18-28-706.2 Mechanical combustion air supply for gas-fired appliances.

   Where all combustion air is provided by a mechanical air supply system, the combustion air shall be supplied from outdoors at the minimum rate of 0.35 ft 3 /min per 1,000 Btu/hr (0.034 3/mm per kW) for all appliances located within the space.

18-28-706.2.1

   Where exhaust fans are installed, additional air shall be provided to replace the exhausted air.

18-28-706.2.2

   Each of the appliances served shall be interlocked to the mechanical air supply system to prevent main burner operation where the mechanical air supply system is not in operation.

18-28-706.2.3

   Where combustion air is provided by the building's mechanical ventilation system, the system shall provide the specified combustion air rate in addition to the required ventilation air.

18-28-707 Direct Connection.

18-28-707.1 General.

   Fuel-burning appliances that are listed and labeled for direct combustion air connection to the outdoors shall be installed in accordance with the manufacturer's installation instructions.

18-28-708 Combustion Air Ducts.