124 posts, read 139,226 times Odd question but am wondering about autos made in the last 15 years, how hot they are after say 1 minute or 5 minutes on a hot sunny day. Like Southern United States summer day. I was told by someone who has lived in Texas that the interior of your car will stay hot for +10 minutes after turning it on... that the AC can't quickly cool down a car that has been baking in the sun. I wonder this about the comfort of living in a place like Houston or Atlanta. Does your vehicle stay +90F until you're halfway home from work? Or does the AC make things comfortable within a minute or two of turning on the car? I feel really stupid for asking this. There are plenty of hot summer days where I live, but nothing like the South, and this winter has gone on for so long that I don't remember what summer is like. Most of my life I've owned vehicles without AC and hated driving on hot days. Any answers replied will have a significant impact in choosing what part of the USA to relocate to in the future!

26,339 posts, read 27,045,866 times 1,256 posts, read 2,002,087 times 8,840 posts, read 12,885,850 times Originally Posted by jambo101 I've always questions that recirc recommendation. If you do that then the AC has to cool 130 degree air instead of outside 90 degree air. ac window unit dimensionsI leave mine on fresh air and lower the windows a bit.air conditioner unit not cold 2,595 posts, read 2,849,865 timeswall air conditioner units installation Originally Posted by NHDave I'm thinking you need to evacuate the very hot air in the car at least for the first few minutes then you can roll up the windows and switch from recirculate.....ooops just realized i got it backwards Recirculate after the car has cooled down and fresh air setting to start the cooling process..

Originally Posted by cdelena Same thing applies to a home window A/C unit, always put it in window that gets minimal sun if possible. When I've owned 4 door cars I would roll the rear windows down when I first got in. That would drop the internal temp 20, 30, 40 degrees in a couple minutes. It also creates a bit of a vacuum to pull the cold air through the vents and out the rear windows. It's not as effective in my truck or coupe, but it still helps. Gotta get that hot air out. My 19 year old pickup takes several minutes before it really starts to cool. My GTO takes about a minute. Then it's a matter of getting all the interior pieces to release their heat. Our air/heater fan only blows air when it is set on high. It makes a hooting noise when it first starts like maybe there is something in the way. I have replaced the blower fan relay switch but that had no effect. These were all excellent. I had to replace both the resistor pack and the blower fan motor.

The video on youtube was great help also. + I definitely agree with the answer from rj713 and just want to add to it. Remember though that bad resistors can be caused by blower motors with a lot of mileage on them.They build up higher resistance and that extra draw can destroy resistor. replacing the resistor may solve the problem for the short time but may re-occur. If that should happen, you may need a new blower motor. To get to the resistor, open your glove box, squeeze in both sides and let it drop down. You should now see the resistor directly behind there. It is about 3" x 1.5" with a 5/16 screw on each end and two wiring connectors. (one big one small). There is also a thermal fuse that I would replace as well since you are already there and the price for it is minor. It is a thermal fuse that goes bad often. So you could replace that as well, but it needs to be soldered. for your resistor repair, there is a Video that will help you with it. the part is readily available at places like this Hope this helps, and I did not mean to bump rj713's answer, but can not attach images to comments.

I've had similar problems with my truck. You will find there is a resistor pack that divides voltage to the fan controlling fan speed. High speed bypasses the pack which is why it still works. The startup noise could very well indicate failing fan bearings--that could have caused the burnout of the resistor pack. The pack usually cost about $20 and is fairly easy to replace--look for it near the fan assembly. If you still have startup noise consider replacing the fan motor also or you will burn out the new pack eventually. Either buy a repair manual for your van or check one out from the Library and make a copy of the wiring diagram. Sounds like the fan bearing is failing.Recirculate versus fresh-air: Tom and Ray settle one family's bet. Mar 1, 2007 (Archives) You must be logged in to leave a comment. The obvious first component of an air conditioning system is the freon itself which is the work horse that carries the heat from one area to the other. Freon is a very efficient thermally conductive gas which simply means it can abosorb and release heat energy very effectively.

