A. The total rating (or adjusted rating) of heat emission devices in each room or space to be heated shall equal or exceed the calculated B.T.U. heat loss of such room or space, except that in bedrooms to be heated, a tolerance of not more than 20 percent less than the calculated B.T.U. required to offset the B.T.U. heat loss from such room will be allowed providing such deficiency is made up in other areas regarded as living area when computing the total calculated B.T.U. required for the dwelling.
B. The total rating (or adjusted rating) of the heat emission devices shall equal or exceed the calculated B.T.U. aggregate heat loss of all the rooms or spaces heated where used as living quarters.
C. The output in B.T.U. of each heat generating and emission unit shall be computed at the location where the electrical energy is converted to thermal (heat) energy. The conversion of electrical energy to thermal (heat) energy shall be considered at an efficiency of 100 percent providing the labeled voltage of the equipment is within 5 percent of the service voltage. Where the labeled voltage of a heat generating or emission unit is greater or less than 5 percent of the service voltage, an adjusted rating of the heat generating or emission unit shall be used in determining the B.T.U. output.
The adjusted B.T.U. rating =
3413 X (Service voltage)2
(Label voltage) 2 X KW name plate rating