The A/C system in my mom's POS Malibu hasn't been working well lately. My dad took the car to the dealer to get the refrigerant recharged. Multiple mechanics there told my dad that running the A/C system in recirculation mode for an extended period of time will damage the A/C system because it puts more load on it or something. I say this is total BS and makes absolutely no sense. I always use fresh air when the inside of the car is still really hot, and then switch over to recirculate for cruising so I am cooling already cool air. Who is right?
Can using recirculate with car A/C systems hurt them?
- Thread starter Sukhoi
- Start date
I'm not a mechanic, but that makes no sense to me. Inside air is cooler than outside air once the AC has kicked in, so it should take less load to cool the air, not more. This is how the AC in your house or apt works, there is a big return duct that sucks inside air back in to cool it more.
Exactly. It makes no sense from a load point of view. The mechanic apparently claimed that it is harder for the blower motor to pull air from the inside of the car, then from the outside air intakes. I suppose this could make sense since those intakes are going to have dynamic air pressure from driving speeds, but I can't imagine it is a significant difference.
Humidity and temperature decreases, reducing the temperature load as well as latent load on the evaporator. If the load gets too low, i suppose the refrigerant can pass through the evaporator with some liquid portion left and liquid-lock the compressor.
That's the only possibly I can think of and I really think it's very unlikely.
That's the only possibly I can think of and I really think it's very unlikely.
They are idiots. Running the A/C on max simply recirculates the air, nothing else. And since the system is cooling air that is already cool, it has to run the compressor less.
The blower isn't "pulling" anything. It's an electric motor, and it's spinning. It happens to have a swirl cage fan attached to it that will move air if it's available.
That's it. It's just sitting there, spinning. You'll have more airflow if you have the mode door set to "fresh" or "normal", since the car's movement will assist the motor, but that neither strains nor eases the motor itself.
The blower isn't "pulling" anything. It's an electric motor, and it's spinning. It happens to have a swirl cage fan attached to it that will move air if it's available.
That's it. It's just sitting there, spinning. You'll have more airflow if you have the mode door set to "fresh" or "normal", since the car's movement will assist the motor, but that neither strains nor eases the motor itself.
Not unlikely, how about impossible.
Before the refrigerant goes through the evaporator, it has to pass through the orifice tube, which is where it turns into a gas.
When the pressure gets low enough on the suction side, the cycling switch will turn the compressor off.
What would happen if it didn't is the system would freeze up, not liquid lock.
The mechanics are idiots. In fact, on most of the cars I've owned, using recirc, it's actually considerably EASIER for the blower to pull air in, as it isn't pulling it through 2 feet of way-too-small ducting that they were able to cram into the dash. As others have pointed out, the difference would be that on recirc, you'd be cooling already cooled air - which I'm sure will have SOME effect on the dynamics of the cooling system... but shouldn't have any ill consequences.
I personally have no idea, but my mechanic told me the same thing once and my AC has been running great ever since. Also, it says in my owners manual to use AC with the fresh air. Doesn't make much sense to me, but I do it.
On my cavalier, if I set it to fresh air I have an A/C button that I can turn on and off. If I set it to recirculate, the A/C comes on regardless of where the button is pushed. If using the A/C on recirculate was bad then why am I foced to use A/C with recirculate?
The advice I've always received is the opposite.
You should always use your AC on recirc - if it's on fresh, all you're doing is pulling in hot humid air and cooling it. That way you get warmer air coming into the car, and your AC has to work harder using more fuel.
If you use recirc you're cooling already cooled and filtered air - so the AC can shut off part of the time.
You should always use your AC on recirc - if it's on fresh, all you're doing is pulling in hot humid air and cooling it. That way you get warmer air coming into the car, and your AC has to work harder using more fuel.
If you use recirc you're cooling already cooled and filtered air - so the AC can shut off part of the time.
Yep, makes no sense to me to do otherwise. I guess if the temperature of the air inside the car is hotter than the air outside it makes sense until the interior is at least as cool as the outside air, but otherwise, I always use recirc.
my mazda3 and it POS air conditioning system says something similar. Use outside air in normal conditions, and inside only when driving on dusty roads or for quick cooling of the interior.
Page 6-2 of the manual
Page 6-2 of the manual
if this were true, why the hell would GM have added the option? It's only been around for 10 years, if that.
and actually, running the AC is good since it apparently also helps keep the seals well lubricated. at least, that's what I read in my car's owner's manual.
And also, since it's hot outside during the summer, I'll have teh AC on most of the time anyway (unless I'm way low on gas, then I use the 5-55 method: 5 windows (sunroof
) @ 55 mph ). and when I have AC on, I also have recirc on (since it also helps keep bad smells OUTSIDE).
And also, since it's hot outside during the summer, I'll have teh AC on most of the time anyway (unless I'm way low on gas, then I use the 5-55 method: 5 windows (sunroof
) @ 55 mph ). and when I have AC on, I also have recirc on (since it also helps keep bad smells OUTSIDE).Your AC can freeze over, which I assume is the reasoning behind not using recirculate continuously.
Recirculating can cause your compressor to short cycle, and it will cause your condenser to freeze up, which will cause more short cycling. I only use recirc to cool down a hot car, then I go to fresh air or when I am passing through a dust storm or range fire.
AgaBoogaBoo
Lifer
- Feb 16, 2003
- 26,108
- 5
- 81
Not sure, but might want to check how hard it is to recharge it yourself. We did it on our Volvo today, second or third time actually, and it takes no more than 10 minutes!
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