There are a number of different types of freon, but in automotive applications only R-134A has been used since 1995. Prior to 1995 R-12 freon was used, but was later banned in the production of new model vehicles due to it's ozone depleting effects when released into the atmosphere. R-134A isn't as efficient as R-12 in it's ability to transfer heat, but is environmentally friendly and much more cost effective to the consumer. The next major component is the A/C compressor, which is the pump that pushes the freon through the system. As the freon leaves the A/C compressor it is in a state of high pressure, hot gas. At this point, the freon enters the condensor which looks a lot like your cars radiator and is most often mounted directly in front of the radiator. As air flows across the condensor it gradually cools the freon down to make it condense into a high pressure liquid. The condensor is also the area where all of the heat that has been absorbed in the passenger compartment is released as air moves over it's cooling fins.

The next stop for our freon is the reciever drier, also called an accumulator on some systems. Both serve the same function but are located on opposite sides of the system. The drier or accumulator serves two main functions. First is it's ability to store liquid refrigerant. As we'll discuss in the next step, the freon will change states again into a low pressure liquid by way of a restricting device that in most cases changes the size of the restriction in the system based on demands of the system to keep it in equilibrium. The drier/accumulator gives that freon a place to hang out until it is needed further down the line. Reciever driers also serve another function in removing any water from the freon. Water and freon mixed together create a corrosive compound that will eat away at the metal components of the system, so it's important that it be removed. This is also why it's critical to change the reciever drier anytime the system has to be opened for any reason. The desiccant material inside the drier is only sufficient to hold a couple of drops worth of water which is an easily attainable amount from just the atmosphere when the system is opened up.

As the freon moves further down the system, it now enters the expansion valve. An expansion valve is a neat little device that acts as sort of the general manager for the entire system. As the high pressure liquid freon enters the valve it passes through an orifice that can vary in size depending on the demands of the system. The result is that the freon moves from being a high pressure liquid to a low pressure liquid. The expansion valve also acts as the over all pressure regulator of the system as it changes the size of the orifices where the freon is going into the evaporator core and the freon coming out of the evaporator core to maintain the optimum pressure at which the freon can most effectively do it's job. From the output side of the compressor to the orifice in the expansion valve is what we call the "high side", or high pressure side of the system. Once the freon leaves the expansion valve it flows into the evaporator core. The evaporator core is like a miniature radiator located in the air box behind your dashboard.

As the hot air from the inside of your car moves accross the core, the freon moving through it absorbs the heat to be carried away leaving you with crisp cool air inside the car. We also have another change in the state of the freon at this point. As it absorbs the heat, it moves from a low pressure liquid to a low pressure gas much like water evaporating as you heat it up. The freon then carries that heat out of the evaporator core, passing through the expansion valve once again (through a seperate low pressure passage). Lastly, this low pressure hot gas move out of the low pressure side of the expansion valve back into the suction, or inlet side of the compressor to start the cycle all over again. From the inlet of the evaporator core to the inlet of the compressor is what we call the "low side", or low pressure side of the system. In most cases it is considered normal to lose up to 1/2lb. of freon per year through sweating of the rubber hoses and losses at fitting connections.

When you consider that most automotive applications hold anywhere from just over 1lb. to 2lbs. of freon, you can see how your system can start to lose it's effectiveness relatively quickly. Courtesy Tire recomends having your system serviced once a year to ensure that you're not only maximizing the benefits of your A/C system, but the freon in your system also carries the lubricating oil for all of the components within the system and the less freon you have, the less oil is getting to critical components which can cause more costly repairs down the road. Your air conditioning system does more than just cool the inside of your car during the summer months. During the winter, your vehicle runs the A/C anytime you have the defroster on. Because a natural by-product of running the A/C is to pull moisture out of the air, running the A/C while blowing warm air accross your windshield will draw the moisture that created the "fog" out of the air making your defroster much more efficient at clearing your windshield faster.