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Community and Q&A

Air sealing a house with no central air circulation or ventilation

kevinjm4 | Posted in Energy Efficiency and Durability on

Would it be a bad idea to tape seams and air seal around the house if you don’t have a central air circulation/ventilation system?

Our house has electric heaters in the bedrooms, and a gas fireplace in living area… We bought the house two years ago and have a long way to go! Just getting started

Since we are re-framing some bedrooms and putting in new bathrooms…. and re-siding/sheathing much of the house as well, it would be nice to air seal while I’m there.

thoughts? Zone 4c – poured concrete foundation/footer perimeter. Unfinished/vented crawlspace.

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  1. Expert Member
    Dana Dorsett | | #1

    It's always better to air seal rather than count on random air leakage to introduce & distribute the ventilation air appropriately. With a tight home you have control over where the air moves.

  2. Expert Member
    Peter Yost | | #2

    Hi Kevin -

    Lots of great resources on GBA for air sealing.

    A good place to start is always the Energy Star Thermal Bypass Checklist. Just type thermal bypass checklist into the Search bar for GBA.

    Also, interesting that you have a vented crawlspace and ask about airtightness. What is in your unvented crawlspace? Hopefully no HVAC equipment or ducts. If so, strongly recommend you make your crawlspace unvented and insulate/airseal at the perimeter walls.

    1. kevinjm4 | | #3

      Thanks for the help, and no nothing but plumbing down there now as we have torn out the homes of the mice- insulated ducts.. We had rodent infestation when we bought the house, which is why we went with electrical heat at least temporarily while we sealed all the holes, and cleaned up down there. Fun. Lots of interesting things were down there, coon skeletons, frogs...

      1. Expert Member
        Dana Dorsett | | #5

        In zone 4C the air is dry enough year round (believe it or not) that vented crawlspaces don't have humidity /mold issues the way they do in 4A. But that doesn't mean a vented crawl won't end up as a critter-condo. A rat slab on top of a vapor barrier and R15 rigid insulation on the crawlspace walls is stil worth it in the end.

    2. charlie_sullivan | | #4

      Sadly, the energy star website is down for the government shutdown, or rather it's limited to providing a notice saying that it is shut down. So one cannot access the checklist. But Martin's article about the checklist is still accessible on GBA.

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