I’ve just discovered that we have been air-conditioning the insides of the walls! Whenever any of the registers is closed, there are currents of cool air in the walls of the first and second floors. Is this normal?–or does it need fixing?
It isn’t just the wasted energy that bothers me. Besides fiberglas insulation and decades of dust, there’s asbestos in them thar walls.
For now, I’m keeping all of the registers open. That keeps the bedrooms too warm and the little-used areas too cold, but it seems safer than stirring up the stuff inside the walls.
Janet
Replies
Unfortunately, yes, it's "normal". That is to say, it's very common to have this serious defect in a home HVAC system -- probably more likely than not in some areas of the country.
(Though so long as these are interior walls, and they don't "communicate" with the attic or some other non-conditioned area, the defect isn't so severe -- the heating/cooling is not "lost", just misdirected. If it's exterior walls, though, that's a big problem from several standpoints.)
Leaking ducts should be sealed; the payback is quicker than almost anything else you can do for energy efficiency.
Sealing should be preceded by making sure, if possible, that the ducts are properly sized, including the return air pathway(s).
Check around to see if anybody in your area does aeresol sealing of the system. This method can seal even encolsed duct systems. Start with the link below.
http://eetd.lbl.gov/l2m2/aerosol.html
Aerosol sealing is new to me. Thank you for the link!
Janet