Do you find yourself fumbling aimlessly for the right air-conditioned settings when the windscreen fogs up? There is a correct way to defog the windows in your car and it’s handy to know how it works when the temperature starts to drop and the fog starts to rise.
Air trapped in a vehicle is usually warmer and more humid than the cold air outside. Windows and windscreens are usually cool from the outside temperatures so, as the warmer air gets in contact with the cool glass, the inside air temperature drops and so does its capacity to hold moisture. This results in water vapour (fog) on the inside of the windscreen and windows.
How to Clear Foggy Windscreens
Having clear vision is imperitive to driving safely. Here are three ways you can try to clear the fog from the car.
1. Air Conditioning
If your windows are ‘fogging up’, try leaving the air conditioning switched on with your heater set at a comfortable temperature. You’ll be surprised how quickly the fog clears. It’s also a good idea to turn the re-circulation off when using the air-conditioning and allowing a little fresh air in when possible.
Using your car’s demister function is an often overlooked way to clear the windscreen of condensation. In most modern cars the demister will engage the air-conditioner and the fan to force dry warmed air on to the windscreen.
In addition to the front windscreen demister, your car is also equipped with a rear window defroster. To keep the glass clear of condensation, the defroster uses an electric element to warm the glass sufficient to evaporate accumulated moisture. It’s a system that works as effectively as your windscreen’s defroster.
3. Keep It Clean
The oil, dust and other contaminants that build up on your windows gives water vapour more surface area on which to hold. A good car windscreen polish is the best way to clean the windscreen and help reduce the effects of condensation.
Clean glass reduces the amount of area these tiny droplets love, meaning your car’s glass will take longer to steam up in the first instance, and be quicker to clear with the methods above once foggy.