PVC for Flue

[Skip Erwin]

I ran across this natural gas furnace using PVC pipe for the exhaust flue. Is that OK? I don't normally see PVC being used for a flue. Thanks.

[Jason1]

Originally Posted by Skip Erwin

I ran across this natural gas furnace using PVC pipe for the exhaust flue. Is that OK? I don't normally see PVC being used for a flue. Thanks.

It's a high efficiency furnace.

[Jason1]

Originally Posted by Skip Erwin

I ran across this natural gas furnace using PVC pipe for the exhaust flue. Is that OK? I don't normally see PVC being used for a flue. Thanks.

There should be one for combustion air as well....... Looks like it is missing??

[Jason1]

Originally Posted by Jason1

There should be one for combustion air as well....... Looks like it is missing??

And don't let the contractor tell you it is ok, it should be drawing combustion air from outside.

[Jason1]

Originally Posted by Skip Erwin

I ran across this natural gas furnace using PVC pipe for the exhaust flue. Is that OK? I don't normally see PVC being used for a flue. Thanks.

Are you a practicing home inspector?

[Skip Erwin]

There is a vent in the floor. It's drawing combustion air from the crawlspace.

[Charles Buell]

Not all High Efficiency furnaces draw there combustion/dilution air from the exterior. While you often see two pipes, it is not "always" the case.

[Jason1]

Originally Posted by cbuell

Not all High Efficiency furnaces draw there combustion/dilution air from the exterior. While you often see two pipes, it is not "always" the case.

Only when the contractor wants to save 30 feet of pipe.

[Jason1]

Originally Posted by Skip Erwin

There is a vent in the floor. It's drawing combustion air from the crawlspace.

High efficient furnaces are sealed combustion units, they don't draw from a vent. They draw from another pipe that should be beside the exhaust pipe, and run outside. Right now that furnace is drawing air from the room.

[dpeterson]

From Goodmans Install Manual"

Dual certification means that the combustion air inlet pipe is optional
and the furnace can be vented as a:
Non-direct vent (single pipe) central forced air furnace in
which combustion air is taken from the installation area
or from air ducted from the outside or,
Direct vent (dual pipe) central forced air furnace in which
all combustion air supplied directly to the furnace burners
through a special air intake system outlined in these
instructions.

[Jason1]

Originally Posted by dpeterson

Dual certification means that the combustion air inlet pipe is optional
and the furnace can be vented as a:
Non-direct vent (single pipe) central forced air furnace in
which combustion air is taken from the installation area
or from air ducted from the outside or,
Direct vent (dual pipe) central forced air furnace in which
all combustion air supplied directly to the furnace burners
through a special air intake system outlined in these
instructions.

I still don't like it, I always recommend they be installed to the exterior of the home.

[Charley L. Bottger]

Originally Posted by dpeterson

From Goodmans Install Manual"

Dual certification means that the combustion air inlet pipe is optional
and the furnace can be vented as a:
Non-direct vent (single pipe) central forced air furnace in
which combustion air is taken from the installation area
or from air ducted from the outside or,
Direct vent (dual pipe) central forced air furnace in which
all combustion air supplied directly to the furnace burners
through a special air intake system outlined in these
instructions.

Atta Boy Donald good post.

[Charley L. Bottger]

Originally Posted by Jason1

I still don't like it, I always recommend they be installed to the exterior of the home.

Personal choice should not enter into a home inspection its either right or its wrong no gray areas. An inspector could end of paying for the pipe if not careful??????

[Jason1]

Originally Posted by cbottger

Personal choice should not enter into a home inspection its either right or its wrong no gray areas.

True, but I don't carry an installation manual for each manufacture around with me. So, IMHO it should be pulling from the exterior. To me it is just a workmanship thing.

[Charles Buell]

Some of the ones that I have seen that are allowed to draw air from the interior do not even have a place to install an intake pipe.