A/C vs. MAX A/C
08-10-2012, 09:40 PM
#21
I understand what you mean when you say that MAX recirculates and cools the existing air in the cabin. That's easy enough to understand. What would really be helpful is to see some kind of video demonstration that shows all the parts up close and what they're doing as you toggle between regular A/C and MAX. Then I could SEE what's happening and understand the difference.
Last edited by djr7572; 08-10-2012 at 10:06 PM.
08-10-2012, 10:14 PM
#22
Well let me see if I can make this drawing from the workshop manual make sense...
The air on regular AC will be coming from under the cowel, which is the plastic between the hood and windshield through number 8 on this drawing. On MAX AC the air flows from inside the cabin through number 10. The air is then directed through the evaporator core (the part that cools the air with AC running) then the temperature blend door decides weather the air goes through the heater core to heat the air or not to let it stay the temp it is through the evaporator (cold if the AC is not, outside temp if not). Then the air goes through the doors that are moved by vacuum motors to either 3 (panel), 20 (defrost) or 17 (floor).
The thinner black lines are the doors, and the dashed lines between them represent the door moving. So the two thin lines connected by the curved dashed line isn't actually two doors, it's just the two (or three on the one door) locations it can be in.
The only thing that actually movies when you change from regular AC to MAX AC is the door between 8 and 10. On regular AC it blocks off 10 so air flows from outside through 8 and on MAX if blocks off 8 so the air flows through 10.
The blower motor also kicks it up one more notch on some vehicles, but not all.
I know it's not a video, but I hope you can figure it out from my explanation and the picture how the airflow works. Ask if you want me to explain something more specifically.
The air on regular AC will be coming from under the cowel, which is the plastic between the hood and windshield through number 8 on this drawing. On MAX AC the air flows from inside the cabin through number 10. The air is then directed through the evaporator core (the part that cools the air with AC running) then the temperature blend door decides weather the air goes through the heater core to heat the air or not to let it stay the temp it is through the evaporator (cold if the AC is not, outside temp if not). Then the air goes through the doors that are moved by vacuum motors to either 3 (panel), 20 (defrost) or 17 (floor).
The thinner black lines are the doors, and the dashed lines between them represent the door moving. So the two thin lines connected by the curved dashed line isn't actually two doors, it's just the two (or three on the one door) locations it can be in.
The only thing that actually movies when you change from regular AC to MAX AC is the door between 8 and 10. On regular AC it blocks off 10 so air flows from outside through 8 and on MAX if blocks off 8 so the air flows through 10.
The blower motor also kicks it up one more notch on some vehicles, but not all.
I know it's not a video, but I hope you can figure it out from my explanation and the picture how the airflow works. Ask if you want me to explain something more specifically.
08-10-2012, 10:39 PM
#23
Senior Member
Maybe I'm still missing something, but if MAX A/C is the ideal way to use your air conditioning, then why aren't vehicles just made that way by default?? Why is there even a choice of "regular/normal" and MAX?
Do you recall the old Cheech and Chong movie where they were smoking grass in a car with the windows rolled up?
Check out the 1:00 minute mark here.
On "Regular" you can smoke and still keep the windows closed, and keep the heat out.
If your passenger has bad BO the fresh air will make the stench less obnoxious.
And some people just like the idea of fresh air coming in, especially with a full vehicle.
But, starting and running the AC on "Max" is always the cheapest and most efficient way to go. The compressor runs less overall.
08-11-2012, 07:04 PM
#24
Well let me see if I can make this drawing from the workshop manual make sense...
The air on regular AC will be coming from under the cowel, which is the plastic between the hood and windshield through number 8 on this drawing. On MAX AC the air flows from inside the cabin through number 10. The air is then directed through the evaporator core (the part that cools the air with AC running) then the temperature blend door decides weather the air goes through the heater core to heat the air or not to let it stay the temp it is through the evaporator (cold if the AC is not, outside temp if not). Then the air goes through the doors that are moved by vacuum motors to either 3 (panel), 20 (defrost) or 17 (floor).
The thinner black lines are the doors, and the dashed lines between them represent the door moving. So the two thin lines connected by the curved dashed line isn't actually two doors, it's just the two (or three on the one door) locations it can be in.
The only thing that actually movies when you change from regular AC to MAX AC is the door between 8 and 10. On regular AC it blocks off 10 so air flows from outside through 8 and on MAX if blocks off 8 so the air flows through 10.
The blower motor also kicks it up one more notch on some vehicles, but not all.
I know it's not a video, but I hope you can figure it out from my explanation and the picture how the airflow works. Ask if you want me to explain something more specifically.
The air on regular AC will be coming from under the cowel, which is the plastic between the hood and windshield through number 8 on this drawing. On MAX AC the air flows from inside the cabin through number 10. The air is then directed through the evaporator core (the part that cools the air with AC running) then the temperature blend door decides weather the air goes through the heater core to heat the air or not to let it stay the temp it is through the evaporator (cold if the AC is not, outside temp if not). Then the air goes through the doors that are moved by vacuum motors to either 3 (panel), 20 (defrost) or 17 (floor).
The thinner black lines are the doors, and the dashed lines between them represent the door moving. So the two thin lines connected by the curved dashed line isn't actually two doors, it's just the two (or three on the one door) locations it can be in.
The only thing that actually movies when you change from regular AC to MAX AC is the door between 8 and 10. On regular AC it blocks off 10 so air flows from outside through 8 and on MAX if blocks off 8 so the air flows through 10.
The blower motor also kicks it up one more notch on some vehicles, but not all.
I know it's not a video, but I hope you can figure it out from my explanation and the picture how the airflow works. Ask if you want me to explain something more specifically.
That definitely helps, thank you
08-11-2012, 07:30 PM
#25
Senior Member
If it just recirculates the air then why have a Max AC button and a recirculate button?
Most cars you either have a Max AC button or a recirculate button but not both because they both do the same thing. "recirculate the air"
Most cars you either have a Max AC button or a recirculate button but not both because they both do the same thing. "recirculate the air"
08-11-2012, 07:31 PM
#26
Originally Posted by O2brich
If it just recirculates the air then why have a Max AC button and a recirculate button?
Most cars you either have a Max AC button or a recirculate button but not both because they both do the same thing. "recirculate the air"
Most cars you either have a Max AC button or a recirculate button but not both because they both do the same thing. "recirculate the air"
08-11-2012, 07:35 PM
#27
Senior Member
Originally Posted by me1234
In my 2000 there is no recirculate button.
On my 2012 Edge Sport I just have recirculate.
Totally confused as to the benefit.
08-11-2012, 07:36 PM
#28
Originally Posted by O2brich
In my 2012 FX4 I have both.
On my 2012 Edge Sport I just have recirculate.
Totally confused as to the benefit.
08-11-2012, 07:39 PM
#29
Meaner than ymeski56
Originally Posted by O2brich
In my 2012 FX4 I have both.
On my 2012 Edge Sport I just have recirculate.
Totally confused as to the benefit.
08-11-2012, 08:41 PM
#30
Senior Member
In my neck of the woods, plenty of people burn leaves so if I'm driving down a road that has leaf smoke, I roll up the windows and put it on recirculate until I'm through the smoke. Then I don't get smoke in the truck.