Document mm0LQYaoevvb4pwm8Dq3B459k

American Society of Heating and Ventilating Engineers Guide, 1934 avoided for obvious reasons. Tables 4 and 5 give the approximate effec tive temperatures at which perspiration is noticeable in different degrees for 95 per cent and 20 per cent relative humidity. In theaters, auditoriums, department stores and other crowded en closures, the amount of heat and moisture given off by the people is so large that normal changes in outside temperature and humidity have relatively little effect on indoor air conditions. The principal object of air 42 Chapter 2--Ventilation and Air Conditioning Standards conditioning in such places is to remove excessive heat and moisture by supplying a sufficient quantity of properly conditioned air. The indoor air conditions, however, must be varied according to the outside tem perature, as already pointed out. Although heat and moisture from the human body constitute the major Table 4. Condition of Sensible Perspiration for Persons Seated at Rest Under Various Atmospheric Conditions56 Degree or Perspiration . Atmospheric Condition 95 Per Cent Relative Humidity 20 Per Cent Relative Humidity E. T.. D.B. Forehead clammy................ ................................ : . Body clammy Body damp------------------------- ----------------------------Beads on forehead.. ____ ______ ______________ Body wet......................................... .. ............... ...... Perspiration on forehead runs and .drips. Perspiration runs down body_________________ 73.0 73.0 79.0 80.0 84.5 88.0 88.5 73.6 73.6 79.7 80.8 85.4 89.0 89.5 W. B. 72.4 72.4 78.4 79.4 84.0 87.6 88.1 E.T. 75.0 75.0 81.0 87.0 86.5 94.0 90.0 D. B. W. B. 87.0 87.0 97.5 109.4 108.5 125.2 116.0 60.7 60.7 67.5 75.2 74.6 85.4 79.5 oForty per cent of subjects registered degree of perspiration equal to or greater than indicated. portion of the cooling load, in most cases where air conditioning is pro vided for comfort and health other factors must also be considered. These include heat from lights, machinery, and processes, as well as the trans mission and infiltration of heat through the building structure. The computations for these'" factors may be made in accordance with data given in Chapters 5 and 7. In many cases, allowance must also be made for sun effect and for heat capacity of the building structure in accordance with studies by the Table 5. Condition of Sensible Perspiration for Persons at Work Under Various Atmospheric Conditions Atmospheric Condition Degree or Perspirations 95 Per Cent Relative Humidity 20 Per Cent Relative Humidity E.T. D. B. W. B. E. T. D. B. W. B. Forehead clammy....... .............. ......... ..................... Body clammy................... ............. ........................... Body damp___ ________________________________ Beads on forehead_____________________________ Body wet.... _________________ ________ ___ Perspiration on forehead runs and drips__ ,__ Perspiration runs down body_______ _________ 59.0 50.0 60.0 68.0 69.0 78.5 79.0 59.4 50.2 60.3 68.5 69.6 79.3 79.8 58.3 49.3 59.3 67.5 68.5 78.0 78.5 69.5 57.0 62.5 76.0 71.0 82.0 81.0 80.5 61.6 -69.6 91.0 82.8 100.5 99.8 56.5 44.2 49.5 63.4 53.0 70.2 69.0 "Forty per cent of subjects registered degree of perspiration equal to or greater than indicated. "Thermal Exchanges.between the Human Body and its Atmospheric Environment, by F. C. Houghten, W. W. Teague, W. E. Miller. W. P. Yant (American Journal Physiology. Vol. 88, No. 3, April, 1929, pp. 386-406). 43