NBS

pubii- Reference

cations

||

“ 2-2539

a40 \3chnical Summary of the Final

Report “Optimal Weatherization of

Low-Income Housing in the United

States: A Research Demonstration

Project"

A 1 1 1 0 b 0

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Environmental Design Research Division

Washington, DC 20234

May 1982

Sponsored by:

iunity Services Administration

ngton, DC 20506

100

. U56

02-2539

1902

NBSIR 82-2539

NONTECHNICAL SUMMARY OF THE FINAL

REPORT "OPTIMAL WEATHERIZATION OF

LOW-INCOME HOUSING IN THE UNITED

STATES: A RESEARCH DEMONSTRATION

PROJECT"

Stephen T. Margulis

Roy E. Clark

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Environmental Design Research Division

Washington, DC 20234

May 1982

Sponsored by:

Community Services Administration

Washington, DC 20506

U S. DEPARTMENT OF COMMERCE, Malcolm Baldrige,

NATIONAL BUREAU OF STANDARDS, Ernest Ambler. Director

U „YiOI.*- lA iUSAO OJ 'W’AHTJAJtDa fcWit

AUG 19 1982

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«
Table of Contents

Page

Abstract v Acknowledgements . vl

1. OVERVIEW 1

2. DETAILS OF THE CSA/NBS OPTIMAL WEATHERIZATION DEMONSTRATION ... 6

2.1 Introduction 6

2.2 Weatherization and Optimal Weatherization 6

2.3 The Sites 7 2.4 Dwelling Selection 8

2.5 Research Design 9

2.6 The Selection of Weatherization Options 10

2.7 Installation of Weatherization Options 13

2.8 Data Collection Procedures 13

3. RESULTS AND CONCLUSIONS 16

4. REFERENCES'......... 21

APPENDIX 22

iii
List of Tables

Page

Table 1. Comparison of the Impact of Extent of Weatherization

on Cost Savings, Energy Consumption and Comfort

Improvement 4

Table 2 . Selected Architectural Options, By City 12

Table 3. Selected Mechanical System Options, By City 14

Table 4. Payback Periods for Weatherized Houses 17

Table 5. Mean Values of Six Measures from CSA Weatherization

Demonstration 19

List of Figures

Page

Figure 1. Sites Selected for the Demonstration 2

iv
Abstract

This report summarizes in nontechnical language the nature and results of

the Community Service Administration’s (CSA’s) Optimal Weatherization Demonstration Research Project carried out by the National Bureau of Standards

(NBS). This summary draws on the final report of the field evaluation of the

Demonstration, an NBS publication entitled Optimal Weatherization of Low-Income

Housing in the U.S.: A Research Demonstration Project (NBS BSS 144). Unless

stated otherwise, this report references the final report.

The CSA/NBS demonstration installed both architectural (building shell) and

mechanical systems weatherization options, and achieved, when both types of

options were used an average reduction in space heating fuel consumption of

41 percent, at an average weatherization cost of $1,862 per house.

This summary report also includes abstracts of all the technical reports

documenting the CSA/NBS project. Directions for ordering available reports

are included.

Key Words: Community Action Agencies; Community Services Administration;

costs of residential weatherization; energy conservation; field

measurement of building energy consumption; optimal weatherization.

v
Acknowledgements

Dr. Richard A. Grot made a number of comments to an earlier version concerning

statistical methods. The author attempted to respond to Dr. Grot's comments.

Dr. Francis T. Ventre made a number of improvements to the narrative and con- ducted the manuscript through the NBS editorial review process.

Ms. Patty Bentz cheerfully typed and revised the manuscript despite an unusually

heavy end-of-the-year workload. The CBT Word Processing Center carried out the

final preparation of the report.

vi
SI CONVERSION UNITS

la view of the present accepted practice for building technology in this country, common U.S. units of measurement

were used throughout the report. In recognition of the position of the United States as a signatory to the General Conference on Weights and Measures, which gave official status to the International System of Units (SI)

in 1960, the table below is presented to facilitate conversion to SI units. Readers interested in making further

use of the coherent system of SI units are referred to: NBS SP 330, 1977 Edition, The International System of Units; and ASTM E621-78, Standard Practice for the Use of Metric (SI) Units in Building Design and Construction.

CUSTOMARY INTERNATIONAL (SI) UNIT U.S. CUSTOMARY UNITS APPROXIMATE CONVERSIONS

LENGTH meter (m) foot (ft) 1 in 3 3.2808 ft millimeter (mm) inch (in) 1 m a 0.0394 in

AREA square meter (m2

) square yard (yd2

) 1 = 1.1960 yd 2 square foot (ft2

) 1 10.764 ft 2

VOLUME cubic meter (m3) cubic yard (yd^) 1 = 1.3080 yd^

cubic foot (ft^) 1 m^ = 35.315 ft3 cubic millimeter (mm^) cubic inch (in^) 1 mm 2 = 61.024 X fl oz

CAPACITY liter (L) gallon (gal) 1 L = 0.2642 gal

milliliter (mL) fluid ounce (fl oz) 1 mL = 0.0338 fl oz

PRESSURE pascal (Pa) pound-force per square

inch (lbf/in2

)

1 Pa = 0.0015 lbf/in2

WORK, ENERGY megajoule (MJ) kilowatthour (kWh) 1 MJ = 0.2778 kWh QUANTITY OF HEAT kilojoule (kJ) British thermal unit (Btu) 1 kJ = 0.9478 Btu

POWER, HEAT FLOW watt (W) British thermal unit 1 W = 3.4121 Btu/h

RATE per hour (Btu/h)

foot pound-force

per second (fflbf/s)

1 W = 0.7376 fflbf/s

COEFFICIENT OF HEAT watt per square meter kelvin Btu per hour square 1 W/m2

-

K = 0.1761 Btu/h “ft 2 • °F TRANSFER [U-value] (W/m 2- K) [=(W/m2 -°C)] foot degree Fahrenheit

(Btu/ft 2 -h'°F)

THERMAL CONDUC- watt per meter kelvin (W/miK) Btu inch per hour square 1 W/m - K = 6.9335 Btu - in/h - ft 2 TIVITY [k- value] [=(W/m*°C)] foot degree Fahrenheit

(Btu - in/h' f

t

2 * °F)

NOTES: (1) The above conversion factors are shown to three or four places of decimals.

(2) Unprefixed SI units are underlined. (The kilogram, although prefixed, is an SI base unit.)

REFERENCES: NBS Guidelines for the Use of the Metric System, 1X1056, Revised November 1977; The Metric System of Measurement, Federal Register Notice of October 26, 1977,

LC1078, Revised November 1977; NBS Special Publication 330, "The International System of Units (SI)," 1977 Edition;

NBS Technical Note 938, "Recommended Practice for the Use of Metric (SI) Units in Building Design and Construction," Revised edition June 1977; NBS Standard E621-78, "Standard Practice for the Use of Metric (SI) Units in Building

Design and Construction," (based on NBS TN 938), March 1978; ANSI 2210.1976, "American National Standard for Metric Practice;" also issued as ASTM

E380-76 e

, or IEEE Std. 268-1976.

vii
. fa .

.

.

.

’

.
1 . OVERVIEW

The "energy crisis" has made American consumers acutely aware that energy

prices are rapidly rising and will continue to rise for the foreseeable future.

Rising energy prices have meant that low-income homeowners often spend a disproportionate share of the family budget on energy. Increasing housing

expenses have forced some low-income homeowners to spend less on other essentials, such as food, clothing, and health care. Resulting Congressional con- cern for the health and well-being of low-income Americans coupled with

Congressional recognition of the value of weatherization as an energy-conserving

strategy led to the passage of the "Headstart, Economic Opportunity, and Community Partnership Act" (Public Law 93-644) in 1975 and the "Energy Conservation

and Production Act" (Public Law 94-385) in 1976. As alternatives to subsidizing

fuel costs, these two laws established energy conservation programs for lowincome families and provided grants for the weatherization of residences. In

Public Law 93-644, Congress directed the Community Services Administration

(CSA) to conduct a nationwide program to estimate how much money could be

saved through optimal weatherization [1].*

In partial fulfillment of this mandate, CSA asked the National Bureau of

Standards (NBS) in 1977 to devise a research plan for measuring the technical

effectiveness of weatherization activities of Community Action Agencies (CAA’s).

