73-1708,

under contract to National Bureau of Standards (July 1973).

National Association of Plumbing-Heating-Cooling Contractors, NAPHCC Labor

Calculator , NAPHCC, Washington, D.C. (1971 and 1975 Revisions) .

BOCA = Building Officials and Code Administrators International

SBCC = Southern Building Code Congress International

IAPM0 = International Association of Plumbing and Mechanical Officials

Marshall, Harold E. and Rosalie T. Ruegg, Efficient Allocation of Research

Funds: Economic Evaluation Methods with Applications in Building Technology , National Bureau of Standards Special Publication (in press).

U.S. Bureau of Census, Projection of Population Growth . U.S. Bureau of Census, Construction Report , Series C25, July 197**.

Marcin, Thomas C, The Effects of Declining Population Growth on the Demand

for Housing , U.S. Department of Agriculture, General Technical Report NC — 11,

225
I

I

I
USNCCIB W-62 COUNTERPART COMMISSION

WATER SUPPLY AND DRAINAGE FOR BUILDINGS

MEMBERS

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JAMES R. MYERS, Professor, Civil Engineering School, Department of

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228
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BUILDING RESEARCH ADVISORY BOARD

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Sociotcchnical Systems concerned with the built environment, lis primary objective is to promote the orderly growth and develop- ment of science and technology to meet societal needs for housing, building, and related community and environmental design and development. In fulfilling this objective the Board works toward: improving the availability and utilization of the human and

natural resources needed to create, operate, maintain, and renew the built environment; identifying the individual, societal, and

physical environmental objectives to be sought in the built environment; increasing the effectiveness of the building process functions of planning, design, construction, operation and maintenance, repair and alteration, rehabilitation and disposal, and recycling of useful materials and products; and extending the base of knowledge concerning the art, science, and technology of building and

stimulating the transference of this knowledge into application. The 36-member Board, together with a number of individuals from federal agencies who serve in a liaison capacity, constitutes a body of recognized authorities in building-interested segments of industry, government, the design professions, and academic and

research institutions; each member serves as an individual and never as a representative of any other organization or interest group. The Board's strength rests in the expertise and dedication of this multidisciplinary membership and that of the hundreds of indi- viduals from both the public and private sectors who respond to its requests that they serve voluntarily on its various working

groups. Composed of these knowledgeable individuals, the Board's Councils, committees, panels, and task groups address and often recommend solutions to important problems and issues that affect the future of the built environment. OFFICERS AND MEMBERS

1976-77

Bernard H. Breymann, Vice Chairman

OFFICERS

Charles E. SchafTner, Chairman Dan E. Morgenroth, Vice Chairman

Robert M. Dillon, Executive Director

J. Neils Thompson, Vice Chairman

MEMBERS

•Bernard H. Breymann, President, Eco-Terra Corp., Chicago,

Illinois Richard B. DeMars, President, Geupel DeMars, Inc., Indianapolis, Indiana G. Day Ding, Head, Department of Achitecture, College of Fine and Appied Arts, University of Illinois. Urbana

•JWalter S. Douglas, Chairman of the Board, Parsons, Brinckerhoff, Quade & Douglas, Inc., New York, New York

William D. Drake, Professor of Urban and Regional Plan- ning and Professor of Natural Resources, University of Michigan, Ann Arbor

•Robert Martin Engelbrecht, AIA, Robert Martin Engelbrecht and Associates, Architects, Planners, Researchers, Princeton, New Jersey {Joseph T. English, M.D., Director, Department of Psychiatry, St. Vincent's Hospital and Medical Center of New

York, New York

•Robert A. Georgine, President, Building and Construction Trades Department, AFL-CIO. Washington, D.C.

Charles P. Graves, Professor, College of Architecture, University of Kentucky, Lexington

Paul C. Greiner, Vice President, Energy Conservation and

Management, Edison Electric Institute, New York, New

York

•Robert Gutman, Professor, School of Architecture, Princeton

University, Princeton, New Jersey Charles M. Haar, Louis D. Brandeis Professor of Law, Law

School of Harvard University, Cambridge, Massachusetts

•Calvin S. Hamilton, Director of Planning, City of Los Angeles, Los Angeles, California Lawrence E. Hinkle, M.D., Professor of Medicine and Director, Division of Human Ecology. Medical College, Cornell University, New York, New York Morton Hoppenfeld, AIA, AIP, Dean, School of Architecture and Planning, University of New Mexico, Albuquerque John C. Horning, Manager, Engineering, Real Estate and

Construction Operation, General Electric Company, Schenectady, New York

Oliver H. Jones, Executive Vice President, Mortgage Bankers Association of America, Washington, D.C. •Rudard A. Jones. AIA, Director and Research Professor of

Architecture, Small Homes Council-Building Research

Council, University of Illinois, Urbana

Kenneth J. Kerin, Director, Economics and Research, National Association of Realtors, Washington, D.C.

Marjorie M. Lawson, Attorney, Lawson and Lawson, Washington, D.C.

