Document RpdMOdMZg1aZpwL2JN2E3MY0X

American Society of Heating and Ventilating Engineers Guide, 1932 per cent. The sensible heat added to the air in the auditorium is 1,000 X 0.665 X 403 = 267,995 Btu per hour. The latent heat added is 1,000 X 0.335 X 403 = 135,005 Btu per hour. Example 8. If the dry- and wet-bulb temperatures of the auditorium were 85 F and 63 F, respectively, how much heat and. moisture would be dissipated to the atmosphere? Solution. From Figs. 6 and 7, respectively, the sensible and latent heat losses per person for a dry-bulb temperature of 85 F are found to be 164 and 225 Btu per hour. NOUVUOUVAS AS OSlVdlSSKI AOU3N3 TV101 JO 1N30 U3J CaV 3-0 * U pj= Jl X3O ,,G*C_> u p3*0 slg sS^eq s No^rlt H n > cV g-S g as u* B* 8.2 s-| 13! th .a aCjg aog *CT L _.r. al gltai S&31 c7 o * 3- w oS5 0 S<o E 2 S" S ggi 11*3="5-? 4, > 3 O *c The water vapor added to the atmosphere is 1,520 grains per hour. The audience will then add 164,000 Btu sensible heat, 225,000 Btu latent heat and 1,520,000 grains or 217 lb of water vapor to the air in the auditorium per hour. Examples 7 and 8 demonstrate that while the effective temperature, and hence, the feeling of warmth and rate of total heat loss, does not differ greatly in the two cases, the relative proportion of sensible and latent heat loss is reversed. In order to maintain the air conditions stipulated the air conditioning equipment must remove 61.6 per cent more. 406 1 Chapter 28--Air Conditioning in Relation to Comfort and Health sensible heat in Example 7 than in Example 8; and 67.8 per cent more latent heat or water vapor in Example 8 than in Example 7. In Example 7, 66.5 per cent of the total heat loss is sensible while in Example 8 only 42.5 per cent of the total loss is sensible. Example 9. Neglecting the gain or loss of heat to an auditorium by transmission or infiltration through the walls, windows and doors, how many cubic feet of outside air, with dry- and wet-bulb temperatures of .65 F and 59 F, respectively, (63.1 deg ET) must be supplied per hour to an auditorium containing 1000 people in order that the inside shall not exceed 75 F (dry-bulb) and 65 F (wet-bulb), respectively? Solution. Figs. 6 and 7 give 265 Btu sensible heat and 905 grains of moisture as the additions per person with a dry-bulb temperature of 75 F in the auditorium. Therefore Table 2. Relation Between Metabolic Rate and Activity3 Acttott Metabolic Rate Btu peb Houb fob Average Man (19J Sq Ft Sur face Abba) AUTBOBITT Seated at rest............... Standing at rest........... Walking 2 mph............ 384 431 761 Walking 3 mph............ Walking 4 mph............ 1049 1388 Walking 5 mph............ 2530 Slow run........................ 2285 Very severe exercise.... 2555 Maximum exertion...... 3333 - 4762 + Tailor......... .................. 482 Bookbinder.................... 626 Shoemaker.................... 661 Carpenter...................... 762 - 963 Metal Worker...,.......... 862 Fainter (ot furniture).. 876 Stonemason................... 1488 Man sawing wood....... 1797 Research Laboratory, American Society of Heating and Ventilating Engineers. Research Laboratory, American Society of Heating and Ventilating Engineers. Average values from (Douglas, Haldane, Henderson and Schneider) and (Henderson and Haggard). Douglas, Haldane, Henderson and Schneider Average values from (Douglas, Haldane, Henderson and Schneider) and (Henderson and Haggard) Douglas, Haldane, Henderson and Schneider Henderson and Haggard Benedict and Carpenter Henderson and Haggard Becker and Hamalainen Becker and Hamalainen Becker and Hamalainen Becker and Hamalainen Becker and Hamalainen Becker and Hamalainen Becker and Hamalainen Becker and Hamalainen "See paper entitled. Heat and Moisture Losses from Men at Work and Application to Air Conditioning Problems. by F. C. Houghten, W. W. Teague, W. E. Miller and W. P. Yant (Heating, Piping and Air Conditioning, June 1931). 265,000 Btu of sensible heat and 905,000 grains of moisture will be added to the air in the auditorium per hour. Taking 0.24 as the specific heat of air, 2.4 Btu per pound of air will be required to raise the dry-bulb temperature from 65 to 75 F and = 110,400 lb of air or 110,400 X 13.4 = 1,479,000 cfh of air will be required. This is equivalent to t = 24.7 c^m AUUU X Ov per person. The moisture content of the inside air as taken from a psychrometric chart is*76 grains per pound of dry air and that of the outside condition is 65 grains. The increase in .. # 905 000 moisture content will therefore be 11 grains per pound of dry air. Hence---- = 82,300 lb of air at the specified condition will be required. This is equivalent to 82,300 X 13.4 = 1,103,000 cfh of air or = 18.4 cfm of air per person. 1000 X 60 407 N!