The most common variables for which the flue must be sized are btu capacity of the furnace the horizontal and vertical length of the flue and the number of elbows and type of vent connector the part of the flue that connects the furnace to the main flue pipe.
Gas furnace flue pipe code.
Masonry flue or shared flue venting.
Termination of flue vent connector at an existing chimney.
Metal flue fire clearance requirements single wall metal pipe flues gas fired equipment.
Many municipalities do not allow metal foil tape either.
In contrast modern high efficiency condensing furnaces exhaust much cooler gasses and need only plastic pipe materials such as pvc cpvc or abs for their exhaust vents some high efficiency furnaces also include a plastic pipe for intake area and all types.
The different types of venting.
8 national fuel gas code z223 1 16 00 and national fuel gas code handbook z223 2 47 00 american gas association a g a 1515 wilson boulevard arlington va 22209 also available from national fire protection association batterymarch park quincy ma 02269.
A gas wall heater or older forced air furnace generally requires a type b double wall metal vent pipe while a new high efficiency furnace requires a schedule 40 pvc vent pipe.
Traditional gas fired forced air furnaces produce hot combustion exhaust gasses and therefore need metal vent pipes or chimneys.
Type b vent pipe.
Also consult local and state codes for proper chimney sizing and application or in the absence of local and state codes the national fuel gas code ansi z223 1 nfpa 54 current edition.
Cloth duct tape is not permitted to be installed on fuel burning appliance vent pipes.
Flue pipe is too small for the amount of combustion gases generated by the furnace.
9 is a typical clearance between a gas fired boiler or furnace flue connector and combustibles.
When we are talking about gas furnace vent pipe code we need to talk about the different types of the vents first after all you want to keep your family safe from harm.
The gas vent pipe from the water heater tank is improperly sloped.
Fundamentals of gas appliance venting and ventilation 1985 american gas.
Intake and exhaust pipes pvc allowed 140 f limit furnace water heater boiler manual size of pipe and allowable lengths support terminations through wall or through roof 12 above grade or anticipated snow level in same pressure location concentric venting kit 25.
Fire clearances required range from 6 to 36 depending on the equipment.
There is a disconnection at the elbow.
This vent pipe is connected to the shared vent stack with the furnace.