The purpose of the demonstration was to provide a technical basis for estimating how much money and energy could be saved by "optimal" weatherization of

houses occupied by low-income families [6]. The Demonstration also sought to

learn about the effectiveness of three broad categories of building retrofit:

(1) increasing the thermal resistance of the building shell by adding insulation or storm windows ("conduction"); (2) reducing infiltration (of cold air)

and exfiltration (of heated air) by such means as caulking and weatherstripping

("infiltration"); and (3) improving the efficiency of heat producing and

distributing systems in houses ("mechanical systems") [6].

The CSA/NBS Demonstration ultimately obtained results from 183 houses at 12

sites (see figure 1) representing a range of U.S. climatic zones. This

climatic variety was needed in order to identify the range of savings that

weatherization could achieve. "Before weatherization" rates of fuel consumption of the houses were established by analyzing two years of recorded fuel

delivery or consumption records. Based on the local climatic conditions, the

local costs of fuel saved, and the local prices of installing various energyconserving retrofit options, a cost-effective set of weatherization options

was selected for installation at each house, using economic (life cycle

benefit-cost) analysis. The criterion used for selecting retrofit options was

that the package would generate the greatest possible net savings, in dollars,

for the dollars spent over the life of the options. These options would provide

* Numbers in brackets "[ ] " are keyed to the references listed in section 4 of

this report.

1
FARGO

(9271)

t/> —i

CD

UJo

CD3 2

Figure

1.

Selected

sites

for

the

demonstration
economically "optimal" weatherization .* Architectural (i.e., conduction and

infiltration-related) and, in many cases, mechanical system options were installed by local Community Action Agency (CAA) crews in the site area, and/or

by local contractors.

Energy use in the houses was monitored for at least one heating season following weatherization. A number of physical measurements of each house (e.g.,

temperature, infiltration rate) were made. Physical measurements, cost data,

and fuel consumption readings were supplemented by interviews with occupants

at nine sites about the wintertime comfort of their homes [2]

.

To clarify the effectiveness of the retrofit installations, several dwellings

in which no weatherization options were installed were measured at each site for

comparison purposes. Thus, the energy use, thermal performance, and occupant

evaluations of comfort of the weathered buildings were compared to otherwise

similar houses "without" weatherization. This comparison was made to isolate

and measure the effectiveness of weatherization strategies for residential

energy conservation.

In summary, at 12 sites across U.S. climatic zones, 142 low-income household's

homes were weatherized; the choices of which options to use were based on economic analyses. In addition, 41 residences were not weatherized and were

used for comparison purposes. Energy use, occupant comfort, costs, and estimated savings were measured. The overall results are summarized in table 1.

The measures in table 1: costs vs. savings (estimated payback period), fuel

consumption, and comfort improvement, all favor weatherization over no weatherization. Furthermore, installing mechanical systems as well as architectural

options, although it will cost somewhat more than installing architectural

options alone, will pay back faster, result in greater reductions in fuel

consumption, and in somewhat greater improvements in wintertime comfort inside

the house.

To better understand the results, each of the row headings in table 1 will be

briefly explained.

Cost of an option reflects actual costs reported by CAA's. Costs include

labor, material, overhead, and profit.

Payback period is a simple savings measure. It is obtained by dividing

the total cost of weatherizing a house by the product of the amount of

fuel saved and the 1980 cost of that fuel. This measure was chosen over more mathematically sophisticated ones, because it is an understandable

measure, meaningful to more people.

* In general, the economically optimal package included mechanical system

retrofits as well as architectural modifications. However, in some cases,

no mechanical options were found to be cost-effective, or feasible, for the

heating system present in a house.

3
Table 1 . Comparison of the Impact of Extent of Weatherization on Costs

Savings, Energy Consumption and Comfort Improvement (All

Values are Averages)

Houses in CSA Demonstration

Weatherized

Nonweatherized

(1)

Arch. & Mech

.

Options

(2)

Arch

.

Options

Only

(3)

Total

Weatherized

(1) & (2)

(4)

Control

Group

Cost of Options $1,862 $1,336 $1,610 —

Payback Period (in years) 6 15 8 —

Percent Savings in Fuel

Consumption

41 17 31 4

Comfort Improvement 0 . 66 0.56 0.61 0.09

Number of Houses in the Sample 74 68 142 41

Percent savings in fuel consumption was generated from a statistical analysis of the relationship between fuel consumption and "degree days" , a term that expresses the amount of coldness during a winter heating season.

The results of this analysis were used to estimate what the pre- and postweatherization fuel consumption of the houses would be for a "typical"

year

.

Comfort improvement is based on the occupants’ evaluations of their

thermal comfort at home during the pre- vs. post-weatherization heating

seasons. This composite measure takes into account changes in thermostat

settings, expressed wintertime comfort, amount of clothing worn indoors

during the winter, and comfort ratings of individual rooms and of the

house as a whole. A 0.0 means the occupants reported no change in comfort. A 1.0 means the occupants reported change in the direction of

improved wintertime comfort on all of the aforementioned indicators [2,

pp . 29 - 30 ]

.

The implications of these results are clear. Weatherization is a cost-effective

alternative to subsidizing fuel costs during the heating season, and a means of

helping to ensure the health and well-being of low-income families pressed by

rising fuel costs. Unlike subsidization of fuel bills, weatherization pays for

itself. After the retrofit package has paid for itself, the householder can

4
put the continuing savings to uses the family considers important. In fact,

as fuel prices continue to rise, weatherization becomes increasingly attractive

as a homeowner investment, since the savings are greater and the payback period

shorter

.

Public money will be saved through weatherization of housing. Also, the

Nation’s dependence on foreign fuel supplies will decrease. Put this statement into perspective: there are now over 84 million dwelling units in the

United States. It is estimated that these units will comprise 85 percent of

all dwelling units available in the year 2000. Today's existing units, then, are the largest share of the Nation's housing stock tomorrow. Most of these

residences could be made more energy efficient. Heating the current housing

stock requires 11 percent of all energy used in the U.S. "Optimal weatherization" could significantly reduce this consumption. If an average 40 percent

reduction in energy use could be achieved in all housing, it would result in an estimated saving of energy equivalent to more than 100 million barrels of

oil a year. This could have a positive effect on the Nation's economy as a whole and on the household budgets of all families paying fuel bills in order

to keep warm.

Going further, although this Demonstration achieved an average 40 percent

fuel savings in optimally weatherized homes, savings as high as 70 percent were achieved in individual houses. Average savings of 50 to 70 percent could

probably be achieved by adding other energy-saving strategies, such as "house

doctoring" and solar heating, to optimal weatherization. House doctoring

involves the use of furnace tests to assess mechanical system efficiencies,

thermography (heat-sensing photography) of walls to determine thermal leakages,

and fan tests to measure air leakages, as bases for selecting needed, housespecific retrofit options. The CSA/NBS Demonstration Project staff have suggested that house doctoring alone could achieve fuel savings of an additional

10 percent.

5
2 . DETAILS OF THE CSA/NBS OPTIMAL WEATHERIZATION DEMONSTRATION

This section is for the reader who wants to lean a bit more about the CSA/NBS

Optimal Weatherization Demonstration than was presented in the Overview section.

2.1 INTRODUCTION

There are 55.5 million single-family residential units in the United States.

This includes 10 million dwellings of low-income homeowners. Among these

houses are many typical of middle-income Americans, particularly those houses

occupied by retired citizens who, because of their change in job status, find

themselves in a low-income category. Thus, the findings of a study of homes

of low-income homeowners are applicable to not only the 10 million homes of

low-income families but also to houses of middle-income Americans that are similar to the dwellings of low-income retired Americans analyzed in this

Demonstration

.

There is good reason to focus on low-income households. They often spend a disproportionate share of their family budget on energy. During the winter,

fuel costs can confront the low-income homeowner with a painful choice between

home heating and the purchase of food, clothing, or health care. Congress

recognized this problem and responded with the passage of Public Laws 93-644

and 94-385. These two laws established energy conservation programs for lowincome families and provide funds for weatherization (i.e., energy conservation retrofitting) grants. Public Law 93-644 also assigned the leadership

role in administering a nationwide evaluation of weatherization to the

Community Services Administration (CSA).

CSA selected the National Bureau of Standards (NBS) to conduct a nationwide

demonstration of how much money and energy could be efficiently saved through

weatherization of low-income families’ homes.

2.2 WEATHERIZATION AND OPTIMAL WEATHERIZATION

Although several alternatives to reducing the impact of rising fuel costs on low-income homeowners were considered by NBS, including the use of renewable

energy sources such as the sun or wind, energy conservation offered the most

savings for the cost. Moreover, the technologies were readily available in

every region of the Nation.

