I'm finishing the basement of my new house and had a cold air return question. The cold air returns for each room will connect to the furnace at ceiling level. Should the cold air returns still be near the floor or should they be at the same level as the duct work that connects to the furnace?
Answer:
Because cold air is heavier than warm, it is imperative that the return air grills be as near the floor as possible. For efficiency, they should also be on walls adjoining the ones that carry the warm air grills rather than opposite or on the same walls.