Otis M. Madcr, Vice President-Consumer Group-Allied Products, Aluminum Company of America, Pittsburgh, Pennsylvania Garth L. Mangum, McGraw Professor of Economics and

Director, Human Resources Institute, University of Utah,

Salt Lake City Frank J. Matzke, Executive Director, State of Illinois Capital Development Board, Springfield D. Quinn Mills, Professor of Business Administration and

Labor Relations, Harvard Business School, Boston, Massachusetts •Dan E. Morgenroth, PE, Manager, Market Development, Owens-Corning Fiberglas Corporation, Toledo, Ohio

Louis W. Riggs, President and Director, Tudor Engineering Company, San Francisco, California •Harold D. Sarshik, Vice President, 20th Century Construction Company, Inc., Cherry Hill, New Jersey •Charles E. Schaffner, Senior Vice President, Syska & Hennessy. Inc., New York, New York

•J. Neils Thompson, Director, Balcones Research Center, The

University of Texas, Austin Warren H. Turner, Engineering Director, Equipment and

Building, American Telephone and Telegraph Company,

Basking Ridge, New Jersey William G. Vasvary, Executive Director, Southern Building Code Congress, Birmingham, Alabama

Arthur M. Weimer, Special Assistant to the President, Graduate School of Business, Indiana University, Bloomington John H. Wiggins, President, J. H. Wiggins Company, Re- dondo Beach, California •Beverly A. Willis, AIA, President, Willis and Associates,

Inc., Architects, Environmental Planners, and Consultants, San Francisco, California •Joseph H. Zettel, Vice President, Director of Research and

Development. Industrial and Building Products, Johns- Manville Products Corporation, Denver, Colorado LIAISON

Gerrit D. Fremouw, PE. Deputy Assistant Secretary for

Facilities Engineering and Property Management, Depart- ment of Health, Education, and Welfare, Washington, D.C. Henry H. Marvin, Director, Division of Solar Energy, Energy

Research and Development Administration, Washington,

D.C. Viggo P. Miller, Assistant Administrator for Construction,

Office of Construction, Veterans Administration, Washington, D.C. Michael H. Moskow, Undersecretary, Department of Labor, Washington, D.C.

Charles J. Orlebeke, Assistant Secretary for Policy Develop- ment and Research, Department of Housing and Urban

Development, Washington, D.C. Nicholas A. Panuzio, Commissioner, Public Buildings Service, General Services Administration, Washington, D.C. William B. Taylor, Chief. Research and Development Office, Office of the Chief of Engineers, Department of the Armv,

Washington, D.C. James R. Wright, Deputy Director, Institute for Applied Technology, National Bureau of Standards, Department

of Commerce, Washington, D.C. EX-OFFICIO MEMBERS OF THE EXECUTIVE COMMITTEE

(Past Chairmen) John P. Gnaedinger, President, Soil Testing Services, Inc Northbrook, Illinois tWalter R. Hibbard, Jr., University Professor of Engineering,

Virginia Polytechnic Institute and State University, Blacksburg, Virginia Herbert H. Swinburne, FA1A, Architect, Philadelphia, Pennsylvania EX-OFFICIO

tPhilip Handler, President, National Academy of Sciences iCourtland D. Perkins, President, National Academy of Engi- ttHarvey Brooks, Chairman. Commission on Sociotechnical neering •Member, BRAB Executive Committee tMcmbcr, NAS

Systems, National Research Council IMembcr, NAE {Member, IOM

235
U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBS SP-553

2. Gov't Accession No. 3. Reeipjenfs Accession No.

4. TITLE AND SUBTITLE

WATER SUPPLY AND DRAINAGE IN BUILDINGS

5. Publication Date August 1979

Performing Organization Code

7. AUTHOR(S)

Lawrence S 0 Galowin and JoAnne R. Debelius

8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, DC 20234

10. Project/Task/WorM Unit No.

11. Contract/Grant No.

13. Type of Report & Period Covere Final12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, state, ZIP) In cooperation with: Counterpart Commission W-62,

U.S. National Committee for the International Council for

Building Research, Studies and Documentation, Building Researc

Advisory Board, Commission on Sociotechnical Systems, National

H4. Sponsoring Agency Code

15. supplementary notes Research Council

Library of Congress Catalog Card Number: 79-600105

I | Document describes a computer program; SF-185, FIPS Software Summary, is attached.

16. ABSTRACT (A 200-word or less tactual summary of most significant information. If document includes a significant bibliography or

literature survey, mention it here.)

This report contains the papers presented at the International Symposium on Water Supply and Drainage convened on September 28-30, 1976 at the National

Academy of Sciences, Washington, D.C. and conducted by the U.S. National

Committee for the International Council for Building Research, Studies and

Documentation (CIB) Counterpart Commission W-62. The meeting provided the

opportunity to exchange information and identify general needs and common perspectives of plumbing in on-going research applications and practices

in the United States and other countries.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name;

separated by semicolons) Building water systems; CIB; international plumbing research; plumbing and

drainage; U.S. research in plumbing.

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