Weatherization refers to the installation or retrofitting of energy conserving

designs or devices on an existing structure. There are two advantages to

investing in weatherization. A particular advantage is that most weatherization options can pay for themselves in saved fuel cost over the term of the

typical home improvement loan. Another is that, as energy prices continue to

rise, weatherization investments act as a hedge against the destructive effects

of inflation on low-income families, particularly those on fixed incomes. In

all, weatherization offers low-income homeowners an opportunity to permanently

increase future consumption of essentials, such as food and clothing, without

drastically reducing their wintertime health and well-being [1].

6
Levels of weatherization can differ. Therefore, a major objective of the CSA

demonstration was to identify and test "optimal" weatherization levels, levels

that took into account local climatic conditions and local supply and demand

factors in the energy and construction sectors. The technical approach to

identifying "optimal" weatherization levels for the low-income families' homes

was explicitly economic. The economic analysis was based on the premise that

improving the efficiency of space heating systems and increasing the thermal

resistance of the building envelope (i.e., adding insulation to, and reducing

air leakage through, the exterior walls, roof, and ground floor that enclose

the house) are nearly perfect substitutes for energy consumption [9]. Therefore, to find the "optimal" level of weatherization investment for a house, it

is necessary to weigh the costs of weatherization against future reductions in

energy consumption. Economic analysis demonstrates that each additional unit

or level of weatherization should result in smaller reductions in energy con- sumption. In this approach, the economically optimal level of weatherization —

the one that results in the maximum net savings over the life of the weatherization option — typically will not be the level that minimizes energy consumption [1]! In other words, low-income homeowners must be careful not to overinvest their scarce dollars in too much weatherization.

The economic analysis developed by NBS for calculating weatherization costs and

savings designates a group of weatherization options for a particular house by

determining for each increment in weatherization whether the additional dollars

saved in energy costs over the life of an option (increment) are greater than

the cost of purchasing and installing that option. The economically-optimal

level, in this life-cycle benefit-cost approach, is that set of options whose

incremental cost equals its incremental savings [1].

An optimal level at any one time or in any one house is unlikely to be optimal

at another time or house. Over time, new technologies and materials are introduced, costs of materials and labor change, fuel costs change, and the like.

Different places offer their particular climatic conditions, fuel costs, and

initial levels of weatherization of the houses. Thus, the 12 sites participating in the CSA Demonstration, each with its unique conditions, require

individual calculation of optimal weatherization options.

2.3 THE SITES

The selection of cities in which the homes of low-income homeowners would be

weatherized was based on the need to accurately measure the effects of as many

important determinants of weatherization savings as possible. Climate, as the

major variable affecting energy consumption, hence, energy savings, was the

principal determinant in site selection. By conducting a weatherization demonstration in a range of climatic conditions, better estimates of nationwide

savings attributable to weatherization options was possible [1].

Based on a careful analysis of climatic conditions and building climate zones,

16 cities representing a variety of climatic conditions were selected initially

as candidate sites for the weatherization Demonstration.

7
Each site had to meet two selection criteria. First, the local Community

Action Agency (CAA) had to be able to provide field crews who could not only

effectively install weatherization options, but who were also able to collect

and organize energy use data from the houses in the Demonstration. Second,

hourly climatic data had to be available for that location on National Weather

Service computer tapes.

The 12 cities that finally participated are shown in figure 1. The number of

degree days (DD) for each city appears in parentheses near the city's name.

2.4 DWELLING SELECTION

To be considered for the demonstration, houses had to meet five criteria [6]:

1. Accurate data on prior energy consumption had to be available.

2. The houses must have been occupied continuously by the same family for the

two years before the Demonstration began (i.e., since April 1975).

3. There had to have been no major changes to the building's envelope or heating system during the two years before the Demonstration began (i.e.,

since April 1975).

4. The house should be in an acceptable state of repair.

5. The shape of the house should be simple, preferably a rectangle.

Additional factors were considered in the selection candidate houses [5, 6].

These were:

6. Housing (building) type, such as single-family detached.

7. Construction material, such as wood frame or masonry veneer.

8. Type of heating system, such as floor furnaces, vented and unvented space

heaters, baseboard heaters, in addition to hot water or hot air circulated

central heat.

9. Age of the house — whether it was pre-World War I or post-World War II

vintage, or was constructed between World Wars.

10. Building size.

11. Percent of wall area consisting of glass.

12. Building orientation.

13. Occupant characteristics.

Factors 6-13 were treated as follows. The variables mentioned in items 6-9 were controlled by NBS. Each site was asked to submit at least three houses

from each of the time periods noted in item 9. Building type and construction

8
materials (items 6 and 7) were controlled by asking local CAA workers to

submit at least five of each locally available combination of one- and twostory detached and attached houses of frame, masonry, masonry veneer, and

adobe construction. Local CAA officials also were asked to submit a variety

of heating system types, such as those noted in item 8. The aim was to have

at least five of each type in the Demonstration. Item 10, building size, was statistically controlled by expressing energy use as Btu's (a unit for measuring energy), per square foot. Items 11-13, glass area of wall, building orientation, and occupant characteristics, were allowed to vary within and across

sites. This was based on the assumption that they would introduce no systematic bias into the results. These attempts at controlling important variables

were generally successful.

In the end, 222 houses were chosen for weatherization and 68 houses for the

nonweathered comparison group. The nonweatherized comparison group (its purpose is explained in the next section) came from the same pool of houses as did the houses to be weatherized, showed similar pre-weatherized fuel consumption as did the to-be-weatherized houses in the site city, but differed

principally from the to-be-weatherized houses in three ways: 1) the building

type and construction material combination were unusual in the pool (i.e.,

five cases could not be found in the city); 2) the house did not have a simple

shape (e.g., it might have been "L" shaped), which made certain thermal

analysis calculations more difficult; or 3) the owners did not want their

house to be weatherized as part of the Demonstration [2, p. 21].

Sufficient data were taken for the required time period from only 142 weatherized

houses and 41 comparison group houses of the original 290 houses identified

Houses were lost from the weatherization group because owners no longer wanted

to participate or the houses were physically abandoned. Comparison group

houses were lost for the same reasons and, in some cases, because the owners partially weatherized their own homes. Of the 142 weatherized houses, 74

received mechanical systems as well as architectural options; see the section

on the selection of weatherized options.

2.5 RESEARCH DESIGN

A research design is the basis for establishing whether there is a relationship

between the events under study (in this case, between weatherization and energy

consumption), what the relationship is (in this case, the prediction that

weatherization should result in a decrease in energy consumption) , and how the

relationship can reasonably be explained (in the present case, that changes in

energy consumption are due to weatherization) [8].

The Demonstration's research design employed two research techniques to help assess the effects of weatherization on energy consumption. First, energy

usage and related factors were measured before and after weatherization.

Second, housing from the same housing pool as the weatherized housing, but

which did not receive weatherization (the comparison housing) also had its

energy usage and related factors monitored during the pre- and postweather ization periods.

9
What relationships among events did the NBS researchers expect? They expected

the weatherized and nonweatherized (comparison) housing within site cities to

have comparable pre-weatherization energy consumption. They expected the wea- therized housing, but not the nonweatherized comparison housing, to save energy,

specifically, to decrease energy consumption during the post-weatherization

period of measurement. (Both expectations were supported by the results.)

The numbers of weatherized houses (from which adequate data were received) are shown in the city-by-city summary data (table 5). The number of nonweatherized

(control) houses at each site from which adequate data were collected ranged

from two to five.

2.6 THE SELECTION OF WEATHERIZATION OPTIONS

For the CSA Optimal Weatherization Demonstration, optimal weatherization was that

group of "architectural" (building shell) and "mechanical” (space heating systems) retrofit options generating the greatest possible dollar value of net

savings over the life of the options. Using techniques of economic analysis,

the group of options for a specific house was selected by analyzing, over the

life of each option, the cost and the future energy savings associated with

each increment in weatherization. The economist’s optimal level of weatherization is the level where incremental cost equals incremental savings. These

options might not result in maximum energy savings, but will be the most costeffective energy-saving option package [1].

An "increment of weatherization" is a single, specific energy saving

modification that can be made to a house. In the case of architectural

options, these increments may include an added inch of insulation, or storm

windows over single glazing, or caulking a door. For mechanical options,

increments may include installing a clock thermostat, installing a flue damper,

or replacing a furnace [4]

.

