GBlist: Ventilation per John Bower

John Salmen (terrain@seaside.net)
Tue, 11 Mar 1997 07:31:12 -0800

The argument for air tight structures is a reasonable one if the goals
as John Bower succinctly gives us of energy efficiency, comfort, and
moisture control can be functionally and consistently realized in all
applications of air-tight design. This is where the design model breaks
down for me and in my work I consistently feel that I am doing nothing
more than 'bumper design' which is what you do with an object that is an
inappropriate design for its purpose - such as cars, which despite the
safety manual, law enforcement and the fact that the operator was
trained, have an unerring tendency to crash into things.

Energy efficiency has been shown to be compromised as a result of
moisture retained in walls that dramatically reduces r-values of most
insulations (speaking of 'bumpers' wool insulation would be a cost and
energy effective alternative - it actually produces a couple calories of
heat when moistened, is healthy and has a lower production and env. cost
than glass). Moisture laden structures are also subject to deterioration
and the increased maintenance and replacement costs need to be
considered as an energy cost/value.

Comfort, other than your basic thermal kind, is a factor of health and
we have been sadly inundated with studies linking deteriorating health
to air-tight structures and the materials and processes used to create
them. This is an unalterable byproduct of the initial design regardless
of the amount of source control in material specification. Healthy
materials may have a lot of resilient properties but at this point there
usage is token or cosmetic. Our code structures in an attempt to achieve
and enforce some of the measurable efficiency goals or to offset their
drawbacks, or simply to accomodate problems of affordability are
increasingly dependent on manufactured components - the net effects of
which we simply cannot predict in day to day usage and these are the
components that will be used in the bulk of affordable structures.

My biggest concern with air-tight design is that it has become the god
to which all our time and resources are given - and in turn it has
created the specifications that drive the industry leaving little room,
resources or even vocabulary for the development of more applicable
design models that tamper less with the health of the end occupant.

I do not believe the public is dumb but I don't think that unless poor
health requires it the public will choose (or be able to afford to) to
effectively participate in a technological maintenance structure for
their homes.

John

John Salmen
TERRAIN E.D.S
terrain@seaside.net
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