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  1. #1
    Join Date
    Nov 2004
    Location
    Boston, MA
    Posts
    4,613

    Default 2012 IECC and Hope

    Well, I surprisingly have hope we are going to meet the 2012 IECC 3 air change requirement for zones above 3. It's not going to be easy, and builders not paying attention are going to get railroaded, but we are finding ways to get there without full spray foam.

    We are going into blower door assisted air sealing with new construction. I'm having the Energy Conservatory make up some blower door canvas without the holes for the fans, we are going to use them in the doors that are missing (garage, basement, etc) and run the blower door once the house is rocked, but long before complete and before the attic is blow in.

    We just did this on a couple houses and we impressed that we got them down from 5 to 3 air changes with not much effort. I have some larger houses coming up that we are going to do this with. Everyone involved has skin in the game so we are working together to try and find a way of doing this without breaking the bank. I am a bit humbled by it, its really significant change in residential construction.

    As always, I'm just in it for a good time, nonetheless, I feel like we are on the cutting edge. Never thought I'd see the day, I remember way back when when I bought my first blower door and everyone thought I was weird. Well now look, everyone wants to be my friend.
    I will never buy a Nissan Cargo Van.

  2. #2
    Join Date
    Jul 2004
    Location
    NOLA
    Posts
    4,018

    Default Re: 2012 IECC and Hope

    Any photos Ted, would be interested in how you are making it happen.

  3. #3
    Join Date
    Jul 2008
    Location
    Suburbia (Washington, DC area)
    Posts
    1,932

    Default Re: 2012 IECC and Hope

    That's a great idea. The un-installed doors are a big hassle!

    I had a chance to talk with a couple of non-boutique raters and builders last week. The raters say a lot of houses are failing, usually not by a whole lot.
    They are using the performance path of IECC to rejigger things so the buildings pass.
    (E.g. add more insulation in the attic, now that counts as a little bit of a "plus" which can overcome a small "minus" in air leakage.)

    The builder is working on townhouses, mostly; they are using their last 2009-code homes as tests, trying to hit 3 ACH even though it is not required. They say it's very challenging and they haven't hit it before the test yet. The problem is the common walls, they told me.

    It will be interesting to see how things go out there!

  4. #4
    Join Date
    Nov 2004
    Location
    Boston, MA
    Posts
    4,613

    Default Re: 2012 IECC and Hope

    Doug,

    Couple things I hope you can comment on because I know you are under 2012 there.

    Where is the trade off in the code for the 3 air changes? I don't see it, is it a MD amendment?

    Also, why are the townhouses exempt? I thought low rise was low rise, attached or not, so why do they get a pass on 3 air changes? We carry 4 blower doors for attached houses, sometimes a 5th. Our testing is guarded.
    I will never buy a Nissan Cargo Van.

  5. #5
    Join Date
    Jul 2008
    Location
    Suburbia (Washington, DC area)
    Posts
    1,932

    Default Re: 2012 IECC and Hope

    Townhouses are not exempt, people are still working on houses that were permitted before 2012 came into effect here. They're running out of those so they are trying to be ready for the ones that will have to meet code.

    I believe if you use the performance path, you model the house using code provisions, it says your total energy use is "X".
    You can change around everything, add insulation here, make the house tighter or looser, and as long as your changed model has a lower energy use than "X", you meet code.
    This is similar to the old ResCheck, but some software (including RemRate which you surely use all the time) allows you to set the ACH50 so you can include it in your sinister machinations.

  6. #6
    Join Date
    Nov 2004
    Location
    Boston, MA
    Posts
    4,613

    Default Re: 2012 IECC and Hope

    I've looked at the Performance Path but from what I see you still need to meet the mandatory sections in the front of Chapter 4 which includes the air tightness...I'll check again.
    I will never buy a Nissan Cargo Van.

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