As noted earlier, the introduction of new materials and technologies; differences

and changes in the cost of materials, labor and fuel; variations in the initial

physical condition of a house; difference in climate; and the like, mean that

what constitutes "optimal" weatherization options for installation will vary

with the location of the house and over time.

Again, the CSA Demonstration focused on the savings related to combinations

of energy conserving retrofits. Future studies could address savings associated

with individual options and other strategies such as alternative energy sources

(e.g., passive and active solar energy options).

To select architectural options, areas of the house considered were walls, the

roof, floors, basement walls, doors, windows, and cracks or holes in these

areas. For each of these areas, each possible incremental installation (option)

was examined for its costs and benefits (estimated savings). Optimal combinations were established taking into account climate, option prices, and fuel

costs

.

10
The cost-benefit ratio was calculated using the following formula:

Benefit = Predicted Fuel Saving s X Present Value Factor X Cost of Fuel

Cost Replacement Factor X Cost of Option

where

Predicted Fuel Savings were calculated, in Btu’s, using a modified version

of the ASHRAE steady-state heat balance equation (discussed in ref. [1]).

Present Value Factor makes future energy savings in dollars comparable to

the present cost of an option.

Cost of Fuel was obtained at each city in the Demonstration, and reflected

local taxes, surcharges, and block rates (which are used for electricity

and natural gas, and affect the price of fuel depending on the amount

used)

.

Replacement Factor relates to options that are not expected to have a 20

year physical life. Twenty years was selected as a criterion because it was the maximum life of most of the weatherization options being considered

by NBS. In some cases, the first cost of an option was adjusted to reflect

the present value of future costs of any replacements needed to achieve a 20 year life.

Cost of an Option includes first costs based on estimates obtained for CSA

officials and contractors in Demonstration site cities, and it includes

any future costs resulting from maintenance, repair, or replacement,

discounted to present value, over a 20 year period of use.

The selected architectural options are summarized in table 2 [4]

.

Unit-by-unit

summaries are in [5].

The mechanical options were selected independently of the architectural ones. For this analysis, it was assumed that architectural options had reduced the

building load by 50 percent and the mechanical systems were "optimized" to

that reduced load. Assumed seasonal efficiencies for oil systems were 60

percent; for gas systems, 70 percent; and for unvented space heaters, 100

percent [4]

.

Whereas architectural options were based on climate, mechanical options were

based on the type of space heating system. Using results of earlier NBS

research on space heating system tests (discussed in [6], pp. 42-54), efficiency improvement values were assigned to each retrofit that could be

physically added to an existing space heating system.

This value was then multiplied by the energy load of the building (reduced by

50 percent to allow for the predicted effects of the architectural options) to

calculate expected energy savings. The calculated equivalent dollar savings

and estimated option cost data (obtained from CSA officials or contractors in

demonstration site cities) were entered into benefit-cost calculations. Next,

11
Table 2. Selected Architectural Options, By City

ARCHITECTURAL

OPTIONS

Seal holes and cracks

Weatherstrip and caulk

Storm windows

Storm windows and insulating

shutters

Triple glazing

Triple glazing and insulating

shutters

Storm door on doors with glass

R 1 1 attic insulation

1 19 attic insulation

X 30 attic insulation

X 38 attic insulation

Wall insulation R 11 basement crawl space

nsulation R 7

Fuel used:

Electricity

Propane

Z

+ e

+ p

12
the options were ranked on estimated Btu's saved. Savings then were recalculated

option-by-option, to allow for the reduced load resulting from the installation

of previously selected options. When discounted savings over 11 years no longer

justified the first cost of an additional option, the cost-effective set of

options had been identified.*

The selected heating system options are summarized in table 3.

2 . 7 INSTALLATION OF WEATHERIZATION OPTIONS

A successful weatherization program requires that options be properly selected,

installed, and used. NBS commissioned and CSA sponsored the preparation of

a Home Retrofit Manual [7] to aid local CAA workers with installation of options.

(Also see ref. [10].)

Options were installed either by local CAA agencies using Comprehensive

Employment and Training Act (CETA) labor or by local contractors. In general,

mechanical options were installed by contractors while infiltration-related

options (e.g., replacing broken glass, resetting glazing, replacing thresholds,

sealing cracks and holes, weatherstripping and caulking windows and doors) was done by CAA's. Insulation (in attics, walls, or in basements or crawl spaces,

for example) was installed by both contractors and local CAA's. Budget and

staffing limits precluded a systematic examination of the quality of the

installations, but informal inspections suggested that the quality of the

installation work varied. Assessing the impact of these variations in adequacy

and quality of installation on energy consumption was beyond the scope of the

present Demonstration.

Starting with the list of selected options for a house, what was actually

installed was affected by the already existing level of weatherization of the

house and the initiative of local CAA personnel in installing the options. The

lack of installation of mechanical options in all houses at certain sites was

a result of local CAA decisions. In some cases, particularly the presence of

a space heater in a home, installation of mechanical options was not feasible.

(See ref. [5], chapter 7 for a house-by-house summary of installed options).

2.8 DATA COLLECTION PROCEDURES

The Demonstration focused on collecting a range of general measurements for

many houses in daily use rather than on highly detailed measurements of a few laboratory houses. The resulting database, documented in reference [3],

allowed an evaluation of the effects of weatherization retrofits on energy

consumption and, as important, will provide an invaluable archive to other

researchers

.

* The formula used for the cost-benefit calculations is on page 16 of ref. [6].

An NBS report in preparation will present a detailed discussion of the

13
Table 3. Selected Mechanical System Options, By City

MECHANICAL

OPTIONS

Flue m vent damper

Flue or vent restrictor

Electron ignition

Two stage gas valve

Derate furnaee(gas)

Replace burner

Optimal nozzle (all)

Replace furnace or space heater

Insulate ducts and pipes

Night setback thermostat

Insulate water heater

Reolace water heater

Reduce hot water temp.

Shower flow restrictor

Timer on elect. water heaters

Aquabooster

Insulate hot water pipes from

water heater

Flue damper water heater

so

t"

to

o

to °

U tofl — TO«

x: js O O

e/5

©

o

to Q,

C/5

soTO O

04) TO

TO «

s r

TO O

o Q=

co3O

+-* 00

04) TO =

E TM

s g 2 is

9 m 9 9 9 all •I • 9 |

9 m •

9 9 9 9 9 i i 9 9

j <* 9 9 l i i i 9 A

• 9 9 9

fj “3

1 ® 1 9

9 9 9 j 9

9 • 9 | 9 I • • 9 © 9 j 9

• 9 • l 9 | • 9 9 9 • (all a!! all •1 9 9

all all all all all all all

| ail all all

j

all ail • 9

all all all all all all all ail all all

| all [all

all 9 9 9 f all 9 LJ all

j 9 |

all all all all all

j all| j all

| all |

1 I i I I 1*1

j •j I*!

1L_LZl

9 all all all L!l 1. 1

9- Installed on a few of the sample homes

all - Installed on all of the sample homes

14
Basically, the pre-weatherization data was based on a two year period and the

post-weatherization data on one year. Including an entire heating season in

the post-weatherization year was the desired (but not always achieved) goal.

Although the houses were carefully instrumented with energy consumption and

running-time meters on heating systems in order to develop a fall-back database,*

the data used for the evaluation of the weatherization retrofits was based,

in most cases, on whole house meter readings. This was done to obtain comparable

pre- and post-weatherization data. Specifically, for houses that were heated

using electricity or natural gas, utility meters on the house were used as the

data source during the pre- and post-weatherization periods. For houses using

oil for space heating, delivery records were used during the pre-weatherization

period, and consumption was measured during the post-weatherization period by

using the heater run time multiplied by the nozzle rate, with the nozzle rate

calibrated against fuel delivery data, whenever possible. (All meters in the

houses were read weekly, thus, providing much richer data for evaluation than

could be obtained from typical utility or fuel delivery records.) For houses

using propane (bottled gas) for space heating, delivery records were used

throughout the Demonstration.

Because fuel consumption is strongly related to outdoor temperature, and

because not all heating seasons are equally cold, it was necessary to normalize the fuel consumption data for the pre- and post-weatherization periods in

order validly to compare the pre- and post-weatherization period data. Normalization was based on a "standard" seven year (1973-1980) average of degree

days for the locale, calculated by NBS from the daily data recorded by the

National Weather Service.

