### APPENDIX 7-D. WEATHER DATA AND TEMPERATURE PARAMETERS

TABLE OF CONTENTS

7-D.1 INTRODUCTION .................................................................................................7-D-1

7-D.2 OUTDOOR TEMPERATURE DERIVATION ....................................................7-D-1

7-D.2.2 Imputation Method.................................................................................................7-D-3

7-D.3 INLET WATER TEMPERATURE.....................................................................7-D-12

LIST OF TABLES

Table 7-D.2.1 Weather Station Data ...........................................................................7-D-4

Table 7-D.3.1 Calculation of Water Inlet Offset for Municipal Treatment Plants ...7-D-13

LIST OF FIGURES

Figure 7-D.2.1 Heating Degree Days (HDD) Versus Mean Temperature ...................7-D-2

Figure 7-D.2.2 Cooling Degree Days (CDD) Versus Mean Temperature ...................7-D-2

Figure 7-D.2.3 Heating Degree Days (HDD) Versus Imputed Mean Temperature

Values ..................................................................................................7-D-3

Figure 7-D.2.4 Cooling Degree Days (CDD) Versus Imputed Mean Temperature

Values ..................................................................................................7-D-4

7-D-i

### APPENDIX 7-D. WEATHER DATA AND TEMPERATURE PARAMETERS

7-D.1 INTRODUCTION

The temperatures for water heater thermostat setpoint, inlet water temperature, and

temperature of the air surrounding the water heater are based on the average annual outdoor air

temperature, for each sample household. The outdoor air temperature for the households in the

water heater RECS sample is not directly available. Similarly, the inlet water temperature is not

available for the sample. This appendix describes DOE’s approach to develop data for these two

parameters.

7-D.2 OUTDOOR TEMPERATURE DERIVATION

RECS 2005 provides data on heating and cooling degree-days but not air temperatures

for each household in the sample. To derive the outdoor air temperatures for the households in

the RECS sample, DOE developed an approach to assign a physical location to each RECS

household. The following steps were performed:

1. DOE assembled weather data from 282 weather stations that provide annual average

outdoor air temperatures. 1, 2 

### The annual average outdoor air temperatures represent 30­

year averages. DOE also gathered the heating and cooling degree-days at base

3 

### temperature 65 o 

### F for year 2005 for these weather stations. The 2005 heating and

cooling degree days match the period used to determine the degree-days in RECS 2005.

2. RECS reports both heating degree-days (HDD) and cooling degree-days (CDD) to base

temperature 65 o 

### F for each housing record. DOE assigned each RECS household to one

of the 282 weather stations by calculating which weather station (within the appropriate

census region or large state) gave the best linear least squares fit of the RECS data to the

weather data.

Figure 7-D.2.1 and Figure 7-D.2.2 show the relationship between the gathered mean

temperature values and the HDD values.

7-D-190Mean Temperature (Fo)Mean Temperature (Fo) 80

70 y = -0.0037x + 72.299

R2 = 0.9734

60

50

40

30

20

10

0

0 5000 10000 15000 20000

Heating Degree Days (HDD)



### Figure 7-D.2.1	 Heating Degree Days (HDD) Versus Mean

Temperature

90

80

70

60

50

30 40 y = 0.0089x + 40.884

R2 = 0.7954

20

10

0

0 1000 2000 3000

Cooling Degree Days (CDD) 4000 5000



### Figure 7-D.2.2	 Cooling Degree Days (CDD) Versus Mean

Temperature

7-D-2

### 7-D.2.2 Imputation Method

To calculate the mean outdoor air temperature, DOE matched the RECS 2005

combinations (255 individual combinations of census divisions plus 4 large states, together with

the HDD and CDD data) to U.S. weather data. DOE used the U.S. weather station closest (or

with minimum “distance”) from the RECS 2005 data combination. The following equation

calculates the “distance” between the U.S. weather data and RECS 2005 data:



## " Distance "

= ( HDD

− HDD ) 2 

## + ( CDD

− CDD ) 2

2 1 2 1



### Where:

HDD 1 

### = heating degree days from U.S. weather data,

HDD 2 

### = heating degree days from RECS 2005 data,

CDD 1 

### = cooling degree days from U.S. weather data, and

CDD 2 

### = cooling degree days from RECS 2005 data.

Figure 7-D.2.3 and Figure 7-D.2.4 show the relationship between the imputed mean

outdoor air temperature values and the RECS 2005 HDD values.

