2009 ASHRAE Handbook - Fundamentals (IP) © 2009 ASHRAE, Inc.

WMO#: 722430

Lat: 29.99N Long: 95.36W Elev: 105 StdP: 14.64 Time Zone: -6.00 (NAC) Period: 82-06 WBAN: 12960

Annual Heating and Humidification Design Conditions

99.6% 99% DP HR MCDB DP HR MCDB WS MCDB WS MCDB MCWS PCWD

1 29.1 32.9 15.0 11.8 38.0 20.3 15.3 41.9 22.2 57.0 19.9 57.3 6.2 0Annual Cooling, Dehumidification, and Enthalpy Design Conditions

DB MCWB DB MCWB DB MCWB WB MCDB WB MCDB WB MCDB MCWS PCWD

7 18.3 96.8 76.6 95.0 76.6 93.3 76.6 80.1 89.0 79.3 88.2 78.7 87.4 7.9 170

DP HR MCDB DP HR MCDB DP HR MCDB Enth MCDB Enth MCDB Enth MCDB

77.9 145.7 82.9 77.2 142.2 82.5 76.5 138.9 82.2 43.5 88.6 42.7 88.2 42.2 87.6 655Extreme Annual Design Conditions

1% 2.5% 5% Min Max Min Max Min Max Min Max Min Max Min Max

19.2 17.5 16.1 83.8 24.0 100.2 6.3 3.1 19.5 102.4 15.8 104.3 12.3 106.0 7.7 108.3Monthly Climatic Design Conditions

Annual Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecTavg 69.3 53.0 56.1 62.4 69.0 76.4 81.3 83.7 83.7 79.2 70.9 61.7 54.0Sd 9.54 9.43 8.30 6.93 4.96 3.41 2.73 3.12 5.25 7.26 9.07 10.43

HDD50 218 78 42 10 0 0 0 0 0 0 1 13 74HDD65 1414 386 273 148 41 1 0 0 0 1 30 168 366CDD50 7278 172 212 394 571 817 940 1044 1044 875 648 362 199CDD65 3001 15 24 67 162 353 490 579 579 426 212 68 26CDH74 29954 45 108 321 1144 3142 5251 6800 6714 4212 1730 407 80CDH80 12848 1 15 36 263 1102 2328 3322 3358 1840 523 57 3

DB 78.3 82.0 83.6 89.2 93.3 96.2 99.1 99.5 97.6 91.2 84.7 79.4MCWB 66.9 65.7 69.5 69.8 75.0 76.8 75.8 76.5 75.8 74.2 72.1 69.8

DB 74.9 77.2 80.5 85.4 90.3 94.0 96.3 97.1 93.9 88.3 81.6 76.2MCWB 65.5 66.3 67.5 70.9 75.2 76.5 76.7 76.6 75.3 73.5 70.6 68.3

DB 72.2 73.7 77.7 83.0 88.3 92.2 94.4 95.2 91.6 85.6 78.7 73.6MCWB 65.3 64.4 66.6 70.0 74.6 76.5 76.9 76.9 75.3 72.4 69.5 67.7

DB 69.3 70.9 74.8 80.6 86.1 90.4 92.7 93.1 89.5 82.7 75.8 70.6MCWB 63.9 64.1 65.5 69.1 73.8 76.4 77.1 77.1 75.0 71.5 68.9 65.5

WB 70.5 70.6 72.5 76.8 79.3 81.0 80.5 80.5 80.2 78.3 75.2 72.4MCDB 73.5 75.7 78.7 82.2 88.2 89.4 89.6 90.2 87.8 83.9 80.0 75.9

WB 69.0 69.2 71.1 74.6 77.9 79.8 79.7 79.8 79.0 77.0 73.4 70.5MCDB 72.5 73.8 76.3 80.5 85.9 87.8 89.0 89.6 86.5 82.9 77.9 74.2

WB 67.3 67.8 69.9 73.2 76.7 78.7 79.1 79.1 78.2 75.8 72.1 68.8MCDB 70.9 72.3 74.7 79.1 84.3 86.7 88.3 88.7 85.9 81.6 76.7 72.7

