I have a Ford Escape 2014 and have a question about the climate "recirculation" button. This is the button that is supposed to enable the inside air to be recirculated.

On this vehicle this button has a 5 minute timer on it, meaning when you enable it, it stays on for 5 minutes and after that the AC starts pushing in outside air.

Now I would have thought that making this a simple on/off switch would have been a bit less effort.

Is there some practical reason why the recirculation has a timer, as opposed to just being an on/off switch?

  • Ridiculous feature. In California right now during fire season and I want to explicitly keep the recirc on but alas this awesome feature turns it off for me every 5 mins and let's the smoke in car. Lovely.
    – user43335
    Nov 17, 2018 at 1:29

6 Answers 6


I also have a 2014 Escape, and the reason for this is actually explained in the owners manual.

The section under "Recirculated air", on. p.104, says the following:

Note: Recirculated air may turn off automatically (or be prevented from turning on) in all airflow modes except MAX A/C to reduce risk of fogging. Recirculated air may also turn on and off automatically in Panel and Panel and Floor airflow modes during hot weather in order to improve cooling efficiency.

Also on p.105 the manual says the following under "HINTS ON CONTROLLING THE INTERIOR CLIMATE":

Note: Prolonged use of recirculated air may cause the windows to fog up.


Note: To reduce humidity build-up inside your vehicle, do not drive with the system switched off or with recirculated air always switched on.

I have not had a need for the MAX A/C setting that much, where I live. With most of the other settings, recirculated air shuts down after 5 minutes. If you have a need for heat (instead of A/C), try enabling both the "Instrument Panel" (button "H" shown on manual p. 103) and "Floor" (button "I" shown on manual p. 103) mode at the same time. This seems to keep recirculation on much longer.


My guess is to keep the a/c unit from icing up. By putting it on a timer you are inducing warmer air after 5 minutes.


My 2006 Honda Civic doesn't have such a timer, but the owner's manual says:

The system should be left in fresh air mode under almost all conditions. Keeping the system in recirculation mode, particularly with the A/C off, can cause the windows to fog up. Switch to recirculation mode when driving through dusty or smoky conditions, then return to fresh air mode.

So with an ordinary switch, you have to remember to turn off recirculation when it's not needed, or your windows might start to fog. If you have a timer, you don't have to remember.


It is recommended that in high heat that you use the max AC and recirc buttions. This will not time out and makes the vehicles AC system much more efficient and use less energy and have a smaller chance of overheating the engine.


In Texas recirculation is almost automatic in the summer. I've driven many miles this way with passengers and never any problem breathing


You can think of this as a safety feature. It is not recommended to keep the recirculation button ON for long time, specially if there is more than 1 person in the car. You will use up all the oxygen. The car body is not perfectly sealed, so the actual chances of you dieing inside the car is pretty slim. But you would still feel symptoms of low oxygen.

With this automatic turn off, the car will draw fresh air after 5 minutes.

  • 2
    I'm skeptical of this argument. Can you point to tests or computations (using reliable data about the rates of human oxygen consumption, etc) that show this is potentially significant? Jan 29, 2015 at 16:58
  • Agreeing with @NateEldredge ... This is one of the only cars I've seen with this "feature" where the recirc turns off automagically. If this was so important of a feature for the reason you stated, ALL vehicles would be mandated to have it this way. You are right, though, a car is not very well sealed, in fact most have permanent vents installed in inconspicuous places which allows the interior to breath quite readily. Jan 29, 2015 at 17:34
  • 1
    I could not find any direct sources for this. Check this site for example: nzta.govt.nz/resources/factsheets/24/fatigue.html Which advices you to turn to fresh air in long trips to reduce fatigue. Air has only 20% Oxygen. This will reduce gradually as you breathe and exhale carbon dioxide. This is the same reason why you have ventilation systems in elevators, or any small confined place for that matter.
    – rana
    Jan 29, 2015 at 19:50
  • @ᴘᴀᴜʟsᴛᴇʀ2 is right, Im pretty sure you cant die from lack of oxygen in a car its not a vacuum.
    – John Dream
    Mar 4, 2016 at 3:39

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