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Venting Condensing boilers

Guy_6
Guy_6 Member Posts: 450
Back in my Munchkin days, I would allow the venting that you are proposing provided that the pitch of the horizontal (below grade) pipe was MORE than the required 1/4 inch per foot back toward the boiler.
If someone were to ask me on the Smith GT/ Hydrotherm GX, I would allow the same, but you really need the blessing of the particular manufacturer to make it fly.

I had one gent run the vent out into his garden and up through a hollowed out dragon. When the boiler ran, the beast would spew steam out it's mouth and nose. Way cool.

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,455


    Venting high efficiency boilers with plastic.

    Is it ok to vent through the foundation wall below grade and elbow up and then terminate. I have asked several boiler manufacturers and can't get a straight answer. Has anyone done this????? Looking at the manufac. instructions they don't show this application.

    Then again they don't say you can't.

    The alternative is to vent through the roof through a first floor closet or chase.

    Kinda like the reason the electrical code book is as big as a phone book now.

    Some knucklehood mounted a circuit breaker panel on a ceiling. The code didn't say you couldn't!!!!!!!!!!


    Ed
  • Perry_2
    Perry_2 Member Posts: 381
    Depends on state and local regs.

    First these systems are usually rated by a federal agency on what is allowable for vent location. By that alone you probably could not do it. However, not all states and localities adopt the federal standards. Some have more restrictive standards - some don't care what you do.

    In my case, my plan is to run the vent pipe upstairs into a closet and out the wall. I will loose some closet floor space and should end up with a nice closet shelf about 1.5 Ft above the floor. Of course, that requires a convienient closet. I also have to get a variance from the city to run the vent pipe out the side of the house.

    Perry
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,455


    Thanks for the replies. Would like to here from some additional boiler and furnace manufacturers. Personally I would think it would be ok as long as enough pitch is left on the pipe. I would assume you would get more condensation with the pipe in contact with the earth.

    Any concerns with the inlet pipe??

    ED
  • Tony_23
    Tony_23 Member Posts: 1,033
    Inlet

    I would keep it 12-18" lower than the exhaust termination, but obviously above snowline. This will help keep it from pulling in moist vent gas and freezing in the pipe, locking it off.

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  • Mitch_6
    Mitch_6 Member Posts: 549
    Weil Mclain

    Has told us we can run on the exterior with the pvc line from the Ultra provided we build an insulated box around the piping (I know that is really no longer exterior).

    The piping is pvc so moisture is not an issue.

    So I do not see why you could not come out under ground and build a box insulated block of some sort below grade then go to wood above grade to a safe height.

    We are doing a job now coming out at grade through a window then up about five feet, we are keeping the window out and taking the siding off the house behind the box to gain as much heat as possible for the rise.

    Mitch S.

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