Foggy Windshields

This is a common culprit when the weather starts to cool down, your windshield fogs up. Most of us have had to deal with a foggy windshield before, but lets talk about why it fogs up, and the most effective way to fix this common problem. 

Fogging is caused when water vapour condenses on the inner surface of the glass on a windshield.

There are 2 ways this could happen:

• Air gets trapped inside your car form the previous day, and that air is more humid than the current air. Warmer air holds more moisture, almost double that of cold air. When the humid air mixes with the cold windshield glass it releases moisture which leaves condensation or fog on the glass.
• When we sit inside a cold vehicle, we are inhaling the cold air but we exhale warm, humid air. Every breath we take projects more humidity to the inside of the car, and this can also condense on the windshield glass, and cause fog.

There are 2 common strategies to clear the fog:

• When temperatures outside are above freezing and fog is created as a result of wet or damp people in the vehicle, run the air conditioner. Running it on cold will be most effective to reduce the fog buildup.
• A quick fix, run heat through your vehicles defrosters. This will help the condensation to evaporate, similar to the way a dryer uses heat. When you catch the fog begin building up on your windshield, and when temperatures are cold, this method is effective.

If your windshield is extremely foggy, you can use a dry cloth first help to clear the fog, and then turn on the air conditioner.