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Why is recirculate the default for AC

Our 2 2017 vehicles do this. Not hard to turn it off, I imagine I could change it somewhere, but I have never used recirculate, why is it the default?

None of my 3 are that way. One of those has automatic climate control…

Do your 2 cars have automatic climate control? Mine will seemingly start at recirculate to get maximum cooling then transition to vent once the temp get close to the setting. But only when very hot.

Maybe your cars default to recirc to cool the car down quicker. Cool the volume of air you have rather than pass a continuous volume of hot air through.

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I suppose it is automatic climate control, kind of you set a temp but have to push the ac button if you want cooling on the GM, and the Toyota. My 2 thoughts, maybe it increases gas mileage, or owners can be impressed by how quickly the car cools. I have never left it on long enough to see if it turns itself off.

I’d have to go look at the wifes car, But

On my Ford I have 2 A/C settings
A/C = Fresh air
MAX A/C = Recirculate and closes a valve in the heater hose

Do they have display screens with menus?
May be buried in the options.
Year, make, model might be helpful.

2017 Toyota Rave, 2017 Acadia limited. I have not delved into the menus, just curious why recirculate is the new default.

Probably because it’s easier to keep air that’s already in the vehicle cool than to continuously cool off warmer outside air? I could easily be wrong.

Last summer while my Corolla was in the shop I rented a 2019 Corolla. Automatic temperature control would only work if I had the air coming through the dash vents. If I set the control to split the air flow between dash and floor it disabled auto temperature control. Beats me why.

It won’t be that way in December. The A/C control module is selecting recirculate in order to cool the interior to the temperature that you selected.

If you set the the temperature to “Low” and not to a reasonable temperature like 70 degrees, the the system will remain in recirc mode.

I have only had 6 vehicles with A/C. None of them had Automatic climate control, all had outside air as the default setting and some of them would turn off the recirculate setting if you engaged defrost. It was sort of fun to see the big rotary knob on the PT Cruiser move by itself.

Why wouldn’t you want the air conditioner to recirculate the air? That’s how your home’s air conditioning works. It’s more effective and efficient.

@Barkydog - I haven’t seen an automatic climate control that requires turning on the a/c. Are you sure you have it in “auto” mode? I get in lots of cars where they have been switched to manual mode.

On my 2013 F150 with manual AC, it does default to recirculate.
On my 2006 Mustang, default is recirculate off, unless Max is selected.

It is maybe just a quirk of mine, I like the concept of fresh air.

So do I, until I drive past the landfill or a cattle feed station. Fortunately, there is no shortage of fresh air in most cars, and I can wait until the car cools down to switch over to a fresh air supply.


A home has a much larger volume of air, and it’s not sealed airtight.
Without some outside air coming in a car you’d suffocate before too long.

2019 Honda Accord in “auto” climate setting would show it is in “recirculate” mode most of the time, but it turns it off every few minutes to vent the cabin.
I was also alarmed at first why it is a “new norm”, but then noticed climate control computer is quite smart in what it does.

… and BTW, Honda’s climate control sucks big time to compare to my older 2012 Nissan Altima, as your cabin gets overly cold when it is sunny and overly warm when it is not… Altima was compensating for all of that and I never had to fiddle with controls of supposedly “automatic” climate control


I never had to touch my '96 ES300, winter or summer. I’m always fiddling with my 2011 MKZ…

I’m pretty sure the recirculate mode allows some outside air into the cabin.

Also, I’ve never been in an airtight car. I’ve never even seen a watertight car, let alone an airtight car.

I’d love to get one of those airtight cars. Which models are they? Being airtight and watertight would sure come in handy if the car is ever submerged in water.

I do believe some fresh air is introduced when in recirculate mode, just not sure why recirculates the new norm in my experience.

Clearly, it varies from make to make, and model to model. The automatic climate control on my friend’s Rav-4 always defaults to “recirculate”, but the climate control on my Outback does not do that.