rxiun 0 TCrU

a 1 1 1 o b atm. hnique for Tracking the Effect

of Weatherization Retrofits on

Low-Income Housing

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Washington, DC 20234

April 1983

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! 83-2676

I 1983

Sponsored by:

Community Service Administration

1200 19th Street, N.W.

Washington, DC 20506
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NBSIR 83-2676

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< f UPltWfT MAY 2 19B3

TECHNIQUE FOR TRACKING THE EFFECT

OF WEATHERIZATION RETROFITS ON

LOW-INCOME HOUSING

Yui-May L. Chang

Richard A. Grot

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Washington, DC 20234

April 1983

Sponsored by:

Community Service Administration

1200 19th Street, N.W.

Washington, DC 20506

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

ABSTRACT

This report presents a technique for analyzing the effect of energy saving

retrofits installed in low-income housing under a nationwide weatherization

demonstration program. This program was undertaken by the Community Services

Administration (CSA) with the technical support of the National Bureau of

Standards (NBS).

A tracking technique, based on the calculated balance-point temperature of each

home prior to the weatherization, was developed to estimate the would-be fuel

consumption over a period of time if the house had not been weatherized. The

savings in fuel consumption for a home can be determined from the difference

between the actual usage after retrofit and the calculated usage if it were not

retrofitted. Besides the overall reduction, the saving in energy usage during

different time periods while the house is being weatherized can be visualized

from the graphical representation of the tracking technique.

Fuel reduction is reported for more than 100 homes using different fuels in seven cities across the nation, selected to represent various climate zones and geographical locations. It was found that the average saving in fuel

consumption for dwellings in each city is about 30 percent.

Key words: Balance point temperature; computer graphics; degree days; energy

conservation; energy consumption; fuel usage records; tracking

technique; weatherization retrofit.

\

iii
FOREWORD

This report is one of a series documenting NBS research and analysis efforts in

energy conservation to support the Optimal Weatherization Demonstration Research

Project sponsored by the Community Services Administration, under Interagency

Agreement No. A8B-0018.
SI CONVERSION UNITS

Physical

Quality

Symbol To Convert

From

To Multiply By

Volume V ft 3 m3 2.83 x 10" 3

Temperature T °F °C T(°C) = [T(°F)-32]/l .8

Energy F Btu kJ 0.9478

v
TABLE OF CONTENTS

Page

ABSTRACT ill

FOREWORD iv

SI CONVERSION UNITS v LIST OF TABLES vii

LIST OF FIGURES viii

1. INTRODUCTION 1

2. DATA COLLECTION 3

3. THE BALANCE POINT CALCULATION 4

4. DESCRIPTION OF THE TRACKING TECHNIQUE 6

5. INTERPRETATION OF RESULTS FROM TRACKING PROGRAM 8

6. SUMMARY AND DISCUSSION 10

7. CONCLUSION 11

8. REFERENCES 12

APPENDIX A. THE BALANCE POINT CALCULATION BY USE OF FUEL BILL RECORDS .. A-l

vi
LIST OF TABLES

Page

Table 1. Architectural Options Considered in Optimum Weatherization

Demonstration Program 13

Table 2. Mechanical Options Considered in Optimum Weatherization

Demonstration Program 14

Table 3. Summary of Installation Options and Percentage of Fuel

Reduction of Dwellings in Colorado Springs, CO 15

Table 4. Summary of Installation Options and Percentage of Fuel

Reduction of Dwellings in Fargo, SC 16

Table 5. Summary of Installation Options and Percentage of Fuel

Reduction of Dwellings in Tacoma, WA 17

Table 6. Summary of Installation Options and Percentage of Fuel

Reduction of Dwellings in Portland, ME 18

Table 7, Summary of Installation Options and Percentage of Fuel

Reduction of Dwellings in St* Louis, MO 19

Table 8. Summary of Installation Options and Percentage of Fuel

Reduction of Dwellings in Allentown, PA 20

Table 9. Summary of Installation Options and Percentage of Fuel

Reduction of Dwellings in Charleston, SC 21

Table 10. Comparison of Average Daily Fuel Consumption in Colorado

Springs House No 41 22

Table 11. Comparison of Average Daily Fuel Consumption in Colorado

Springs House No. 6 23

Table 12. Average Percentage Savings in Fuel Consumption of All

Dwellings in Each City 24

vii
LIST OF FIGURES

Page

Figure 1. Sites selected for the demonstration program 25

Figure 2. Graphical comparison of average daily fuel consumption of

Colorado Springs house no. 41 26

Figure 3. Graphical comparison of average daily fuel consumption of

Colorado Springs house no. 6 26

Figure 4. Graphical comparison of average daily fuel consumption of

Fargo House no. 17 27

Figure 5. Graphical comparison of average daily fuel consumption of

Fargo House no. 30 27

Figure 6. Graphical comparison of average daily fuel consumption of

Fargo House no. 13 28

Figure 7. Graphical comparison of average daily fuel consumption of

Tacoma House no. 4 28

Figure 8. Graphical comparison of average daily fuel consumption of

Tacoma House no. 83 29

Figure 9. Graphical comparison of average daily fuel consumption of

Tacoma House no. 58 29

Figure 10. Graphical comparison of average daily fuel consumption of

Portland House no. 7 30

Figure 11. Graphical comparison of average daily fuel consumption of

Portland House no. 25 30

Figure 12. Graphical comparison of average daily fuel consumption of

St. Louis House no. 70 31

Figure 13. Graphical comparison of average daily fuel consumption of

St. Louis House no. 42 31

Figure 14. Graphical comparison of average daily fuel consumption of

St. Louis House no. 10 32

Figure 15. Graphical comparison of average daily fuel consumption of

Allentown House no. 23 32

Figure 16. Graphical comparison of average daily fuel consumption of

Allentown House no. 27 33

viii
LIST OF FIGURES (Cont.)

Page

Figure 17. Graphical comparison of average daily fuel consumption of

Charleston House no. 25 33

Figure 18. Graphical comparison of average daily fuel consumption of

Charleston House no. 19 34

Figure 19. Percentage savings achieved for each dwelling in the

demonstration program 35

Figure 20. Histograms of fuel reductions of dwellings including water

heater usage 36

Figure 21. Histograms of fuel reductions of dwellings excluding water

heater usage 37

ix
.

i
1 . INTRODUCTION

A nationwide weatherization demonstration program was undertaken by the

Community Services Administration (CSA), with the technical advice and support

of the National Bureau of Standards (NBS) , to measure the reduction in energy

consumption for low-income housing by applying retrofit options to those houses

[1]. Test sites were selected to represent the major climate zones in the

United States, as shown in figure 1.

The dwellings selected for the demonstration program were low-income type

occupied continuously by the same family and having complete and accurate fuel

bill records for two years prior to the program. Other factors for selection

include age, size, orientation, and occupants of the house [1].

With the agreement of owners, two groups of homes were chosen for collection of

fuel consumption data before and after weatherization. Homes with retrofitted

improvements belong to the sample group, while those without improvements

belong to the control group. Thus, the effect of seasonal changes can be

identified from the fuel usage records of a control home.

Of over 200 homes selected in the demonstration program, approximately one

third are in the control group. Tables 1 and 2 indicate the architectural and

mechanical retrofit options given consideration for implementation in each

dwelling of the sample group. The cost estimates for the weatherization retrofits were analyzed and the list of retrofitted options were prescribed in each

city so that all sample homes would be brought up to a certain standard in a given city [2]. Architectural options were selected assuming a 20-year physical life for building material [3]. In general, similar sample group homes in

each city have identical options after retrofit. However, mechanical options were dependent on the evaluation of the overall efficiency of the mechanical

system in energy savings. Therefore, they were chosen on a house-by-house

basis, and were installed separately from the architectural options.

The principal purpose of the demonstration program was to determine the

effectiveness of house retrofit options in energy conservation. Several techniques have been developed for assessing energy savings potential of dwellings

from weatherization [4]

.

Air infiltration measurement using the air bag method

can determine air leakage [5, 6]. Thermography can be used to identify areas

of missing insulation or improper insulation [7]. The balance point calculation

technique was adapted to established the heating balance point and the rate of

energy usage in Btu/degree day for each house. In this report, a tracking

technique based on the calculated balance-point temperature of each home prior

to the weatherization was developed to estimate ("predict") the would-be fuel

consumption over a period of time if the house had not been retrofitted.*

Another applied research for residential energy conservation program was conducted at the same time as this demonstration program (from 1975 to 1980)

to investigate the effectiveness of attic insulation using actual fuel usage

records and weather data [8]

.

The results of this investigation were in the

form of reduction in fuel consumption rate after the attics were insulated.

1
Besides the overall reduction, the saving in energy usage during different time

periods while the house is being weatherized can be visualized from the graphical representation of the tracking technique. The following sections will

discuss procedures for data interpretation and will present a generalized

result of fuel reduction in seven cities. The cities and their code name are given in alphabetical order as:

ABE Allentown, PA

CHA Charles , GA

CSP Colorado Springs , CO

FAR Fargo , ND

POR Portland, ME

STL St. Louis, MO

TAC Tacoma , WA

Tables 3 to 9 indicate which architectural and mechanical options were

installed on each house of these cities (the 'X's in the tables). Among these

dwellings, options not selected imply they were already in place (the ' E's),

or they were not applicable (the ' N's). For example, wall insulation was not

recommended for dwellings in Charleston, SC due to the warm climate in the

south. Other options that were treated as nonapplicable were those where the

home owners objected to certain options to be installed or work could not be

completed due to a strike by employees of contractors.

