Document 2jZB3EOByp93K2p192n74qgRL

1953 Guide / The Technical Advisory Committee on Weather Design Conditions has suggested that wet-bulb design temperature be taken as that wet-bulb temperature which has been equalled or exceeded in 5 percent of the hours during months, of the period of record. While not available for the 1953 edition of The Guide, due to the tremendous task of compiling these data, it is hoped that they will be available for some stations for future editions. The wind velocity to be used in design should be that wind velocity which accompanies-the design temperatures in each instance, but since these data are not available, the average summer wind velocities for the period of record were taken from U. S. Weather Bureau records revised to 1948. - It is pointed out that this is not necessarily the velocity which coincides with the design temperatures, but it may serve as a guide to the designer. Other weather data, such as daily range of temperature, are useful particu i larly when making cooling load calculations for an early morning peak on an east exposure. Daily range of temperature is the difference between the average of the daily maximum dry-bulb temperatures and the average i of, the daily minimum temperatures. This range is highest in semi-arid or desert regions and at high elevations, and lowest near the oceans or very large lakes. The daily range of temperature (Fahrenheit degrees) in July for the principal areas of the United States can be approximated from the following tabulation: East Sea Shore..............12 to 18 Gulf Sea Shore.............. 12 to 18 Great Lakes Shore .... 18 to 21 West Sea Shore............. 15 to 20 East of Mississippi River................................ 19 to 24 Mississippi River to Rocky Mountains___ 24 to 33 Rocky Mountain Area...................... ............ 33 to 42 West Coastal States...........................................20 to 36 Ventilation Rate The introduction of outside air is necessary for the ventilation of condi tioned spaces. Chapter 6 suggests minimum outdoor-air requirements for representative applications; but it is to be emphasized that minimum re quirements are not necessarily adequate requirements for all psychological attitudes and physiological responses. Where maximum economy, in space and load are essential, as in submarines or other restricted, spaces, as little as 1 cfm of outside air per person has been found to be sufficient provided that satisfactory ventilation is simultaneously obtained by an adequate decontamination of recirculated air.2 Local codes and ordinances frequently specify ventilation requirements for public places and for industrial installations. For operating rooms, minimum requirements for safe practice are given in National Board of Fire Underwriters' pamphlet.3 This pamphlet does not require 100 percent outside air in operating rooms, although 100 percent outside air is normally used and recommended. Recommended and minimum ventilation rates for the most common applications are summarized in Table 3. For further general applications, a basis of estimating the cfm per person may be taken as: 1. People not smoking.................................... ... 7$ Recommended 2. People smoking..................................................... 40 Recommended 5 Minimum 25 Minimum The cooling load due to the introduction of outside air for ventilation is determined once the indoor and outdoor design conditions are fixed. Cal culations will be discussed subsequently. Cooling Load 267 Table,2. Summer Climatic Conditions* Suggested Design Wet-Bulb and Dry-Bulb Temperatures Col. 1, . State Col. 2 Station1* Col. 3 Dleva- noN Ft Col. 4 Period Record*1 ' . Col. 5 Highest Temp. .Ever Recorded F Col. 6 Design Dry-Bulb Temp, on T.A.C. 2|% F Col. 7 Design Dry-Bulb. 'Temp, in Common Use* F Col. 8 Design Wet-Bulb Temp, in Common Use' F Col. 9 Average StTMMEB Wind Velocity Mph Ala....... CO 733 Birmingham... CO 711 AP 615 CO 143 AP 219 CO ' 293 .AP 226 Aria...... CO 6957 AP 3473 CO 1122 .AP 1112 AP 2561 CO 4853 AP 4899 CO 146 CO 545 AP 463 CO 451 AP 282 Calif.... AP 499 .AP 740 AP 1925 CO 132 CO 387 .AP 281 CO 534 AP 21 Red Bluff..... CO 305* AP 346 AP 579 CO 116 AP 22 CO 90 AP 34 CO 164 CO 100 ..AP 124 CO 5398 AP 5379 Durango....... CO 6558 4587* CO 4770 ..AP 4810 Conn.... CO 229 AP 20 CO 180 ..AP 17 D. C. .. Washington... CO 128 Washington... AP 20 Fla....... Apalachicola.. ..CO 23 CO 104 ..AP 29 Key West__ CO 23 AP 48 CO 253 AP 13 Pensacola__ CO 67 AP 113 Tampa........ CO 111 Tampa......... AP 12 ..AP 52 Ga...... AP 1020 Augusta....... CO 195 Augusta....... AP 424 Macon.......... CO 408 ..AP 432 Savannah__ CO 115 ..AP 56 Idaho. ..CO 2818 Boise........... AP 2849 Burley......... ..AP 4150 ..AP 4744 Lewiston..... CO 763 Pocatello..... CO 4522 111... AP 4467 CO Chicago....... CO 601 Chicago....... ..AP . 615 Moline......... ..AP 594 1893-1947 1893-1945 1939-1947 1872-1947 1940-1947 1872-1947 '1938-1944d 1899-1947 . 1935-1939 1895-1947 1933-1947 vj935-1939 Up to 1946 1937-1947 1876-1946 1882-1945 1945-1947, 1879-1942d 1942-1947 1937-1946, 1931-1947d 1935-1939 1886-1947 1887-1939 1939-1947 1877-1947 1929-1947 1877-1934 1944-1947 1935-1939 1877-1947 1938-1947 1871-1940 1939-1947 1875-1947 Up to 1946 1935-1939 1871-1947 1934-1947 Up to 1946 Up to 1946 1889-1938 1939-1947J 1905-1940d 1940-1947 1872-1947 1943-1947 1871-1947 1935-1939 1922-1947 1871-1947 1938-1947 1871-1947 1939-1947 1896-1947 1940-1947 1879-1947 1943-1947 1890-1940, 1941-1946 1935-1939 1935-1939 1871-1946 1939-1947 . 1899-1947 1939--1947. 1871-1945 1939-1947 1864-1939 1939-1947 1935-1939 T935--1939. 1900-1944 1899-1947 1938-1947 ' 1872-1947 Up to 1946 1935-1939 1932-1947 105 107 103 103 104 107 103 93 107 118 117 112 . . 107 103 120 113 107 110 107 113 111 113 85 115 111 109 102 115 112 . 112 114 108 no 106 101 ' 106 116 105 104 99 105 104 104 101 98 101 94 106 106 102 104 105 . 100 95 96 100 103 105 98 98 98 102 106 105 105 102 105 105 112 109 104 100 117 105 103 106 105 107 106 94 92 99 i07 102 95 97 104 94 104 i03 80 ioi 79 i03 93 95 88 84 . 92 '94 89 90 93 93 95 94 88 92 92 94 95 78 95 78 ' 5^4 95 - 8;0 95 78 " 90 65 105 ' '76 elo . i05 72 100 iio *78 . 95 6-i. 95 '78 '' i.i 105 70 .90 '65 1U5 '90 . *70 100 7.9 5.S ioo '72 7.9 ... . 85 '85 65 IQ.7 91 95 64 95 95 65 65 <L3 95 93 *76 95 '75 7^4 *95 `78 5^9 95 95 78 8.4 98 78 '21 79 8.7 95 '78 95 '78 7 A . 95 76 7.9 98 95 78 95 *78 - k'.b 95 '65 , 5.8 95 65 95 98 78 95 75. 9.5 96 76