Document pOjpXLxx9bYkvqaw5aax7YRE

290 CHAPTER 13 1958 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 this edi tion 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 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 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 East of Mississippi River.......... .............. 19 to 24 Gulf Sea Shore............ 12 to 18 Mississippi River to Rocky Mountains__ 24 to 33 Great Lakes Shore.... 18 to 21 Rocky Mountain Area............... .............. 33 to 42 West Sea Shore........... 15 to 20 West Coastal States....................................20 to 36 Ventilation Rate The introduction of outdoor 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 a National Board of Fire Underwriters' pamphlet.3 This pamphlet does not require 100 percent outdoor air in operating rooms, although 100 percent outdoor air is nor mally 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...................................... Recommended 5 Minimum 2. People smoking..............................................40 Recommended 5 Minimum. The cooling load due to the introduction of outdoor air for ventilation is determined once the indoor and outdoor design conditions are fixed. Cal-culations will be discussed subsequently. 291 Table 2. Summer Climatic Conditions* Suggested Design Wet-Bulb and Dry-Bulb Temperatures Col. 1 State Col. 2. Station1* Col. 3 Eleva tion' Ft Col. 4 Pebiod RBCOBDd Col. 5 Col. 6 Col. 7 Highest . Temp. Eveb RiOOBDEDd Design Dby-Bulb Temp, ok T.A.C. 2i% Design Dby-Bulb Temp, in Common Basis* Use^ F F Col. 8 Design Wet-Bulb Temp, in Common UsEr Col. 9 Average Summer Wind Velocity CF Mph Calif.. Colo.. Conn... D. C... Fla..... Ca.. Idaho.. Anninston........... CO Birmingham____ CO Birmingham____ AP Mobile....................CO Mobile....................AP Montgomery____ CO Montgomery.... AP Flagstaff................CO Kingman.............. AP Phoenix................. CO Phoenix................. AP Tucson...................AP Winslow.................CO Winslow................ AP Yuma..................... CO Fort Smith..........CO Fort Smith..........AP Little Rock......... CO Little Rock......... AP Bakersfield.......... AP Burbank............... AP Daggett................. AP Eureka................... CO Fresno.................... CO Fresno.................... AP Los Angeles.........CO Oakland...............AP Red Bluff.............CO Red Bluff.............AP Redding...............AP Sacramento........ CO Sacramento........ A P San Diego............ CO San Diego............AP San Francisco...CO San Jose...............CO Williams................AP Denver................. CO Denver.................. AP Durango............... CO Grand Junction.CO Pueblo................. CO Pueblo................... AP Hartford............... CO Hartford............... AP New Haven........ CO New Haven........ AP Washington......... CO Washington......... AP Apalachioola___ CO Jacksonville.... CO Jacksonville AP S'yWeat........... ,'co Key West............. AP Miami pft Miami.. !! ! AP Pensacola............. CO f'ensaoola AP Tampa............ .^CO .............. AP tltusville... ip Atlanta. Augusta.;co iS*........$p Savannah.............CO Savannah ap Boise.. Boise .................... Y Burley. Idaho Fall, tematon___ Pocatello.. Pocatello. AP co CO VS te:::: -g 733 711 615 143. 219 293 226 6957 3473 1122 1112 2561 4853 4899 146 545 463 451 282 499 740 1925 132 387 281 534 21 305e 346 579 12126 90 34 164 100 124 5398 5379 6558 4587* 4770 4810 229 20 180 17 128 20 23 104 29 23 48 253 13 67 113 111 12 52 1020 195 424 408 432 115 56 2818 2849 4150 4744 763 4522 4467 319 601 615 594 1895-1947 1893-1945 1939-1947 1872-1947 1940-1947 1872-1947. 1938-1944d 1899-1947 1935^1939 1895-1947 1933-1947 > 1935-1939 Up to 1946 1937-1947 1875-1946 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 1939-1947, 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 1941-1946d 1935-1939 1935-1939 1871-1946 1939-1947 1899-1947 1939-1947 1871-1945d 1939-1947 1864-1939 1939-1947 1935-1939 1935-1939 1900-1944d 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 . 102 115 112 112 114 108 110 106 101 106 116 105 104 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- 107 102 .95 97104 94 104 i03 SO. ioi. 79: i0393 '951 88 8492 94 89 90. 93 93 95 94 88 92 92 94 95 95 95 95 90 io5 ios 100 iio 95 95 ios 90 105 90 85 100 ioo 85 85 91 95 95 95 95 93 95 95 95 95 98 gi 95 95 95 ' 98 95 95 95 95 95 98 95 96 78 78 80 78 65 76 72 70 78 ' 76- 78 70 65 74 70 65 70 72 68 65 70 64 65 65 65 75 75 78 80 78 78 79 78 78 76 76 78 78 65 5.4 8.0 6.0 6.1 6.2 7.9 5.8 7.9 10.7 6.9 6.3 7.4 5.9 8.4 8.7 7.4 7.9 8.0 5.8 65 65 78 75 9.5 76