Fogging Up

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Jan 19 2016 / By DriveitHOME
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It’s that time of year again. Cold weather has descended on a large part of the country. Help your teen driver get prepared for whatever the elements might bring.

Here’s one that can flummox most adult drivers: window fogging.

It’s a common occurrence, but also a potentially dangerous one. Fog can block the driver’s view of the road and make a tricky driving situation—especially with snow, ice and slush on the road—even riskier.

Windshield fogging occurs because of the temperature and moisture difference inside of your car versus the outside. Generally, it’s colder and drier outside of the car than inside of the car, thanks to the heater, and the body heat and moist breath from the driver and any passengers in the car.

To use the defogger correctly, turn off the air-recirculating feature, if your car has it. On many cars, this button has an icon of a car with a curved arrow pointing to the right, but other cars may have a different icon, so check your car’s manual to be sure.

The air-recirculating feature is great in the summer to optimize the car’s air-conditioning, but in cold weather, it can actually make the fog situation worse by recycling all the humid air in the car. Pulling fresh air in from the outside and using the car’s heater to fog is the best bet.

Sometimes, fog will cover the window quickly and it may take a while for the defogger to kick in. The first thing to let your teen know is: don’t panic. It can be scary to have the window fog over and block the view of the road. Your teen may be tempted to wipe it away, but it’s dangerous to do while driving and it won’t last; the fog will creep back and the window will be streaked, making visibility worse.

Instead, your teen should pull over as quickly and safely as possible. The quickest way to dissipate fog is to use the defogger without heat or to open the windows. Since it’s cold outside, the blast of chilly air will take care of the fog by bringing down the temperature and humidity in the car, but it’s not very comfortable. Your teen should use this method only to clear the fog in an emergency. Once it’s safe to return to the road, your teen can use the method above to keep the windows clear (and stay warm).

Having a clear windshield and maximum visibility will help your teen contend with other weather hazards on the road, so make sure to keep this back pocket tip handy.

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