90

80

70

60

50

40

30 y = -0.0037x + 71.98

R2 = 0.9419 20

10

0

0 2000 4000 6000 8000 10000 12000

HDD (days)



### Figure 7-D.2.3 Heating Degree Days (HDD) Versus Imputed Mean

Temperature ValuesMean Temperature (Fo)

7-D-3Mean Temperature (Fo) 90

80

70

60

50

y = 0.0073x + 45.127 40 R2 = 0.7132

30

20

10

0

0 1000 2000 3000 4000 5000 6000

CDD (days)



### Figure 7-D.2.4 Cooling Degree Days (CDD) Versus Imputed Mean

Temperature Values

Table 7-D.2.1 shows the imputation results for all RECS locations. Note that some

weather station data matches with several of the RECS 2005 255 HDD & CDD combinations.

Table 7-D.2.2 shows a subset of the data matches.

Table 7-D.2.1 Weather Station Data

Station Location Mean HDD CDD

State Code Temp (2005) (2005) City

BDL 50.2 6219 1003 AK KODIAK



### BDR 52.1 5361 1046 AK KING SALMON



### BOS 51.6 5902 888 AK ANCHORAGE



### ORH 47.2 6670 714 AK BETHEL



### CAR 39.2 9166 236 AK BIG DELTA



### HUL 39.9 8989 247 AK BARROW



### PWM 45.7 7218 471 AK BETTLES



### CON 45.9 7385 602 AK COLD BAY



### MWN 27.2 13063 0 AK FAIRBANKS



### PVD 51.1 5824 1010 AK GULKANA



### BTV 45.2 7425 729 AK HOMER



### ACY 53.5 5109 1278 AK JUNEAU



### EWR 54.5 4949 1526 AK MCGRATH



### ABE 50.6 5704 1085 AK NOME



### CXY 53.3 5187 1243 AK KOTZEBUE



### ERI 50.0 6318 907 AK ST PAUL ISLAND



### IPT 49.8 6038 965 AK TALKEETNA

7-D-4AK UNALAKLEET 

### PHL 55.3 4735 1530

AK VALDEZ 

### PIT 50.9 5765 929

AK YAKUTAT 

### MLI 50.2 5750 1344

AL BIRMINGHAM 

### ORD 49.1 6076 1166

AL HUNTSVILLE 

### PIA 50.8 5514 1431

AL MONTGOMERY 

### RFD 47.9 6421 1030

AL MOBILE 

### SPI 52.7 5168 1427

AL MUSCLE SHOALS 

### EVV 56.0 4317 1548

AL TUSCALOOSA 

### FWA 49.9 6153 1008

AR FORT SMITH 

### IND 52.5 5263 1295

AR FAYETTEVILLE 

### SBN 49.5 6243 1044

AR LITTLE ROCK 

### ANJ 40.1 8375 339

AZ DOUGLAS 

### APN 42.5 7941 444

AZ FLAGSTAFF 

### DTW 49.7 6189 1098

AZ WINSLOW 

### FNT 46.8 6906 763

AZ PHOENIX 

### GRR 47.6 6642 891

AZ TUCSON 

### HTL 43.1 7858 462

AZ YUMA 

### LAN 46.8 6585 908

CA BAKERSFIELD 

### MKG 47.1 6583 780

CA BLYTHE 

### SAW 38.7 8548 427

CA EUREKA 

### CAK 49.5 6215 884

CA FRESNO 

### CLE 49.6 6067 997

CA LOS ANGELES 

### CMH 52.9 5355 1250

CA MT SHASTA 

### CVG 54.2 4981 1342

CA PASO ROBLES 

### DAY 51.5 5730 1059

CA REDDING 

### FDY 50.2 6067 1020

CA SACRAMENTO 

### MFD 48.7 6320 833

CA SAN DIEGO 

### TOL 49.5 6210 1031

CA STOCKTON 

### YNG 48.5 6328 711

CA SAN FRANCISCO 

### GRB 44.4 7392 647

CO ALAMOSA 

### LSE 47.3 6754 1014

CO COLORADO SPRINGS 