2
2. DATA COLLECTION

Houses selected for the weatherization program were required to have complete

and accurate records of fuel usage for the past two years. For periods prior

to the beginning of the weatherization program, the bill records for fuel

consumption were those submitted by the occupants. Basically, monthly or bimonthly utility meter readings were used for gas and electric heated homes,

while meter readings of delivery trucks were used for bottled gas and oil

heated homes. Detailed description of data collecting, editing, handling,

recording, and storing from fuel usage records can be found in other reports

[2, 9]. Fuel consumption data before weatherization were stored in disk files

under the name: [CTC].D[#H], where [CTC] and [#H] represent the city code and

house number, respectively [9]. For example, CSP.D12 is the fuel consumption

of house #12 in Colorado Springs, Colorado.

During the period of weatherization, as retrofit options were being applied to

the sample houses, meters and other measuring devices were installed in sample

and control homes. The type of meters installed depended on the fuel type.

In order to determine the total amount of time a furnace or space heater was

on and the number of its on-off cycles, a run-time meter and a cycle counter

were installed. In houses with natural gas and electricity, a utility (gas or electric) meter was installed to read the overall fuel usage for the whole

house, including space heating and hot water heating as well as appliances if

they are of the same fuel type. In houses with propane or bottled gas, gas

consumption for space heating was metered independently.

For houses with oil or kerosene heating systems, fuel consumption was calculated using burner nozzle rate and readings of the run-time meter. Thus,

the established result was somewhat inaccurate due to the lack of accuracy of

those meter constants.

Data from house meters were collected every week during and after

weatherization. After data were interpreted as fuel consumption of dwellings

in the same format as [CTC].D[#H], they were stored in disc files under the name [CTC].W[#H]. Therefore, fuel consumption before and after weatherization

is available for purposes of comparison and evaluation.

Besides the fuel consumption records of each dwelling, the weather data from

each city were also required for the balance point calculation. Weather tapes

obtained from the National Climate Center were used to represent the weather of

each city to calculate the outdoor temperature for the same period of time as in fuel records.

3
3. BALANCE POINT CALCULATION

The fuel consumption F of a dwelling during a billing period can be linearly

related to the degree days by the equation

F=b0 +b1

» DDX (1) a

where F is the fuel consumption;

bQ refers to the base load at base temperature Ta ;

bi is the rate of fuel usage per degree day;

DD-j is the degree days at base temperature Ta

. a

The base (or balance point) temperature of a dwelling is an outdoor temperature

at which the solar and internal gains will offset the heat loss of the house;

and thus the average degree days at this temperature can be determined. In

general, 65°F is employed as the base temperature for normal engineering practice to perform calculations of energy requirement for residences [10]. However, the balance point temperature for each individual dwelling is unique and

it can be determined from the fuel records and weather data.

In order to estimate the fuel consumption of a dwelling for the period after

weatherization as if no retrofits were installed to the house, it is required

to establish the balance point temperature of the dwelling prior to weatherization. This balance point temperature (of a dwelling) can be determined from

the fuel records before weatherization such that the fuel consumption is linearly related to the weather of the site. Since all participating residences

had monthly or bimonthly fuel records from 1975 to 1977, statistical analysis

through regression technique was employed to determine the balance point temperature of each home. Detailed description of the balance point temperature

calculation is included in appendix A.

For a base temperature Ta , the one-parameter model of the least square

regression to fit a straight line to the average daily fuel consumption with

daily degree days established from the weather data of each building period is

given as

F D

(k) = b

o (a) + bl

(a) * ®°T

(k) k = 1, 2, ... N (2)

where F^^) is the average daily fuel consumption in the k

tb billing period;

DDt the average daily degree days for a base temperature T in the

i a ktb billing period.

4
By fitting a series of straight lines at base temperature between 45° F and

75°F, in the increment of 0.5°F, the case of 'best fit' is obtained by the

occurrence of maximum correlation coefficient r^ (the majority of r^ obtained

has a value greater than 0.95). The base temperature corresponding to the

'best fit' is defined as the balance point temperature T0 and the parameters

corresponding to the 'best fit' are defined as the house parameters b

0

^ 0 ' and

b^' 0 ' at the balance point temperature T

Q

.

Once the balance point temperature, T0 of a dwelling is determined a good

measure of fuel consumption for the house can be predicted by the linear

equation (3):

F

D

= b

o

(0) + b

l

(<>) * TMTQ <3)

where Fp is the average daily fuel consumption;

b

0

^°) is the base load at T

Q ;

b-j^°^ is the rate of fuel usage per average daily degree days;

DD-j is the average daily degree days at T0

. o

For comparison, prediction of fuel consumption were also performed to cases

of 1) Ta = 65° F and 2) bQ

= 0. The latter corresponds to zero base load, an ideal case.

5
4. DESCRIPTION OF TRACKING TECHNIQUE

Based on the balance point calculation from each home's fuel bill records

before weatherization, sets of house parameters (b0 , b^ and Ta) corresponding

to the 'best fit', as well as at Ta

- 65°F, and at bQ= 0 were obtained. As

architectural and mechanical options (see Tables 1 and 2) were being installed

in the sample homes, savings in fuel consumption could be calculated by comparing fuel billing records after weatherization with "predicted” fuel usage. A

computer program was developed on the Interdata 7/32 minicomputer to track the

reduction of fuel usage by producing tables and graphs for both sample homes

and control homes.

Ordinarily, the percentage saving of fuel consumption would be calculated from

the date of installation through the end of the period of calculation. On the

other hand, the percentage saving in fuel usage between certain periods of time

such as between different weatherization options, can also be established by

entering to the computer program the beginning and ending dates of such periods

There are two major branches in the tracking program; 1) to calculate the

predicted fuel consumption from weather data and sets of house parameters (bQ , b]_, and T0 ) ; and 2) to interpret the fuel bill records of meter readings.

Hence, the comparison of actual and predicted fuel usage can be produced by the

tracking program in the forms of tables and graphs. As a result, from the

balance point calculation, three sets of house parameters were selected:

1 ) "best fit” corresponds to the set of maximum correlation coefficient (r^ is

a maximum); 2) ”Ta

= 65°F” corresponds to the set that the base temperature is

equal to 65°F; and 3) ”b0 = 0” corresponds to the case where the base load

residues are zero. For each set of house parameters, the predicted fuel con- sumption was given by equation (3) with the average degree days (DD^^ ') calculated from weather data. The output table from the tracking program contains

the city code, house number, beginning and ending dates of calculation, actual

fuel consumption, predicted fuel consumption and average degree days for all

three sets of house parameters, period length, dates of installation, and percentage savings after the date of installation (see table 10 as an example).

The unit of actual and predicted fuel usage from the best fit are given in kBtu

as well as in its own fuel unit. The graph presents information similar to

that contained in the table, with the additional advantage of visualizing the

variation of fuel usage (see figures 2 to 18).

In general, results of predicted fuel consumption from all three cases are close unless their correlation coefficient, r^'s, are very low. As an example,

table 10, produced by the tracking program, gives a comparison of actual (F)

and predicted (F^, F2 , and F3 for all three sets of parameters) fuel consumptions from 5/28/75 to 4/16/80 of house #41 in Colorado Springs, CO. This house

uses gas for both space heating and hot water heating; and its fuel units is in

100 cu. ft. Values of F and F^ are given both in kBtu and 100 cu. ft. As

indicated in table 10 , predicted fuel consumption from all three cases are fairly close to each other and to the actual fuel usage, F, before the installation date, 10/4/79. After that, readings of F have a significant drop from

those predicted usages (F]_, F 2 , F3 ), and the percentage savings of fuel

consumption was about 35 percent.

6
Figure 2 compares predicted fuel usage from the "best fit" parameters (with

connecting curve) and actual readings (with symbol *). Prior to January 1979,

this house was not weatherized (see table 3); the predicted fuel consumption

curve seemed to be tracking with the actual readings quite well, which supports

and validates the use of the "best fit" parameters from the balance point calculation as a predictor for post-weatherization calculations. As various

retrofit options began to be installed in this particular house (the dates are shown in table 3), substantial savings of gas consumption began to show on figure 2. Note that there is a minimum gase usage equivalent to about 100

kBtu per day in the non-heating season, representing the minimum load including

hot water usage in summer months. Since the fuel usage for heating hot water

will not be the same in the summer months and in the winter months, the base

load of fuel consumption is only an indication of minimum load in the summer months [11]. All dwellings selected in Colorado Springs use natural gas for

space heating and hot water heating, and will have the same characteristics.

Figure 3 is a similar plot for a control home (#6) in Colorado Springs. As

expected, both predicted and actual fuel usage of this house are tracking with

each other all the way. The fuel reduction of this house, as shown in table 11 was found to be only 0.4 percent since 10/1/79. In order to compare the percentage saving in fuel consumption between sample homes and control homes, an arbitrary date (10/1/79 for Colorado Springs) was chosen for control homes in

each city, equivalent to the installation date of the sample homes, for

calculation.

Tables 3 to 9 give listings of sample and control homes selected in each city

along with their retrofit options, installation dates, and percentage savings

in fuel consumption. Information on retrofit options selected for each residence and their cost of the entire demonstration program can be found in other

reports [1, 2, and 3].

7
5. INTERPRETATION OF RESULTS FROM TRACKING PROGRAM

Among the dwellings chosen for the weatherization program, some use different

fuel types for space heating and hot water heating. As an example, house // 1

in Fargo, ND has a gas space heater and electric hot water heater. Since the

fuel records included only gas bills, without considering the electricity for

hot water heating, fuel usage in the non-heating season was very low, or even

vanished. Figure 4 demonstrates this phenomenon as both the actual and predicted

fuel consumption are approaching zero in those summer months. Table 4 indicates

that the installation of house retrofit options were begun in 11/78, and the

fuel reduction since this date can be observed from figure 4. The percentage

savings of gas consumption since 7/79 (completion of architectural options) was calculated to be about 44 percent (see table 4). In fact, the real saving due

to weatherization would be even higher if savings occurred during installation

periods were included.

