Why Do Car Windshields Fog Up?

Sep 18, 2018, 16:21 PM by Discount Auto Glass

What’s worse than running late when you're running out the door to be somewhere? Not being able to see through a condensation-filled car window when you’re already late. So why do car windows get foggy and what can you do to eliminate this issue? We have a few tips and helpful reminders that’ll get you back on the road in no time!

First things first, why do car windows fog up? When the warm interior of the car meets colder air, the glass surface creates condensation. Simply put, when there’s there too much water in the air it condenses on the inside of the glass, and when it’s too cold outside that lowers the relative humidity point.

So how do we eliminate interior window fog? The simple answer is that you need to reduce one or both of the conditions that are causing it. This can be done by either reducing the level of humidity or increasing the temperature of the windows. Most vehicles are programmed to turn on the air conditioning when the windshield defroster is turned on, which will dehumidify the air and clear the windows faster in most cases. Since warm air contains more moisture, it’s the humidity that you want to eliminate. Your air conditioner both cools and dehumidifies the cabin so even if it’s the dead of winter and you’re frozen to the core, let it run for a minute or two on the defroster setting.

One final pro tip is to use fresh air instead of your car’s recirculated mode when running the defroster. This will work to recycle and replace the moist air that was the cause of the problem as opposed to circulating the same moist air around the cabin.

Luckily foggy glass is a simple hurdle to fix on your own, but if you’re experiencing more severe windshield issues, come see our expert installers at Discount Auto Glass to find the best solution to your glass needs. Our team of glass specialists offer the best warranty and guarantee superior workmanship and professionalism. Get a quote or find your nearest location and stop by to see us today!

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