### MKE 47.5 6612 954

CO DENVER 

### MSN 46.1 6837 848

CO GRAND JUNCTION 

### ALO 47.2 6845 862

CO PUEBLO 

### DBQ 46.9 6791 839

CO TRINIDAD 

### DSM 50.0 5817 1330

CT HARTFORD 

### SUX 48.3 6189 1313

CT BRIDGEPORT 

### CNK 53.5 5057 1618

DC WASHINGTON 

### DDC 55.2 4488 1683

DE WILMINGTON 

### GLD 50.7 5353 1117

FL DAYTONA BEACH 

### ICT 56.4 4342 1846

FL KEY WEST 

### TOP 54.3 4803 1627

FL FT LAUDERDALE 

### DLH 39.1 8985 296

FL FORT MYERS 

### INL 37.4 9876 240

7-D-5FL GAINESVILLE 

### MSP 45.4 7003 1003

FL JACKSONVILLE 

### RST 43.4 7434 705

FL ORLANDO 

### STC 41.8 7797 640

FL MIAMI 

### COU 54.0 4663 1581

FL WEST PALM BEACH 

### MCI 54.2 4777 1635

FL PENSACOLA 

### SGF 56.2 4254 1758

FL TALLAHASSEE 

### STL 56.3 4352 1898

FL TAMPA 

### BIS 42.3 7795 557

FL VERO BEACH 

### DIK 41.8 8215 344

GA ALBANY 

### FAR 41.5 8283 566

GA AUGUSTA 

### GFK 40.3 9227 404

GA ATHENS 

### ISN 40.9 8326 465

GA ATLANTA 

### JMS 41.4 8376 423

GA WAYCROSS 

### BFF 47.8 6254 741

GA BRUNSWICK 

### GRI 49.9 5748 1215

GA COLUMBUS 

### LBF 48.7 6228 1025

GA MACON 

### LNK 51.1 5762 1439

GA SAVANNAH 

### OFK 48.7 5979 1229

HI HONOLULU-OAHU 

### OMA 50.7 5749 1472

HI HILO-HAWAII 

### VTN 47.2 6558 959

HI LIHUE-KAUAI 

### ABR 43.8 7868 660

HI KAHULUI-MAUI 

### ATY 42.8 7847 657

IA WATERLOO 

### FSD 45.1 6999 871

IA DUBUQUE 

### HON 45.3 7173 985

IA DES MOINES 

### PIR 47.5 6802 1110

IA SIOUX CITY 

### RAP 46.6 6533 834

ID BOISE 

### DCA 57.5 4154 1702

ID LEWISTON 

### ILG 54.4 4991 1296

ID POCATELLO 

### ABY 66.3 1763 2658

IL MOLINE 

### AGS 63.2 2475 2151

IL CHICAGO 

### AHN 61.5 2841 1805

IL PEORIA 

### ATL 62.1 2754 1843

IL ROCKFORD 

### AYS 66.7 1630 2438

IL SPRINGFIELD 

### BQK 68.6 1596 2464

IN EVANSVILLE 

### CSG 65.1 2019 2421

IN FORT WAYNE 

### MCN 63.7 2202 2385

IN INDIANAPOLIS 

### SAV 66.2 1948 2370

IN SOUTH BEND 

### BWI 54.6 4714 1343

KS CONCORDIA 

### SBY 56.6 4858 1101

KS DODGE CITY 

### AVL 54.8 4083 891

KS GOODLAND 

### CLT 61.4 3279 1660

KS WICHITA 

### GSO 58.1 3504 1631

KS TOPEKA 

### HAT 62.8 2884 1896

KY BOWLING GREEN 

### ILM 63.8 2650 2002

7-D-6KY JACKSON 

### RDU 59.6 3314 1913

KY LEXINGTON 

### CAE 63.6 2545 2198

KY PADUCAH 

### CHS 65.3 2003 2427

KY LOUISVILLE 

### GSP 60.0 3024 1754

LA BATON ROUGE 

### LYH 55.4 4375 1167

LA LAKE CHARLES 

### ORF 59.6 3484 1767

LA LAFAYETTE 

### RIC 57.6 3674 1823

LA NEW ORLEANS 

### ROA 56.3 3948 1329

LA SHREVEPORT 

### BKW 51.6 5360 659

MA BOSTON 

### CRW 54.5 4436 1289

MA WORCESTER 

