// CODE SNIPPET
G2427.6.9 (503.6.10) Size of Gas Vents
Go To Full Code Chapter
Venting systems shall be sized and constructed in accordance with Sections G2427.6.9.1 through G2427.6.9.4 and the appliance manufacturer's installation instructions.
G2427.6.9.1 (503.6.10.1) Category I Appliances
The sizing of natural draft venting systems serving one or more listed appliances equipped with a draft hood or appliances listed for use with Type B gas vent, installed in a single story of a building, shall be in accordance with one of the following methods:
- The provisions of Section G2428.
- For sizing an individual gas vent for a single, draft hood-equipped appliance, the effective area of the vent connector and the gas vent shall be not less than the area of the appliance draft hood outlet, nor greater than seven times the draft hood outlet area.
- For sizing a gas vent connected to two appliances with draft hoods, the effective area of the vent shall be not less than the area of the larger draft hood outlet plus 50 percent of the area of the smaller draft hood outlet, nor greater than seven times the smaller draft hood outlet area.
- Approved engineering methods.
G2427.6.9.2 (503.6.10.2) Vent Offsets
Type B and L vents sized in accordance with Item 2 or 3 of Section G2427.6.8.1 shall extend in a generally vertical direction with offsets not exceeding 45 degrees (0.79 rad), except that a vent system having not more than one 60-degree (1.04 rad) offset shall be permitted. Any angle greater than 45 degrees (0.79 rad) from the vertical is considered horizontal. The total horizontal distance of a vent plus the horizontal vent connector serving draft hood-equipped appliances shall be not greater than 75 percent of the vertical height of the vent.
G2427.6.9.3 (503.6.10.3) Category II, III and IV Appliances
The sizing of gas vents for Category II, III and IV appliances shall be in accordance with the appliance manufacturer's instructions. The sizing of plastic pipe that is specified by the appliance manufacturer as a venting material for Category II, III and IV appliances, shall be in accordance with the manufacturer's instructions.
G2427.6.9.4 (503.6.10.4) Mechanical Draft
Chimney venting systems using mechanical draft shall be sized in accordance with approved engineering methods.
Upcodes Diagrams
Related Code Sections
G2427.6.9 Fuel Gas, (503.6.10) Size of Gas Vents
story of a building, shall be in accordance with one of the following methods: The provisions of Section G2428. For sizing an individual gas vent ...
G2427.6.9 Fuel Gas, (503.6.10) Size of Gas Vents
story of a building, shall be in accordance with one of the following methods: The provisions of Section G2428. For sizing an individual gas vent ...
G2427.6.9.4 Fuel Gas, (503.6.10.4) Mechanical Draft
Chimney venting systems using mechanical draft shall be sized in accordance with approved engineering methods ...
G2427.6.9.2 Fuel Gas, (503.6.10.2) Vent Offsets
Type B and L vents sized in accordance with Item 2 or 3 of Section G2427.6.8.1 shall extend in a generally vertical direction with offsets ...
G2427.6.9.2 Fuel Gas, (503.6.10.2) Vent Offsets
Type B and L vents sized in accordance with Item 2 or 3 of Section G2427.6.8.1 shall extend in a generally vertical direction with offsets ...