18-28-925.1 Independent gas piping.

   Gas piping serving heating gas utilization equipment shall be permitted to also serve cooling equipment where heating and cooling equipment cannot be operated simultaneously.

18-28-925.2 Connection of gas engine-powered air conditioners.

   To protect against the effects of normal vibration in service, gas engines shall not be rigidly connected to the gas supply piping.

18-28-925.3 Clearances for indoor installation.

   The installation of air-conditioning equipment shall comply with the following requirements:

   1.   Listed air conditioning equipment installed in rooms that are 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.

   2.   Air-conditioning equipment 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 and installed in accordance with the manufacturer's instructions.

18-28-925.4 Assembly and installation.

   Air-conditioning equipment shall be installed in accordance with the manufacturer's instructions. Unless the equipment is listed for installation on a combustible surface such as a floor or roof, or unless the surface is protected in an approved manner, it shall be installed on a surface of noncombustible construction with noncombustible material and surface finish and with no combustible material against the underside thereof.

18-28-925.5 Furnace plenums and air ducts.

   A furnace plenum supplied as a part of the air-conditioning equipment shall be installed in accordance with the manufacturers instructions. Where a furnace plenum is not supplied with the equipment, any fabrication and installation instructions provided by the manufacturer shall be followed. The method of connecting supply and return ducts shall facilitate proper circulation of air. Where the air conditioner is installed within a room not large in comparison with the size of the equipment, the air circulated by the equipment shall be handled by ducts that are sealed to the casing of the equipment and that separate the circulating air from the combustion and ventilation air.