Originally Posted By: rking This post was automatically imported from our archived forum.
Hi All,
Anyone have anything to say about an "Ultra High Efficiency Carrier' furnace, direct vent, five years old, being vented through an attic space, then through the roof with the PVC exhaust vent being wrapped in a foam like insulation?
The termination point was about 18" above roof line and it looked just like a plumbing vent (other than colour) so there was standing water in the pipe and slight drops of water under the inducer fan housing which luckily is plastic.
I have never seen a direct vent going through a roof space. I have never seen exhaust pipes being wrapped with insulation.
I recommended servicing for the furnace anyway because of the water, and the missing electronic filter and disgustingly dirty furnace filter, upon start up there was a also a pretty good rattle coming from the burners.
-- Muskoka Home Inspections
"Wisdom is the Anticipation of the Consequences"
Steering Committee Member At Large
Originally Posted By: janderson This post was automatically imported from our archived forum.
Was there some reason it was not vented through an exterior wall. Here is an example of one installation that is typical in my area.
Slab on grade home, the existing furnace is a downflow type installed in an interior furnace room/closet. The older forced air furnace is replaced with an energy efficient type that has a direct vent. The old furnace had a steel vent stack that exited straight up through the ceiling, attic, and exited the roof. Since it's an interior room, no direct access to an exterior wall to vent through. Most installations I am seeing will run the 2 pvc pipes up through the ceiling, attic, and the roof. The intake vent will have an elbow shortly after the roof termination and the exhaust vent is straight.
-- Within the seeds of ignorance lie the fruits of denial
Originally Posted By: rking This post was automatically imported from our archived forum.
Jeremiah,
Close.
The furnace was installed in a closet in the upper portion of a side split home with the flexible ducting running through the attic space (wrapped, supported and well done) and terminating in the ceilings of each room, generally close to the middle of the room.
The house had a two bedroom apartment added in the basement and the entire house was at one time electric baseboard with a few surviving in the basement.
The vents could have gone out the front of the house through a second closet space adjacent to the furnace but did not.
The termination of both vents is as you say. The straight termination of the exhaust allowing water in did not seem very logical to me and as I said earlier I have never encountered the exhaust vent being wrapped with insulation before.
I have however spoke with a couple of heating contractors in my area and they inform me they do this to prevent the pipes from 'sweating' and producing a lot of condensation in the attic space.
In that particular attic space there were signs of mildew on the underside of the sheathing as well and I did recommend improving the ventilation too.
-- Muskoka Home Inspections
"Wisdom is the Anticipation of the Consequences"
Steering Committee Member At Large
Originally Posted By: janderson This post was automatically imported from our archived forum.
Quote:
The house had a two bedroom apartment added in the basement and the entire house was at one time electric baseboard with a few surviving in the basement.
Quote:
What was the total square footage? Not a very cheap heating meathod. What if they lost electricity in the winter time  Brrr
I have however spoke with a couple of heating contractors in my area and they inform me they do this to prevent the pipes from 'sweating' and producing a lot of condensation in the attic space.
Sounds logical to me. Most of the ones I find run inside an existing chimney chase or flue so they are not visible in the attic.
Quote:
In that particular attic space there were signs of mildew on the underside of the sheathing as well and I did recommend improving the ventilation too.
Good call. Was this just from inadequate venting or were their other moisture problems. You can already rule out the sweating exhaust pipe
-- Within the seeds of ignorance lie the fruits of denial
Originally Posted By: rking This post was automatically imported from our archived forum.
Jeremiah,
My fingers are crossed that it was mainly a venting problem, there was also a bathroom vent running through a flex house to the soffit and I suggested they make that arrangement a little better too as the termination was just resting on the soffit.
-- Muskoka Home Inspections
"Wisdom is the Anticipation of the Consequences"
Steering Committee Member At Large