18-28-918.9.1 General.

   Due to safety and health considerations, a central heating furnace may only supply heated air to a single residential living unit.

18-28-918.9.2.

   Central heating furnace installations in bedrooms or bathrooms shall comply with one of the following:

   1.   Central heating furnaces shall be installed in a closet located in the bedroom or bathroom, the closet shall have a weather-stripped solid door with a self-closing device, and all combustion air shall be obtained from the outdoors.

   2.   Central heating furnaces shall be of the direct vent type.

18-28-918.9.3 Clearance.

18-28-918.9.3.1.

   Listed central heating furnaces installed in rooms large in comparison with the size of the equipment shall be installed with clearances per the terms of their listing and the manufacturer's instructions.

18-28-918.9.3.2.

   Central heating furnaces installed in rooms that are not large (such as alcoves and closets) in comparison with the size of the equipment shall be listed for such installations.

18-28-918.9.3.3.

   Front clearance shall be sufficient for servicing the burner and the furnace.

18-28-918.9.3.4.

   Where the furnace plenum is adjacent to plaster on metal lath or noncombustible material attached to combustible material, the clearance shall be measured to the surface of the plaster or other noncombustible finish where the clearance specified is 2 inches (50 mm) or less.

18-28-918.9.3.5.

   The clearance to this equipment shall not interfere with combustion air, draft hood clearance and relief, and accessibility for servicing.

18-28-918.9.4 Assembly and installation.

   A central heating furnace shall be installed in accordance with the manufacturer's instructions and shall be installed on a floor of noncombustible construction with noncombustible flooring and surface finish and with no combustible material against the underside thereof, or on fire-resistive slabs or arches having no combustible material against the underside thereof.

   Exceptions:

      1.   Appliances listed for installation on a combustible floor.

      2.   Installation on a floor protected in an approved manner.