Figure 5 is the graph of fuel consumption of another sample home in Fargo,

where natural gas is used for both space heating and hot water heating. The

minimum load of about 50 kBtu per day exists, including the hot water usage.

Figure 6 illustrates the fuel consumption of a control home in Fargo with

similar types of fuel supply (also with minimum load).

House #4 in Tacoma, WA is a total electric home, with electric space heater and

electric hot water heater. Figure 7 shows the actual and predicted electric

consumption of this home, including the minimum load of 200 kBtu per day from

the usage of hot water, appliances, and lights in the summer months. Figure 8

and 9 show the results of two homes (a sample home and a control home, respectively) in Tacoma that use natural gas for space heating and electricity for

hot water heating. As expected, the gas usage in summer months was extremely

low. Information on fuel saving and retrofit options of dwellings in Tacoma

can be found in table 5.

The majority of the sample homes in Portland, ME use oil for space heating.

Some have electric hot water heaters and some have the hot water attached to

the furnace; houses #7 and #25 are examples of these two types of homes, respectively. There were no control homes available in Portland. Figures 10 and 11

give the predicted and actual oil consumption of these two houses and they both seem to attain higher percentages of savings in the second winter (1979-80).

This may be due to the fact that the modification of mechanical systems and

replacement of hot water heaters were completed (7/79) more than a year after

the architectural options (5/78), as given in table 6.

In St. Louis, MO all dwellings selected used natural gas for space heating and

hot water heating. According to table 7, the majority of the house retrofit

options in St. Louis were started after 1/79 and were completed around 1/80.

Hence, most of the calculated fuel savings do not include a whole heating season. House #70 is one of the few houses in St. Louis on which retrofit options were installed between 7/79 and 10/79. The percentage fuel saving after 10/79 was found to be 21 percent; and figure 12 illustrates both predicted and actual

fuel consumption for this house with no significant fuel reduction shown until

10/79. On the other hand, house #42 is a sample home in which retrofit options

8
were installed between 1/79 and 1/80. Figure 13 illustrates that fuel

reduction does exist after weatherization is partially done. The percentage

savings of gas consumption after 1/80 was reported about 38 percent. Figure 14

shows that the predicted and actual fuel consumption of a control home (#10) in

St. Louis are in agreement, with the predicted values slightly below the actual

values. Thus the percentage savings after 1/80 was calculated to be negative

12 percent, as given in table 7. Other information about saving and options

are also included in table 7. The mechanical and water heater options were never installed in dwellings of St. Louis due to a worker strike.

Allentown, PA is another city in the demonstration program having different

fuel for their homes. Figures 15 and 16 show the fuel consumptions (actual and

predicted) of gas homes #23 and #27 in Allentown, in which less than one year

of fuel bill records were available after weatherization, and though some of

the retrofit options were completed at a later date (see table 8). Even so,

the calculated percentage saving of fuel consumption was to be 18 percent and

42 percent, respectively. The reason of much lower fuel saving in house #23

than that in house #27, may be that the mechanical system options were never installed to house #23, as the pre-weatherization fuel usage of these two

houses were fairly similar.

In Charleston, SC most sample and control homes use bottled propane for space

heating. For the hot water heaters, they use gas, electric, or propane, and

some homes do not have hot water heaters at all. Furthermore, none of them

have mechanical system options installed. Due to uncertainties in the weekly

readings of fuel consumption after weatherization, fuel delivery bills were

used even though there were only monthly delivery records. Figure 17 shows the

predicted and actual fuel consumptions of house #25 in Charleston. As fuel

consumption was based on delivery records, their magnitudes only represented

the total consumption between deliveries. Therefore, both the magnitude and

the frequency of fuel delivery should be observed in order to identify the

variation of actual fuel consumption. Figure 18 is a similar graph of house

#19 in Charleston, a control home. The percentage savings of fuel consumption

for house #25 and #19 were calculated to be 30 percent and 4 percent respectively (see table 9). Note that, by using delivery records, there were data

gaps for actual fuel usage and a complete picture of continuous fuel

consumption can be seen.

9
6. SUMMARY AND DISCUSSION

According to the availability of fuel bill records, meter readings, and

weather data, more than 120 dwellings were chosen from the weatherization program for tracking the effectiveness of house retrofit options with the end of

conduction work as installation date for calculation. Those houses are in seven cities that represent different climate zones of the United States (see

figure 1). Figure 19 shows the distribution of dwellings in sample and control

groups in each city with regard to percentage saving in fuel consumption. From

figure 19, it appears that, in each city, the distributions of homes between

those including water heater usage and those excluding water heater usage are similar. The average and median values of percentage saving in fuel consumption are for all homes given in table 12.

In general, the average saving in fuel consumption for dwellings in each city

was above 30 percent, except in Charleston, St. Louis and Allentown. Due to

the fact that no mechanical system modifications were applied to houses in

Charleston and St. Louis (no hot water heater modification was applied to St.

Louis), lower reduction in saving was expected. As for Allentown, infiltration

work for all houses was finished after the calculation of fuel savings began;

therefore, saving was smaller than in those cities in which infiltration work

was finished earlier. Furthermore, fuel data after weatherization for Allentown were not available until 8/79 so that saving in some homes due to earlier

retrofit was not included. On the other hand, high saving in fuel consumption

was obtained from dwellings with longer periods of fuel records after weatherization. For homes in Portland, retrofit options were installed in 1978 and in

early 1979 (see table 6). Two years of fuel data were available after those

houses were weatherized. The percentage saving for fuel consumption was found

to be over 40 percent. In figures 20 and 21, histograms show the number of

dwellings that achieved various levels of saving in fuel consumption including

water heater usage and excluding water heater usage, respectively, for both

sample and control groups in all seven cities. Of those homes in the sample

group, about 50 percent show a saving between 20 and 40 percent, and over 80

percent show a saving between 10 and 50 percent, as illustrated in figures 20

and 2 1

.

Since there were no retrofits installed to the dwellings in the control group

the fuel savings was based on chosing an arbitrary day as the beginning date

for calculation. Figures 20 and 21 indicate that the change in fuel usage in

the control homes is between -30 to +30 percents. The intention to select

control homes as well as sample homes was to identify the effect of seasonal

change from the fuel records of the control group. However, the graphical

representation by the tracking technique for fuel usage in control homes (see

figures 3, 6, 9, and 14) provides support to this method, as both predicted and

actual fuel consumption are tracking each other before and after weatherization.

10
7 . CONCLUSIONS

A method is presented to determine the saving in fuel consumption realized from

implementation of the CSA Weatherization Program. Based on the balance point

calculation and interpretation of fuel bill records, changes in fuel consumption over time can be calculated. The computer program includes numerical calculations of percentage savings for house fuel usage from a certain date, and

tablet and graphical outputs of predicted and actual average daily fuel usage

before and after weatherization. Percentage saving over the same periods of

time is established as various retrofit options begin to be installed to

dwellings

.

Over 120 homes (about 100 in the sample group and 25 in the control group) were

selected to demonstrate this technique for tracking the effects of retrofit

options installed in homes. It was found that about 50 percent of the sample

homes had a saving between 20 and 40 percent after weatherization. On the

other hand, 50 percent of the control homes show a saving between 0 and 20 percent. Note that numerical results of the control group are based on an arbitrary date as the beginning date for percentage calculation for each house.

Furthermore, graphical interpretation of fuel usage provides a visualized understanding to the house performance before, during, and after weatherization, and

also validates the house parameters established from the balance point

calculation prior to weatherization.

11
8.

REFERENCES

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

Weatherization Demonstration Project Plan," NBSIR 79-1706, March 1979.

2. Crenshaw, R. , and Clark, R. , "Optimal Weatherization of Low-Income

Housing in the U.S.: A Research Demonstration Project," NBS Building

Science Series 144, September, 1982.

3. Chapman, R.E., Crenshaw, R.W., Barnes, K.A. , and Chen, P.T., "Optimizing

Weatherization Investments in Low-Income Housing: Economic Guidelines

and Forecasts," NBSIR 79-1948, February 1980.

4. Grot, R.A. , "Field Techniques for Measuring the Savings of Energy

Improving Retrofits in Single Family Dwellings," Proceedings of the

International Colloquium, Comparative Experimentation of Low-Energy

Houses, p. X, Liege, Belgium, May 1981.

5. Grot, R.A., "A Low-Cost Method for Measuring Air Infiltration Rates in a Large Sample of Dwellings," NBSIR 79-1728, April 1979.

6. Grot, R.A. and Clark, R.A. , "Air Leakage Characteristics and

Weatherization Techniques for Low-Income Housing," Thermal Performance of

Exterior Envelopes of Buildings, DOE/ASHRAE Conference, Orlando, Florida,

December 1979.

7. Grot, R.A. , "An Assessment of the Application of Thermography for the

Quality Control of Weatherization Retrofits," Proceedings of

Thermosense II, Second National Conference on Thermal Infrared Sensing

Technology for Energy Conservation Programs, American Society of

Photogrammetry , pp. 193-208, Falls Church, VA, 1980.

8. Scanlan, T.F., Bayne, C.K., and Johnson, D.R., "Investigation of Attic

Insulation Effectiveness Using Actual Energy Consumption Data," ORNL-5825,

September 1982.

9. Clark, R. , "The CSA Weatherization Demonstration Data Base: Contents and

Descriptions," NBS Technical Note 1156, February 1982.

10. American Society of Heating, Refrigeration, and Air Conditioning Engineers,

1980, System Volume, New York, N.Y.

