When a car has been sitting in the heat is it good or bad to open a window while using your AC - to 'vent' the heat?

Answer 1

It is always better to roll down the windows. One thing is it will let the hot air out very quickly and thus allow the inside to cool quickly. Also when heated up the car dashboard and the airfreshners produce toxic benzene, which if inhaled can cause serious health hazards. So keeping the windows will let the toxic gas out and it will be much safer.

I don't know whether this is good for the car or not, but I always do this. I believe it makes the car cool much faster. Even if it's 90 degrees outside, it may be over 100 degrees in the car, and the hotter air will want to move out. Also the AC's fan will help to cool the car. I often leave the door open until the AC starts putting out cool air.

I would say that it would be a good thing, the reason being that in hot weather the heat outside and the extreme cool air on the inside of the car could cause a window to implode or at least break due to the change of air pressure in the car, so cracking the window open will allow the cool air to push the heated air out of the crack in the window instead of building pressure.

Temperatures in a car will not cause a window to break!!! It will not harm the car. Yes it is quicker to cool off the interior of the car because the hot air has a place to escape while the cool air is trying to cool down the inside. If your extra fan(s) on the engine are working it does pull more air across the radiator to help compensate for the extra work the engine is doing for the ac. I personally found my cars engine overheating when I turned on the ac one summer, but it was only because the extra fan was not working. In this case it was only a blown fuse. After replacing the fuse it worked great!! Air conditioning is also a dehumidifier if you find steamy windows, try the ac and it should help. Cars will steam up too if you have the fresh air vent shut too long.

It's not a question of good or bad as neither really applies. It's a question of efficiency and comfort. The air conditioning system in any modern vehicle is designed to work in conjunction (and hopefully, harmony) with other basic systems found in/on the vehicle. Water pump, radiator, heater core, coolant, etc.

When attempting to cool off the interior of a car that has been sitting in the heat for a while, just do the following. 1. Roll down a window or two or leave a door open before starting the car. 2. Allow the engine to run for a minute or two before turning on the air conditioning. 3. Make sure the �system� is set in the �fresh air vent� position instead of the �recirculation� position. 4. Once you feel the air from the vents start to cool, roll up all of the windows except the driver�s window. (If you have power windows, obviously you will have more control over this situation, but I don�t want someone with manual roll-up windows reaching across the vehicle to roll up the passenger side window while driving.) 5. Drive the car until you can feel the interior start to cool. 6. At this point, move the selector from �fresh air vent� to �recirculation,� and roll up the (remaining open) window.

NOTE: Most cars air conditioning systems will benefit from being �drafted.� (having one window open about 1/8 of an inch. This also increases defroster efficiency.)

Windows in automobiles do not implode or explode from changes in temperature. Other factors would have to be involved.

ANSWER windows can break from temperature changes generally they wont when cooling car with a/c crack a window about 1/2 an inch when u first start. switch a/c on and let it do its thing when car has cooled from a/c close window if car is sitting in sun and u set to fresh air, all you are doing is bring in hot air from outside. if you want to cool it use your a/c that is what is for

ANSWER

The owners manual for my Dodge truck suggests that you should open the window when you start your vehicle to let out excess heat. When the interior temp is close to the outside temp and the air conditioner is blowing cool air, then close the windows. Some vehicles like mine, don't have a recirculation switch, it's automatic. This is to allow the fan to draw cooler air from the floor area to be recirculated through the air conditioning to further cool it. Without the recirculation on, the fan will draw hot outside air into the air conditioning and it won't cool very much. Opening a window when the air conditioning is on will only draw out the cooled air from inside. This effect also happens when the recirculation switch is not turned on and the cooled air is drawn out through the hidden vents that all cars have. For those vehicles with a recirculation switch, it should come on automatically when the air conditioning is turned on or you have to do it yourself. Most air conditioners i have seen, blow through the interior vents and not on the windshield (which would only heat the air from the glass), so windows breaking is unlikely.

NOTE: I have seen a windshield shatter in the winter, when the heater was turned on only after the engine was warmed up. The extreme difference in temperature (- 20 outside vs +70 from the heater) and scratches from a diamond ring from someone wiping the fog from the windshield was the cause.