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 

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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-1 

EE-2006-STD-0129 COMMENT 56.10
 

 

 

 

 

 

 

 

 

90 

Mean 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 

EE-2006-STD-0129 COMMENT 56.10
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: 

 HDD1 = heating degree days from U.S. weather data, 

 HDD2 = heating degree days from RECS 2005 data, 

 CDD1 = cooling degree days from U.S. weather data, and 

 CDD2 = 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 Values 

Mean Temperature (Fo) 

7-D-3

EE-2006-STD-0129 COMMENT 56.10
Mean 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 City Code Temp (2005) (2005) 

AK KODIAK BDL 50.2 6219 1003 

AK KING SALMON BDR 52.1 5361 1046 

AK ANCHORAGE BOS 51.6 5902 888 

AK BETHEL ORH 47.2 6670 714 

AK BIG DELTA CAR 39.2 9166 236 

AK BARROW HUL 39.9 8989 247 

AK BETTLES PWM 45.7 7218 471 

AK COLD BAY CON 45.9 7385 602 

AK FAIRBANKS MWN 27.2 13063 0 

AK GULKANA PVD 51.1 5824 1010 

AK HOMER BTV 45.2 7425 729 

AK JUNEAU ACY 53.5 5109 1278 

AK MCGRATH EWR 54.5 4949 1526 

AK NOME ABE 50.6 5704 1085 

AK KOTZEBUE CXY 53.3 5187 1243 

AK ST PAUL ISLAND ERI 50.0 6318 907 

AK TALKEETNA IPT 49.8 6038 965 

7-D-4

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AK 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-5 

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FL 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-6 

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KY 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-7 

EE-2006-STD-0129 COMMENT 56.10
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MT 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-8 

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OH 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-9 

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TX 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-10 

EE-2006-STD-0129 COMMENT 56.10
 

 

 

WY 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 

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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 

+
 ratio
 ∗
 sin (0.986 (30 ) 90) ⎛ Δ

⎜

⎜

⎝

Tmains =
 air ,avg + offset
 ∗
 ∗ month
 #
 − − 30
 lag
 −

Where:
 

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

Tair,avg = annual average outdoor air temperature, °F,
 

ΔTair,max = maximum difference between monthly average outdoor air temperatures
 

(i.e. MAX(Tair,month) - MIN(Tair,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 

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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 

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

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 

Wilmington, DE 59.6 54.4 5.2 864,764 

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 

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Albany, 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 

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

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 

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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. 

Census. Washington, DC. <http://www.census.gov/popest/estimates.php> 

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