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Does anyone know of a good 12x12 vent for a boiler room that can be shut sometimes when cold out?

Joseph_4
Joseph_4 Member Posts: 271
I have a customer where the boiler is being built on the second floor. The boiler room is right on the external wall and the inspector wants a 12x12 opening at the top of the room and a 12x12 opening at the bottom of the wall in the boiler room. The pipes are a few inches away from the outdoors and I am concerned that if I put a regular vent, then on a freezing cold day the pipes might get too cold even though I am going to put fiberglass insulation. Is there a kind of vent that anyone knows of that has a shutter that can be closed or even somewhat closed on a very cold day?

Comments

  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    Danger! Danger!
    If you need the vents for combustion air, then you really need the vents when it's cold or you'll starve the unit for combustion air and could create either a backdrafting and/or high CO...so don't close it off.
    What type of boiler is this (make/model)? Maybe you can bring combustion air right into the unit and forgo the openings.
    steve
    ChrisJ
  • SlamDunk
    SlamDunk Member Posts: 1,571
    edited September 2019
    Yeah, you need so many sq inches of outside air opening per mbtuh for combustion. We have an entire outside wall open to the outside and had to heat trace and insulate all pipes. Insulation without heat traces are not helpful.
  • Cody350
    Cody350 Member Posts: 11
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    Although a good article, the OP is looking to close them when it's cold and the unit needs to run.
    So that may help a little, but more info about the boiler and can combustion air be brought directly into the boiler would help.
    steve
  • Steamhead
    Steamhead Member Posts: 16,796
    Maybe a duct from the opening to near the boiler, with a motorized damper as described? This could get the cold air away from the pipes.................
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • JUGHNE
    JUGHNE Member Posts: 11,042
    Could you consider the "Fan in a Can"?
    STEVEusaPA
  • Joseph_4
    Joseph_4 Member Posts: 271
    Its a Green Mountain GMPVB series 2 induced draft boiler 150k input.. Once the Village inspector asked for it.. i need the 12 by 12.. should I not be worried about the very cold?
    thanks
    joe
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    With that boiler it looks like leave the openings, but @JUGHNE 's idea of a 'Fan in a Can' and no openings is probably the best idea.
    steve
  • Jamie Hall
    Jamie Hall Member Posts: 23,177
    Joseph_4 said:

    Its a Green Mountain GMPVB series 2 induced draft boiler 150k input.. Once the Village inspector asked for it.. i need the 12 by 12.. should I not be worried about the very cold?
    thanks
    joe

    You certainly should do something about the possibility of the cold freezing the pipes.

    However.

    That does not include shutting off the required combustion air for the boiler. Doing so will create a very dangerous -- quite possibly fatal -- condition, and you really don't want to do that.

    Creating fan assisted, closed combustion air and exhaust is one option -- but if you are going that route, it has to be done right, so there is no possibility -- none -- of combustion gas getting into the house. Unless the boiler and burner system is designed for it, that is, to my mind, a rather iffy option.

    Another would be to reroute the problematic plumbing so it isn't in the same space as the boiler.

    Another would be to heat trace and insulate the piping.

    I'd prefer rerouting the problematic plumbing, myself.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England