Recent Comments and Answered Questions on Green Building Advisor

  • Jonathan Lawrence CZ 4A New Jersey | May 24,2018 07:09 AM EDT
    Dana, Thanks for the response. Size wise, we are at a 4-ton unit at the design temp, (high R, but large footprint) and without the Hyperheat, Mitsubishi wants to have 2 - 48kbtu PUMY's to meet ...
  • Martin Holladay | May 24,2018 05:20 AM EDT
    Arden, Q. "R-49 is the minimum insulation we discussed above, but what would you recommend for a total R-Value in this ceiling for zone 7?" A. From a building science perspective, anything in ...
  • Martin Holladay | May 24,2018 04:56 AM EDT
    Neo, First of all, can you tell us your name? Q. "Can the supply plenum simply be a 4-inch length between the unit and the trim/grille?" A. As far as I know, the answer is yes. Q. "Same ...
  • John Prospect | May 24,2018 04:56 AM EDT
    David, Thanks for the mention of the CSV. I had not heard of it and have found the information online quite interesting. The company makes a good case for how it works. I would be curious how ...
  • Martin Holladay | May 24,2018 04:50 AM EDT
    Phil, First of all, I envy you. I imagine it's a beautiful building. Second, it's important for you (a) to comply with all local regulations, of which I am ignorant, and (b) to get local ...
  • | May 24,2018 12:15 AM EDT
    Martin, Thank you for your reply. Funny you mentioned it, but I actually did read the 'Plan Ahead for Insulation' article prior to building. Here's the sad part... every contractor I talked ...
  • Bruce Haupers | May 23,2018 11:07 PM EDT
    I know that Matt Risinger uses Positive Energy in Austin and they will design using the Multi city if you want. I'm just getting my plans together for a new build and trying to educate myself as ...
  • | May 23,2018 09:02 PM EDT
    Thanks for everyone's input. I will have to get an expert in here to try to figure it out. Thanks again.
  • Phil Jamison | May 23,2018 08:49 PM EDT
    I'm restoring a small 150-year-old stone house with a hip roof in France. It has a slate roof and no sheathing. The rafters are narrow (10cm X 10cm; about 3-7/8"), and the ceiling is low above our ...
  • Dan Kolbert | May 23,2018 07:11 PM EDT
    I've long worried we don't really know what we're doing re ventilation - glad that studies like Brian's are starting to help.
  • Dana Dorsett | May 23,2018 05:43 PM EDT
    In a vented roof in Seattle you can safely go with open cell foam too. Even at R49 open cell foam is more vapor open than standard latex ceiling paint, and it would dry into the vent space faster ...
  • Dana Dorsett | May 23,2018 05:33 PM EDT
    I'm not sure I have anything of substance to add here. Daikin is the world's largest vendor of variable refrigerant volume systems in commercial HVAC, and in your location you don't really need ...
  • Rick Evans | May 23,2018 04:47 PM EDT
    Thanks so much Martin- I will go with PVC. I haven't actually priced out the PVC yet to compare it to the HPDE pipe... My local lumber yards don't seem to carry perforated PVC at the moment ...
  • Martin Holladay | May 23,2018 04:22 PM EDT
    Rick, I'm not very familiar with HPDE pipe. I haven't seen any warning in online sources that HPDE won't work for a radon system. That said, most radon systems use PVC. The conservative ...
  • Rick Evans | May 23,2018 04:10 PM EDT
    Hello All, I'm installing a passive radon mitigation system (new construction) under a slab. Just curious what kind of pipes people are using under the slab. 1.) Do the pipes have to be ...
  • Jon R | May 23,2018 03:56 PM EDT
    "Carbon dioxide is useful as an indicator of general air quality only in buildings where there are significant metabolic or combustion sources of carbon dioxide. ...
  • David Baerg | May 23,2018 02:14 PM EDT
    I would agree that this is a very good starting point for further research. I think we need to go deeper than suggesting that people keep their doors open if there are good reasons to keep them ...
  • Martin Holladay | May 23,2018 02:06 PM EDT
    Cramer, You're right. I've made the correction. Thanks for pointing out the error.
  • Cramer Silkworth | May 23,2018 01:56 PM EDT
    the equation should be AC capacity = CFA divided by sf/ton, not multiplied, no?
  • Jeremy Good | May 23,2018 12:50 PM EDT
    That's a good article, thanks. I've been in my house less than a year, so thermostat data gave me a much more precise estimate and in a target outdoor temp range. I have 12 months of the previous ...
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!