My car is a 2010 XK Coupe 5.0. I've been driving recently with the A/C recirculate mode turned on. The outside temp is around 90 degrees. I notice that after around 15 minutes or so, the recirculate mode turns off on it's own. I manually put it back to recirculate and it will always turns off and back to automatic. Is this normal in our cars? Thanks all.

 

Yes , my 2012 did the same.

 

If I understand correctly, (RTFM, I didn't), the Recirc system was designed for congested areas and traffic where the designers figured they didn't want the excess emissions and such from the said traffic congestion entering the environmental system of our Jags. I always thought it was to keep cool or warm air inside the vehicle, but I guess not. Fresh, CLEAN air is far superior to Recirculated, as far as car designers go.

 

And it's quite handy when following a diesel, a worn-out rice burner, or an older hot rod.

 

I know in Auto mode it does what it wants. Especially if the defogger comes on, the recir is turned off.

 

I believe its to control the humidity in the car. It does seem to be higher than other cars. (perhaps cause i dont use it daily)

It does it on the heater too.

 

Thanks, I thought it might be the normal function for the a/c. It is annoying to keep putting it back on, but who is going to want fresh air these days??.

 

Found this from Toyota that explains it well.

What causes condensation inside a vehicle?

One or a number of the following things could cause condensation inside the car:

• Wet clothes/shoes/pets – water on these items will slowly evaporate into the cabin air or, if heavily soaked, cause the seats and carpet to become wet.
• Breath – when you or your pets breathe, that exhaled air contains a large amount of water vapour which is released into the cabin.
• A water leak.
• No circulation of fresh air.

Are new cars more prone to condensation build up?

Modern cars have much better seals, meaning they tend to be more water tight. This means that it’s more difficult for any air inside the vehicle to get out.

If movement is created with a fresh air source, moisture levels will decrease. Well-sealed and insulated newer cars means this movement cannot happen.



Increased insulation also allows modern cars to stay warmer longer after being parked; the longer the air inside the vehicle is warmer than the air outside, the more condensation will appear on the cold windows of the vehicle.

How can I reduce condensation in my car?

As condensation collects in the air inside the cabin, the level of moisture will increase. If this air is not vented to the outside then the condensation problem will increase.

The most efficient way to remove moisture from the air is to use the vehicle’s air conditioning system. This system draws air from the cabin through an evaporator, which causes moisture in the air to condensate in a controlled way and drain out of the vehicle.

If the cabin air is not regularly refreshed then condensation will accumulate, as the moisture-filled air will not be removed. However, you can force this by changing the re-circulation feature from internal to fresh air.

 

Press and hold the re-circulation button for about 5 seconds and release. It will stay on after that.

 

In the frigid northeast we always understood the "recirculate" button to be to heat the car more qiuckly, as it keeps reheating the same air through a heater. (I suppose the same would be true of AC on a brutally hot day) I can attest that it works as advertised-- and it made sense that it was designed to turn off automatically. I never thought of the "keep the world out" function.

 

That is an interesting concept. Every car with climate control that I have ever owned has only automatically switched to recirculate to cool the car down as quickly as possible so I wonder why they don't use it to heat quickly as well? Maybe it would fog up too quickly due to the moister air?

At least my last three Jags have had air quality sensors as well but I have never seen them switch over e.g. when sitting behind a stinky diesel.

 

That's exactly how my 2013 XJ works. The short press displays "Timed recirculation on". Press and hold the button and the display shows "Latched recirculation on".

I haven't driven my XKR in a while and don't remember if there are any display messages like my XJ. I'll have to check later.

 

Yes, that is how to activate the recirculation mode. I hold it in for a few seconds.....However, it will always switch back to automatic on it's own within a certain time period, usually within 15-20 minutes on a very warm day.

 

Yes, that is how I activate it.....however.....It will not stay in the recirculate mode indefinitely. Usually, on a very warm day, it will switch back to automatic on it's own.