Gas Furnace Flue Pipe Sizing

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.

Gas furnace flue pipe sizing. You would core a hole 1 4 to 1 2 inch bigger than the outer diameter of the pipe. Traditional gas fired forced air furnaces produce hot combustion exhaust gasses and therefore need metal vent pipes or chimneys. 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 pipe then slips into the hole and is sealed with a high temperature silicone caulk.

Conditions for listing as stated in the product catalogs and embossed on the vent pipe. The different types of venting. Reduce furnace flue vent connector size below furnace outlet size. The size would depend on your furnace s flue pipe connection.

So let s calculate or why don t we skip those calculations and i ll give you the answers. I want to purchase a new boiler to heat both sides which i have zoned. Clearance installations must provide the proper clearances to combustible materials as specified in the appropriate underwriters laboratories inc. Oct 13 2012 brent said.

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.