### EKN 49.8 5644 680

MD BALTIMORE 

### HTS 55.0 4375 1516

MD SALISBURY 

### MRB 54.0 5044 1118

ME CARIBOU 

### BHM 62.2 2587 2089

ME HOULTON 

### HSV 60.6 3007 1968

ME PORTLAND 

### MGM 65.0 2104 2326

MI SAULT ST MARIE 

### MOB 66.8 1507 2600

MI ALPENA 

### MSL 61.0 2956 2004

MI DETROIT 

### TCL 64.0 2416 2307

MI FLINT 

### BWG 57.2 3980 1601

MI GRAND RAPIDS 

### JKL 55.9 3946 1537

MI HOUGHTON LAKE 

### LEX 55.2 4525 1451

MI LANSING 

### PAH 56.8 4145 1554

MI MUSKEGON 

### SDF 56.9 4085 1792

MI MARQUETTE 

### JAN 64.1 2257 2414

MN DULUTH 

### MEI 64.7 2283 2234

MN INT'L FALLS 

### TUP 61.3 2669 2298

MN MINNEAPOLIS 

### BNA 58.9 3459 1954

MN ROCHESTER 

### CHA 60.0 3140 1824

MN SAINT CLOUD 

### CSV 54.5 4166 1091

MO COLUMBIA 

### MEM 62.3 2629 2582

MO KANSAS CITY 

### MKL 59.4 3443 1771

MO SPRINGFIELD 

### TRI 54.9 4201 1153

MO SAINT LOUIS 

### TYS 58.4 3517 1610

MS JACKSON 

### FSM 61.2 2920 2359

MS MERIDIAN 

### FYV 57.7 3825 1619

MS TUPELO 

### LIT 62.1 2941 2179

MT BILLINGS 

### BTR 67.0 1443 2920

MT CUT BANK 

### LCH 67.9 1312 3099

MT KALISPELL 

### LFT 68.3 1292 3225

MT GLASGOW 

### MSY 68.8 1102 3203

MT GREAT FALLS 

### SHV 65.7 1868 3001

MT HELENA 

### HBR 59.8 3379 2200

MT MILES CITY 

### OKC 60.1 3178 2132

7-D-7MT MISSOULA 

### TUL 60.8 3303 2323

NC ASHEVILLE 

### DUG 61.5 2369 1963

NC CHARLOTTE 

### FLG 46.2 6634 111

NC GREENSBORO 

### INW 55.2 4096 1259

NC CAPE HATTERAS 

### PHX 74.2 732 4714

NC WILMINGTON 

### TUS 68.7 1207 3417

NC RALEIGH DURHAM 

### YUM 75.3 504 4629

ND BISMARCK 

### ALS 40.8 7751 97

ND DICKINSON 

### COS 47.8 5870 554

ND FARGO 

### DEN 50.1 5730 925

ND GRAND FORKS 

### GJT 51.8 5047 1119

ND WILLISTON 

### PUB 51.7 5217 1026

ND JAMESTOWN 

### TAD 51.0 5110 945

NE SCOTTSBLUFF 

### BOI 51.9 5424 975

NE GRAND ISLAND 

### LWS 52.4 4814 851

NE NORTH PLATTE 

### PIH 46.5 7131 398

NE LINCOLN 

### BIL 47.4 6560 652

NE NORFOLK 

### CTB 39.7 8206 128

NE OMAHA 

### FCA 42.6 7603 92

NE VALENTINE 

### GGW 42.6 8000 541

NH CONCORD 

### GTF 43.7 7443 320

NH MT WASHINGTON 

### HLN 44.0 7478 461

NJ ATLANTIC CITY 

### MLS 46.3 7217 720

NJ NEWARK 

### MSO 44.8 7527 312

NM ALBUQUERQUE 

### ABQ 56.8 3767 1562

NM CLAYTON 

### CAO 53.3 4563 968

NM CARLSBAD 

### CNM 62.8 2619 2211

NM ROSWELL 

### ROW 60.8 3028 1974

NV ELKO 

### EKO 46.4 7169 448

NV ELY 

### ELY 44.8 7001 259

NV LAS VEGAS 

### LAS 68.1 1582 3595

NV LOVELOCK 

### LOL 50.1 5181 1075

NV RENO 

### RNO 51.3 4900 970

NV WINNEMUCCA 

### WMC 49.3 6464 550

NY ALBANY 

