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aguz1126
Proper Furnace Venting question

I recently purchased my first home, a three bedroom ranch with a finished basement in Rochester, NY. Ive began looking around the furnace and noticed that the "furnace exhaust" is being vented outside via 4" PVC that runs out the side of the house. In all other homes that ive seen, the furnace is vented out through the roof via the same pipe the hot water heater is vented through. Is it ok how it is? Should i vent it out the roof? can i use the 6 inch vent that the hot water heater vents out through? I appreciate your help.

bp21901
Re: Proper Furnace Venting question

What is the make / model of your furnace?

It is not unusual to have a high efficiency / power vented furnace using a PVC pipe for a "flue". Yours may be this type of furnace.

aguz1126
Re: Proper Furnace Venting question

From what I could gather the furnace is an Armstrong Air Ultra sx 95 high efficiency furnace. What i was wondering was if it is ok to be vented out of the side of the house or should it go out the roof?

ed21
Re: Proper Furnace Venting question

High effiency furnaces can safely be vented through a sidewall if they are designed for it.
The exhaust is powered by a blower & doesn't rely on gravity to carry the exhaust up. The furnace extracts so much heat from the exhaust that what comes out of the house is about as hot as a hand dryer or less. That's why they can use pvc.
I can't imagine an installer would make that kind of mistake.
You should look on the company website. I bet they have some diagrams to show how they work & explain why.

bp21901
Re: Proper Furnace Venting question

http://www.althoffhome.com/res/Products/Armstrong/ultrasx95.htm

The link above has a description of your furnace and it can use PVC as an exhaust pipe. Whether it was actually installed correctly by your installer is not something I can "see" from here. :)

If it makes you feel any more secure, we have a Bryant high efficiency LP furnace that is power vented through a side wall rather than the roof.

JLMCDANIEL
Re: Proper Furnace Venting question

The high E furnaces are designed to be vented out the side of the house. Because the flue gasses are at such a low temp you would not get proper rise to go up through the roof and and the blower is not designed for enough force to overcome the weight of the air in a tall stack.
Jack

aguz1126
Re: Proper Furnace Venting question

Thank you for all of your help. I did some more research along with the helpful comments and learned that this is the correct positioning of the flue. Thanks.

jim d
Re: Proper Furnace Venting question

I have a high eff furnace that is vented out the side of the house the problem is at around 0 degrees the intake freezes up with mosture and funace will not run y has this happened and what do i do to fix it

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