Q. I live in a 1,000 square foot house to which an addition was added several years ago. The bathroom and bedroom in the addition are always cold, as they are the rooms farthest from the furnace.

If the duct is a standard size, remove the register and drop the fan into the boot. Secure it to the floor on each side with screws. If the duct is smaller than standard, see photos below. Plug the ...