I noticed that our exposed sheet metal basement dryer duct gets quite
cold here in the frigid North -- acting like a "reverse" radiator when
the dryer is not in use.
Part of the problem may be due to the fact that their is no louver on
the exterior penetration (it goes through a window pane that has been
replaced with a sheet metal panel with integrated, un-louvered hood).
So, 2 questions:
1. Should the dryer duct be insulated and if so with what product?
2. Would replacing the penetration with something louvered be likely to
make a significant
difference (and be advisable)?
Interestingly, the intake/exhaust pipes on our high efficiency furnaces
don't seem to "radiate" as much cold despite also being unlouvered --
probably because they are PVC rather than metal and also smaller diameter.