WB 64.7 65.6 68.5 71.9 75.7 78.0 78.4 78.4 77.5 74.4 70.5 66.7MCDB 68.6 69.5 73.2 77.5 82.9 86.0 87.4 87.7 85.2 80.1 75.1 70.3

MDBR 18.9 18.7 19.6 19.4 18.0 17.4 18.3 19.1 19.4 20.0 19.6 18.9MCDBR 21.5 21.4 20.0 20.1 18.8 19.5 20.4 21.6 21.3 20.6 20.3 19.4MCWBR 14.0 11.9 10.2 8.9 7.0 6.0 5.4 5.6 6.6 8.4 11.6 12.7MCDBR 17.6 16.7 16.4 15.4 16.6 16.9 18.2 18.8 17.3 16.2 17.5 17.2MCWBR 13.5 11.6 10.4 8.2 7.0 6.2 5.8 5.9 6.5 7.8 12.2 13.3

0.358 0.379 0.396 0.410 0.436 0.478 0.499 0.503 0.452 0.383 0.364 0.3502.317 2.230 2.190 2.181 2.145 2.028 1.970 1.959 2.116 2.345 2.370 2.400275 279 282 281 273 260 254 252 261 275 272 27336 42 46 47 49 55 58 58 48 37 34 32

CDDn Cooling degree-days base n°F, °F-day Lat Latitude, ° Period Years used to calculate the design conditions CDHn Cooling degree-hours base n°F, °F-hour Long Longitude, ° Sd Standard deviation of daily average temperature, °F DB Dry bulb temperature, °F MCDB Mean coincident dry bulb temperature, °F StdP Standard pressure at station elevation, psi DP Dew point temperature, °F MCDBR Mean coincident dry bulb temp. range, °F taub Clear sky optical depth for beam irradiance Ebn,noon } Clear sky beam normal and diffuse hori- MCDP Mean coincident dew point temperature, °F taud Clear sky optical depth for diffuse irradiance Edh,noon } zontal irradiances at solar noon, Btu/h/ft2 MCWB Mean coincident wet bulb temperature, °F Tavg Average temperature, °F Elev Elevation, ft MCWBR Mean coincident wet bulb temp. range, °F Time Zone Hours ahead or behind UTC, and time zone code Enth Enthalpy, Btu/lb MCWS Mean coincident wind speed, mph WB Wet bulb temperature, °F HDDn Heating degree-days base n°F, °F-day MDBR Mean dry bulb temp. range, °F WBAN Weather Bureau Army Navy number Hours 8/4 & 55/69 Number of hours between 8 a.m. PCWD Prevailing coincident wind direction, °, WMO# World Meteorological Organization number

and 4 p.m with DB between 55 and 69 °F 0 = North, 90 = East WS Wind speed, mph HR Humidity ratio, grains of moisture per lb of dry air

Hours8 to 4 &55/69

2%

Coldest month WS/MCDB

2%

MCWS/PCWDto 99.6% DB0.4%

1%

1%

MCWS/PCWDto 0.4% DB

Enthalpy/MCDB1% 2%0.4%

ColdestMonth

HottestMonth

Humidification DP/MCDB and HR99.6% 99%Heating DB

0.4%

5% DB

taub

Monthly Design Dry Bulb

and Mean Coincident

Wet BulbTemperatures

Monthly Design Wet Bulb

and Mean Coincident

Dry BulbTemperatures

Mean DailyTemperature

Range

0.4%

2%

5%

10%

1% 2%0.4%

Clear Sky Solar

Irradiance

Dehumidification DP/MCDB and HR

Ebn,noonEdh,noon

ExtremeMaxWB

Extreme Annual DB n-Year Return Period Values of Extreme DB

0.4%

Extreme Annual WS

taud

10%

0.4%

2%

5%

n=10 years

1%

5% WB

n=20 years n=50 years

HOUSTON BUSH INTERCONTINENTAL, TX, USA

Temperatures,Degree-Days

and Degree-Hours

HottestMonth

DB Range

Cooling DB/MCWB Evaporation WB/MCDB

Mean Standard deviation n=5 years