I never know which to use, cold or hot, to defrost my windshield. Before anyone suggests the obvious, yes, I know to use hot air when the windshield has ice on it. Say it starts to rain after you've been driving for half an hour, and the rain does not appear to be subsiding anytime soon. It has caused your windshield to fog up; do you use hot or cold air with the defroster? Also, if you could please answer the question in regards to any other relevant scenario; I just never know when to use which. Thanks!
2007-08-12 16:51:09 · 14 answers · asked by Curtysaurus Rex 2 in Cars & Transportation ➔ Other - Cars & Transportation
Warm to hot, you trying to dry out moisture on the INSIDE of your windshield during spring to fall, and hot in the winter to melt moisture,(ice, snow), on the OUTSIDE. No question is stupid, just the rude crap that answers people who have a sincere question.
2007-08-12 17:00:39 · answer #1 · answered by Anonymous · 5⤊ 1⤋
Most vehicles now route defroster air through the air conditioner, so you get dry air over the windshield whenever you use the defroster. This causes the windshield mist to clear very quickly.
The problem I've found with this arragement is that using cold air from the defroster during warm, humid weather actually causes mist to form on the outside of the window.
The answer is to use an intermediate setting in warm weather, balancing comfort against vision- I usually err on the side of vision, for safety: I set the control just warm enough so that mist doesn't form on the outside.
2007-08-12 17:11:09 · answer #2 · answered by Beaugrand 3 · 1⤊ 0⤋
Put the selector on the defrost setting. Use hot air. When you turn on the defrosters, it will also turn on the AC. This is to remove moisture from the air, and use the heater to warm up the air. Hot air can hold more moisture. So now you have hot dry air blowing on the windshield. That is the quickest way to remove the fog on the glass. That is unless you have a rag or paper towels on the front seat.
2007-08-12 17:22:21 · answer #3 · answered by Fordman 7 · 3⤊ 0⤋
Hot is generally better, because hot air is generally drier than cooler air because it's less dense. If you have air conditioning, always use it with the defroster, even with the heater on. Many cars automatically activate the air conditioning when the defroster is on because air conditioned air is much drier than ambient air and it clears the windshield and other windows much faster. In fact, my Neon has such a system, and it can't be overridden. Defroster on = A/C on. Also, you should always use outside fresh air to defrost the inside of the car rather than setting your system on "recirculate". Check your manual for this if you're unsure of how to set it. Recirculated air in the car gets progressively more humid because of your breath and your body. The more people in the car, the worse it gets. Humid air will never defog a window.
2007-08-12 17:02:47 · answer #4 · answered by Me again 6 · 3⤊ 0⤋
When it's cool and rainy or warm and rainy, turn the AC on and select the temp that works best. Too cold and you'll see moisture forming on the glass just above the vents. Turn the temp selector towards warm a bit until the moisture disappears. Some cars don't have a seperate button for the AC and they automatically select the AC when you go to defrost. The AC helps to get the humidity down and dry quicker. However if the inside of the glass is significantly cooler than the outside in rainy weather you'll get moisture forming just above the vents. Just have to adjust the temp for best clearance.
2007-08-12 17:03:23 · answer #5 · answered by mustanger 7 · 0⤊ 0⤋
If it is a really cold day, turn on the defroster immediately. That way the first air won't be very warm at first. You risk cracking your windshield if you let the air get hot before it hits the cold windshield.
2007-08-12 19:42:46 · answer #6 · answered by Linda B 2 · 1⤊ 2⤋
Supposedly cold air out of the air conditioner is very dry which decreases condensation on the inside of the windshield. If you have ice on your windshield you need warm air at first then switch to cold once its clear. Ok, I lived in south carolina..very humid...cold air! I also lived in the mountains...very very cold....warm to defrost the ice, then cold to keep the fog off the inside...even though its FREEZING.....which also sucks...which is why I MOVED!!
2007-08-12 17:02:00 · answer #7 · answered by jillianszoo 2 · 1⤊ 0⤋
I always use hot. If your windows fog up, the heat will help to remove moisture from the car via evaporation. I don't think cold air would work as well for that.
2007-08-12 16:57:39 · answer #8 · answered by Anonymous · 0⤊ 0⤋
hot air it will dry up any of the moisture in the air like a clothes dryer it is steamy for a few minutes and then will dry
2007-08-12 16:59:01 · answer #9 · answered by Anonymous · 1⤊ 0⤋
That's an interesting question!
2016-08-24 11:55:54 · answer #10 · answered by Anonymous · 0⤊ 0⤋