11. Dutt, G., Lavine, M. , Levi, B., and Socolow, R. , "The Modular Retrofit

Experiment: Exploring the House Doctor Concept," PU/CEES Report No. 130,

Princeton University, Princeton, NJ, June, 1982.

12
Table 1. Architectural Options Considered in Optimum

Weatherization Demonstrations

INFILTRATION

1. Replace broken glass

2. Reset glazing

3. Replace threshold

4. Seal structural cracks

5. Weatherstrip windows

6. Caulk doors

7 . Weatherstrip doors

8. Weatherstrip attic hatch

WINDOW

10. Install storm windows

11. Install insulation drapes (R = 1.14)

12. Install insulating shutters (R = 7.8)

13. Install low emlssivity films

14. Install triple glazing

DOORS

15. Install storm door

16. Install second wood door (R = 2.18)

17. Replace exterior door with insulating door (R = 6)

INSULATION

18. Install attic insulation (R = 11, 19, 30 38)

19. Install wall insulation (R = 11+ vapor barrier where possible)

20. Install first floor insulation (R = 19, 30)

21. Install basement wall insulation (R = 7)

22. Install perimeter slab insulation

13
Table 2. Mechanical Options Considered in Optimum

Weatherization Demonstration

FURNACE

1. Install flue or vent damper

2. Install flue or vent restrictor

3. Install electronic ignition

4. Install two-stage gas valve

5. Derate furnace - downsize orifice or nozzle size and install diverter

6. Replace burner

7. Replace furnace (change distribution system when required)

DISTRIBUTION & CONTROL SYSTEM

8. Insulate ducts and pipes

9. Install reflectors behind radiators

10. Install night setback thermostat

11. Relocate thermostat

HOT WATER HEATER

12. Install hot water heater

13. Replace hot water heater

14. Reduce temperature setting on hot water heater

15. Install flow restrictor on shower

16. Install timer on electric water heaters

17. Install flue damper in gas water heaters

14

3
Table 3. Summary of Installation Options and Percentage of Fuel

Reduction of Dwellings in Colorado Springs, CO

SAMPLE GROUP " * NUMBERS

OPTIONS INSTALLED — 7 11 13 14 17 20 23 24 26 28 31 34 37 41 43 44 47 49

ARCHITECTURAL BeS in

End

Replace Broken Glass

1/79 1/79 1/79 1/79 2/79

8/79 11/79 9/7910/79 9/79

X X X X X

1/79 1/79

8/7910/79

X X

2/79 1/79 1/79 1/79

3/79 9/79 4/7910/79

X X X X

2/79 1/79 1/79 1/79

9/79 11/79 10/79 10/79

X X M X

1/79 1/79 1/79

10/79 9/79 10/79

N X N

Reset Glazing X N X X X N N N X X N X N N N N X N

Replace Threshold X X X X X X X X X X X X X X X X X N

Seal Cracks & Holes X X X IT X X N N X X N X X X X X X N Weatherstrip Windows X E X E X E E X X E E X E E E E X E Caulk Windows X X X X X X X X X X X X X X X X X X Weatherstrip Doors X X X X X X X X X X X X X X X X X X Caulk Doors X X X X X X X X X X X X X X X X X X Weatherstrip Attic Hatch E E X X E E X E X X X X V E

X X E E Fireplace Damper N N N N N N N N N N X N N N H N N

Insulate Attic R-30 X X X X X X X X X X X X X X X X X X Install Storm Windows X X X X X X X X X X X X X X X X X X Insulate Basement Wall,

Slabs or Crawl Spaces X X X X X E X E X X X X X X X X X X Insulate Walls X X X X X X X E X E X X X X X X X X

HEATING SYSTEM Be8 in

End

Flue or Vent Damper

2/79 4/79

1/80 12/79

X N N

10/79

12/79

X

1/80

1/80 N

1/80 10/79 3/79 12/79

1/80 12/79 11/79 1/80 N X X X N

12/79

1/80

X

12/79

1/80

X

1 12/7912/79 12/79 12/79 1/80

1/8012/79 12/79 1/80 1/80

X H H ? *

4/79

1/80

X Electronic Ignition N N N N X X X X X H

X X X X X X N X Two Stage Gas Valve N N N N N N N X N N N N N N N N X N Derate Furnace N N N N N N N X N N n_ N N N N N X N Replace Furnace N N N N N N N N N N N X N N N N N N

Insulate Ducts A Pipes X X N N N N N N X N N X X X _ N N N X Night Setback Thermostat X X N X N N X X X N X X X N N X N X

WATER HEATER End 12/79 12/79 12/79 11/79 11/79 11/79 12/79 2/80 1/80 12/79 10/79 12/79

Insulate Water Heater X X X N N N X X X N N X N X X X X X Reduce Temp Water Heater N X X N N N X X X N N X N X X X X X Shower Flow Restrictor N N N N N N X X N N N N _ N X N X N X Flue Damper Water Heater X N N iJ N N X X X N N X N N X X X Timer on Water Heater N N N N N N N N N N N N N N N N N N

APPLIANCES

Dryer Vent Diverter N N N X N N X N N N X N N N N X H

X

PERCENT SAVING IN FUEL CONSUMPTION 24 46 1 30 29 13 30 30 18 9 47 40 36 35 38 47 40 57

INSTALLATION DATE USED (all in 1979) 8/31 11/12 9/24 10/25 9/14 8/31 10/22 3/10 9/28 3/28 10/22 9/17 11/16 10/4 10/1 10/26 9/26 10/5

CONTROL GROUP (Installation Date Used : 10/1/79)

HOUSE NUMBERS 01 05 06 08 10

PERCENT SAVING IN FUEL CONSUMPTION 2 -19 0 11 11

X: Options Installed

E: Existing options

N: Options not judged to be applicable

15
Table 4. Summary of Installation Options and Percentage of Fuel

Reduction of Dwellings in Fargo, SC

SAMPLE GROUP —JjOUSE NUMBERS

installeB""——__ 2 5 6 10 11 15 17 25 27 30 32 35 36

ARCHITECTURAL Begin 11/78

End 7/79

Seal Cracks & Holes N

10/78

6/79

N

11/78

11/79

N

11/78

9/79

N

11/78

7/79

X

11/78

2/79

X

11/78

11/79

11/78 11/78

10/79 11/79

N N

1/79

11/79

N

10/78

2/79

N

10/78

11/79

N

11/78

10/79

N Weatherstrip Windows X X X X X X X X X X X X X Caulk Windows E X X X X X X X X E E X X Weatherstrip Doors X X X X X X X

' X X X X X X Caulk Doors E X X X X X ~7~

X X E E X X Weatherstrip Attic Hatch X X X X X X X X X X X X X Install Triple Glazing X X X X X X JT" X X X X X X Insulate Attic R-38 X X X X X X X” X X X X X X Install Wall Insulation X X X X X X X" X X X E X X Insulate Basement Walls,

Slabs or Crawl Spaces X X X X X X X X X X X E X Install Insulating Shade T“ X E E E E X X X X E E E

HEATING SYSTEM

2/79

9/79

7/79

7/79

2/79

5/79

1/79

1/79

9/79

9/79

12/78

9/79

2/79

2/79

2/79

9/79

2/79

9/79

9/79

9/79

9/79

9/79

Flue or Vent Damper X X X X N N X N N X X N N Electronic Ignition ~T~ N N N N N X N N X X N N Derate Furnace X X N N N N X X X X X X X Replace Furnace N N X X N X N N N N N N N Two Stage Cas Valve TT N N N N N a M N N X N N Night Setback Thermostat X X X X X X X X N X X N N

WATER HEATER

£nd 9/?9 11/79 3/79 2/79 9/79 9/79 3/79 9/79 3/79 11/79 9/79 9/79 9/79

Insulate Water Heater X X X X X X X X X X X N N

Replace Water Heater N N N N N N N N N N X N N Timer on Water Heater N X X N N X N X N N N N Flue Damper TT- N N N X X N N N N N N X Shower Flow Restrictor X X N N X X N X N X X X X PERCENT SAVING IN FUEL CONSUMPTION 36 56 3.5 15 21 43 44 16 36 39 12 20 22

CONTROL GROUP (Installation Date Used 7/1/79)

HOUSE NUMBER 13 22 23 26 34

PERCENT SAVING IN FUEL CONSUMPTION 2 2 16 7 -1

X: Options installed

E: Existing options

N: Options not judged to be applicable

16
Table 5. Summary of Installation Options and Percentage of Fuel

Reduction of Dwellings in Tacoma, WA

SAMPLE GROUP

OPTION? -JKWSE NUMBERS

INSTALLED * 21 39 45 49 55 57 81 83 87

ARCHITECTURAL Begln

End

Replace Broken Glass

2/79

11/79

N

11/79 1/79 : 1/80 10/79 : X N10/79 10/79

L/80 11/79 N N

9/79 2/79 2/79 2/79 10/79

1/80 7/79 11/79 12/79 12/79 X X N N N

Reset Glazing N X N N N X N N N N Replace Threshold N N N X N N N N N N Seal Cracks 6 Holes N N N X N N N N N N Weatherstrip Windows X X X X E X X X X X Caulk Windows X X X X X X X X X X Weatherstrip Doors X X X X X X X X X X Caulk Door6 X X X X X X X X X X Gaskets on Electric

Plugs & Switches E E E E E E E E E E Weatherstrip Attic Hatch X X X E E X E X E E Fireplace Doors N N N N N N N N N N Install Storm Windows X X X X E X X X X X Insulate Attic R-30 X X X X X X X X X X Insulate Walls E X X X X X X X X X Insulate Basement Walls,

