MAX AC

[wax87]

Other than turning the fan to HIGH, does anyone know if the MAX AC button does anything else?
If you hit the MAX AC button and then turn down the fan speed, the MAX AC remains illuminated.

Thanks

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[Ozarkbeard]

Other than turning the fan to HIGH, does anyone know if the MAX AC button does anything else?
If you hit the MAX AC button and then turn down the fan speed, the MAX AC remains illuminated.

Thanks

Recirculae engaged, if not already. It may also increase compressor speed, but not sure.

If you hit Max A/C again (to turn it off), it should return the fan speed to what you had it set on previously. This is using Manual mode. I don't know what happens when one uses Auto. I never use that setting because I don't like sudden unpredictable changes to the HVAC settings made by computer.

 

[Blue_Max]

It recirculates the air. Instead of repeatedly cooling outside air, it continues to cool the air already inside, and that's what makes it "max."

If you live in a high-humidity area (such as Florida, where I live), you use Max A/C all the time.

 

[MakinDoForNow]

Other than turning the fan to HIGH, does anyone know if the MAX AC button does anything else?
If you hit the MAX AC button and then turn down the fan speed, the MAX AC remains illuminated.

Thanks

It runs the system at max capacity using the the reduced fan speed. The ice will remain on to help satisfy the current needed for the condenser (someone posted that the condenser is 3 phase and had 36 volts usage which I have not verified. When I had my hybrid checked for possible coolant leak a long with a reprogram done which took 2 hours the tech had left the AC on max cool to keep the ice on, I was told). If you want to turn fan down just turn off max ac and auto will match fan speed to condenser speed and fan speed will be reduced with set fan speed limited to the set fan speed = win win.

 

[wax87]

Compressor speed? Because it is electric it can run at different speeds? Is it just two speeds or is it variable?
If I wanted to cool quicker, but not have the loud fan in the cabin, shouldn't I run MAX AC and turn the fans speed down?

 

[Ozarkbeard]

The Hybrid electric A/C compressor is variable speed, similar to the Mini-Split Inverter (DC) compressor Heat Pumps in my house. No OFF/ON or even two-speed of conventional compressors. Turn down the fan in the truck and the compressor can run at lower capacity (depending on several variables).

 

[inline_five]

Condenser speed? Because it is electric it can run at different speeds? Is it just two speeds or is it variable?
If I wanted to cool quicker, but not have the loud fan in the cabin, shouldn't I run MAX AC and turn the fans speed down?

Turn temp to LOW and let system figure it out. It should run ac compressor at max speed as long as you're drawing the cold away from the condenser. I wouldn't think MAX would run condenser at max rpm if you aren't taking the cold temp away by using the fan.

My experience with hybrid car a/c is it tends to be best to set it and forget it, ie set temp to low and max fan speed at first, then once car is cooling down set temp to desired and select head and foot vents. I normally run speed 3 on my Mav in summer highway driving.

Also, always use recirc.

 

[Baloo]

Besides recirculate it also, at least in the EcoBoost, drops the temp setting to 60 degrees.

 

[MakinDoForNow]

Condenser speed? Because it is electric it can run at different speeds? Is it just two speeds or is it variable?
If I wanted to cool quicker, but not have the loud fan in the cabin, shouldn't I run MAX AC and turn the fans speed down?

Raise your hood and turn on AC MAX go to front of truck And listen to condenser and ice running. Go back and turn fan speed down. Go back to front of truck and listen.. Set AC to auto and listen with temp set to 1° below ambient temp, listen, then set temp to 2° below ambient, repeat maybe in larger steps the condenser if it is variable speed will increase in noise if it needs to cool 20° more so than if it needs to only cool 2°. I normally use my ac on automatic with fan on 2 and if Its not keeping up I just increase fan speed to 3 or more. It might be worth high speed fan noise for 3 or 5 minutes to get temp down.

 

[wax87]

The Hybrid electric A/C compressor is variable speed, similar to the Mini-Split Inverter (DC) compressor Heat Pumps in my house. No OFF/ON or even two-speed of conventional compressors. Turn down the fan in the truck and the compressor can run at lower capacity (depending on several variables).

fascinating, where can I find some more in-depth details on this set up?

 

[wax87]

Turn temp to LOW and let system figure it out. It should run ac compressor at max speed as long as you're drawing the cold away from the condenser. I wouldn't think MAX would run condenser at max rpm if you aren't taking the cold temp away by using the fan.

My experience with hybrid car a/c is it tends to be best to set it and forget it, ie set temp to low and max fan speed at first, then once car is cooling down set temp to desired and select head and foot vents. I normally run speed 3 on my Mav in summer highway driving.

Also, always use recirc.

Thank you, I am not really asking how to operate the system, I am wanting to know the engineering principles and logic on how the system works.

 

[DWV]

It runs the system at max capacity using the the reduced fan speed. The ice will remain on to help satisfy the current needed for the condenser (someone posted that the condenser is 3 phase and had 36 volts usage which I have not verified. When I had my hybrid checked for possible coolant leak a long with a reprogram done which took 2 hours the tech had left the AC on max cool to keep the ice on, I was told). If you want to turn fan down just turn off max ac and auto will match fan speed to condenser speed and fan speed will be reduced with set fan speed limited to the set fan speed = win win.

You mean the "compressor" not the condenser! Yes the compressor is electric and uses 3 phase for efficiency and is a variable speed device.

The condenser is a radiator like device that is cooled by air flow and
"condenses the refrigerant from a gas back to a liquid.

 

[Markii56]

If you live in a high-humidity area (such as Florida, where I live), you use Max A/C all the time.

I live in the Tampa Bay area, and almost never use the recirculate; too many downsides. The only time I turn it on is when I can see construction up ahead with lots of dust and dirt.

 

[Blue_Max]

I live in the Tampa Bay area, and almost never use the recirculate; too many downsides. The only time I turn it on is when I can see construction up ahead with lots of dust and dirt.

What are the downsides to cooler, drier air?

 

[Markii56]

What are the downsides to cooler, drier air?

1) the air gets stale, especially if you're a smoker. 2) windows will fog up, even ice up in the winter in the colder climates. 3) Try wearing contact lenses in recirculate mode; they dry out and it feels like your eyes are full of sand.

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