Maintaining clear, clean windows is important when driving. If your car's windows fog up, it may lower your visibility and increase your risk of getting into an accident. While you can't control the humidity, there are ways to prevent your car's windows from fogging up, beginning with the five tips listed here.
#1) Don't Recirculate Air
Most automotive climate-control systems have a button or know that recirculates air throughout the cabin. When this button or knob is turned on, air doesn't escape the car's cabin. Instead, it recirculates without ever leaving the cabin. Recirculating air is usually a good idea if you're driving through an area with heavy smog -- or during the spring if you suffer from allergies, but you should avoid using it if you're worried that your car's windows will fog up.
#2) Avoid Using Heater During Winter
If possible, try to avoid using your car's heater during the winter. Windows typically fog up when the air outside of a car is cooler than the air inside of the car. This is because the moisture vapor inside your car's cabin is trying to balance with the less-humid air outside. By avoiding or minimizing use of your car's heater during the winter, you'll experience clearer windows.
#3) Use the Defroster
The next time your windows fog up, turn on the defroster. A component of your car's climate-control system, the defroster emits warm, dehumidifier air into your car's cabin and over the windows. Running it for just five to seven minutes should clear up most fog from your windows.
#4) Beware of Heater Core
If you're struggling to keep your windows clear, you may have a faulty heater core. The heater core is responsible for converting heat from coolant into warm or hot air. It consists of a series of tubes through which hot coolant flow. There's a fan in front of the heater core that blows air over these tubes to create warm or hot air. If your heater core is leaking, however, liquid coolant may drip into your car's cabin, creating a moist and humid environment that fogs up your windows.
#5) Use an Anti-Fog Product
There are actually products available that can protect your car's windows from fogging up. Known as anti-fog products, they contain a proprietary blend of ingredients that works to repel moisture. Just spray a light layer over the inside of your car's windows to prevent them from fogging up.