Slabs or Crawl Spaces X X X X X X X X X X

HEATING SYSTEM Begin

End

Insulate Ducts & Pipes

9/79

9/79X

1/80

1/80 X N N

10/79

10/79 N X

8/79

9/79X

8/79

8/79X

9/79

9/79X

12/79

12/79

X Night Setback Thermostat n N N N N N X N X N

WATER HEATER End 9/79 1/80 8/79 12/79 12/79 8/79 8/79 9/79 12/79

Insulate Water Heater X X X N N X X X X X Reduce Temp Water Heater X X X N X X X X X X

Shower Flow Restrictor X X X N N N N X X N Timer on Water Heater X X N N N X X X X N PERCENT SAVING IN FUEL CONSUMPTION 18 23 40 40 34 49 57 22 41 27

INSTALLATION DATE

USED (all in '79 except as indicated

7/31 :1 / 16 / ; 80

7/24 1/17/

80 11/21 12/3 7/25 7/16 8/2 12/18

CONTROL iGROUP (Installation Date Used : 7/31/79)

HOUSE NUMBER 37 58 76 98

PERCENT SAVING IN FUEL CONSUMPTION -4 1 11 29

X: Options installed

E: Existing options

N: Options not judged to be applicable

17
Table 6 Summary of Installation Options and Percentage of Fuel

Reduction of Dwellings in Portland, ME

SAMPLE GROUP

OPTIONS BOUSE NUMBERS

I N STALLOT —~

4 7 10 11 12 18 19 20 21 23 25 26

ARCHITECTURAL ®e ® in

End

3/78 10/78 2/78 3/78

10/78 5/79 6/78 2/79

3/78 10/78 9/78 2/78 2/78 3/78 3/78

10/78 12/78 12/78 10/78 3/78 10/78 5/78

2/7

2/7

Replace Broken Class X N N X X N N X X X N X Reset Glazing X N X X X N N X X X N X Replace Threshold N N N N N N N N X N N N Seal Cracks 6 Holes N N X N N N N N X X N N Caulk Windows X X X X X E E X X X X X Weatherstrip Doors X X X X X X X X X X X X Caulk Doors X X E X E E E X X X E E Weatherstrip Attic Hatch X X E E X E E X E X X E Triple Glazing N N N N X N N N N N N X Install R-30 Attic

Insulation X X X X X X E X X X X X Insulate Walls R-ll X X X X X X X X X X X X Insulate Basement Wall,

Slabs or Crawl Spaces X X X X X E E X X X E X Store Doors X E X E X E E E X E X X Store Windows E X X X X E E E X X X X

HEATING SYSTEM End (all 7/79)

Flue or Vent Damper X N N N N X X X X X

tf X Derate Furnace N N N N N N N H

X X N Replace Burner N N N N H q N X N N N X Replace Furnace X . X N . X ? X N if X N H N Insulate Ducts & Pipes N N N N N N N X H N X X Night Setback Thermostat X X N X X X X N X X X X

WATER HEATER End (all 7/79)

Insulate Water Heater N N N N N, N N N N X N If Replace Water Heater X N N N t N N X N N X X PERCENT SAVING IN FUEL CONSUMPTION 38 43 30 53 25 71 37 51 35 30 59 47

INSTALLATION DATE USED (all in 1978

except as indicated)

10/

24 11/30 11/ 2/1/ 10/ 12/30 79 19 31 12/

31 10/

16 2/2810/ 5/ 79 20 31 2/28/

79 *CONTROL GROUP IS NOT AVAILABLE

X: Options installed

E: Existing options

N: Options not judged to be applicable

18
Table 7 • Summary of Installation Options and Percentage of Fuel

Reduction of Dwellings in St. Louis, MO

SAMPLE GROUP —JjOUSE NUMBERS

6 7 17 34 38 41 42 49 55 56 70 77 92 93

ARCHITECTURAL Begin

End

Replace Broken Glass

2/79

6/79 N

1/79

1/80N

2/79

2/79N

1/79

1/80

N

2/79

1/80N

6/79 1/79 2/79

1/80 1/80 1/60

N N N

2/79

1/80 N

6/79

1/80

N

7/79

10/79 N

2/79

1/80 N

7/79

1/80 N

2/79

1/80

N Reset Glazing N N N N N N N N N N N N N N Replace Threshold N N N N N N N N N N N N N N

Seal Cracks & Holes N N N N N N N N N N N N N N Caulk Windows X y E y k X X E X X X X X x Weatherstrip Windows X i E X y X X E X X X X X X Caulk Doors E E E E E E E E E E E E E E Weatherstrip Doors X X E X X X X X X X X X X X Install Storm Windows X X E X X X E X X X X X X X Insulate Attic R-30 X k X X X X X X X X X X X X Insulate Walls E X E X X E X X X E E —F~ E —5c

Insulate Basement Walls,

Slabs or Crawl Spaces E X E X X E X X X X E X E X PERCENT SAVING IN FUEL CONSUMPTION -13 35 0 0 16 20 38 26 25 13 22 40 19 45

INSTALLATION DATE USED (all in 1980

except as indicated)

6/28/ 1/31 2/28/

79 79 1/31 1/31 1/10 1/31 1/8 1/31 1/10 1/31/79 1/31 1/4 1/10

CONTROL GROUP (Installation Date Used: 1/31/80)

HOUSE NUMBER 04 10 23

PERCENT SAVING IN FUEL CONSUMPTION 26 -12 -32

X: Options installed

E: Existing options

N: Options not judged to be applicable

19
Table 8 Summary of Installation Options and Percentage of Fuel

Reduction of Dwellings in Allentown, PA

SAMPLE GROUP MOUSE NUMBERS

3 4 12 20 22 23 25 27 28 31 33 39 42

ARCHITECTURAL Begin 4/79

End 10/79

Broken Glass x

2/79

11/79

X

1/79

10/79X

4/79

9/79 N

4/79

9/79

X

3/79 2/79

11/79 11/79

X X

1/79 2/79 2/79 2/79 9/79 9/79

11/7911/7911/7911/7910/79 9/79

X X X N X X

X X X N N X X X N X X X N Seal Larce Cracks 4 Holes X N N N N N X N N N N N N Weatherstrip Windows X X X E E X E E X E X X E Caulk Windows X X E E E E E E E E X X E Weatherstrip Doors E X E X E E E X * E X X X X Caulk Doors X X E E E E E E E E E E E Weatherstrip Attic Hatch E X E X E E E X E X E E E Install Triple Clazing X X X X E X X E X X E E E Insulate Attic R-30 X X X E X X X X X X X E E Insulate Walls X E X X X X E X X X X E E

HEATI KG SYSTEM Begin

End

Flue or Vent Dairper N

6/79

6/79

N

5/79

5/79

JL_ N

1/80

1/80

X

5/79

12/79

N *

7/79

7/79

N

9/79 9/78

1/80 1/80

N X

7/79

1/80

X

5/79

1/80

X N Derate Furnace N N IL_ N X N X N X X X X N Replace Furnace N N - -.11 —XL. XL Xi_ N N X N N N N Night Setback Thernostat N X X N N N X X X X X X N

WATER HEATER End 6/79 5/79 1/79 5/79 7/79 5/79 7/79 9/79 9/79 7/79 1/80

Replace Water Heater N N £L_ N XL XL_ N N N N N N N Insulate Water Heater N H_ E_ X N N N N N N X X X Reduce Ter.p Water Heater N X X X X X X X X X N N X

PERCENT SAVING IN FUEL CONSUMPTION 53 0 23 8 12 18 18 42 19 7 14 18 10

’

INSTALLATION DATE

USED (all in 1979) 9/12 9/24 9/12 9/24 9/18 3/30 9/12 2/28 2/22 9/13 2/18 11/1 11/1

CONTROL GROUP (Installation Date Used : 11/1/79)

HOUSE NUMBER 38

PERCENT SAVING IN FUEL CONSUMPTION 12

X: Options installed

E: Existing options

N: Options not judged to be applicable

20
Table 9. Summary of Installation Options and Percentage of Fuel

Reduction of Dwellings in Charleston, SC

SAMPLE GROUP

NUMBERS

0PT1“^Sra——

_

1 2 3 8 9 16 18 20 22 23 25 27 39 44 47 49

ARCHITECTURAL

3/79 2/79 2/79 2/79 2/79 2/79 2/79 2/79

3/79 3/79 3/79 3/79 3/79 2/79 2/79 3/79

2/79 6/79 3/79 2/79 2/79 2/79

2/79 6/79 3/79 2/79 3/79 2/79

2/79

2/79

3/79

3/79

Replace Broken Clast X X X X N X X X X X X X X X _u _H

Reset Glazing X N N N X N X X X X X N N X _H N Replace Threshold X X X X X X X X X X X X X X X X Seal Cracks A Holes X X X X X X X X X X X X X X X X Weatherstrip Windows E X X X E X X X X X X X E X X _E

Caulk Windows X X X X X X X X X X X X X X X X Weatherstrip Doors E X X X E X X X X- X X X X X X _E

Caulk Doors E X X X X X X X X X X X X X X X Weatherstrip Attic Hatch E X X X X X X E E X X X X X X X Insulate Attic R-ll X E E E E E E E E E E E E E E _E

Insulate Attic R-19 fe X X X X X X X X X X X X X X X Insulate Basement Walls,

Slabs or Crawl Spaces X X X X E X X X X X X X X X X X Install Storm Windows E E E E E E E E E E E E E E X E WATER HEATER End 8/79 8/79 8/79 8/79 8/79 8/9 9/79 8/79 8/79 8/79 8/79 8/79

Insulate Water Heater N X N N N X N X N X N X N X X N Replace Water Heater N N N N N N N N N N N N N N X N Timer on Water Heater X N X X X X N X N N N X N X X X PERCENT SAVING IN FUEL CONSUMPTION 30 21 16 34 33 38 19 23 31 18 30 13 64 34 14 35