### SLC 52.0 5321 1203

NY WATERTOWN 

### CPR 44.9 6939 465

NY BINGHAMTON 

### CYS 44.9 6610 449

NY BUFFALO 

### LND 45.0 7203 563

NY NEW YORK 

### RKS 42.8 7849 291

NY ROCHESTER 

### SHR 44.5 7091 602

NY SYRACUSE 

### WRL 45.4 7214 671

NY UTICA 

### ADQ 40.5 8058 0

OH AKRON CANTON 

### AKN 34.5 10001 0

OH CLEVELAND 

### ANC 36.2 9265 8

7-D-8OH COLUMBUS 

### BET 29.9 12013 12

OH CINCINNATI 

### BIG 28.6 11876 19

OH DAYTON 

### BRW 10.4 18659 0

OH FINDLAY 

### BTT 22.9 14513 37

OH MANSFIELD 

### CDB 38.4 8794 0

OH TOLEDO 

### FAI 26.7 13011 53

OH YOUNGSTOWN 

### GKN 27.1 12420 2

OK HOBART 

### HOM 38.1 8496 0

OK OKLAHOMA CITY 

### JNU 41.5 7676 2

OK TULSA 

### MCG 26.9 13086 23

OR ASTORIA 

### OME 27.1 13214 12

OR BAKER 

### OTZ 21.8 15012 16

OR BURNS 

### SNP 35.0 9601 0

OR EUGENE 

### TKA 33.9 9692 22

OR MEDFORD 

### UNK 27.2 12349 21

OR NORTH BEND 

### VWS 38.3 7542 23

OR PENDLETON 

### YAK 39.5 8201 0

OR PORTLAND 

### HNL 77.5 0 4992

OR SALEM 

### ITO 73.9 0 3666

PA ALLENTOWN 

### LIH 75.7 0 4308

PA HARRISBURG 

### OGG 75.8 0 4088

PA ERIE 

### AST 51.0 4588 18

PA WILLIAMSPORT 

### BKE 45.4 7453 179

PA PHILADELPHIA 

### BNO 44.2 7450 268

PA PITTSBURGH 

### EUG 52.1 4612 263

RI PROVIDENCE 

### MFR 54.4 4133 859

SC COLUMBIA 

### OTH 52.5 4288 2

SC CHARLESTON 

### PDT 52.3 5258 608

SC GREENVILLE 

### PDX 53.5 4150 445

SD ABERDEEN 

### SLE 52.6 4574 319

SD WATERTOWN 

### ALW 54.2 4770 910

SD SIOUX FALLS 

### BLI 50.8 5269 22

SD HURON 

### EAT 51.9 5562 819

SD PIERRE 

### GEG 47.3 6485 417

SD RAPID CITY 

### OLM 49.6 5078 86

TN NASHVILLE 

### SEA 52.3 4437 164

TN CHATTANOOGA 

### UIL 49.1 5272 12

TN CROSSVILLE 

### YKM 48.9 5867 494

TN MEMPHIS 

### ALB 47.5 6607 913

TN JACKSON 

### ART 45.7 7565 576

TN BRISTOL 

### BGM 45.8 7089 674

TN KNOXVILLE 

### BUF 47.9 6644 880

TX ABILENE 

### LGA 55.1 4707 1597

TX WACO 

### ROC 47.6 6735 795

7-D-9TX ALICE 

### SYR 47.4 6636 909

TX AMARILLO 

### UCA 46.6 7195 709

TX AUSTIN 

### BFL 65.0 1797 2144

TX BROWNSVILLE 

### BLH 71.3 889 4251

TX CORPUS CHRISTI 

### EKA 52.9 4857 0

TX DALLAS FT WORTH 

### FAT 63.2 1881 2080

TX DEL RIO 

### LAX 63.3 1128 525

TX EL PASO 

### MHS 49.2 5629 272

TX GALVESTON 

### PRB 58.5 2437 963

TX HOUSTON 

### RDD 61.6 2466 1775

TX LUBBOCK 

### SAC 61.1 2345 1180

TX MIDLAND ODESSA 

### SAN 64.4 858 657

TX SAN ANTONIO 

### SCK 61.8 2061 1482

TX SAN ANGELO 

### SFO 57.3 2267 71

TX WICHITA FALLS 

### ABI 64.4 2316 2475

TX VICTORIA 

### ACT 66.6 1837 3030

UT SALT LAKE CITY 