* This store of data

management control

is likely to be of interest to

systems. See reference [3].

specialists in energy

15
3. RESULTS AND CONCLUSIONS

The key findings are summarized in table 1.

Results are presented for four measures: the actual cost of installed options,

the estimated payback period, in years; the percent savings in fuel consumption;

and occupant-indicated comfort improvement. The number of houses in each sample

is given. These measures were explained in the Overview section.

The Demonstration results suggest the following conclusions:

L. When houses receiving both mechanical system retrofits and architectural

modifications were compared with houses receiving only architectural

options, the houses with both mechanical systems and architectural options

reported

:

a. the average price for purchase and installation of options was higher

($1,862 vs. $1,336), as expected. However, in houses with both

types of option,

b. the percent savings in fuel consumption was larger (41 percent vs.

17 percent),

c. the payback period was shorter (6 years vs. 15 years), and

d. occupants reported somewhat greater improvments in comfort (average

0.66 vs. 0.56, where 0.0 = no comfort improvement reported and

1.0 = all indicators of improvement reported; see discussion of

comfort indicators on page 4)

.

2. Comparing all weatherized units with nonweatherized comparison units,

the results indicate that the weatherized units:

a. had a much larger percent reduction in fuel consumption (31 percent

vs. 5 percent), and

b. showed much greater improvements in comfort as indicated by occupants

(0.61 vs. 0.09).

The small changes in fuel consumption and comfort registered in the non- weatherized comparison group suggests that fuel consumption and comfort over the Demonstration period were relatively stable.

The conclusion is clear: weatherization conserves fuel and more weatherization

(particularly economically-optimal levels) conserves even more fuel.

Table 1 does not indicate the variation in fuel savings for individual houses.

Some dwellings saved up to 70 percent and a few increased their fuel usage [4]

.

There are no unequivocal explanations of this variability, but several possible reasons may be suggested. One suggestion has been that variations in the

quality of the installion might account for these differences. Another possible

16
explanation is that occupants operate and maintain their heating systems

differently. Another is that even properly installed and operated retrofits

do, in time, suffer a decline in performance.

A final explanation bears particular attention: the nature of the statistical

analysis itself. Project staff assumed a 10 percent standard error in measuring

fuel use. It is therefore possible that some residences reporting extremely

high fuel savings reflect the situation where pre-weatherization fuel use readings on a residence were on the "high" side of the standard error of the

measurement, while the post-weatherization fuel use readings for that residence

were on the "low" side of the standard error. This logic applies also, except

in reverse, to residences reporting either low or no fuel savings. Therefore,

extreme values reported for fuel savings should be used cautiously.

One objective of the Demonstration was to assess how much money could be

saved by weatherization. Focusing on the homeowner who has weatherized his

or her home, the best available indicator is the estimated payback period.

Table 1 indicated an average payback period of 11 years; this was an encouraging

result since the Demonstration had aimed to achieve a payback period of this term.

Table 4 lists the distribution of payback periods.

Table 4. Payback Periods for Weatherized Houses

Payback Period

in Years

Cumulative Percent of

All Weatherized Homes

Achieving Payback by

the End of this Period

1-3 8

3-5 24

5-7 43

7-9 53

9-11 65

11-13 (11.4 overall mean) 71

13-15 81

If the assumed life of the options is 20 years, then in about half that time,

(i.e., the end of the 9th year), 53 percent of homeowners will have been paid

back the cost of these options in saved fuel costs, leaving the remaining

years to reap the permanent savings the options will afford. If fuel prices were to rise faster than the cost of purchasing and installing weatherization

17
options, then the cost of retrofits will be paid back to homeowners even

sooner

Table 5 presents the averages for the five variable rows of table 1, plus

average cost of weatherization on a site-by-site basis for weatherized units.*

Sites are listed alphabetically within degree day climate zones. This table

is included for readers seeking site-specific information.

In summary, there is no doubt that weatherization can result in considerable

fuel savings for households, particularly if both architectural and mechanical

system options are installed. Nevertheless, the results do show a range of

fuel savings and of costs. Energy savings ranged from net increases in fuel

use (i.e., non-savings, in 10 percent of the experimental houses) to savings

of 70 percent. Costs to retrofit a house varied from $24 to $4000. As

expected, the greater savings were achieved when both architectural and

mechanical options were installed in colder climates, with a higher number of

degree days per year.

Although savings of 40 percent were achieved in "optimally'* weatherized homes,

the project staff had expected savings of 50 to 70 percent. The discrepancy

resulted, in part, from the high level of existing weatherization found in

colder areas of the Nation. For example, most houses in Fargo already had wall

insulation, R-30 attic insulation and storm windows. Despite this, savings of

nearly 40 percent (see table 6) were achieved there. Quality of installation,

while difficult to measure, also appeared to vary considerably. This, too, can affect fuel consumption. It has been suggested that variations in quality

of installation of retrofits that occurred in the Demonstration might be

representative of what happens in typical retrofitting [4].

Although weatherization costs and percent savings in fuel consumption are two measures used in the Demonstration, there is not a perfect relationship between

them. This is a consequence of using economic criteria for determining optimum

levels of weatherization. That is, more money might have been spent intentionally on a house with a lower percent savings and high fuel prices in order to

obtain greater dollar savings.

Perhaps the best indicator of the success of the CSA Weatherization Demonstration

is the payback period [4]. NBS originally anticipated an 11 year payback

period. The measured overall average was 11.4 years. This average, however,

was raised by a small number of houses with unusually long payback periods

(see table 6, data for Atlanta, for a site-wide indication of this). Statisticians are aware that a small number of aberrant cases in a sample might lead

to misrepresentation. To illustrate this point and to provide a more accurate

interpretation, the reader should examine table 4. This shows that over half

(53 percent) of the weatherized houses had a payback period of nine years or less

* There are two to five nonweather ized houses per site. Because the number of

houses per site was so small, only the aggregated values are being presented

in table 5. Readers wishing detailed results should see table 28 of [5].

18
Table

5.

Mean

Values

of

Six

Measures

from

CSA

Weatherization

Demonstration a i 0 1 0 1 O 1

19.7 (38) 19.4 (38) 4.4

(41)

60*0 (61) 1111 111l H CM <3- O- /-I lO as

at r-i • CM • • • no Csl • < 04 ID i—

Oi as

O 10 IO' in

pt4 as r-

v-/ co K- • 1—1 o O /-v 00 1—1 04 0 • • • vD <3 CO CO vO i-l CM o 2 oo r-i ^ i—l 04 z »—i z

CO vo 03 <rm in i

ftS <T« • <t • • <4 i—l • co o -s- 00 0 03 i—i ^ CM m 0 a n f—1 V-/ Z CM

CO

O ^ 00 co r^. in iO a ri • vO • • • i-l v4> • CO iH 04 in O 0 r^. in O 43 CM w H -fr t-H 1—1

r^. <t lO CO ON

M 04 • O • • <3 <r • as

33 0 v£> r-l <r as COm 10

O 43 CM i0 T—

CO z 04

CM /-n co 0. m lO 01 a 04 • CO • • • co • CM

CQ 00 *<f r-l o co

O 10 o i—i < S3 r-l W f—

04 i—l v-/

m

O

m f—

l-i i—i o 00 • 03 • • * o • f—

o ^ 1—1 CO * oo oi

E-4

m CM 1—1 T—

S3

O /-N 00 r—

1—1 09 4-s

m • 00 • • • 00 • O

H o 00 0 CO

O 0 1^* ON r—

CO -4}- 04 10 CM V-X 1—1 r-lW

H 09 r“i o 00 -d- o CO 0 * • • -K CM • <3 oi as * as i—l 3 CO r—

CM i—

43

m

O /-v o in O'* •’—i i—l 00 4-1 a cn • 00 • • • LO i—

• vO H o o CM O 10 CM O 10

<! co CM CM i—l i—l CO

Ol on ^ in iO CO ri o 2 O • 00 • • • <r • ^ <3 oi co 10 co n o 09 43 O 04 CM CM CM CM 10 0

CM as iO 00

<d o • CO • • • r>. • 33 as r—

09 o ID

O 0 CM

W T—

CO as

C/D •• So

>1 0 0 Q

•HO 00 0 0 0 60 0 0

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<00

PQ3o0 3

4-1

O a i-9 r-i a 4J o 3 K) P 0 n • 3 0 04 0 9-14-1 O 0 0

42 'll. 0 4-1 O 0 0 0 3 (U « h S ^

9-1 a)

