Originally published Washington Post in 2003, this Q&A from House Detective, Barry Stone is essential knowledge for every home owner.
DEAR BARRY: We have a split-level house and have had problems heating the downstairs family room. It just doesn’t get as warm as the rest of the house. This room is side by side with the walk-in sub-area, and we’re wondering if we should close the sub-area vents during the cold winter months. Do you think this would help to conserve heat? — Janet
DEAR JANET: Under no circumstances should you close the vents to your sub-area, especially during the winter. The purpose of sub-area vents is to allow humidity caused by ground moisture evaporation to exit the space below the building. Without adequate ventilation, this moisture will condense on the subfloor structure and may cause fungus, dry rot and mold. During the winter, ground moisture increases, and cold encourages condensation wherever ventilation is inadequate.
Some homeowners make the same mistake with attic ventilation, closing attic vents with the intention of conserving heat. This can also promote condensation and thus damage the roof and ceiling.
If parts of your home are not adequately heated, have the situation checked by a licensed heating contractor. The problem may simply be natural convection of downstairs heat to upper levels of your home. Ceiling fans could resolve that problem. You should also make sure the downstairs portion of the building is adequately insulated.
Barry Stone is a professional home inspector. If you have questions or comments, contact him through his Web site, www.housedetective.com