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By the way, I think the Green Builder Advisor is one of the best sources for builders there is. There is a lot of free stuff, but I think I'm going to renew my subscription for their premium service, I think it is worth it. $149/yr.
By the way, I think the Green Builder Advisor is one of the best sources for builders there is. There is a lot of free stuff, but I think I'm going to renew my subscription for their premium service, I think it is worth it. $149/yr.
Allan,
It is a good article.
So.... which ventilation strategy do you plan to use on your next house in Houston?
I am planning on using Zip Wall, Icynene, OVE, creating a tighter envelope. So ERV has great interest. And as Martin advises, a dehumidifier.
At last week's builder show, one of the top Dupont guys tried to tell me the Zip Wall was too tight, doesn't allow the house to dry properly. I was going back and forth between Huber and Dupont, I thought those guys were going to rumble it got so disagreeable.
My assembly is going to be Zip Wall-Stucco Wrap-foam-Grade D paper-3 coat stucco. Huber offered to have their scientist analyze this assembly for me. (Do they have scientist on staff :)
John B, what do you think, isn't an ERV a no-brainer for our climate? How do you size these. Aren't they being required in Austin?
As Joe L, says "build tight, ventilate right".
Ok,
Since you posted your question first
I think for the meantime NO HRV or ERV is the best choice.
Supply ventilation with a controller will be best for most GOOD homes.(our climate)
Extremely tight and well insulated homes (sim to Passivhaus) I would say HRV with a stand alone dehumidifier.
Last edited by John B; 01-24-2010, 08:47 AM.
Reason: added our climate
I went to a seminar by Steve Easley, this guy is also very good on Building Science. He said in doing analysis, the two areas that always leak air, even in well constructed homes, are at the top and bottom plates.
Define "extremely tight and well insulated". Why HRV rather than ERV.
I would say to justify and pay for an HRV/ERV..... the enclosure should be good enough to elminate the need for our (Texas)conventional Forced Air system.
If the enclosure is any less I would just say throw another PV panel or 2 on the Bar-bee
Maybe I should not speak for Houston on the ERV question
I think you should look at every day/ hour of the year....
Some days and some hours those HRV's and or ERV's are working against us and they should be bypassed.
I would say to justify and pay for an HRV/ERV..... the enclosure should be good enough to elminate the need for our (Texas)conventional Forced Air system.
If the enclosure is any less I would just say throw another PV panel or 2 on the Bar-bee
Maybe I should not speak for Houston on the ERV question
I think you should look at every day/ hour of the year....
Some days and some hours those HRV's and or ERV's are working against us and they should be bypassed.
John
I’m a recovering “don’t give a flip about energy efficiency builderâ€, so you might have to get a bit more basic. If we eliminate the conventional Forced Air system, what is it replaced with? And what is the source of fresh air to replace the stale inside air in a tight house?
I’m a recovering “don’t give a flip about energy efficiency builderâ€, so you might have to get a bit more basic. If we eliminate the conventional Forced Air system, what is it replaced with? And what is the source of fresh air to replace the stale inside air in a tight house?
Allan,
We can not properly ventilate without mechanical forced air..... When I say "conventional" I am talking about recirculating air systems.
Passivhaus homes do not recirculate air like "we"(Texans) do.
They heat (or cool) the incoming air stream.......This may be hard to wrap your head around.
It is more of a one way flow..
It will only work in a mild climate or with a very,very good enclosure.(think Passivhaus standards)
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