Here are a set of plans for a relatively easy to build Heat Recovery
Ventilator that should provide good performance and a good life.
An HRV pulls fresh air into the house and exhausts stale air to the
outside. In the HRV, the fresh and stale air pass through a heat
exchanger that recovers most of the heat remaining in the stale air to
heat the incoming fresh outside air -- thus providing a significant
saving in energy to heat the incoming air.
Thanks
very much to Paul in BC for digging up this article and mailing me a
copy!
DIY HRV Plans
This is an article that was published in the 80's and provides good detail on
building a Heat Recovery Ventilator from Coroplast sheets.
The HRV is not an easy environment for materials in that water and even ice
may be present at times. I think that the Coroplast sheets should stand up
well to this environment, but the plywood housing may have a limited life.
One suggestion I'd offer is to consider using Medium Density Overlay (MDO)
plywood for the housing MDO is a high quality plywood with resin
impregnated face sheets -- it is used for chemical tanks and concrete forms it
is quite durable and water resistant. Most lumber yards can get it -- it
costs about twice as much as regular plywood.
Tthe article is an excerpt from Solplan6: An Air Exchanger for Energy
Efficient Well-Sealed Houses by Robert Besant -- this was a set of plans that
covered both building the heat exchanger and also provided material on blower
selection. This set of plans used to be available for a small fee, but (as
far as I can tell) is no longer offered -- if you have any leads on finding
these (or other HRV plans), please let me know.
Note that this kind of ventilator will only be needed on a house that is very
tight. Most homes have more than enough natural leakage to provide fresh
air. Depending on the fans chosen, the ventilator will use a
non-negligible amount of electricity, so it should not be used unless your house
is tight enough to actually need the ventilation.