INSTALLATION DATE USED (all in 1979) 3/7 3/3 3/3 3/2 2/13 2/12 2/28 3/5 2/28 6/15 3/13 2/8 2/13 2/21 2/16 3/9

CONTROL GROUP (Installation Date Used: 3/1/79)

HOUSE NUMBER 5 19 21 24 28 PERCENT SAVING IN FUEL CONSUMPTION 18 4 18 23 -7

X: Options installed

E: Existing options

N: Options not judged to be applicable

21
Table 10 Comparison of Average Daily Fuel Consumption in Colorado

Springs House No 41

Fua:(<)

CT rtf DATE Of IE FUEL CONSUMPTION/ DAY (KBTUl

BEClfc t NO ACTUAL PREDICTED IUITH DECREE OAVSI (100 (Mil

n/ o/ y n/ o/ tr BEST FIT 10-60.5 It-U IO>«

f FI Ml n oo2 F 3 00)

PERCENTAGE

F FI tlUMS

CSP 41 5 28 75 6 28 75 193.5 186.4 5.2 180.6 7.8 191.8 16.1 1.9 1.8 -3.8

CSP 41 6 28 75 7 28 75 120.0 lib. 9 0.5 105.4 1.7 85.9 7.2 1.2 1.1 -2.7

CSP 4 1 7 28 75 8 26 75 117.2 117.8 0.6 104.9 1.7 86.0 7.2 1.1 1.1 0.4

CSP 41 • 26 75 9 25 75 163.3 163.2 3.6 161.9 5.9 159.1 13.4 1.6 1.6 -C.l CSP 41 9 25 75 10 20 75 242.4 252.) 9.6 255.7 12.0 261.3 22.0 2.4 2.4 3.9 CSP 41 10 28 75 11 26 75 455.2 418.6 20.8 418.4 24.7 419.0 35.2 4.4 4.1 -8.7

CSP 41 11 26 75 12 29 75 5)3.3 479.4 24.9 4 78.5 29.2 473.8 39.8 5.2 4.7 -11.3

CSP 41 12 29 75 1 28 76 610.0 566.4 30.7 558.7 35.1 543.6 45.7 5.9 5.5 -7.7

CSP 41 1 28 76 2 27 76 500.0 4)3.1 21.8 4)6.5 26.1 436.7 36.7 4.9 4.2 -15.4

CSP 41 2 27 76 3 29 76 483.4 453.8 23.1 453.7 27.3 451.4 37.9 4.7 4.4 —E .6 CSP 41 3 29 76 4 27 76 348.3 308.9 13.4 317.9 17.3 331.6 27.9 3.4 3.0 -12.

CSP 41 4 27 76 S 26 76 286.2 253.8 9.7 264.7 13.4 278.9 23.4 2.8 2.5 -12.6

CSP 41 5 26 76 6 25 76 166.7 161.5 3.5 162.3 5.9 166.9 14.0 1.6 1.6 -3.2

CSP 41 b 25 76 7 27 76 143.9 117.1 0.5 105.0 1.7 84.0 7.1 1.4 1.1 -22.6

CSP 41 7 27 76 8 25 76 141.4 119.1 0.7 110.4 2.1 95.8 8.1 1.4 1.2 -16.7

CSP 41 • 25 76 5 24 76 153.3 154.5 3.1 155.5 5.4 160.1 13.5 1.5 1.5 0.7

CSP 41 9 24 76 10 26 76 306.3 308.7 13.4 315.3 17.2 323.9 27.2 3.0 3.0 0.6

CSP 41 10 26 76 11 26 76 406.5 408.9 20.1 413.4 24.4 416.5 35.8 3.9 4.0 C .6 CSP 41 11 26 76 12 28 76 531.3 5)3.6 28.5 528.9 32.9 517.8 43.5 5.2 5.2 t.4

CSP 41 12 28 76 1 27 77 603.3 605.4 33.) 594.3 37.7 574.0 40.3 5.9 5.9 0.3

CSP 41 1 27 77 2 28 77 471.9 494.2 25.9 492.8 30.2 486.2 40.9 4.6 4.8 4.5 CSP 41 2 28 77 3 26 77 496.2 447.9 22.7 449.2 27.0 447.2 37.6 4.0 4.3 -10.6

CSP 41 3 26 77 4 27 77 331.3 345. 1 15.8 352.7 19.9 361.1 30.3 3.2 3.4 4.0 CSP 41 4 27 77 5 26 77 179.3 180.6 5.3 193.1 8.2 205.7 17.) 1.7 1.8 4.9

CSP 41 5 26 77 6 27 77 121.4 1)6. 1 1.8 132.2 3.7 128.2 10.8 1.2 1.3 10.4 CSP 41 b 27 77 7 27 77 126.7 1 16.7 0.5 103.8 1.6 86.1 7.2 1.2 1.1 -8.5

CSP 4 l 7 27 77 8 25 77 124.1 116.4 0.5 106.7 1.8 98.8 0.3 1.2 1.1 -t.b

CSP 41 0 25 77 5 26 77 121.9 150.2 2.8 148.4 4.9 147.8 12.4 1.2 1.5 18.9 CSP 41 9 26 77 10 25 77 2 34.5 247.6 9.) 253.8 12.6 263.3 22.1 2.3 2.4 5.3

CSP 41 10 25 77 11 25 77 396.8 384.5 18.5 389.0 22.6 393.5 33.1 3.9 3.7 -3.2

CSP 41 11 25 77 12 27 77 518.8 466.5 24.0 467.3 28.) 463.9 39.0 5.0 4.5 -11.2

CSP 41 12 27 77 1 26 78 620.0 606.4 33.4 595.2 37.7 575.6 40.4 6.0 5.9 -2.2

CSP 41 1 26 70 2 27 78 584.4 597.4 32.8 507.1 37.1 568.8 47.0 5.7 5.8 2.2 CSP 41 2 27 70 3 28 78 441.4 432.5 21.7 434.0 25.9 434.8 36.5 4.) 4.2 -2.1

CSP 41 3 28 78 4 26 79 296.6 292. 3 12.3 302.1 16.2 315.3 26.5 2.9 2.8 -1.5 CSP 41 4 26 78 5 25 73 255.2 290.2 12.2 293.5 15.5 298.9 25.1 2.5 2.8 12.1 CSP 41 5 25 78 6 26 73 143.8 177.0 4.6 175.2 6.9 170.4 14.) 1.4 1.7 18.

b

CSP 41 b 26 78 7 26 78 113.3 125.1 1.1 111.8 2.2 90.0 7.6 1.1 1.2 9.4

CSP 41 1 3 74 1 31 79 706.3 710. 1 40.3 689.6 44.7 657.9 55.) 6.9 6.9 C.5 CSP 41 l 31 75 3 7 79 430.4 614.0 33.9 616.2 39.3 626.2 52.6 4.2 6.0 25.9

CSP 41 3 7 79 4 4 79 367.9 437.9 22.1 440.9 26.4 440.3 37.0 3.6 4.3 lf.O CSP 41 4 4 79 5 16 79 356.8 365.7 17.2 390.0 22.6 447.0 37.6 3.5 3.6 2.4 CSP 41 5 16 79 6 13 79 154.5 197.7 6.0 204.5 9.0 215.1 18.1 1.5 1.9 21.9

CSP 41 b 13 79 7 11 79 139.8 124.6 1.0 116.8 2.6 102.8 8.6 1.4 1.2 -12.*

CSP 41 7 11 79 8 8 79 110.4 117.9 0.6 106.6 1.8 86.7 7.) 1.1 1.1 E.4

CSP 41 8 8 79 9 5 79 110.4 1)5.1 1.8 132.5 3.7 132.2 11.1 1.1 1.3 18.3

CSP 41 9 5 79 10 3 79 114.0 159.8 3.4 159.3 5.7 160. 1 13.5 1.1 1.6 20.

b

CSP 41 10 3 79 10 31 79 169.2 265.2 10.5 269.6 13.9 276.3 2 3.2 1.6 2.6 36.2

CSP 41 10 31 79 11 28 79 320. P 504.0 26.5 501.2 30.8 493.0 41.4 3.1 4.9 36.5 CSP 41 11 20 79 12 31 79 337.1 511.0 27.0 509.0 31.4 500.5 42.1 3.3 5.0 34.1

CSP 41 12 31 79 1 23 80 J4C.3 534.0 28.5 528.4 32.9 515.8 43.3 3.3 5.2 3C. j CSP 41 1 23 ID 2 20 80 371.5 599.9 32.9 589.1 37.1 569.9 47.9 3.6 5.8 38.1 CSP 41 2 20 80 3 19 90 301.4 448.5 22.8 452.2 27.2 454.8 38.2 2.9 4.4 32.B CSP 41 3 19 80 4 16 80 305.3 463.

b

23.8 464.5 28.1 460.9 38.7 3.0 4.5 3*.l

NO. OF PT. FOR WEEKLY READINGS • 5*

NO. OF PT. FOR PREOICTEO VALUES • M

PERCENTAGE SAVINGS 35.5 35.1 34.0

DATE BEGIN - 1 1 75 DATE EMC - 6 1 80

PERIOD OATS - 23 INSTALLATION DATE - 10 4 79

22
Table 11. Comparison of Average Daily Fuel Consumption in Colorado

Springs House No. 6

FuELiGAS

CT H » DATE CATE FUEL coNsunpn ON/OAv (K.8TUI « ICO CUFTI BEGIN ENC ACTUAL PREDICTED I KITH DECREE OAVSt

H / 0/ Y Pf1 0/ Y fcEST FIT TO-56.5 TO- 65 80-0

F FI GDI F2 GD2 F3 003 F FI

CSP 06 6 18 75 7 lb 75 bt.l 66.0 0.6 47.2 2.5 45.5 3.5 0.6 0.5

CS? 06 7 18 75 8 18 75 67.7 52.2 0.3 33.8 1.8 36.0 2.8 0.7 C.5 CSP 06 8 18 75 9 17 75 oC.r 63.6 1.5 62.1 3.6 61.1 4.7 0.8 0.7

CSP 06 9 17 75 10 17 75 15t.7 156.5 6.3 159.0 10.7 163.9 12.7 1.5 1.4 CSP 06 10 17 75 11 18 75 3 If .b 257.0 13.5 265.5 Id.