4-1 M-9 c3O 3

i-4

O

O. 1-1 a 4-i

q 3 3 Q

IdN • 0 i-t 04 0 9-14-1 O <11 M-4 si "i H 4J 3 0 0 4-1 3 0 CQ In 3 ^ ao00

CO 0 0) GO 94 0 60 0 0) > <2 0

C/3 (0 0 -d cn 0 0 >i U 91 H 0 0 0 0 PQ 0

01 s_x <J 00a0>o0

a.a

4J0o x

4-1 0 S ”2 O 0 a h 00

t—

r-l 0 O 0 Q 0

4-1 0 O 0 00« 0 0 d3

03O 0 O O

'dO

•H000

03 St 0 O 0 0 0

43 >4 >.0 0 0 i-4

T300

600

S3

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-000

43IZ

030

030

4=000000

030000000N0a0

03 433

030

60000>00o0 0

030

4200O0

03000

i-t>00

to6000000 . 00O000 003 0 T3 5 0 0 i-l 00 s 42 0 0 0

1-1 43 0 O 0

i-l 4-t

r-l 0 O 42

X! 0 00 0 0 0

43 0 § 3 3 O Z 42

O00Oo000

CO 0 0o

•d0N

•H00 0 42 O000oo00o 030

&4

0360 • 3 0 0 C/3 0 W i

a 2 03 co 0— 0 O -d o

•3 3 a 0 0 0 0 0 0 o O 0 3 60 0 0 C 0 O O 0 0 O 04 2 ill

II II II II

04CO <

04 0i CO o - O 04 2 04 a0

420

rH

4300

PQ 3 42 3 m rj O 5 0 0 3

43 s 3 O o 0 O 0 4J 60 0 O 0 a a c 0 O 0 43 o CD o . o rH 0 0 0 T3 0 0 rH a • i—

0 0 C/3 H o 0 a a 3

1—

a a O II II II ii a 0 0 3 . a 03 03 0 a 0 S3 'd 60 O W M

03 3 C o 0 H <3 2

03 0 0 a COH < O 0 0

42 0 03 0 03 0 0 a 3 3 0 O 0 3 O 3 St 0 rH o

•H

O o > oO C/3 T) 42 0 0 03

C/D 0 43 0 T—

r < <3

0) 03 03 a •H C/D 3 OO 3

C/D 0 0 0 03 0)

OO 3 43 •d a * > CO 0 - 0 O 3 0 00 00 O 0 O Q H C * z *

03 T3 0 0 0 0 0 0 0 4t! 42 0 o o 0 60 > 0 0 0 0 0 0 0 43 42 0 03 60 0 0 3 C 3 33

II II II 2 S3 CO

<;h c o <: 3

19
The main objective of the Demonstration — to evaluate the savings in fuel

and in dollars, given the costs of weatherization , of retrofitting low-income

families' houses — was accomplished. Fuel consumption savings averaging nearly

20 percent overall and 40 percent for "optimally" weatherized homes, with associated average payback periods 11 years overall and 8 years for "optimally" weatherized homes were achieved. Additional fuel savings can be achieved, as noted

in the Overview section, by employing other energy-conservation strategies.

20
4. REFERENCES

[1] Chapman, Robert E., Crenshaw, Richard, W., Barnes, Kimberly A., and

Chen, Phillip T., "Optimizing Weatherization in Low-Income Housing:

Economic Guidelines and Forecasts," National Bureau of Standards (U.S.)>

NBSIR 79-1948, February 1980, 141 p.

[2] Clark., Roy E., "Effects of Home Weatherization on Occupant Comfort:

First Report of a Field Study," National Bureau of Standards (U.S.)»

NBSIR 81-2335, September 1981, 83 p.

[3] Clark, Roy E., "The CSA Weatherization Demonstration Data Base: Concepts

and Descriptions," National Bureau of Standards (U.S.) Technical Note

1156, February 1982.

[4] Crenshaw, Richard, CSA Optimal Weatherization Demonstration/Research

Project. In Optimal Weatherization - Proceedings of the National

Conference on Optimal Weatherization - December 1980 . Silver Spring, MD,

Information Dynamics, 1981.

[5] Crenshaw, Richard and Clark, Roy E., "Optimal Weatherization of Low-Income

Housing in the U.S.: A Research Demonstration Project," National Bureau

of Standards (U.S.) Building Science Series 144.

[6] Crenshaw, Richard, Clark, Roy, Chapman, R.obert, Grot, Richard, and

Godette, McClure, "Community Services Administration Weatherization

Demonstration Project Plan," National Bureau of Standards (U.S.)

NBSIR 79-1706, March 1979, 73 p.

[7] Energy Resources Center. Home Retrofit Manual. Chicago, University

of Illinois, 1979.

[8] Margulis, Stephen T., "A Methodology for Evaluating Housing in Use: A

Case Study Approach," National Bureau of Standards (U.S.), NBSIR 81-2258,

June 1981, 221 p.

[9] Petersen, Stephen R. , "Retrofitting Existing Housing for Energy

Conservation: An Economic Analysis," National Bureau of Standards (U.S.),

Building Science Series 64, December 1974.

[10] Trechsel, Heinz R. and Launey, Sheila J., "Criteria for the Installation

of Energy Conservation Measures," National Bureau of Standards (U.S.),

Special Publication 606, July 1981, 196 p.

21
APPENDIX

Abstracts of Reports Documenting the CSA Weatherization Demonstration Project

This appendix presents titles, abstracts, and, for available documents, ordering

information for all current technical reports and presentations, published and

in preparation, documenting the CSA Weatherization Demonstration Project. A

useful supplement, a report on criteria for the installation of energy conser- vation measures, by Trechsel and Launey, also are included.

Items are listed alphabetically by authors' names.

t

22
R. Chapman, R. Crenshaw, K. Barnes, and P. Chen, "Optimizing Weatherization

Investments in Low-Income Housing: Economic Guidelines and Forecasts."

(NBSIR 79-1948), National Bureau of Standards, Washington, DC, 1980.

This study establishes a framework for systematically analyzing the economic

viability of alternative methods of weatherizing low-income housing. These

methods include, but are not limited to, insulation, weatherstripping and

caulking, and installation of storm windows and doors. The economic framework is illustrated through the development of a series of forecasts (economic

guidelines) which show the optimal level of weatherization for low-income

residences in 15 cities across the Nation. These economic guidelines are designed to assist the Community Services Administration in carrying out its

Weatherization Demonstration Program. In particular, they are designed to

achieve a more balanced level of weatherization per dollar spent. The optimal

level of weatherization is balanced in the sense that, for a given weatherization

budget, no increase in net savings (total savings minus total costs) can be

achieved by trading one method for another.

Available from the National Technical Information Service (NTIS) as PB 80-162142,

price: $11.00 for hardcopy; $3.50 for microfiche.

23
R. E. Clark. "The CSA Weatherization Demonstration Data Base: Content and

Descriptions." Washington, DC, National Bureau of Standards, Technical Note

1156, February, 1982.

The Community Services Administration (CSA) Optimal Weatherization Demonstration

assembled what is probably the most comprehensive collection of measurements

of actual energy use in occupied housing. The data comes from 240 houses in

12 sites. The sites cover the range of climatic conditions found in the U.S.

The data prescribed to be collected by the CSA Demonstration project included,

in addition to five years of whole-house utility consumption records, many

other energy-use and energy use-related measurements: 1) one year or more of

weekly readings of: furnace or heater consumption, run times, and cycle

counts; water heater energy consumption and ^hot water usage; utility (gas and

electric) meters; (representative) floor temperatures; and indoor humidity;

2) two years of monthly measurements of natural air infiltration rates and

of temperature stratification patterns in the house; 3) "before" and "after"

measurements of furnace or heater steady-state efficiency; 4) "before" and

"after" fan tests (induced depressurization of the house to measure tightness/

leakiness); 5) thermography of all insulated walls; 6) measurements of possible

leakage of heat into unheated attic spaces; 7) comprehensive "costs of

weatherization options" data; and 8) data about occupants' behaviors and

attitudes that may affect house energy consumption.

This report lists and describes, house-by-house, the actual information in

the data base, since not all prescribed measurements were received from all

houses in the Demonstration. It also describes the media and formats in which

the data exist. This report should facilitate the effective and efficient use

of the data by other researchers.

Available from Center for Building Technology, National Bureau of Standards,

Washington, DC 20234.

