Section 27-742. Devices producing incidental heat

Where a room or space
  contains equipment that  produces  heat,  such  as  motors,  generators,
  resistors,  lights,  compressors,  steam heated vessels, etc., and where
  such equipment is in constant use during the period  of  occupancy,  the
  equipment  may  be  considered  as  a  supplementary heating device. Its
  heating capacity may be deducted  from  the  required  capacity  of  the
  heating devices in the room.