It seems that sometimes when you’re driving in cool, wet weather, it’s hard to keep your windshield from fogging up. The wiper blades wipe the windshield but they leave streaks. The outside of the windshield is clean but the inside is all fogged up. What is the best way to keep your windshield clear in cool, wet weather?
Keeping your windshield clean and clear depends on a few systems working together:
- Windshield wipers
- Heating and air conditioning system
- Windshield defogger (defroster)
How systems work together to keep a clear windshield
While it may seem obvious that the windshield wipers, the heater, and the windshield defogger need to operate, air conditioning is also an important factor. Air conditioning does more than provide a cooling effect inside your vehicle. It also removes moisture from the interior, whether the air temperature inside is warm or cool. The drier air helps prevent the inside of your windows from fogging up in any sort of weather conditions. Air conditioning works especially well in combination with the defogger to not only dry the fog from the inside of the windows but to remove it from the cabin altogether.
The windshield defogger blows air directly on the windshield from the dash when the heater controls are set to the defogger setting. The air movement "dries" the moisture from the windshield, and clears the windshield for improved visibility.
The heat from the defroster also melts ice and snow on the windshield to allow the wiper blades to clear the windshield well. Some vehicles are also equipped with a couple defroster lines where the windshield wipers park to assist in melting ice and snow from the windshield in that area. That way the wipers don’t get stuck to the glass and can continue to clear the windshield properly. In that way, the wipers work better with the defroster activated.
This article originally appeared on YourMechanic.com as Do Wipers Work Better With the Defroster On? and was authored by Jason Unrau.