By Barry Stone
Dear Barry,
When we bought our condo, the home inspector said we might have trouble with the dryer vent, and he sure was right. The laundry is located in the middle of our home, in a hall closet; so the dryer has to vent vertically, up through the roof. This causes two problems. The vent becomes clogged with lint, and moisture in the duct causes the ceiling to become wet. Can anything be done to correct this problem? - Bob
Dear Bob,
A vertical exhaust vent for a clothes dryer is typically problematic because it acts as a moisture condenser. The sheet metal duct, cooled by the outside air in the attic, causes the steam from your dryer to become liquid on the inner surfaces of the vent. Then two things happen: First, the water runs down the inside surfaces of the duct, causing wetness and possible mold wherever leakage may occur (such as your ceiling); and second, the moisture in the duct tends to collect lint, which forms an increasingly thick layer on the vent surface, thereby reducing the efficiency of your dryer. Vertical dryer vents should probably be prohibited by code, but unfortunately, they are not.
The problem originated when the designer of the building selected an impractical location for the laundry. The solution is to relocate your dryer to the garage or another area that is near an exterior wall. Then the dryer vent can be a short, horizontal duct, less prone to condensation and lint build-up. Otherwise, you may have to make the best of a bad arrangement. For alternate solutions, an appliance repair technician may be able to determine a practical upgrade, based upon an on-site inspection of your situation.
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