### ALI 72.3 743 4026

VA LYNCHBURG 

### AMA 57.0 4045 1432

VA NORFOLK 

### AUS 69.0 1578 3181

VA RICHMOND 

### BRO 73.3 346 4380

VA ROANOKE 

### CRP 71.5 690 3807

VT BURLINGTON 

### DFW 65.5 1953 3122

WA WALLA WALLA 

### DRT 69.7 1210 3464

WA BELLINGHAM 

### ELP 64.7 2146 2556

WA WENATCHEE 

### GLS 71.2 848 3673

WA SPOKANE 

### IAH 68.8 1221 3292

WA OLYMPIA 

### LBB 59.7 3173 1925

WA SEATTLE TACOMA 

### MAF 63.4 2604 2273

WA QUILLAYUTE 

### SAT 68.7 1277 3328

WA YAKIMA 

### SJT 64.5 2209 2420

WI GREEN BAY 

### SPS 63.1 2597 2556

WI LACROSSE 

### VCT 70.0 1108 3334

WI MILWAUKEE 

### DAB 71.0 763 2981

WI MADISON 

### EYW 78.1 68 4743

WV BECKLEY 

### FLL 75.4 135 4222

WV CHARLESTON 

### FMY 74.9 284 3814

WV ELKINS 

### GNV 68.6 1193 2711

WV HUNTINGTON 

### JAX 68.0 1358 2670

WV MARTINSBURG 

### MCO 72.8 527 3404

WY CASPER 

### MIA 76.7 109 4435

WY CHEYENNE 

### PBI 75.3 232 4021

WY LANDER 

### PNS 68.2 1305 2775

WY ROCK SPRINGS 

### TLH 68.0 1520 2737

WY SHERIDAN 

### TPA 73.1 522 3505

7-D-10WY WORLAND 

### VRB 73.2 463 3479

Table 7-D.2.2 Subset of Data Matches

Location DOE ID HDD CDD Division

BOS 2977 5771 839 1

BOS 43 5788 900 1

BOS 396 5791 834 1

BOS 703 5796 833 1

BOS 2389 5817 828 1

BOS 1470 5874 894 1

BOS 385 5874 894 1

BOS 4354 5879 902 1

BOS 3952 5885 876 1

BOS 1529 5899 888 1

BOS 2381 5911 885 1

BOS 825 5913 894 1

BOS 2005 5922 880 1

BOS 2064 5931 801 1

BOS 4040 5933 879 1

BOS 1428 5933 879 1

BOS 535 5951 884 1

BOS 894 5956 873 1

BOS 2211 5958 873 1

BOS 1548 5959 873 1

BOS 3239 5965 871 1

BOS 620 5968 864 1

BOS 2533 5975 853 1

BOS 697 5979 865 1

BOS 4067 5980 865 1

BOS 3506 5983 866 1

BOS 1369 5994 864 1

BOS 4113 5994 932 1

BOS 1726 5997 861 1

BOS 1671 5998 861 1

BOS 328 6012 918 1

BOS 3790 6018 856 1

BOS 3890 6020 841 1

BOS 2587 6024 854 1

BOS 281 6028 839 1

BOS 87 6028 855 1

BOS 1440 6052 847 1

BOS 2152 6057 832 1

BOS 4140 6059 831 1

BOS 2949 6061 845 1

BOS 675 6062 876 1

BOS 1079 6071 843 1

BOS 178 6072 801 1

BOS 2487 6072 842 1

BOS 3111 6084 825 1

BOS 1797 6097 821 1

BOS 3333 6107 694 1

7-D-11

### 7-D.3 INLET WATER TEMPERATURE

The daily hot water use and the water heater energy use depend on average inlet water

temperature. The inlet water comes to the water heater either from a municipal treatment plant or

from ground well sources. DOE determined the water source using RECS 2005, which provides

information about households in the sample with a well. Households without a well presumably

use water from municipal treatment plants.

