Why do I have cold air drifting out of one of my heat registers (heat is not on)?
Is there some sort of convection drawing out the air sitting in the ductwork? There are no leaks in the duct. Trying to find out why my bath is so cold relative to the rest of the house. It is in the southwest corner of an ICF house which seems to me should be a warm spot.
Thanks, John
Replies
Second floor? Poor attic insulation? R-6 covering exposed to exterior temperatures?
Jeff
First and only floor. R38 attic insulation. What do you mean by R6 exposed to outside air temps? John
What do you mean by R6 exposed to outside air temps?
The insulation wrap for ductwork is typically on R6 when correctly installed (which is middling rare).
Ducts that are run in vented attic, behind kneewalls, in vented crawlspaces are functionally exposed to outside ambient temperatures.
That's "functionally" because those un-conditioned spaces can have a whole range of temperatures. Yesterday (Wednesday) my attic peaked about 93, and was above ambient (deltaT of 5º or more) for about 5 hours. Today, it was overcast, ambient never got much above 83º, attic peaked at only 87º, and then only for an hour. In a couple of months, my attic will head out to 20ºdeltaT's over ambient, and for 6-8 hours perday--not the best environment for ductwork.Occupational hazard of my occupation not being around (sorry Bubba)
Exactly. Cold air gets through the R6 and drops down the duct.
Jeff
Also keep in mind that no ductwork is "tightly sealed" unless you did it yourself during construction.
What is wanted is not the will to believe, but the will to find out, which is the exact opposite. --Bertrand Russell
Cold air gets through the R6 and drops down the duct
LoL!
Has not been "cold" air in my ductwork since February <g>. Brownian motion air currents would be mostly foiled from having all ceiling registers, too (being at the top of the convection air flow column).Occupational hazard of my occupation not being around (sorry Bubba)
Air goes in one register, out another.
Do you have a bathroom vent that automaticly turns on with humidity? That might be drawing the air in.
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
If your hair looks funny, it's because God likes to scratch his nuts. You nut, you.