If you have ever struggled in vain to defog your vehicle’s windows, you are not alone: Many people are unsure of the correct way to defog car windows. This is a real problem, because foggy windows significantly limit a driver’s visibility. Limited visibility leads to accidents.
The problem increases during the winter months, when snow, ice and cold temperatures make windows harder to defog. Understanding how to defog your car’s windows in cold weather may help protect you from traffic accidents this winter.
Why windows get foggy
You produce a lot of moisture from your skin, sweat and breath – even more when you are talking or singing. In rainy or snowy weather, you also bring moisture into your vehicle via wet hair, clothes and shoes. When the temperature inside the car gets warmer than the temperature outside, that moisture condenses on the inside of your vehicle’s windows.
How to defog windows in cold weather
In cold winter weather, it is almost always warmer inside your car than outside. Fortunately, most cars have equipment to combat this problem.
- With your car’s engine running, turn your heater up to the hottest setting.
- Engage the A/C button. Many people think this always means cold air; however, your car’s air conditioning system works to remove moisture from the air inside the vehicle.
- Disengage the recirculate button. The cold air coming in from outside contains less moisture than the warm air inside the vehicle.
- Crack open the windows to let the warm, humid air out and the cold, dry air in.
In addition to defogging, be sure to remove any ice and frost from the outside of windows (using a scraper or an alcohol-and-water spray) before venturing out in cold weather.