Recent Comments and Answered Questions on Green Building Advisor

  • Martin Holladay | Feb 17,2018 06:25 AM EST
    Andy, To the best of my knowledge, if there is any chance that a radon mitigation fan's attempt to depressurize the soil under a basement slab we be defeated by the presence of a drain to ...
  • Martin Holladay | Feb 17,2018 06:21 AM EST
    Jake, Green builders avoid the use of XPS, which is manufactured with a blowing agent that has a high global warming potential. Either EPS or polyiso would be a better choice. For more ...
  • Martin Holladay | Feb 17,2018 06:08 AM EST
    Stephen, Q. "Why does leaving the door open work?" A. On the molecular level, the molecules in the air -- mostly nitrogen, but also oxygen and other molecules -- are always bouncing around, as ...
  • Jake Rabe | Feb 17,2018 02:07 AM EST
    Hi Joshua. Yes i do in fact have 5x 5" insulated ceiling can lights penetrating the ceiling into the attic. They all are using 4.5w LED bulbs. These were a new addition this ...
  • | Feb 16,2018 09:55 PM EST
    Jake, Do you have any can lights or other large penetrations between the top floor and the attic that could be letting warm moist air into the attic? Could you link to the earlier ...
  • Jon R | Feb 16,2018 07:14 PM EST
    > market participation the minimum can be set no greater than 100kw 100kw @ 250V = 400A. Not practical for the typical electric car at home (unless aggregation is allowed).
  • Jon R | Feb 16,2018 06:31 PM EST
    Nice article. Here is a source for open door flow calculation. I get 322 CFM at 5F. http://members.questline.com/Article.aspx?articleID=21224&accountID=1289&nl=11875 A 20" box fan ...
  • Michael Maines | Feb 16,2018 05:54 PM EST
    Douglas, even the PHPP struggles a bit with accurately modeling basements--it's complicated for all of the reasons you mention, and more. You're correct, BeOpt does not have an option for sub-slab ...
  • Erich Riesenberg | Feb 16,2018 05:32 PM EST
    Oh, and my energy use is about 500 kwh per year for cooling, maybe 3,000 kwh for heating. And that is without a real heat pump. This is just testing things out for me. I use a portable heat pump ...
  • Erich Riesenberg | Feb 16,2018 05:26 PM EST
    Hi Martin. GBA did not allow me to post to last week's discussion. Drupal is a great website infrastructure, I am sure GBA will get it figured out one of these decades. My comment in that ...
  • | Feb 16,2018 05:20 PM EST
    Thanks Martin, and Michael for the vote of confidence In BEopt. Yes indeed, U.19 windows. Single glazed plain glass windows would do better than U1.9. This is based on the only quote I've ...
  • Erich Riesenberg | Feb 16,2018 05:17 PM EST
    Hi Dana. I am sorry for your confusion. Perhaps you should slow down and read before posting. My comment about solar not producing during peak power was based on a New York Times article, based ...
  • Michael Maines | Feb 16,2018 05:14 PM EST
    Sizing steel beams is trickier than sizing wood beams--for each nominal dimension of an "I beam" (technically called a W-section, the kind most often used because it has the strongest overall ...
  • Andy Freeman | Feb 16,2018 04:44 PM EST
    No, the radon pipe will not be connected to the perimeter drain, it will be placed 7-8' out from the wall, which means it will be around 6' from the interior drain. We'll have a continuous bed of ...
  • | Feb 16,2018 04:39 PM EST
    Forte is excellent, if you know how to use it properly. You could size your beam from the tables in the Ontario Building Code. Scroll all the way to the bottom of Part 9 of Division 2 and you ...
  • Steve Knapp CZ 3A Georgia | Feb 16,2018 04:34 PM EST
    Andy, Just to clarify, you are not connecting the radon pipe and the perimeter drain. The exterior footer drain ties into the window well drains and then drains to the sump. Is this correct? Is ...
  • | Feb 16,2018 04:33 PM EST
    I really wouldn't expect leaving the door open to have higher air / heat movement than a dedicated fan, but this does seem to make a significant difference. Why? Edit: Nevermind. I see ...
  • Joel Cheely | Feb 16,2018 04:24 PM EST
    A free program that lets you size joists and beams is Forte by Weyerhauser. Takes a little learning, but very valuable. Of course it's all wood based products, so no steel. There are some free ...
  • | Feb 16,2018 04:08 PM EST
    @T CARLSON With my 2x oversized, 30+ year old steam boiler, $1.5/therm and $.20/kwh, I saw about 30% savings in temps above 30. With the recent cold snap in January in New England, I switched ...
  • | Feb 16,2018 04:08 PM EST
    Which kind of rigid foam should I use, and thanks for your help!
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