What does "Max A/C" do?

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So, I know it used to be "recirculate" but my Focus has these Buttons "A/C" "Recirculate" and under them "Max A/C". So if it is on recirc, and I hit Max, what does it to exactly?
 
Maybe that's the secret eject button
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I'm not sure what it could be other than recirculate. I've never seen recirculate and max a/c together. My truck has the max a/c setting and I know for it, max a/c is just recirculate.
 
MAX and recirculate are the same thing.

it recirculates the cabin air,doesn't let fresh air/out side air in,it's easer to keep cold air cold vs cooling warm/hot air from out side.
 
Max should turn the fan on full blast, probably just to the dash vents, recirculate for full cooling power. Be empirical: try putting it on a few different settings of direction, fan speed & recirculate and then hit MAX!!!!! to see what happens.
 
Recirc can be used in any setting. Max ac saves hitting an extra button, I think.
 
Our Accord has the same setup.

Hitting max ac turns on recirculate. Hitting recirculate does not change it over to max ac.

Who knows. But from here on out, I'll think of Max Power every time I hit that button, so life is a bit better now.
 
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MAX does not allow the compressor to cycle and keeps the rec locked. Good for cooling down the car but, should not be used continually because the evaporator can freeze up.
 
From the Ford Focus owners manual, although it doesn't describe the difference between Recirculate and Max very well.

11. Recirculated air: Press to activate/deactivate air recirculation in the vehicle. Recirculated air may reduce the amount of time needed to cool down the interior of the vehicle and may also help reduce undesired odors from reaching the interior of the vehicle. Recirculated air engages
automatically when MAX A/C is selected or can be engaged manually in any airflow mode except (defrost). When the ignition switch is turned off and back on, the climate system will return to the recirculated air mode only if the A/C button LED is illuminated and the air distribution selection is either (panel) or (panel/floor).
12. MAX A/C: Distributes recirculated air through the instrument panel vents to cool the vehicle. This re-cooling of the interior air is more economical and efficient. Recirculated air may also help reduce undesirable odors from entering the vehicle. Press the MAX A/C button again for normal A/C operation.
 
Originally Posted By: Eddie
MAX does not allow the compressor to cycle and keeps the rec locked. Good for cooling down the car but, should not be used continually because the evaporator can freeze up.


Totally absurd. I have used that setting on every car I've ever owned that had it labeled as "Max" instead of "recirc". That setting stays there 100% of the time for at least 10 months of the year.Freeze up indeed......
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When you live in deep South Texas there is no other setting unless you desire to soak the seats with sweat. I'd think someone from Florida would know better than to post such drivel.
 
Originally Posted By: Eddie
MAX does not allow the compressor to cycle

Variable displacement pumps don't cycle, all others DO or you would have freeze ups.

that stament is crazy....
 
Originally Posted By: Nick R
So if it is on recirc, and I hit Max, what does it to exactly?

What does the owner's manual say?

Typically, Max A/C will set your fan to the highest setting and will turn recirc on.
 
I always understood that MAX A/C and RECIRC were NOT the same thing at all. In "traditional" systems, the MAX setting would cause the compressor to run all the time (or cycle on more than it would have) whereas the RECIRC setting would simply keep outside air our and inside air in. Note well that you can use the RECIRC setting in the winter to keep warm air in and various noxious odors/fumes out. RECIRC may come on automatically in many cars when MAX is selected, but that does not make them the same thing.

In the newer automatic systems, the need for MAX is reduced. Set the temp you want, and let the system sort out how to get there ASAP. I would note, however, that my Camry has an "ECO" setting which would seem to be the reverse of traditional MAX. It causes the variable speed compressor to run at a reduced setting, thereby drawing less juice off the traction battery. The manual contains a note to the effect that AC effectiveness will be reduced on this setting. I typically use it, and find that only on the hottest and sunniest days does the AC fall behind. It does raise an interesting question, though: if you want to cool your interior from 120 down to 80, you gotta do it one way or the other. As any good physicist will tell us, there's no "energy free lunch".
 
In my Camry, MAX and RECIRC do essentially the same thing. MAX is at the full cold side of the temperature dial. If I move it down to MAX, the RECIRC LED illuminates, to indicate that the system is in RECIRC mode. If I move the temperature dial back "up" one notch to simply full cold, the RECIRC LED goes out, indicating that I'm getting outside air.

I can also request RECIRC mode by pressing the RECIRC button. And, if my A/C is also on and at the coldest setting, this would be the same as me turning the temperature dial down to MAX.
 
Originally Posted By: ekpolk
In the newer automatic systems, the need for MAX is reduced. Set the temp you want, and let the system sort out how to get there ASAP. ... As any good physicist will tell us, there's no "energy free lunch".


Using MAX to maintain a cold environment should be more economical, and it wouldn't be a "free lunch" in this case. You're cooling air that is already cooler than ambient, so you're asking for less of a heat loss. I run using MAX A/C often, simply because it's more efficient to cool 70*F air to 50*F than it is to cool 90*F air to 50*F.

Getting down to a comfortable temperature from a heat-soaked car, I agree that it would not make a difference which mode you used; you'll have to cool it off from 140*F anyway, regardless of how you do it.
 
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