WINTER AIR CONDITIONING Comfort as Affected by Method of Heating. —The object of air conditioning for human comfort is not to heat or cool the body but to control its rate of heat loss within certain limits by methods that are most conducive to comfort and health. Temperature and humidity are means to an end. Their values depend on the system used, the main objective being the comfort and health of the individual. Heating systems are usually designed on a basis of warmth rather than of comfort, although the two terms are often used synonymously. The basic assumption is that the degree of warmth or comfort experienced depends solely, or largely, on the rate of heat loss by radiation and convection combined, irrespective of their relative proportions. This is not necessarily true. A room with walls and ceiling uniformly at 80 F. and air at 60 F. is as warm