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It is called condensation, warm and humid inside, cooler outside.

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โˆ™ 2010-08-15 12:58:56
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Q: Why do car windows fog up when the heat is not on?
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Why do car windows fog up in winter?

moisture from your breathing for example condensing on the cold glass

Why does sunlight energy pass through car windows but the energy radiated from objects inside the car does not?

sunlight passes through exciting the particles in the car warming it up. The heat is then in the air molecules which can't pass through the glass.

When is the defogger in a car is used?

When you push the button. They are not automatically engaged on most vehicles but there are newer models that have integrated moisture sensors that can detect fogging of the rear window. The system is designed so that when fog builds on the inside or outside of the rear window (typically but also side mirrors) the little lines that run through the glass are actually heat coils that get warm as electricity passes through them thereby "burning" off the moisture from the window, can also be engaged to warm the glass to remove ice in such climates that produce ice. The front windshield and side windows are also given a form of defogger or defroster, they are air driven via your vehicles heat and a/c system. when there is high humidity and the windows reach the scientific dewpoint the windows will get the moisture build up aka fog, the resulting combat to this is to engage your defogger/defroster air system, it will either blow the cold air from your hvac or the warm air from your hvac across the windshield and the mirror area of your side windows. the most common days that the defogger will be used is when it is rainy, usually in the afternoon or evening when the ambient exterior temperature has decreased but the humidity has remained constant or increased

Can you die of suffocation sleeping in car?

Technically speaking, you can not die of suffocation just by sleeping in the car. A car in not 100% air tight and oxygen keeps flowing in through the various opening in the car. These openings could include points where the brake and clutch pedals connect to the engine compartment, air vents, etc.However, under certain conditions, you can die of suffocation in the car. One of these condition is heat buildup. When you park your car in the sun with the windows rolled up, the heat entering the car gets trapped inside causing the temperature to rise considerably.If a car is parked in the sun with outside temperature of 90oF (32oC), the temperature inside the car could rise up to 140oF (60oC) because of the trapped heat. Normal body temperature is 98.6oF... At 107oF (42oC) we begin to lose consciousness and the body stops to function. Under these circumstances, the small openings discussed above are insufficient to prevent heat build up.REMEMBER: It could take as little as 10 minutes for this heat buildup to occur.Secondly, suffocation could occur if exhaust fumes build up inside the cabin of the car. As mentioned above, the car is not 100% air tight and if you have the engine running in an enclosed space like a garage, or if the fumes are somehow leaking into the cabin directly, it could lead to suffocation. A good term to search on the Internet in this regard is "CO (Carbon Monoxide) Poisoning."

What is the purpose of a heat exchanger in a cooling system water?

Similar function to a car radiator or an air conditioning condenser. The heat from the fluid is pressurized to build up heat. As it passes through the heat exchanger, the heat from the heated fluid is exhanged to the ambient air which passes through the cooling fins.

Related questions

Why do car windows fog up?

well it could be because of the heat. if its cold out and you have the heat on in the car, then you will get hot and that will cause the window to fog.

How do you fog up your car windows?

get a girl. get busy. TADA!! fog :)

Why do brand new car windows fog up inside in cold weather?

Windows fog because the glass is cold and the humidity is high inside the car. It has nothing to do with the age of the car. Try turning the fan up to circulate the air better, and if that doesn't work, turn the AC on -- but turn the heat up so it doesn't get cold. That will do it for sure.

Why do car windows fog up in winter?

moisture from your breathing for example condensing on the cold glass

Will the blend door failure cause windows to fog in a car?

No the blend door not functioning will not cause fog; it may however prevent the windows from being defogged or defrosted. If the widows only fog up when the defroster is on, then you either have a coolant leak in the heater core or your air conditioner compressor isn't working (the AC is used to dry the air when the heat is on).

How do you fog up car windows?

Well there is an easy way and a hard way, first, you could only do whatever it is you are up to in the winter, it will be colder and when you blow on the windows mist or fog comes up, or you could boil a kettle in their. Hope you got a backseat and a boyfriend or a girlfriend ; )

What would cause the windows on a 2003 Windstar to fog up in cold weather with the heat on?

Any type of moisture including your breath.

Why do windows fog up in 2001 Chevy Malibu heater core has been checked is OK?

If the heater core is ok, check to insure your ac unit is working. The ac works in conjunction with the heat when running defrost, and without the ac air windows will fog up .

Why do car windows fog up when making out?

Two people, breathing heavily. There's a lot of water vapor in your breath, and when two people are going at it they breathe a lot more causing more water. If it's cold outside, the windows fog up like crazy.

How do i clear steamed up car windows?

Rub them with soap then clear the soap of with a cloth or paper this will reduce the amount it wil fog in the future as well.

Why do cars warm up when there closed?

Cars warm up to a temperature higher than the surroundings because of the glass in the car windows. This is called the greenhouse effect. High-energy heat waves from the sun are able to pass through the glass of the windows, and this energy is absorbed by the materials inside the car, causing it to heat up. The glass does not let the less energetic heat waves being let off by the warm car pass through the windows. Therefore the heat is "trapped" inside the car, causing it to get warmer than the surroundings.

I have a 1992 Chevy blazer my air works but my heat doesnt....i hear the fan blowing but no heat comes in?

If your windows fog up you thermostat may not register because you heater coil may be broken.

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