6

266.5 20.9 3.1 2.5

CSP 06 11 lb 75 12 18 75 51b.

553.7 25.5 440.2 31.6 438.4 34.0 5.0 4.3

CSP 06 12 18 75 1 19 76 553.8 577.5 27.6 471.5 13.9 468. 4 16.1 5.3 4.6

CSP Ob 1 19 7b 2 19 76 577.5 310.5 22.0 395.0 28.2 395.3 30.6 4.6 3.6 cs? 06 2 19 7b 3 19 76 537.9 393. 1 22.5 400.8 28.7 400.8 31.1 4.3 3.9

CSP 06 3 19 7b 5 18 76 263.3 236.6 12.2 254.1 17.9 259.7 20.L 2.6 2.3 CSP 06 5 18 7b b 17 76 90.

C

95.0 3.1 104.8 6.7 108.7 6.4 0.9 0.9

CS® 06 b 17 7b 7 19 76 68.6 b 3.

1.0 53.4 2.9 51.4 4.0 0.7 0.6

CSP 06 7 19 7b 8 17 76 5fc.f 51.3 0.3 42.1 2.1 40.7 3.2 0.6 0.5

cs? 06 8 17 7b 9 lb 76 70.0 70.5 1.5 63.9 4.1 69.3 5.4 0.7 0.7

CSP 06 9 lb 7b 10 18 76 20C.C 172.5 8.0 187.9 12.9 192.7 14.9 1.9 1.7 CSP 06 to 18 7b 11 17 76 373.3 330. 7 18.2 141.7 24.3 344.2 26.7 3.6 3.2 CSP 06 11 17 7b 12 17 76 58b.

544,. 6 25.5 442.0 31.7 440. 1 34.1 4.7 4.3

cs? 06 12 17 7b 1 19 77 539.4 526.

b

10.3 514.3 37.1 509.4 39.5 5.2 5.1 cs? 06 1 19 77 2 17 77 535.5 532.2 24. 7 432.0 31.0 4 30.6 31.4 4.2 4.2

CSP 06 2 17 77 3 21 77 375.0 599.0 21.1 410.1 29.3 409. 8 31.8 3.6 4.9

CSP 06 3 21 77 5 20 77 253.3 277.1 14.7 291.6 20.6 295.3 22.9 2.5 2.7

cs? 06 4 20 77 K 19 77 75.9 111.6 5. 7 131.8 8. / 136.8 10.6 0.7 1.2 cs? 06 5 19 77 t 2G 77 65.

b

81.0 2.2 82.6 5.1 84.0 6.5 0.6 C.8

cs? 06 6 20 77 7 20 77 5fc . 7 55.6 0.5 41.2 2.0 38. 1 3.0 0.6 0.5

CSP 06 7 20 77 8 18 77 6b .f 50. 9 0.2 33.3 1.9 37. 7 2.9 0.6 0.5

cs? 06 a 18 77 9 19 77 59.5 67.3 1.3 64.7 3.8 65.6 5.1 0.6 0.7 CSP 06 9 19 77 10 18 77 151.4 152.5 6.3 163.1 11.0 166. 5 12.9 1.4 1.5 CSP Oa 1C 18 77 11 17 77 25b. 7 2 3 7.1 12.2 251.9 17.6 256.3 19.9 2.5 2.3 CSP 06 11 17 77 12 19 77 503.1 380. 1 21.3 386.1 2 7.6 386. 8 10.0 3.9 3.7

CSP 06 12 19 77 1 19 7? 587.1 505.9 29.4 496.1 35.7 491.9 Id . 1 4.7 4.9

cs? 06 1 19 78 2 17 73 59b.

b

559. 5 32.9 542.1 19.1 535.8 41.5 4.8 5.4

CSP 06 2 17 78 3 21 7’ 3b4.5 49 3.1 22 .

8

405.

b

29.0 405.2 31.4 3.7 3.9 CSP 06 3 21 78 5 16 71 201.7 237.6 12 .2 252.4 17.7 256.9 19.9 2.0 2.3 cs? 06 5 13 78 6 19 79 90. f. 115.3 5.3 121.8 8.0 124.6 9.7 0.9 1.1 CS® 06 6 19 78 7 19 79 63.3 60. 5 0.9 42.9 2.1 36.7 3.0 0.6 0.6

CSP 06 1 2 79 1 30 71 588.

t

bl 7. 3 37.3 609.4 44.1 600. 1 46.5 5.7 6.2 CSP 06 1 30 79 2 27 71 567.2 556. 7 26.3 451.5 32.4 449.0 34.9 4.5 4.4

cs? 06 "

' ;2 27 79 3 21 71 371.5 381.9 21.5 388.4 27.7 386. 8 30. L 3.6 3.7 CSP 36 3 27 79 4 24 71 2 50.1 252.0 12.5 252.8 17.7 255.6 19.8 2.4 2.3

CSP 06 5 25 79 5 22 71 180.2 193.

9.5 201.8 14.5 214.8 lb.1.8 1.9 CSP 0 6 5 22 79 b 19 71 1 Ob . 7 1C 9. 3 3.9 1 1 7.0 7.6 120.2 9.3 1.0 1.1 CSP 06 6 19 79 7 17 71 73.

63.1 0.4 41.4 2.0 39.0 3.0 0.7 C.5

CSP 06 7 17 79 8 15 71 69.0 52.6 0.4 40.5 2.0 37.9 2.9 0.7 0.5

CSP 06 6 15 79 9 11 79 73.

b

61.7 0.9 57.1 3.2 57.0 4.4 0.7 0.6 CSP 06 9 11 79 1C 9 79 99.3 I n 2. 6 3.6 110.1 7.1 113. 1 6.6 1.0 1.0

cs? 06 10 9 79 11 b 71 2 57.5 253.5 12.6 254.4 17.8 257.6 20.0 2.5 2.4 CSP 06 11 b 79 12 4 79 558.

8

571. 5 27.2 465. 3 13.4 462. 3 35.8 4.4 4.6

cs? 06 12 5 79 12 31 71 555.0 525.0 24.2 425.2 30.5 424.0 32.9 4.4 4.1 cs? 06 12 31 79 1 29 81 58t.b 5 07.0 29.5 496.7 35.9 492.4 38.2 4.7 4.9

cs? 3 6 0 29 tc 2 26 1C 5 70.

9

560.8 25.9 44 7.9 32.1 445.7 34.6 4.6 4.4

CSP 06 2 26 to 3 25 91 377.7 3?0. 6 21.4 389.5 27.7 390. 1 30.

3.7 3.7 CSP 06 3 25 to 4 22 91 305.0 316.2 16.5 342.1 24.3 343.1 26.6 1.0 3.3

NO. IF f>T. FOR RtEKLY READINGS - 52 NO. OF PT. FOR PREDICTED VALUES - 52

PERCENTAGE savings 0.4 0.6 0.4

DATE BEGIN - I X 75 DATE ENt « t 1 8J

PER I

:J 7 JAYS - 2 3 INSTALLATION DATE - 1C 1 79

PERCENTAGE SAVINGS

-16.1 -25.

t

-It.

-7.7

-22. b -If .5 -13.9

- 22 .. — 1C. L -11.3

5.c -E.7

-14. t O.fc -If .9 -12.9

-9.5

- 7.9 -C.5

f.l

F.b

3f .5

l c .O -3.7

-If.c

11.7

7.3

- f .. -f . 1 3.7

11... A.

If .1 EC. -*.b

7.0

- 7.3 7.7 -3.5

f -b 1.5 -3E.7

-37.9 -19.7

3... -f.b

9.C

-< . t *.L -5.5

f.b

f.l

23
Table 12. Percentage

Dwellings

Saving in Fuel Consumption

in Each City

of all

City Code Average Median

Sample Control Sample Control

ABE 18.5 12.0 17.5 12.0

CHA 28.3 11.0 26.4 17.5

CSP 31.5 1.2 32.9 0.4

FAR 31.0 4.9 34.6 2.1

POR 43.2 40.6

STL 23.4 - 5.9 21.1 -12

TAC 35.0 11.3 36.8 6.0

24
Figure 1. Sites selected for the demonstration program

25
» ACTUAL v PREDICTED (B.F.) COLORADO SPRINGS, CO. H# 4] FUEL : GAS

Figure 2. Graphical comparison of average daily fuel consumption of

Colorado Springs house no. 41

* ACTUAL v PREDICTED (B.F.) COLORADO SPRINGS, CO. H# 6 FUEL: GAS

Figure 3. Graphical comparison of average daily fuel consumption of

Colorado Springs house no. 6

26
FUEL

CONSUMPTION

PER

DRY

(

KBTU/DRY

)

£

FUEL

CONSUMPTION

PER

DRY

(

KBTU/DRY

)

