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    <p>Hi Ben, <br>
    </p>
    <p>Two things.  </p>
    <p>I have 4 heat pumps that provide zoned forced air heat.  I love
      them.  Propane in Ontario is very expensive and the rates somewhat
      volatile. Electricity somewhat less so. Heat loss for the house is
      calculated at 44K BTU, and the 4 heat pumps total 36KBTU. No
      problems and the systems aren't running past peak efficiency.  I
      do have a wood stove that I use on really cold days to offset the
      load, but that's on -30C and relatively rare. <br>
    </p>
    <p>I have a steel roof with no decking (soon to be installed vapour
      barrier between insulation and steel--builder's error and fixed at
      his cost). when I looked at it, CCF was an option for a steel
      roof, but the risk of rust is still present.  I'd do Rockwool.</p>
    <p>Glad this list is still going!</p>
    <p>Lynelle<br>
    </p>
    <div class="moz-cite-prefix">On 2024-02-18 1:33 p.m., Mike O'Brien
      wrote:<br>
    </div>
    <blockquote type="cite"
      cite="mid:5B2BEE1D-FA0F-4E7A-B085-E19985520CD8@hevanet.com">
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      Hi, Ben—
      <div><br>
      </div>
      <div>Our house plans specified closed-cell foam in our roof, but
        without asking, our general contractor installed open cell foam.
        Now, 16 years later, there is rot in the roof sheathing and a
        very expensive repair job ahead. So I would caution against ever
        specifying either foam, as a mistake can be catastrophic years
        later.</div>
      <div><br id="lineBreakAtBeginningOfSignature">
        <div dir="ltr">Best, Mike O’Brien
          <div>Sent from my iPhone</div>
        </div>
        <div dir="ltr"><br>
          <blockquote type="cite">On Feb 18, 2024, at 8:13 AM, Benjamin
            Pratt <a class="moz-txt-link-rfc2396E" href="mailto:benjamin.g.pratt@gmail.com"><benjamin.g.pratt@gmail.com></a> wrote:<br>
            <br>
          </blockquote>
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        <blockquote type="cite">
          <div dir="ltr">
            <div dir="ltr">
              <div>Hi. I've been on this forum for many years, but I am
                not an architect or qualified expert.  I came across
                this article today and had some concerns about this
                project. <br>
              </div>
              1. By air source heat pump, I assume they mean
              mini-split(s). I did some calculations rencenty and found
              that electricity is about 9 times more expensive per therm
              than gas. Combining with the very cold temperatures we
              typically get, I imagine The bill will be higher than if
              they had a gas boiler. Also, they now have to deal with
              uneven temperatures throughout the house and leaving doors
              open to all the rooms they want heated.  What do you
              think?<br>
              <div>2. I have read about dangers of using spray foam in
                an old house--especially the potential for rot.  What do
                you think?</div>
              <div>   <br>
                This article reads as an advertisement for doing this
                sort of remodel without mentioning any of the potential
                downsides.  I'd love to hear your thoughts.<br>
              </div>
              <div><a
href="https://www.mprnews.org/story/2024/02/18/renovating-old-1909-st-paul-house-into-all-electric-green-home"
                  moz-do-not-send="true" class="moz-txt-link-freetext">https://www.mprnews.org/story/2024/02/18/renovating-old-1909-st-paul-house-into-all-electric-green-home</a><br>
                <br>
              </div>
              <div>Ben Pratt<br>
              </div>
              <div>
                <div><br>
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