Q I have a metal sliding glass door that freezes shut in the winter. Any advice on how to prevent this?
A Unfortunately, there’s no inexpensive solution to this problem except to lower the humidity level inside your house. Metal is a good heat conductor, so it cools rapidly in cold weather and provides an ideal surface for moisture to condense on. The colder it gets, the more condensation builds up and the more likely it’ll freeze your door shut.
Condensation commonly occurs when warm humid indoor air strikes cold windows, leaving moisture on the glass (and metal frame in your case). When thermostats are lowered at night and the temperature drops, condensation increases. Ideally, as the day warms up, the door should warm up and dry within a few hours with the curtains open.
To reduce your indoor humidity level, run bath fans while showering and kitchen fans while cooking, and reduce the number of house-plants. If that strategy doesn’t work, or your indoor humidity is already low, increase air circulation by leaving curtains open. Set a forced-air furnace so the fan runs continuously until the condensation problem stops.
If nothing works, consider replacing the metal door and frame with a more energy-efficient one.
