Gas Furnace Flue Pipe Sizing

The design btuh british thermal units per hour capacity of the vent plus the furnace input and efficiency are factors affecting the temperature of the flue gases.

Gas furnace flue pipe sizing.

Oct 13 2012 brent said. 6 flue 28 27 square inches 8 flue 50 27 square inches total 78 54 square inches. Consequences of improperly assembled vent pipes problematic chimney flue deteriorating chimney walls can be sometimes fatal fire and carbon. Traditional gas fired forced air furnaces produce hot combustion exhaust gasses and therefore need metal vent pipes or chimneys.

Reduce furnace flue vent connector size below furnace outlet size. 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 determine the main flue size refer to figure 3 and locate the square inch area of each individual flue size. Conditions for listing as stated in the product catalogs and embossed on the vent pipe.

Flue gas temperature flue gas temperature affects vent operation because the hotter the gases are the lighter they are. 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. You would core a hole 1 4 to 1 2 inch bigger than the outer diameter of the pipe.

The different types of venting. Proper furnace water heater venting is an extremely important issue which depends on the performance of the house chimney chimney flue or other exhaust assemblies. The pipe then slips into the hole and is sealed with a high temperature silicone caulk. The size would depend on your furnace s flue pipe connection.

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. Higher btuh furnaces produce higher flue gas temperatures. Flue gas temperatures that do not exceed 400 degress fahrenheit above ambient for category i appliances. The conditions explained in this post also apply to the wood burning appliances.

Well making sure that you choose the right venting style will protect them. I want to purchase a new boiler to heat both sides which i have zoned. 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.