I probably use A/C more in Winter than summer due to window fogging.
Before we go any further afield, I would like the OP to clarify one point with his son:
Does your son believe that the stream of refrigerated air for the car’s HVAC system… somehow… passes through the car’s engine?
Please verify his beliefs on this topic, and be prepared to send him to a class in basic car maintenance if he… somehow… believes that the refrigerated air for the car’s HVAC system passes through the engine.
That works on some cars - yours and probably others.
My 2007 Town and Country does not permit Recirc when in defrost mode. If it’s in defrost and I push the Recirc button, the indicator light on that button flashes briefly and the light goes out - indicating it is not in Recirc mode. The defrost button’s indicator light stays on.
I think Chrysler engineers’ preference for Fresh is that it cuts down on the retention and buildup of moisture in the interior - so the defroster works better, and other windows are less likely to fog.
Yes I had a couple of molars that would not let you adjust temperature in recir/max mode. Hated it.
Molar = Mopar = Chrysler product?
There is no problem adjusting the temperature in recirc/max mode on my 2007 Town and Country. It will not run in Recirc when in the defrost mode. That helps defrost and prevent frost or condensation on the windows. That’s OK with me. Works great here in MN and WI. What problem does it present to you?
Those were an 84 and a 91. The situation in Florida is the 95/95 weather. Run AC on max until interior is cold enough then leaving setting in max use temperature control to achieve desired temperature and drier air. On my Dodge and on the (company owned) K car adjusting the temp changed it to outside air bringing in the moisture laden air.
Just saw your correction! Yes, spellcheck changed Mopar to molar !!
Having grown up in WI and MN I surely wish I could spend May to October up there! Brained area please.
I agree, the evaporator chilling the air to around 40F effectively wrings the moisture out of it, that’s why there’s a puddle of water under the car in the parking lot when the AC is running. That’s moisture that was removed from the air in the interior.
Do you open the windows in your home when the AC is on?
There is a new kind of clothes dryer called a heat pump dryer, it recirculates the air in the dryer and the wet air that was blown through the clothes first gets cooled by the evaporator of the heat pump chilling it to around 40F which removes the moisture and then that chilled cools the condenser and becomes warm and very dry to be returned to the clothes drum to dry the clothes some more. No vent is needed, just a water drain pipe.
They are popular in Europe because of their energy efficiency and ease of installation in apartments and condos. They need no dryer vent to the outside.
Note, even in “recirculating” mode, a small amount of outside air still comes into the car, it’s just that the air coming out of the AC is not 100% outside air.
I use the outside air mode when the weather is cool and I’m not using the AC.
As others have said, the only difference for the engine is how hard it has to work to cool the air off in the cabin. In the summer, I typically leave it on fresh until the cabin is about the same temp as outside. My rationale is that if it’s 110º in the car and 90º outside, the AC will cool the outside air off more than the inside air.
In the winter time humidity and condensation (ahem) ‘cloud’ the issue, so things are a bit different, but since you asked about A/C i’ll Leave that to another thread.
Unless you drive around in one of the most underpowered cars in existence,as far as today’s motors are concerned, a driver can scoff at the idea of that driving an AC unit requires any attention what so ever as far as longevity is concerned.
To look at it another way, a typical gas engine on a mid range whole house generator produces less then 10hp and is required to run The whole house ac unit as just one of its many tasks. It does it for days at a time, for thousands of hours over its life time. You typically have a 150 to 300 hp car engine where providing current to run a compressor is an afterthought. It has no measurable effect on its life expectancy compared to how the driver actually operates the motor for propulsion while driving the car. One extra oil change during the life of a car would have a much bigger influence on wear imo.
After being without for about a dozen years I had my AC restored last summer. It was not cheap - everything needed to be replaced front to back but with leather interior and hotter, humid summers in my area I have no regrets. Anyway the mechanic recommended using recirculate pretty much exclusively. I looked in my manual (94 Suburban, front and rear air) and there is nothing specific against using MAX or recirculate all the time. The manual just says I will get maximum cooling from the setting without any parameters for its use. It does say that if the air conditioner develops high system pressure under the regular setting it will automatically switch to the MAX mode. This leads me to think there is less stress on the system while operating on REC or MAX but I could be wrong. At least it hasn’t really affected my already crappy gas mileage.