GBlist: Ventilation per John Bower

John Bower (healthy@bloomington.in.us)
Wed, 12 Mar 1997 18:51:17 -0600

For the life of me, I can't see the advantage of loose construction,
except for the fact that you (supposedly) don't need a ventilating fan.
You've gotta have an air exchange, so you can either rely on Mother
Nature or you can mechanically ventilate. When relying on Mother Nature
to ventilate a loose house, the average rate may be just fine (something
that will be hard to predict while the house is being built), but at any
one time it's either feast or famine. Suppose you are having a group of
people over and the wind isn't blowing (or there is no stack effect).
What do you do, hand out fans? I think it's easier to flip a switch.

When you talk about a house breathing, think about an airplane flying.
The airplane flys differently than a bird, but both accomplish the same
thing. I think a house can PERSPIRE naturally (i.e. build a house
without a diffusion retarder) as long materials are selected carefully,
but then, natural perspiration probably isn't going to handle the amount
of moisture generated inside most houses. For the benefit of people, you
must provide an air exchange, so you need an air-pressure difference to
push air through holes (either random holes or deliberate holes). I just
think a fan does a better and more reliable job than Mother Nature.

-- 
John Bower, The Healthy House Institute
http://www.hhinst.com/    email: healthy@bloomington.in.us
430 N. Sewell Road, Bloomington, IN 47408
Phone/fax 812-332-5073
__________________________________________________________________
This greenbuilding dialogue is sponsored by Oikos (www.oikos.com)
and Environmental Building News (www.ebuild.com). For instructions
send e-mail to greenbuilding-request@crest.org.
__________________________________________________________________