24
R. E. Clark. "Effects of Home Weatherization on Occupant Comfort: First Report

of a Field Study." (NBSIR 81-2335) National Bureau of Standards, Washington, DC,

1981.

This study reports preliminary examination of data testing the hypothesis that,

when existing residences are treated with weatherization retrofitting measures

intended primarily to save fuel, house occpants are likely to report improvement in wintertime comfort. Data were gathered through questionnaire-guided

interviews with individuals in 108 experimental houses and 37 control

houses. These houses, at nine sites representing a range of U.S. climates were

part of a three year National Weatherization Demonstration, sponsored by the

Community Services Administration and planned and managed by researchers at the

Center for Building Technology of the National Bureau of Standards. The

experimental houses had been weatherized to determine how much their fuel usage

could be reduced by cost-effective retrofitting. The control houses had not

been weatherized in the Demonstration. Interview topics included: thermostat

setting patterns, impressions of comparative comfort, amounts of clothing worn,

and specific comfort and temperature ratings for the house as a whole and for

individual rooms in the house. Preliminary examination of the data has focussed

on: 1) a composite "comfort change" index, comprised of: indicators of change

« in comfort-related attributes of the indoor environment, amounts of clothing worn in winter, and comfort ratings of the house and of individual rooms; 2)

the specific comfort ratings; and 3) the specific temperature ratings. The

results present strong indications of support for the hypothesis.

Available from the National Technical Information Service (NTIS) , Springfield,

VA 22161 as PB 81-245-334, price: $9.50 for hardcopy; $3.50 for microfiche.

25
R. Crenshaw, R. Clark, R. Chapman, R. Grot, and M. Godette, "CSA Weatherization

Demonstration Project Plan." (NBSIR 79-1706), National Bureau of Standards,

Washington, DC, 1979.

This report comprises the plan of a research and Demonstration effort to

determine the fraction of energy that may be saved by installing weatherization

retrofits in poor peoples' homes throughout the United States. Two broad groups

of weatherization retrofits are considered for application in each dwelling:

1) "architectural", those affecting the building shell; and 2) "mechanical",

those affecting space heating and service hot water systems. The optimum

combination of weatherization options is defined as that set of retrofits which

maximizes net savings (the difference between savings in fuel usage and the cost

of the retrofit) over 20 years for a particulr house and climatic environment.

The retrofits will be selected through present-value benefit/cost analysis.

The savings will be established through analysis of utility billings and fuel

delivery records before and after weatherization. The report presents the

background of the Demonstration, the research tasks associated with the

Demonstration, a description of the diagnostic tests to be used, the rationale

for economic decisions, the tests for evaluating mechanical systems, and the

calculation methods used in selecting architectural options.

• Available for National Technical Information Service (NTIS) as PB 293-498,

price: $6.00.

26
Energy Resources Center. Home Retrofit Manual. Chicago, University of Illinois,

1979.

A manual for the nonprofessional installer of architectural weatherization

options that discusses the following retrofits: replacing broken windows,

resetting glass, weatherstripping windows, packing and caulking of windows and

doors, fixing windows, installing plastic storm windows, installing glass storm

windows, installing window insulating shutters and panels, replacing existing

windows, installing door thresholds and bottom seals, weatherstripping doors,

installing storm doors, and replacing existing doors. For each retrofit option,

the text and illustrations cover the selection of materials, and preparation

and installation procedures.

Available as: Paul Knight. The Illustrated Guide to Home Retrofitting for

Energy Savings. New York, NY, McGraw-Hill, price: $14.95, 365 p.

27
Energy Resources Center. Home Evaluation Manual . Chicago, University of

Illinois, n. d.

Contains three sets of bound evaluation forms for planning and weatherization

of homes, one set each for single-family residences, multi-family buildings,

and rental units. Each booklet contains 13 evaluation forms covering occupants'

retrofit preferences, general building information (covering heating systems),

windows, doors, basements, crawl spaces, slabs-on-grade , walls, finished and

unfinished attics, holes/cracks, and mechanical systems. Descriptive material

about the household, the dwelling unit (e.g., number of rooms), temperature

(indoors), etc., is also covered.

28
R. A. Grot. "An Assessment of the Application of Thermography for the Quality

Control of Weatherization Retrofits," In Proceedings of Thermosense II (Second

National Conference on Thermal Infrared Sensing Technology for Energy Conservation

Programs). Falls Church, VA, American Society for Photogrammetry , 1980.

Approximately 65 single-family low-income homes in eight cities (Portland;

Maine; Minneapolis/St. Paul; Minnesota;- Fargo, North Dakota;, Tacoma, Washington;

St. Louis, Missouri; Washington, DC; Atlanta, Georgia; and Charleston, South

Carolina) were retrofitted using a series of weatherization techniques which

included air infiltration reducing measures such as caulking and weatherstripping,

adding attic insulation, installing storm windows and doors, insulating basements

and crawlspaces and insulating exterior walls with either ureaformaldehyde (UF)

foam or blown-in cellulosic insulation. Thermographic surveys of these dwellings

were performed after the weatherization work was completed in order to assess

the effectiveness of installation and to determine the percentage of wall not

insulated by the contractors and the defects which still existed in the dwelling.

It was not uncommon to find large areas of the wall still uninsulated, ceilings

with improperly installed insulation, heat losses around door and window frames,

excessive heat losses from eaves and soffits, shrinkage and fissures in the

insulation, excessive basement heat losses and air penetration into interior

cavities. Examples are presented of typical deficiencies still existing in the

dwelling, and data are presented showing the frequency of deficiencies revealed

by thermographic inspections. In an effort to assess the inspection techniques

being employed by thermographic inspection services, a comparison is made of

the results of thermal inspection by private thermographic contractors and

those performed by the National Bureau of Standards. The preliminary results

of this comparison indicate a need for further development of thermographic

inspection methods, training of thermographic inspectors and possibly the

certification of thermographic operators for the inspection of buildings.

Proceedings are available from the American Society for Photogrammetry,

105 North Virginia Avenue, Falls Church, VA 22046.

29
R. A. Grot and R. E. Clark, "Air Leakage Characteristics and Weatherization

Techniques for Low-Income Housing," Thermal Performance of Exterior Envelopes

of Buildings . In Proceedings of the DoE/ASHRAE Conference, December 1979.

New York, NY, American Society of Heating, Refrigerating, and Air-Conditioning

Engineers, 1981.

Data are presented on the air leakage characteristics of approximately 250

dwellings occupied by low-income households in 14 cities, in all major climatic

zones of the United States. Two types of measurements were used: a tracer-gas

decay technique using air sample bags, which was developed at the National

Bureau of Standards to measure natural infiltration rates of buildings; and a fan

test, developed to measure induced air exchange rates. The data presented here

show that for this group of dwellings natural air infiltration rates are distributed approximately lognormally.

The induced air exchange rates are a measure of the tightness of building

envelopes. There is little correlation between the natural air infiltration

rates and the induced air exchange rates in these dwellings, unless the buildings

are divided into classes of similar buildings. The use of fan depressurization

as a diagnostic tool to assist weatherization crews in tightening buildings is

discussed. Preliminary estimates are presented of the reduction in induced air

exchange rates that may be achieved by applying building weatherization techniques.

For the availability of this proceeding (ASHRAE SP 28), contact the American

Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc.,

345 East 47th Street, New York, NY 10017.

30
R. A. Grot and R. E. Clark. "Techniques for the Field Evaluation of Residential

Building Envelope Weatherization Retrofits." National Bureau of Standards,

Washington, DC, in preparation.

Measurement and data analysis techniques for the field evaluation of residential

building envelope weatherization retrofits being applied to approximately 200

low-income dwellings in 12 cities in the continental United States [1] are described. Techniques which use fuel bill records and weather data for predicting the past and future energy consumption of dwelling are developed, and

their application to the evaluation of the energy savings realized from groups

of weatherization retrofits is presented. Submetering requirements, simple

methods for monitoring the interior environment of a dwelling and methods for

handling the data analysis from these measurements are specified. Several

procedures for determining the air leakage characteristics of a building are developed: a simple low-cost procedure for measuring the actual air infiltration rates of each dwelling in this weatherization Demonstration using a tracer

gas and air sample bags and the measurement of tightness of a dwelling using a fan depressurization technique. The inspection of dwellings using thermographic

techniques for locating the major heat losses is discussed. The application

of thermography as a quality control tool for assessing the effectiveness of

various weatherization retrofits and methods for analyzing and representing

the results of thermographic inspections are developed. The location of not

obvious air leakage path still remaining after normal weatherization techniques

have been applied using fan pressurization and infrared thermal scanning equipment is described. Measurement techniques for determining, in the field, the

thermal conduction values of the major components of the building heating load

are described and the location of heat flow sensors using the results of the

thermographic inspectors of the dwelling is treated. The determination of the

amount of temperature stratification occurring in the dwellings and methods

for analyzing temperature stratification data are highlighted. A procedure

for identifying the existence of attic bypass heat losses is discussed. Preliminary data gathered from each of these tests is included.

