A/C and MAX A/C

[Premium Speed]

I know how to be REAL economical, don't use the A/C. I don't, and I live in Texas! Besides, I always either have my windows rolled down or my top down.

lol...you need to come sit in houston traffic with me every afternoon.....

 

[mrvax]

It uses more gas to ride at highway speeds with the windows down than to use the A/C on low.

 

[GT-03]

It uses more gas to ride at highway speeds with the windows down than to use the A/C on low.

I think that is only true if you have a roof.

 

[Thundermouse]

you know.. like the heat that's transfered out from your car.
I have a little AC on my window in my room and if i go outside to the rear end of the AC, there's a radiator and a little fan that blows all this heat out. Isn't that the removed heat from the air that the AC sucks in? I dunno i may be completely wrong about this

No, you're right. Running the A/C is a heat transfer, and the heat inside your car won't just disappear, it has to go somewhere. So yes, you will build up more heat under the hood with the A/C on.

 

[YardSpecial]

When you get old, sit in traffic for 4 hours a day.

A/C is great !

If your car gets too hot, something is wrong............


Police cars use A/C all day long and never overheat.

I won't own a car without A/C now days, too much traffic.

 

[brodie2323]

Wow what a great post. I always wondered about this and never asked. Thanks to all those who gave insightful info.

 

[billyfe390]

Basically the heat is transferred to the refrigerent in your A/C system in cars it is R-134a or R-12 by the evaporator. The hot humid air either inside if set on max or outside if set on normal is circulated through the evaporator and the heat is extracted from it along with the moisture.

Here is how it the whole system works.
The low pressure vapor is then pumped into the condensor as a high pressure vapor. As it travels through the condensor it comes out as a high pressure liquid. It then travels through a dryer to remove any moisture inside the system then to the expansion valve. After it enters the expansion valve it is then transformed into a high pressure vapor which absorbes heat. There will be either a pressure switch, temperature switch or a variable displacement compressor in the system to cycle the compressor on and off. The vapor in the system can travel through the lines faster than the liquid and there is always a pressure differential between the two. If the high side pressure is allowed to build eventually somewhere in the system a line will explode.

 

[KLozeR]

Basically the heat is transferred to the refrigerent in your A/C system in cars it is R-134a or R-12 by the evaporator. The hot humid air either inside if set on max or outside if set on normal is circulated through the evaporator and the heat is extracted from it along with the moisture.

Here is how it the whole system works.
The low pressure vapor is then pumped into the condensor as a high pressure vapor. As it travels through the condensor it comes out as a high pressure liquid. It then travels through a dryer to remove any moisture inside the system then to the expansion valve. After it enters the expansion valve it is then transformed into a high pressure vapor which absorbes heat. There will be either a pressure switch, temperature switch or a variable displacement compressor in the system to cycle the compressor on and off. The vapor in the system can travel through the lines faster than the liquid and there is always a pressure differential between the two. If the high side pressure is allowed to build eventually somewhere in the system a line will explode.

lol that was hard

 

[5spd GT]

Max a/c vs. "plain" a/c...is similar to overdrive vs. drive...a lot of people automatically think that max a/c means more colder air...just like some people think overdrive gives you more power...

 

[twogts4us]

This is one of the best threads ever - I still wonder why they call it "max a/c"...? It's rather misleading.

 

[Black_Cobra]

I'm with Joeymatt on this one and I'm surprised some of you didn't know how your AC controls work .

BTW, did you guys notice that your AC kicks on a tiny bit when you use the windshield defogger? It does that to dry the air, so leave it off when you race.

 

[alfman9]

Max A/C is more economical for the compressor. It has nothing to do with gas mileage or the strain on the motor. A/C and Max A/C engage and cycle the compressor with the same regulator valve (the proper name leaves me at the moment) in the pressure line. Check out www.howstuffworks.com or take an ASE class.

 

[SilverStallion]

Is there a way that you should start your a/c if you have not used it in a while? I recall reading somewhere that if it is not working properly, there is something that you should run first for a few minutes prior to turning on the a/c - does that make sense?
Mine is not blowing cold from my 2000 GT...I can't recall where I read that suggestion.
Any tips?
~Darren

 

[alfman9]

I dont know if this is what you are referring to, but I was once instructed to never start a vehicle with the a/c on. I was told that "cranking" on the compressor would reduce its life span. I do know that on the computer climate controlled systems of GM, that the compressors do not engage for the first 30 seconds from starting the vehicle.

 

[twogts4us]

Starting the car with the A/C on puts strain on the starter motor, but I dunno about the compressor itself.

 

[ToplessStang]

You can start the car with your A/C on. The computer will only start the compressor about 10 seconds after the car is running.

 

[twogts4us]

I'm with Joeymatt on this one and I'm surprised some of you didn't know how your AC controls work .

BTW, did you guys notice that your AC kicks on a tiny bit when you use the windshield defogger? It does that to dry the air, so leave it off when you race.

It's not drying the air! It's cooling or heating the windshield (your choice) to try to match the air temp outside and prevent or stop the windshield from fogging. Also, I think it's known as a "defroster".
So much for knowing how your A/C controls work.

 

[GT-03]

It's not drying the air! It's cooling or heating the windshield (your choice) to try to match the air temp outside and prevent or stop the windshield from fogging. Also, I think it's known as a "defroster".
So much for knowing how your A/C controls work.

Are you sure? I am pretty sure that the windshield defroster setting ran the A/C system in order to dehumidify the air (that's drying the air) first, then passes the dryer, dehumidified, air through the heater core to warm it up.

Blowing warm dry air at the windshield does the best, fastest, job of clearing off any condensation (fog).

 

[Mustang5L5]

It's not drying the air! It's cooling or heating the windshield (your choice) to try to match the air temp outside and prevent or stop the windshield from fogging. Also, I think it's known as a "defroster".
So much for knowing how your A/C controls work.

Um, it's dehumidifying the air. Your windows can't fog up if there isn't any moisture in the air. Sure, the wamr or cool air will help, but taking the moisture out of the air (via the A/C) will work more efficiently at keeping your windows from fogging up.

Black_cobra is right

 

[Mustang5L5]

I dont know if this is what you are referring to, but I was once instructed to never start a vehicle with the a/c on. I was told that "cranking" on the compressor would reduce its life span. I do know that on the computer climate controlled systems of GM, that the compressors do not engage for the first 30 seconds from starting the vehicle.

Most vehicles have something like that. When you crank a car, power is killed to the compressor as well as most other accesories, only after it's started that power is returned and the A/C compressor can engage.

On the Mustang, the A/C will engage 5-10 seconds after the car is started if you start it with it on.