[GSBN] Can bale buildings be air tight?

[Chris Magwood]

Thanks all!

John, it's good to hear that the range to aim for is between 1-2 ACH at 50. 
I wasn't sure where the Passive House number came from, but I was 
attempting to get there just because I've talked to so many PHers who 
have told me there's no way to get there with bale walls, and especially 
not with clay plasters. But if we're in the right zone to be a good low 
energy house, then I'm happy with that!

Chris

On 12-11-13 8:02 AM, John Straube wrote:
> Well done Chris!
> Although it seemed possible in theory (at least I always said so) it 
> is great to get some real confirmation to be definitive.
> Getting to 1 ACH at 50 is a real accomplishment in any housing type.
> A tiny bit of air will likely leak through some earth plasters 
> (especially if they have straw in them) as we now have found that a 
> tiny bit of air leaks through some plywood and OSB. Maybe 0.2 or or 
> 0.3 ACH at 50 worth.  This is not really a performance issue, but it 
> happens.
> It is hard to get to 1 ACH at 50 without really good windows, so you 
> likely have those (casements in Canada tend to be good, double hungs 
> in the US are routinely leaky).
> It is also important to remember that there is nothing magic about 
> 0.6ACH at 50, it is just a number someone picked.  While tighter is 
> always better, as I speak to more people at the edge of advanced 
> housing and they gain experience the more it seems that numbers 
> between 1 to 2 ACH at 50 look like a good spot to be.  There is almost no 
> benefit to going from 1 down to 0.5 and there starts to be some odd 
> effects (like challenges with exhaust range hoods, bath fans etc) as 
> we get to the 0.2 to 0.6 range (effects we have learned more about as 
> people target those numbers).
> Suffice it to say, you have shown that you get as tight as needed for 
> a low-energy, healthy and comfortable home, even in very cold places.
>

-- 
Chris Magwood
Director, Endeavour Centre
www.endeavourcentre.org