Intake/Exhaust 90%+ Furnace

[kgouker]

I saw something really weird the other day... I was in a basement, and saw a 90%+ furnace. Two pvc pipes coming out of it, intake and exhaust. Here's where it got strange... The pipes went up from the furnace, turned and went under the floor joists, and CONNECTED together and ran out of the house as ONE pipe. This did not make any sense to me at all. All of the 90%+ systems I have ever seen have had two pipes all the way out.

Can anyone explain this to me?

[James 3528]

Do you mean actually connected together with a fitting or ran outside next to each other though a larger PVC sleeve? I see what you mean and if that is the case that they are glued togeather with a fitting, that is a little strange

[Edited by James 3528 on 08-29-2005 at 12:16 PM]

[kgouker]

I wish now that I had taken a picture of it. The two pipes came together in a "Y" and exited as one pipe. It wasn't just a larger sleeve that housed both pipes.

[James 3528]

That is weird. I probably have seen four 90% installs in my area and I did them because they were spec'ed that way . I agree, that just does not make sense. Might be some new kind of pipe on the market that keeps them seperated inside.

[woowoo]

Was it a concentric connection?

[James 3528]

If it were concentric it would make sense that at the Y the diameter would just about double at that point and out athe house.

I was thinking much of the same thing but this would mean rapid condensation of the exhaust air in the pipe.

[James 3528]

Explained here> http://aireheating.com/Furnace%20gallery.html


Oh gosh! I'am right! it does double.





[Edited by James 3528 on 08-29-2005 at 12:45 PM]

[ct2]

By the looks of the pic both of the 2" lines going into the fitting , the straight pipe in the center will run up the center of the 3"pipe --call it the exhaust- and the other will get its supply air from the surrounding area encompased in the 3"

[James 3528]

The intake is up against the house. They wouldn't put the exhaust up against the wall. Look close at the picture. The furnace is on. You can see the fumes from the middle pipe.

[kgouker]

That was exactly like what I saw. Thank you James 3528 for doing the research on this!

(I'll be able to sleep better at night now that I know what they did...) LOL

[James 3528]

You're welcome.

[James 3528]

Technically, that is not a Y but a 45 degree branch fitting.


I think

[spotts]

Originally posted by James 3528
Technically, that is not a Y but a 45 degree branch fitting.


I think

Technically it's a y and a 45°