How to Defog a Windshield
Fog on a windshield can be either annoying or dangerous depending on how much condensation is on the windshield and how it affects your vision. Even if you use your car's air conditioner and defogger to get rid of the moisture, chances are it will reappear in a few minutes. The fogging is a result of the windshield on the inside being at a different temperature than on the outside of the car. If you want to eliminate the fog completely while driving, you need to get the inside air temperature close to the outside air temperature.
Other People Are Reading
Instructions
-
-
1
Allow fresh air into the car by cracking the windows open. The circulation of outer air alone will often be enough to defog the windshield without the heater/air conditioner. This might not be possible sometimes due to cold or rain, but installing vent visors on the windows can reduce problems like rain.
-
2
Turn the heater/air conditioner on to the maximum fan setting, set it to the "defroster/defogger" setting and start it at a warm temperature. The warm air from the vents will absorb the moisture on the windshield faster because warm air holds more vapor. However, it will also re-fog quickly, so you won't keep it this warm for long.
-
-
3
Reduce the temperature of the vents' air gradually. Get the temperature of the vents' air very close to that of the air outside the car so the windshield is the same temperature on both sides.
-
1
Tips & Warnings
Reverse the process if you are defrosting the windshield. Start up the vents with cold air until the frost is removed (since the frost is on the outside). Once the windshield is clear, turn the temperature up until it's at the right level to keep the fog away.
References
More Like This
Comments
-
Sharyce Newby The rainx outside is part of the problem with my streaky windshield when it rains. As long as I don't run the windshield wipers the rain beads up but if it's raining too hard to not run them then I get this streaky thing going on. I thought it was the wipers so I replaced them - not.
-
try a rain x inside defogger and rain x on the outside -works for me!
-
In the summer! AGH! I was afraid that would be the answer - I think I'll stick with running the windshield wipers. ;)
-
You're getting condensation on the outside because the air is humid and your windshield is cooler than the air. Try heating up the windshield instead of cooling it down.
-
My problem is not fog on the INSIDE of the windshield - it's on the OUTSIDE! I have to run the wipers all the way to work most mornings. What is wrong with this picture?
