Every winter we get phone calls from homeowners upset that they have water or frost on their windows or exterior door knobs. In some cases, this can lead to damage to walls, baseboards and window casings, and flooring. It is the homeowner’s job to control the humidity in your house, and winters in Edmonton can mean your humidity needs to be lower than comfortable in order to avoid getting water or frost on your windows.

Humidity is what we call the amount of water in the air. The water and ice you sometimes see on your windows in the winter comes from the warm indoor air coming into contact with a cold surface, which cools the air off. Cold air does not hold as much water as warm air, so the water collects on the coldest surface, and if it stays there long enough it will freeze into ice. Your windows are always the coldest spot in the wall, and doorknobs will sometimes get frosty because they are directly connected between the indoor and outdoor temperature.

If you do see frost or water condensing on your windows (usually at the bottom of the window at the edge of the glass), here’s how to get rid of it:

1. Turn down the humidity setting on your humidifier to its lowest setting. Try turning the humidifier all the way down and waiting a day or two until you no longer have condensation on the window, then turn it up gradually to the point where it just starts to form. This can be tricky, as the outside temperature and other indoor sources of moisture such as showers and cooking mean the amount of water in the air, and the amount of water the air can hold, are always changing.
2. Turn on your furnace fan and let it run continuously. The constant airflow around the window will keep the air moving so it can’t deposit its moisture on the glass. Some homeowners complain about the extra electricity useage from keeping the fan on continuously, but it is much cheaper to leave your furnace fan running than it is to replace damaged baseboard, casing, drywall, and flooring.
3. Make sure your blinds and curtains are pulled away from the window for as much of the day as possible. It takes time for the water to condense out of the air, so keeping the air moving as much as possible will keep your windows clear. Even if there is frost or water on the glass in the morning after leaving the curtains or blinds closed overnight, if you leave them open all day with the furnace fan running in most cases your windows will be clear by the time you get home from work.
4. Make sure there is nothing blocking your heat vents so you get as much air circulation as possible around your windows.

If you have a lot of water or ice on the windows, consider using a floor fan aimed at the window. Running a floor fan for a few hours will completely remove all the water or ice from even a badly-frosted window. NEVER USE A HAIR DRYER OR OTHER HOT AIR SOURCE TO REMOVE WATER OR ICE FROM A WINDOW IN WINTER. Using hot air to remove the ice might seem like a good idea, but the sudden temperature change can easily cause the window glass to crack, and make the situation even worse.

In our climate in the winter, we are constantly fighting the battle between condensation and comfort. You might find it is necessary to have a small amount of condensation at the bottom of your windows in order to keep the indoor air comfortable and healthy, but following the steps above will help you keep the condensation from turning into a problem.