FGC 620 — Unit Heaters

Section FGC 620: Unit Heaters

620.1 General. Unit heaters shall be tested in accordance with ANSI Z83.8/CSA 2.6 and shall be installed in accordance with the manufacturer's instructions. 620.2 Support. Suspended-type unit heaters shall be supported by elements that are designed and constructed to accommodate the weight and dynamic loads. Hangers and brackets shall be of noncombustible material. 620.3 Ductwork. Ducts shall not be connected to a unit heater unless the heater is listed for such installation. 620.4 Clearance. Suspended-type unit heaters shall be installed with clearances to combustible materials of not less than 18 inches (457.2 mm) at the sides, 12 inches (304.8 mm) at the bottom and 6 inches (152.4 mm) above the top where the unit heater has an internal draft hood or 1 inch (25.4 mm) above the top of the sloping side of the vertical draft hood. Floor-mounted-type unit heaters shall be installed with clearances to combustible materials at the back and one side only of not less than 6 inches (152.4 mm). Where the flue gases are vented horizontally, the 6-inch (152.4 mm) clearance shall be measured from the draft hood or vent instead of the rear wall of the unit heater. Floor-mounted-type unit heaters shall not be installed on combustible floors unless listed for such installation. Clearances for servicing all unit heaters shall be in accordance with the manufacturer's instructions. Exception: Unit heaters listed for reduced clearance shall be permitted to be installed with such clearances in accordance with their listing and the manufacturer's instructions and as approved by the department. 620.5 Installation in commercial garages and aircraft hangars. Unit heaters installed in garages for more than three motor vehicles or in aircraft hangars shall be installed in accordance with Sections 305.9, 305.10 and 305.11.