Central heating systems of the forced air type shall conform to the general installation requirements of this Code. The equivalent KW capacity of such a system shall equal the calculated heat loss of the living quarters of the dwelling in B.T.U. per hour, at design conditions, plus not less than 10 percent greater than the total building heat loss in size, when it is the only source of heating. The total output of such a system in B.T.U. shall be computed at the location where the thermal (heat) energy is converted and/or transferred to the circulated air.
resistance electric heating elements the conversion of electric energy to
thermal (heat) energy shall be considered at an efficiency of 100 percent.
electrically operated heat pump equipment, acceptable evidence of equipment
heating performance characteristics shall be provided and the equivalent KW
capacity determined therefrom.