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insulation gaskest for electrical boxes

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  • #16
    Re: insulation gaskest for electrical boxes

    Whoa... from electrical cover plate gaskets to PERSIST. That's an enormous leap!

    Firstly, the thin foam gaskets have virtually no insulation value - they are air-sealing gaskets, since in most conventional homes with 2x4 or 2x6 walls, fiberglass insulation (probably not behind the electrical boxes) and no air barrier, outlets are a major vector for infiltration and this is one of the least expensive and most cost-effective energy conservation remediations.

    Secondly, as for the PERSIST (and its cousin REMOTE) approaches to cold-climate building, they are the building scientist's (and perhaps builder's) wet dream.

    Contrary to Ray Moore's enthusiastic statement, these super-sealed houses are "advanced" only in the sense of being far removed from the kind of shelter that co-evolved with human beings and served us well for millions of years. The systems DO take modern building science to its extreme in terms of isolating the structural frame from the exterior environment, but this also isolates the human occupants from the same environment.

    Most building scientists, being scientists, seem to forget that buildings are meant for human habitation and need to be designed around our needs. Most of the current global crises and much of our modern pandemic of ill-health are secondary to our increasing separation and isolation from the natural world in which we evolved. We were not meant to live in a plastic box, kept minimally habitable by complex mechanical systems of life-support. The only place such a structure is appropriate is in outer space - i.e. a completely inhospitable environment.

    Our skin and our clothing must breathe (transpire moisture) in order to maintain an inner environment amenable to life. Our shelters, which are our third skins, also need to breath. The Bau Biologie (biology of the house) movement, which integrates shelter with health, understands this.
    Robert Riversong
    Master HouseWright

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    • #17
      Re: Why seal at the boxes?

      Originally posted by Ray Moore View Post
      I asked Chris Makepeace if there was a good way to seal the air leaks in an electrical box and he asked me in return why I was trying to stop the air movement at the level of the drywall when that was such a difficult location to seal...
      And, contrary to Makepeace's protestations, I find the air-tight drywall approach is the simplest way to create a continuous air barrier, which is why Joe Lstiburek invented it years ago in Canada for energy-efficient houses.

      The American Air Barrier Association uses the air-permeance of drywall as the standard against which all other materials are rated as air barrier elements. In a cold climate, putting the air barrier on the inside skin stops humid interior air from entering the thermal envelope and the structural skeleton, and allows the long-term integrity of the air barrier to be easily monitored and repaired.
      Robert Riversong
      Master HouseWright

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      • #18
        Re: insulation gaskest for electrical boxes

        Robert, how about posting something about that over at the Passive House Institute (PHIUS)'s bb? They are quite firm in their assertion that it's impossible to use ADA for air sealing, since "you can't fix any problems because you've covered them up before you test".
        Have you been able to bring any houses down to .6 ACH @50pa? before insulation? Not that I think that's a necessary number to hit...
        Doug

        Favorite tool this week: Makita double-battery "worm drive" framing saw
        http://www.jlconline.com/author/doug-horgan

        www.bowa.com

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        • #19
          Re: insulation gaskest for electrical boxes

          Originally posted by ThingOfBeauty View Post
          Robert, how about posting something about that over at the Passive House Institute (PHIUS)'s bb? They are quite firm in their assertion that it's impossible to use ADA for air sealing, since "you can't fix any problems because you've covered them up before you test".
          PH afficionados tend to be "true believers" and there is little point in trying to have a critical discussion with them. If your primary building goal is 0.6 ACH50 tightness, then certainly it makes no sense to use any air-sealing system that can't be tested and corrected in process.

          If, on the other hand, your goal is to build a house that is tight enough to eliminate excessive uncontrolled energy loss through air leakage and reduce air leakage enough to eliminate moisture problems in the thermal envelope and structural system, then ADA is a fine and simple and cost-effective approach.

          It's not too difficult to train a framing crew to use Tremco acoustical sealant or gaskets between framing sections. One of the major problems with ADA for many who are not builders but building contractors, is to find a drywall crew that is willing to apply Tremco to bottom and top plates and polypans as they hang the gypsum - or willing to have someone else stay ahead of them with the Tremco.

          But apparently ADA was used successfully in Canada when they were years ahead of the lower 48 in superinsulation and efficiency, and it made sense to its inventor, Joe Lstiburek, who is now a proponent of REMOTE/PERSIST, spray foam, and other air-sealing systems.

          Have you been able to bring any houses down to .6 ACH @50pa? before insulation? Not that I think that's a necessary number to hit...
          I've had only one house blower-door tested, and it came in at 2.13 ACH50, or 0.10 ACHnatural, with the passive make-up air inlets taped - which, prior to PH standards, made it an extremely tight house, particularly for one built with green, rough-sawn lumber.

          I'd rather build a house that allows a minimum of passive air exchange when the power is out (to me, that makes it a truly "passive" house), and mechanically maintain a slight negative pressure to prevent any exfiltration of inside air, since infiltration does not cause condensation in a cold climate. And design it to be breathable in both directions and built with hygroscopic building materials, like wood and cellulose, which can tolerate small amounts of moisture accumulation and allow it to be released diurnally and seasonally.
          Robert Riversong
          Master HouseWright

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