For availability of this document, contact Dr. R. A. Grot, Building Thermal and

Service Systems Division, Center for Building Technology, National Engineering

Laboratory, National Bureau of Standards, Washington, DC 20234.

31
R. A. Grot and R. W. Beausoliel. "Estimating Savings from Modification or Replacement of Residential Furnaces and Hot Water Heaters." National Bureau of

Standards, Washington, DC 20234, in preparation.

This report presents the methodology used in the CSA/NBS Optimal Weatherization

Demonstration for the selection of mechanical system retrofits which can be

applied in low-income housing. Simple test procedures are given for determining

the condition of the heating system, heat distribution system and domestic hot

water heater. The tests described consists of: 1) measurement of the steadystate efficiency of the heating system; 2) an energy and flow balance on the

heat distribution system; 3) a safety inspection of the heating system; 4) a combination efficiency test of the water heater; 5) a recovery efficiency test

for the water heater; and 6) measurement of the flow rate of the showers.

For the availability of this document contact Dr. R. A. Grot, Building Thermal

Performance Division, Center for Building Technology, National Engineering

Laboratory, National Bureau of Standards, Washington, DC 20234.

32
R. A. Grot, "A Low-Cost Method for Measuring Air Infiltration Rates in a Large

Sample of Dwellings," In C. M. Hunt, J. C. King, and H. R. Trechsel (Eds.)>

Building Air Change Rate and Infiltration Measurements , ASTM STP 719, American

Society for Testing and Materials, 1980, pp. 50-59.

A method for collecting air infiltration data in a large sample of dwellings is

presented. The method consists of a tracer gas dilution technique employing

air sample bags that are analyzed in a central laboratory. The method was later

applied in a Community Services Administration Optimal Weatherization Demonstration to approximately 200 dwellings at 12 sites throughout the United States.

The method will yield air exchange rates under typical heating season conditions

for each dwelling in the Demonstration. Preliminary data on air infiltration

rates in low-income housing in Portland, ME are presented.

A limited number of complimentary reprints are available from Dr. R. A. Grot,

Building Thermal and Service Systems Division, Center for Building Technology,

National Engineering Laboratory, National Bureau of Standards, Washington, DC

20234.

33
R. A. Grot. Fi eld Techniques for Measuring the Savings of Energy Improving

Ret rofits In Single-Family Dwellings . Liege, Belgium: Conference on Comparative

Experimentation of Low-Energy Houses. University of Liege, May 1981.

Instrumentation and data handling methods for determining the energy savings

from applying retrofits to existing dwellings are described. The application

of these techniques to an optimum weatherization program carried out in over 200

dwellings in 12 cities in the United States during the last four years are presented. The techniques used include methods for measuring the air infiltration rates in the dwellings, analysis of fuel records, testing of the mechanical

systems, thermographic inspections to determine the quality of workmanship,

tests for determining the existence of heat bypasses, and metering requirements.

Sample data from these tests are given and several methods using the results of

these tests for estimating the savings due to various retrofit measures are presented

.

34
H. R. Trechsel and S. J. Launey. "Criteria for the Installation of Energy

Conservation Measures." (NBS Special Publication 606), National Bureau of

Standards, Washington, DC 20234, 1981.

Standard installation practices were developed to assist in assuring the

effectiveness and safety of energy conservation measures installed under the

Residential Conservation Service (RCS). They serve as mandatory standards

under RCS but are recommended guides for all installations of the covered

materials and products. The criteria are being used by DoE to develop training

manuals for installers, inspectors, and energy auditors.

Part I provides information on the intended use of the practices, outlines the

RCS program, and discusses major technical and related issues that were con- sidered in the development of the standards: moisture and surface-building

retrofit, attic ventilation, electrical wiring, recessed and surface-mounted

fixtures, the use of diagnostic tools (infrared thermography, air change rate,

and window air leakage measurements), and product certification.

Part II provides the actual practices together with commentary and additional

recommendations. The products covered are loose-fill, batts and blankets,

rigid foam boards, UF foam and reflective insulations, window devices, caulks

and sealants, water heater insulation, oil burner replacements, and vent dampers.

Available from Superintendent of Documents, U.S. Government Printing Office,

Washington, DC 20402, as Stock #003-003-02337-0, price: $6.00.

35
S. F. Weber, M. J. Boehm, and B. C. Lippiatt, "Weatherization Investment Costs

for Low-Income Housing." (NBSIR 80-2167), National Bureau of Standards,

Washington, DC 20234, 1980.

This report presents the results of a project involving the collection and

tabulation of field data on the costs of retrofitting low-income houses for

energy conservation. This project is part of the Community Services Administration Weatherization Demonstration Program being carried out through the

National Bureau of Standards. The program involves the installation and evaluation of a broad range of energy conservation techniques for over 200 singlefamily houses in 14 Demonstration sites throughout the United States. The

energy conservation techniques discussed in this report consist of a variety

of architectural modifications to building envelopes for the purpose of reducing

heat losses due either to air infiltration or conduction. The methods used to

collect and synthesize the field data on the major cost components of installing

these techniques are described. An analysis of these costs is presented in

the form of summary statistics including the weighted mean and standard deviation of the unit cost of installing each architectural option in each demonstration site. The significant inter-city variation found in the mean unit cost

of most techniques suggests that unique cost estimating procedures may be

needed for each city. Possible sources of variation in the mean unit costs

are discussed. Recommendations for further research include investigating the

effect on cost that can be attributed to selected sources of variation.

Available from National Technial Information Service (NTIS) as PB-81-133829

,

price: $9.50 for hardcopy, $3.50 for microfiche.

36
NBS-114A (rev. 2.80

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

1. PUBLICATION OR

REPORT NO.

2. Performing Organ. Report No. 3. Publication Date

SHEET (See Instructions) NBSIR 82-2539 August 1982

4. TITLE AND SUBTITLE

NONTECHNICAL SUMMARY OF THE FINAL REPORT "OPTIMAL WEATHERIZAT ION OF LOW-INCOME

HOUSING IN THE UNITED STATES: A RESEARCH DEMONSTRATION PROJECT"

5. AUTHOR(S)

Stephen T. Margulis and Roy E. Clark

6. PERFORMING ORGANIZATION (If joint or other than NBS, see instructions) 7. Contract/Grant No. NATIONAL BUREAU OF STANDARDS CSA A-8B-0018

DEPARTMENT OF COMMERCE 8. Type of Report & Period Covered

WASHINGTON, D.C. 20234

Final (Sept77-Sept 81)

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State. ZIP)

Community Services Administration

1200 19th Street, NW

Washington, D.C. 20506

10. supplementary notes

Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bi bliography or literature survey, mention it here)

This report summarizes in nontechnical language the nature and results of the

Community Service Administration’^ (CSA’s) Optimal Weatherization Demonstration

Research Project carried out by the National Bureau of Standards (NBS) . This

summary draws on the final report of the field evaluation of the Demonstration,

an NBS publication entitled Optimal Weatherization of Low-Income Housing in

the U.S.: A Research Demonstration Project (NBS BSS 144) . Unless stated

otherwise, this report references the final report.

The CSA/NBS demonstration installed both architectural (Building shell) and

mechanical systems weatherization options, and achieved, when both types of

options were used, an average reduction in space heating fuel consumption of

41 percent, at an average weatherization cost of $1,862. per house.

This summary report also includes abstracts of all the technical reports

documenting the CSA/NBS project. Directions for ordering available reports

are included.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

Community Action Agencies; Community Services Administration, costs of residential

weatherization; energy conservation; field measurement of building energy

consumption; optimal weatherization.

13. AVAILABILITY

[xj Uni imited

14. NO. OF

PRINTED PAGES

| | For Official Distribution. Do Not Release to NTIS

Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.

43

15. Price

(Xj Order From National Technical Information Service (NTIS), Springfield, VA. 22161 $7.50

USCOMM-DC 6043-P80
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