HE furnace intake and exhaust question

[blazenut]

I was at a home today that had a high efficiency furnace with pvc intake and exhaust (see pics below). As you can see they joined in the attic before a single pipe exited the home. Why would one do this? I would think that this would re-use the exhaust as intake-no? I havent seen this before. Thoughts would be appreciated.

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[Robert Jones]

What brand is the furnace? I have never seen that exhaust setup before and doesn't seem right to me for the reason you listed above.

[Brandon Whitmore]

Google: Concentric vent termination kit.

The only reason I can think of why this is better than running 2 separate pipes would be to have only one penetration instead of two. PS: That kit is over $100.00-- someone's making a killing.

Make sure the exhaust is connected to the inner part of the pipe.

[blazenut]

It was a Payne, 10 years old.

[Bill Kibbel]

If you're not familiar with concentric vent systems, you should read the installation instructions to be sure it's installed and terminated correctly. I have an old set that I can send you if you don't have it available.

[blazenut]

Thanks alot guys. It is still interesting to me that this would be allowed knowing that the intake and exhaust locations are so close to each other...

[Brandon Whitmore]

Here's one set of instructions: http://www.luxaire.com/PDFFiles/66641-U ... 87-000.pdf

[Robert Jones]

Thanks Brandon.

[hausdok]

Hi,

I've seen them a lot in a couple of developments that I've been doing a lot of houses in. It's a category IV - they don't care if a little CO2 mixes with the intake on those because they're sealed away from the interior. Besides they're usually sucking in so much extra air that the amount of CO2 is negligible.

ONE TEAM - ONE FIGHT!!!

Mike