Document DDzDw4eQkwnY2xknr16dwMx3d

HEATING VENTILATING AIR CONDITIONING GUIDE 1941 Therefore, there is no absolute optimum of air temperature or other environmental conditions, which will meet all cases. With moderate relative humidity and minimum air movement, an air temperature of 80 F has been found ideal for the lightly clothed subject at rest in a semi-reclining position. In factories where light work is performed in summer time, the ideal has been found to be about 76 F. For children CHAPTER 2. PHYSIOLOGICAL PRINCIPLES Fig. 3. 30 40 50 60 70 80 90 100 110 EFFECTIVE TEMPERATURE DEG LossRelation Between Total Heat from the Human Body and Effective Temperature for Still Air3 Curve A--Persons working so as to have a metabolic rate of 1310 Btu per hour. Curve B--Persons working so as to have a metabolic rate of 850 Btu per hour. Curve C--Persons working so as to have a "metabolic rate of 660 Btu per hour. Curve Z>--Persons seated at rest, or with a metabolic rate of 400 Btu per hour. Curves B and D based on test data covering a wide temperature range. Curves A.and C based on test data at an Effective Temperature of 70 deg and extrapolation of Curves B and D. All curves ate averages of values for hi^h and low relative humidities which apply with satisfactory accuracy for most considerations. For special problems requiring a higher degree of accuracy see more detailed A.S.H.V.E. .Research Laboratory reports. . (who have a high metabolism) at school, in winter clothing, 70 F has been considered correct; while in a gymnasium, 55 F is .a desirable temperature. The wide variations in metabolic activities with which the engineer must be prepared to cope and the influence of such variations in metabo lism on the heat load contributed by the human body to the environment are given in Table 4 and in Figs. 3, 4 and 5. The curves in the figures are based on certain averages of test results with different humidities, and Fig. 4. Relation Between Sensible Heat Loss from the Human Body and Dry-Bulb Temperature for Still Air3 1.100 -1,000 O' 900 a> z 800 <2 700 c tr UJ $ 600 cr o t 500 400 => 300 200 7,000 C </) 6,000 ~ < 2 V f// -- 5.000 (U3J <S ^ ---N S^UJN 3c cr 3 V // // // // 4.000 rcar o X // - 3.000 / / /c // /y/y/ r/S/ DX' - 2,000 - 1,000 52 - 30 40 50 60 70 80 90 100 DRY-BULB TEMPERATURE DEG FAHR Fig. 5. Latent Heat and Moisture Loss from the Human Body by Evaporation, in Relation to Dry-Bulb Temperature for Still Air Conditions3 aLoc. Cit. See footnote a. Fig. 3. 51