DOE derived the inlet water temperature using an approach developed by the National

Renewable Energy Laboratory. 4, 5

,max 

### ⎟ ∗ ⎞

⎟
⎠ T 

# ( T 

# ) air



### 2 sin 

# ( 0.986 

# ( 30 

# ) 90 

# ) + ratio ∗ ⎛ Δ

⎜ ⎜ ⎝ ∗ ∗

− − # 30

− T

mains 

### = offset month lag + air

, avg



### Where:

T

mains 

### = mains (supply) temperature to domestic hot water tank, °F,

T

air,avg 

### = annual average outdoor air temperature, °F,

Δ T air,max 

### = maximum difference between monthly average outdoor air temperatures

(i.e. MAX( T air,month 

### ) - MIN( T air,month 

### )), °F,

0.986 = degrees/day (360/365),

month# = number of month of the year (e.g. January = 1),

offset = given by a distribution of values as shown below, °F,

ratio = 0

. 4 + 0

. 01 × (T - 44 ) , and amb,avg



### lag = 35

− 1.0 × (T - 44 ) , °F. amb,avg



### DOE calculated the offset term separately for the households using municipal treatment

plants and ground well sources.

For households with wells DOE calculated offset value using a triangular distribution

with min value of 0, average value of 2, and maximum value of 4.

The municipal plants offset was calculated using typical long-term water temperature

average values for households with water coming from municipal treatment plants, as well as

1,2

, 6

, 7 

### annual air temperature data, and population by state for 75 cities. The difference between

these two averages was then calculated. The average population weighted average offset was

calculated to be 3.72 with a standard deviation of 5.94. These values where used in the LCC

spreadsheet to create a normal distribution for the offset (See Table 7-D.3.1).

