Gas Furnace Flue Pipe Sizing

The different types of venting.

Gas furnace flue pipe sizing.

Well making sure that you choose the right venting style will protect them. You would core a hole 1 4 to 1 2 inch bigger than the outer diameter of the pipe. 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. Clearance installations must provide the proper clearances to combustible materials as specified in the appropriate underwriters laboratories inc.

So let s calculate or why don t we skip those calculations and i ll give you the answers. Flue gas temperatures that do not exceed 400 degress fahrenheit above ambient for category i appliances. 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. To make it simple if you have a gas water heater with a 3 draft hood and a furnace with a 4 flue collar connected to the same chimney flue you d calculate that chimney flue size based on the 3 draft hood the smaller of two.

Reduce furnace flue vent connector size below furnace outlet size. The size would depend on your furnace s flue pipe connection. Traditional gas fired forced air furnaces produce hot combustion exhaust gasses and therefore need metal vent pipes or chimneys. Oct 13 2012 brent said.

I have a single 2650 sq ft home that was once subdivided one side had a 133 000 btu oil boiler and i have a 115 000 gas boiler.