We have several high efficiency gas furnaces. The furnace itself is cool to the touch as are the insulated ducts. The only warm-to-hot part is the sheet metal supply plenum that is uninsulated.
Since the furance is in our unfinished basement, it seems logical to insulate the plenum right?
- Would a water heater blanket work well to insulate the plenum?
- Any other suggestions for insultating material? (I know regular fiberglass batts are cheaper but I don't know if they are rated for contact with a supply plenum)?
Also as a related question, we have a circa 2003 water heater who outside is barely warm to the touch (if at all). Would there still be any measurably signiicant benefit to wrapping it in a water heater blanket or is it already well insulated enough?
Thanks!