Furnace Vent Height Above Roof
When the vent is withdrawing air from the house it expels the gas outside through the vent.
Furnace vent height above roof. Gas vents 12 inches 305 mm in size or smaller with listed caps shall be permitted to be terminated in accordance with figure g2427 6 5 provided that such vents are at least 8 feet 2438 mm from a vertical wall or similar obstruction. Exhaust vents must be protected against rain and equipped with back flow prevention features e g flap dampers. Vents must be tall enough so burned gases exit above a roof line and. Above the roof surface with a listed cap or listed roof assembly.
The master flow 4 in. Exhaust vents must not be located where they might be obstructed by drifting snow consult local experience as to the height of snow drifts against buildings. Details about chimney height rooftop clearance requirements on buildings for all types of chimneys is at chimney height clearance code. What it means is that top of the chimney should be 3 feet above the roof surface through which it protrudes and 2 feet above anything within a 10 radius measured horizontally those are minimums.
For oil and wood burning appliances there is a very simple formula that regulates this chimney height requirement it is called 3 foot 2 foot 10 foot rule. All gas furnaces must be vented to allow exhaust gases from the combustion process to escape. It s made of zinc coated galvanized steel for durability and reliability. As an illustration of this principle refer to figure 3.
Roof pitch rise run in inchesminimum height flat to 7 12 1 0 foot above the roof surface 7 12 to 8 12 1 5 feet above the roof surface 8 12 to 9 12 2 0 feet above the roof surface. Goose neck vent the master flow 4 in. Vent caps 12 and smaller may terminate a distance above the roof if 8 feet or more away from a vertical surface as follows. This retards the ability of the flue gases to set up a good flow before encountering resistance.
This vent is designed to be used on 4 in. In 3a the air leaving the heat source has only a short distance to travel before encountering atmospheric pressure. Goose neck vent in black can be used to cover exhaust pipes extending through your roof or for attic ventilation. This structure generally uses the furnace vent pipe through roofbecause the b venting pipe is designed in vertical manner.
In all areas exhaust vents should be at least 1 foot above roof surface. How to vent a furnace in a roof.