903.2 Gas-Fired Air Conditioners and Heat Pumps.

Gas-fired air conditioners shall comply with Section 903.2.1 through Section 903.2.7.

(3) In the case of vents leading outdoors, means shall be

employed to prevent water from entering this piping and also to prevent blockage of vents by insects and foreign matter. (4) Under no circumstances shall a regulator be vented to the

appliance flue or exhaust system.

(4) Under no circumstances shall a regulator be vented to the

appliance flue or exhaust system. (5) In the case of vents entering the combustion chamber,

the vent shall be located so the escaping gas is readily

(5) In the case of vents entering the combustion chamber,

the vent shall be located so the escaping gas is readily ignited by the pilot and the heat liberated thereby does not adversely affect the normal operation of the safety shutoff system. The terminus of the vent shall be securely held in a fixed position relative to the pilot. For manufactured gas, the need for a flame arrester in the vent piping shall be determined. (6) A vent line(s) from an appliance pressure regulator and a

bleed line(s) from a diaphragm-type valve shall not be

903.2.1 Independent Gas Piping. Gas piping serving heating appliances shall be permitted to also serve cooling appliances where heating and cooling appliances cannot be operated simultaneously. [NFPA 54:10.2.1] 903.2.2 Connection of Gas Engine-Powered AirConditioners. To protect against the effects of normal vibration in service, gas engines shall not be rigidly connected to the gas supply piping. [NFPA 54:10.2.2] 903.2.3 Clearances for Indoor Installation. The installation of air-conditioning appliances shall comply with the following requirements: (1) Listed air-conditioning appliances shall be installed

with clearances in accordance with the terms of their

(1) Listed air-conditioning appliances shall be installed

with clearances in accordance with the terms of their listing and the manufacturer’s installation instructions. (2) Unlisted air-conditioning appliances shall be

installed with clearances from combustible material

(2) Unlisted air-conditioning appliances shall be

installed with clearances from combustible material of not less than 18 inches (457 mm) above the appliance and at the sides, front, rear and in accordance with the manufacturer’s installation instructions.

[NFPA 54:10.2.3(2)] (3) Listed and unlisted air-conditioning appliances shall

be permitted to be installed with reduced clearances

Diaphragm-type valves shall be equipped to convey

bleed gas to the outdoors or into the combustion chamber adjacent to a continuous pilot.

Listed and unlisted air-conditioning appliances shall

be permitted to be installed with reduced clearances to combustible material, provided that the combustible material or appliance is protected as described in Table 303.10.1 and such reduction is allowed by the manufacturer’s installation instructions. [NFPA 54:10.2.3(3)]

182 2019 CALIFORNIA MECHANICAL CODE

INSTALLATION OF SPECIFIC APPLIANCES

(4) Where the furnace plenum is adjacent to plaster on

metal lath or noncombustible material attached to

(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 (51 mm) or less. [NFPA 54:10.2.3(4)] (5) Listed air-conditioning appliances shall have the

clearance from supply ducts, within 3 feet (914 mm)

(5) Listed air-conditioning appliances shall have the

clearance from supply ducts, within 3 feet (914 mm) of the furnace plenum be not less than that specified from the furnace plenum. No clearance is necessary beyond this distance. [NFPA 54:10.2.3(5)] 903.2.4 Assembly and Installation. Air-conditioning appliances shall be installed in accordance with the manufacturer’s installation instructions. Unless the appliance 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. [NFPA 54:10.2.4] 903.2.5 Furnace Plenums and Air Ducts. A furnace plenum supplied as a part of the air-conditioning appliance shall be installed in accordance with the manufacturer’s instructions. Where a furnace plenum is not supplied with the appliance, 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 an enclosure, the installation shall comply with Section 904.7.3. [NFPA 54:10.2.5] 903.2.6 Refrigeration Coils. The installation of refrigeration coils shall be in accordance with Section 904.8 and Section 904.9. [NFPA 54:10.2.6] 903.2.7 Switches in Electrical Supply Line. Means for interrupting the electrical supply to the air-conditioning appliance and to its associated cooling tower (if supplied and installed in a location remote from the air conditioner) shall be provided within sight of and not over 50 feet (15 240 mm) from the air conditioner and the cooling tower. [NFPA 54:10.2.7]

904.1.1 Self-Closing Doors. Self-closing doors shall swing easily and freely, and shall be equipped with a selfclosing device to cause the door to close and latch each time it is opened. The closing mechanism shall not have a hold-open feature. 904.1.2 Gasketing. Gasketing on gasketed doors or frames shall be furnished in accordance with the published listings of the door, frame, or gasketing material manufacturer. Exception: Where acceptable to the Authority Having Jurisdiction, gasketing of noncombustible or limitedcombustible material shall be permitted to be applied to the frame, provided closing and latching of the door are not inhibited.