20,0

40,0

60£

80£

10,00

J1

,00

og

0

20£

40£

6^9

80£

10,00

1 _

2,00

* ACTUAL s PREDICTED (B.F.) FARGO, N. D. H# 17 FUEL: GPS

T

75 76 77 78 79 80 DATE

ire 4. Graphical comparison of average daily fuel consumption of

Fargo House no. 17

* ACTUAL v PREDICTED (B.F.) FARGO, N. D. H# 30 FUEL : GAS

75 76 77 78 79 80 DATE

Figure 5. Graphical comparison of average daily fuel consumption of

Fargo House no. 30

27
• OCTUOL v PREDICTED (B.F.) FORGO, N. D. H# 13 FUEL:GQS

Figure 6. Graphical comparison of average daily fuel consumption of

Fargo House no, 13

• OCTUOL v PREDICTED CB.F.) TOCOMO, WO. H# 4 FUEL : ELECTR 1C1 TY

Figure 7. Graphical comparison of average daily fuel consumption of

Tacoma House no. 4

28
• ACTUAL v PREDICTED (B.F. I TACOMA. WA. H# 83 FUEL: GAS

Figure 8. Graphical comparison of average daily fuel consumption of

Tacoma House no. 83

* ACTUAL N PREDICTED (B.F. ) TACOMA, WA. H# 58 FUEL : GAS

Figure 9. Graphical comparison of average daily fuel consumption of

Tacoma House no. 58

29
• QCTUQL v. PREDICTED CB.F.) PORTLOND. MP1NE Hi 7 FUEL:OIL

Figure 10. Graphical comparison of average daily fuel consumption of

Portland House no. 7

* OCTUQL v PREDICTED (B.F. ) PORTLOND, MOINE Hi 25 FUEL:01L

Figure 11. Graphical comparison of average daily fuel consumption of

Portland House no. 25

30
• ACTUAL 'v PREDICTED (B.F. ) ST. LOUIS. HO. H# 70 FUEL : GAS

Figure 12. Graphical comparison of average daily fuel consumption of

St. Louis House no. 70

• ACTUAL v PREDICTED (B.F.) ST. LOUIS. MO. Ht 42 FUEL:GAS

Figure 13. Graphical comparison of average dally fuel consumption of

St. Louis House no. 42

31
• PCTUPL x PREDICTED CB.F.) ST. LOUIS, MO. H# 10 FUEL: GPS

Figure 14. Graphical comparison of average daily fuel consumption of

St. Louis House no. 10

* PCTUPL x PREDICTED (B.F . ) PLLENTOWN, PP. H# 23 FUEL:CPS

Figure 15. Graphical comparison of average daily fuel consumption of

Allentown House no. 23

32
• ACTUAL v PREDICTED CB.F.) ALLENTOWN, PR. H* 27 FUEL : GRS

Figure 16. Graphical comparison of average daily fuel consumption of

Allentown House no. 27

* RCTURL v PREDICTED (B.F. ) CHARLESTON, S.C, H# 25 FUEL : PROPANE

Figure 17. Graphical comparison of average daily fuel consumption of

Charleston House no. 25

33
FUEL

CONSUMPTION

PER

DRY

(

KBTU/DRY

)

100

20,0

30.0

400

500

60O * RCTUfiL x PREDICTED (B.F. ) CHARLESTON, S.C. H« 19 FUEL:PROPfiNE

rk I h

n

t r -C

<s 1

-1 1 1 1 1

I

1 1 11 1 1 1 r r

7 17 17 17 17 75 76 77 78 DRTE

79

1 780

Figure 18. Graphical comparison of average daily fuel consumption of

Charleston House no. 19

34
70

60

50

40

30

20

10

0

-10

-20

-30

i n m n m n rr

Q

8

Bo

B

°

B

I

8

o

-O-OB

o

o

oo

-0-

J_l L J I I L J II II

ABE CHA CSP FAR POR STL TAC

DEMONSTRATION SITE

Sample group including water

heater usage

Sample group excluding water

heater usage o Control group including water

heater usage • Control group excluding water

heater usage

19. Percentage savings achieved for each dwelling in the

demonstration program

35
NUMBER

OF

DWELLINGS

NUMBER

OF

DWELLINGS

SAMPLE GROUP

SAVINGS (%)

CONTROL GROUP

SAVINGS (%)

Figure 20. Histograms of fuel reductions of dwellings including water

heater usage

36
NUMBER

OF

DWELLINGS

NUMBER

OF

DWELLINGS

SAMPLE GROUP

SAVINGS (%)

CONTROL GROUP

SAVINGS (%)

Figure 21. Histograms of fuel reductions of dwellings excluding water

heater usage

37

APPENDIX A. THE BALANCE POINT CALCULATION BY USE OF FUEL BILL RECORDS

A condition that a home be selected as a participant in the optimal

weatherization demonstration was that an adequate history of fuel consumption

be available for a period of at least two years prior to the start of demonstration. This record of fuel consumption was utilized to determine the parameters

bQ , b^ and Ta of equation (2) before weatherization. Equation (2) will then be

used as a predictor of how the dwelling would perform if no weatherization optimum would have been applied. The theoretical procedure used for determining

these parameters consists of fitting a series of straight lines* to the billing

history of a dwelling:

FD

(k) = b

(ot) + b, (ct) DDt

(k) k = 1, ..., N (A. 1) u o i i a

where F_/ k ^ is the average daily fuel in the k

c^ billing period, DlL, ^ k ^ is

the average daily degree days in the k

Ln billing period calculated for a base

temperature Ta

. The average daily fuel consumption and the average daily degree

days were used in equation (A. 1) due to the normal variation in the number of

days in a billing period, specially for fuels such as oil and propane which are developed either on demand or at more or less constant degree day intervals.

The parameter b^ a ' and b^ a' were determined using standard least

square regression techniques:

>1

. . (I E DDt

( k >F (k) - v nn

(a)

_ N k=1

u FD DDTa

>

/ N

( i E DDt \N k=1

T

a nn_ ( k ^DDT

(k ^ - DD

A T

a

1

b

o

< “) = FD

- b

l <a) DDT

where Fp and DD-p are given by

a

f =

1

r f ( k) D N k=l

D

:)

— i n — (k> ddt

= L E dd

i t

a N k=i

i a

(A. 2)

(A. 3)

(A. 4)

(A. 5)

* The procedure outlined here is a variant of that given in reference [ A. 1 ]

.

A-l
The balance point T0 is then chosen to be the base temperature which gives the

smallest residues (or maximum correlation) of the family of straight lines

determined by equations (A.l) to (A. 3).

This balance point T0 is defined as the temperature which produced the smallest

8 (a) ’

where

N

r/

k> br, <o) - t>i <a) DD_ (k>

) 2

CN-1) k-1

D ° 1 T

o

s (a) 2 - — 1 (A. 6)

or equivalently the maximum correlation coefficients r^ , where

2

2 , 8 (a)

r

z = 1 - —*

(A. 7)

where Sp is the estimate of the variation of daily fuel consumption, where

N

s p

z = -±- Z (Fd °° - Fd

) 2^1 2

N-l k=1

(A. 8)

The average daily degree days (based on Tot) for each billing period was calculated using weather tapes for each city obtained from the National

Climatic Center.

The weather tapes were decoded to produce an hourly or three hourly weather

file, depending on the particular weather station. A daily weather file was then processed by entering only the maximum and minimum temperature for each

day. The degree days were calculated using a daily temperature profile T(t)

by assuming a sinusoidal function with a period of 24 hours and a peak at 3

o'clock in the afternoon:

^ __ ( max min \ i 1 ( rp k 2

' ~2 '‘max Tmir.) cos [ 2n(t-3) i 24

(A. 9)

The degree days at the base temperature Ta for a given day, DEVp was determined

by: a

24

DDt

- Z [Ta - T(t ) ] only for [T2-T(t)] > 0, a I t=l

where I is the number of t's such that [Ta

- T( t ) ] > 0.

(A. 10)

AThe average daily degree days in the k was then tk billing period, DDT

calculated by: a

DD„ (k) = L Z DDt

(m) (A. 11) a M m=l a

where M is the number of days in the k

tk billing period,

DDt

is the degree days for m

tk day in the ktk billing period,

a

A3
REFERENCE

[ A. 1 ] Woteki, T.H. and Mayer, L.S., "Fuel Consumption as Coldness of a Month," Energy and Building, Vol. 1,

a Function of

1978.

ANBS-114A (REV. 2-80

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 83-2676

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

4.

TITLE AND SUBTITLE

TECHNIQUE FOR TRACKING THE EFFECT OF WEATHERIZATION

RETROFITS ON LOW-INCOME HOUSING

5.

AUTHOR(S)

Yui-May Chang and Richard A. Grot

6.

PERFORMING ORGANIZATION (If joint or other than NBS. see instructions)

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8. Type of Report & Period Covered

9.

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

Community Services Administration

Washington, DC 20506

10.

SUPPLEMENTARY NOTES

J 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

bibliography or literature survey, mention it here) This report presents a technique for analyzing the effect of energy saving retrofits

installed in low-income housing under a nationwide weatherization demonstration

program. This program was undertaken by the Community Services Administration (CSA)

with the technical support of the National Bureau of Standards (NBS)

.

A tracking technique, based on the calculated balance-point temperature of each home

prior to the weatherization, was developed to estimate the would-be fuel consumption

over a period of time if the house had not been weatherized. The savings in fuel

consumption for a home can be determined from the difference between the actual usage

after retrofit and the calculated usage if it were not retrofitted. Besides the

overall reduction, the saving in energy usage during different time periods while

the house is being weatherized can be visualized from the graphical representation

of the tracking technique.

Fuel reduction is reported for more than 100 homes using different fuels in seven

cities across the nation, selected to represent various climate zones and geographical

locations. It was found that the average saving in fuel consumption for dwellings in

each city is about 30 percent.

12.

KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) Balance point temperature; computer graphics; degree days; energy conservation;

energy consumption; fuel usage records; tracking technique; weatherization retrofit.

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