The specific heat of moist air at constant pressure cpa is defined as the heat required to raise its temperature 1°F(0.56°C) at constant pressure. In(inch-pound)I-P units, it is expressed as Btu/lb°F(inSI units,asJ/kg K).InEq.(2.34),the sensible heat of moist air qsen,Btu/h(W),is represented by