How do you route a furnace exhaust?

Quote from the video:
Quote from Youtube video: The Installer must route the flue. And the combustion air pipes in the most direct route as possible also be sure that you use the minimum amount of elbows 45s. And other fittings.

How do I stop my furnace exhaust from icing up?





To prevent this, your furnace installer should ensure that intake and exhaust vent pipes are properly sloped with grade back toward the furnace, supported, and installed with as short a distance between your furnace and the intake/ exhaust termination as possible with the fewest number of elbows.

Should furnace exhaust be higher than intake?

The exhaust pipe should be pointing up and the intake pointing down. If your intake is above the exhaust terminal, the intake might be sucking up exhaust gases (carbon monoxide, etc.) back into the home!

Can a gas furnace be vented horizontally?

Direct Vents



These furnace vents can be installed horizontally through an exterior wall, or vertically so exhaust fumes go out through the roof. Although more costly than a natural vent, a direct vent is also a more efficient and safer option.

Does a furnace exhaust have to be straight?

The vent connector should exit the furnace straight for at least 18 in. before any turns are made. This allows the flue gases to gain some velocity before meeting any resistance to flow.

How far should furnace exhaust be from intake?





Wall intakes must be located at least 10 feet from any appliance vent or any vent opening from a plumbing drainage system. Wall intakes must also be 10 feet from any exhaust fan discharge outlet unless that outlet is 3 feet or more above the intake location.

Should furnace exhaust pipe be insulated?

Since furnace exhaust vent pipes are a prime suspect for air leaks around the chases, sealing around them before insulating can great reduce infiltration and wasted heat.

Why does my furnace exhaust freezing up?

Ice typically appears on furnace exhaust vents due to moist, condensed air. The air released from furnaces condenses quickly because it is already cool, creating heavy moisture that can freeze inside pipes and vents before it has the opportunity to fully leave the furnace system.

Does furnace vent need to be sloped?

A vent connector shall be installed without dips or sags and shall slope upward toward the vent or chimney at least 1/4-inch per foot (21 mm/m),” according to the Florida Building Code Residential Edition (FBC) and the International Residential Code (IRC) at G2427.

Can you use B vent for horizontal venting?



3. Can Type B Gas Vent terminate horizontally on a wall? No, only Cat III 1738 approved systems can terminate on a side wall.

How long can a furnace vent pipe be horizontal?

Each manufacturer has a specific vent limit for their model of furnace as well as the input rating of the furnace. For example, 50K BTU furnace you can use 2″ pipe for 50ft but for a 80k furnace you can only use 2″ for 10ft. Once you exceed that limit, you’ll have to increase to larger pipe size diameter.

Can a high efficiency furnace be vented vertically?

Sidewall Venting (High efficiency appliances)



Venting can also be vertically vented through the roof (be wary as there can be unforeseen problems with venting through the roof as they are not easily maintained). Separate venting pipes are an optimal choice here as well.

Can you put an elbow on a furnace exhaust pipe?



Bend It. A direct vent stove can have an elbow in the vent, and those vented through a wall instead of the roof often do. This is because it is recommended that the pipe run vertically for a certain distance before reaching the outside. In these cases the elbow may be either inside or inside the wall.

How should a high efficiency furnace be vented?

Proper sidewall venting requires installing separate vent pipes horizontally so that they vent to the outdoors through a wall of your home. These ventilation pipes should be isolated from the furnace combustion chamber and made airtight to eliminate the possibility of combustion gas leakage.

How far can you run a vent for a high efficiency furnace?

Because high-efficiency furnaces use sidewall vents, they’re more susceptible to airflow blockages. The area around the sidewall vents should be clear of all airflow blockages for a minimum two feet in all directions. When air intake is blocked or hindered, fuel combustion suffers, and the furnace locks out.

Can you vent a furnace with PVC?

Ironically, even though the presence of plastic vent pipes has become synonymous with high-efficiency condensing furnaces, PVC pipe manufacturers do not recommend PVC for this application. Nor are there any official ASTM standards for plastic pipe used as combustion gas venting.

Does you need cold air return with high efficiency furnace?



The architecture of high-efficiency furnaces means that they have their own fresh air intake. This means that they don’t use the air inside your home; rather, they draw air from outside. However, this doesn’t mean you don’t need an external fresh air intake because you’ve installed a 90% furnace.

How long can a furnace exhaust pipe be?

The maximum vertical distance you can run a furnace exhaust vent is about 15 feet.

How much slope should a furnace vent have?

Slope the vent and combustion air piping downward towards furnace a minimum of ¼ in per foot. Failure to support and slope the pipe can result in nuisance short cycling, frozen vent termination, and/or no heat situations.