7-D-12

### Table 7-D.3.1 Calculation of Water Inlet Offset for Municipal Treatment Plants

Site Average

Water Inlet

Temp (°F) Average

Annual Air

Temp (°F) Difference

(Offset),

Temp (°F) Population by

State (Census

2007 Est)

Anchorage, AK 38.6 36.2 2.4 683,478

Birmingham, AL 71.7 62.2 9.5 4,627,851 Montgomery, AL 66.4 65 1.4

Little Rock, AR 63.9 62.1 1.8 2,834,797

Phoenix, AZ 82.3 72.8 9.5 6,338,755

Los Angeles, CA 72.8 63.3 9.5

36,553,215 San Diego, CA 76.2 64.4 11.8

San Francisco, CA 67.7 57.3 10.4

Denver, CO 61.3 50.1 11.2 4,861,515

Hartford, CT 56.6 50.2 6.4 3,502,309

Washington, DC 63.9 57.5 6.4 588,292

Dover, DE 61.9 56.8 5.1 864,764

864,764 Wilmington, DE 59.6 54.4 5.2

Miami, FL 75 76.7 -1.7 18,251,243 Tallahassee, FL 76.7 68 8.7

Atlanta, GA 62 62.1 -0.1 9,544,750 Savannah, GA 68.1 66.2 1.9

Honolulu, HI 76.8 77.5 -0.7 1,283,388

Des Moines, IA 60.3 50 10.3 2,988,046

Boise, ID 45.3 51.9 -6.6 1,499,402

Chicago, IL 53.9 49.1 4.8 12,852,548

Indianapolis, IN 49 52.5 -3.5 6,345,289

Topeka, KS 59 54.3 4.7 2,775,997

Louisville, KY 56.3 56.9 -0.6 4,241,474

New Orleans, LA 64.9 68.8 -3.9 4,293,204

Boston, MA 59.3 51.6 7.7 6,449,755

Baltimore, MD 56.8 54.6 2.2 5,618,344

Portland, ME 63.5 45.7 17.8 1,317,207

Detroit, MI 49.9 49.7 0.2 10,071,822

Minneapolis, MN 45.8 45.4 0.4 5,197,621

Kansas City, MO 51.1 54.2 -3.1 5,878,415 St. Louis, MO 61.3 56.3 5

Biloxi, MS 64.9 67.4 -2.5 2,918,785 Jackson, MS 67.8 64.1 3.7

Helena, MT 41.8 44 -2.2 957,861

Raliegh, NC 71.8 59.6 12.2 9,061,032

Bismark, ND 51 42.3 8.7 639,715

Lincoln, NE 53.5 51.1 2.4 1,774,571

Concord, NH 65.6 45.9 19.7 1,315,828

Trenton, NJ 55.3 52.9 2.4 8,685,920

Albuquerque, NM 76.2 56.8 19.4 1,969,915

Carson City, NV 58 50.6 7.4 2,565,382

7-D-13Albany, NY 51.5 47.5 4

19,297,729 Binghamton, NY 59.9 45.8 14.1

Buffalo, NY 49.2 47.9 1.3

Long Island, NY 53 52.4 0.6

New York, NY 57.6 55.1 2.5

Plattburgh, NY 50.6 44.5 6.1

Potsdam, NY 48.5 43.3 5.2

Poughkeepsie, NY 56.8 48.8 8

Rochester, NY 57 47.6 9.4

Rome, NY 51.3 46.6 4.7

Syracuse, NY 54.7 47.4 7.3

Watertown, NY 51.7 44.7 7

Columbus, OH 54.8 52.9 1.9 11,466,917

Oklahoma City, OK 58.8 60.1 -1.3 3,617,316

Portland, OR 51.6 53.5 -1.9 3,747,455

Philadelphia, PA 56 55.3 0.7 12,432,792 Pittsburgh, PA 58 50.9 7.1

Providence, RI 49.7 51.1 -1.4 1,057,832

Columbia, SC 59.2 63.6 -4.4 4,407,709

Sioux Falls, SD 55.3 45.1 10.2 796,214

Chattanooga, TN 67.7 60 7.7

6,156,719 Knoxville, TN 55 58.4 -3.4

Memphis, TN 55 62.3 -7.3

Dallas, TX 68.3 65.5 2.8 23,904,380 Houston, TX 65.9 70.5 -4.6

Salt Lake City, UT 70.5 52 18.5 2,645,330

Richmond, VA 59.1 57.6 1.5 7,712,091

Montpelier, VT 47.8 42.9 4.9 621,254

Seattle, WA 41.1 52.3 -11.2 6,468,424

Greenbay, WI 44.7 44.4 0.3 5,601,640 Milwaukee, WI 46 47.5 -1.5

Charleston, WV 62.8 54.5 8.3 1,812,035

Cheyenne, WY 51.7 44.9 6.8 522,830

Mean 3.72

Standard Deviation 5.94

7-D-14

### REFERENCES

1. National Oceanic and Atmospheric Administration, Normal Daily Mean Temperature,

Deg F, 2005. < http://lwf.ncdc.noaa.gov/oa/climate/online/ccd/meantemp.html >

2. Williams, C. N., Jr., M.J. Menne, R.S. Vose, and D.R. Easterling., United States

Historical Climatology Network Monthly Temperature and Precipitation Data. , 2007.

Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S.

Department of Energy,. Oak Ridge, Tennessee.

< http://cdiac.ornl.gov/epubs/ndp/ushcn/usa_monthly.html >

3. National Oceanic And Atmospheric Administration, Degree Days Statistics, 2005.

< http://www.cpc.noaa.gov/products/analysis_monitoring/cdus/degree_days >

4. Burch, J. a. C. C., Towards Development of an Algorithm for Mains Water Temperature

. National Renewable Energy Laboratory.

< http://www.energystar.gov/ia/partners/prod_development/new_specs/downloads/water

_ heaters/AlgorithmForMainsWaterTemperature.pdf >

5. Hendron, R., R. Anderson, C. Christensen, and M. Eastment, P. Reeves, Development of

an Energy Savings Benchmark for All Residential End-Uses, August, 2004. National

Renewable Energy Laboratory. Report No. NREL/BK-610-28044.

6. Abrams, D. W. and A. C. Shedd, Commercial Water Heating Applications Handbook

, 1992. Electric Power Research Institute. Palo Alto, CA. Report No. EPRI TR-100212.

7. U. S. Department of Commerce - Bureau of the Census, Population Estimates , 2007. U.S.

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