Keeping the temperature comfortable inside your car may mean battling foggy windows. In order to reduce or eliminate the fog or condensation, you should try to adjust the temperature on the inside of the car to match the outside temperature as closely as possible. The reason for foggy windows has to do with temperature and the air’s moisture content. On a cold day, any moisture in the air inside your car, from passengers exhaling, snow on your boots, turns to condensation when it hits air next to the windows that’s below a certain temperature, called the dew point. The condensation is what makes your car’s windows appear foggy.
No matter if the fog is on the inside or the outside of your windows, any time you cannot see clearly in all directions, it is potentially dangerous. So, it’s important to know how to make sure all the windows are clear. When you’re dealing with cold weather outside and you turn on the heater inside your car, the fog typically will start to form on the inside of your car windows. To help defog the windows, turn the heat on its maximum setting, because hot air can hold more moisture. Then, turn the air conditioner on, which will pull the moisture from the air as it passes over the cooling coils. Finally, turn off the re circulation button so colder, dryer air is brought into the car. If possible, crack your windows for a couple minutes to help exchange the humid interior air for dryer outside air.
It is recommended to those who want to be warm while driving to turn on the defroster and blow warm air across the windshield to evaporate the accumulating moisture. If your vehicle’s ventilation system has a recirculate feature, turn it off. When this feature is on, your car’s heat reuses the air inside the car instead of continually pulling in air from outside.
Use your windshield wipers. This will help get rid of the condensation until you’ve balanced out the temperature. It will keep snow, ice, or frost from forming on the windshield, and impairing your vision. Trying to see through fogged-up windows can be a driving hazard. So make sure the windows are completely cleared before you drive.