Thread: Is this furnace exhaust vent pipe acceptable?

Greetings - I came across this furnace exhaust vent pipe joint in a attic of a newly constructed home today (2012). I haven't seen this application before. Is this acceptable? OR, did the HVAC contractor use what he had on his truck?

Thanks in advance,

T.Furnace exhaust vent pipe 1.JPGFurnace exhaust vent pipe 2.JPGFurnace exhaust vent pipe 3.JPG

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Thomas, I have seen this used before and it is allowed if allowed by manufacturer. My question would be. How did it penetrate the roof deck and what is installed above the roof deck? This material seems to be too flexible to stand up on it's own and support a cap. I would be interested to hear from a HVAC pro. By the way Brian, I really like the similar threads feature.

That looks like acceptable flex flue vent. Normally, there is a label on them, describing the proper application and use.

Thank you, gentlemen.

I can not see the label but that looks like a b-vent flexconnector that is used to connect an appliance collar to the base of a b-vent vent.

If it is what I think I see, it is approved only as a connector in the same room, not to be run into the attic. It is like a appliance connector, both ends in the same room not for through a wall or anyplace.

Again don't see a label or listing.

It might be ok but it all depends on the material used. When I see these types of flue pipes, I grab them with my hand and give a squeeze. More than once, it has bent easily with hand pressure and turned out to be clothes dryer duct and not at all rated for the way it was being used.

Originally Posted by Nick Ostrowski

It might be ok but it all depends on the material used. When I see these types of flue pipes, I grab them with my hand and give a squeeze. More than once, it has bent easily with hand pressure and turned out to be clothes dryer duct and not at all rated for the way it was being used.

If I can't find the label, I write it up as possible non conforming use of flex vent.

I believe the material would have to be stainless steel.