Force recirculation to stay on?

Whenever I wonder about the behavior of my SE's controls and that behavior isn't discussed in the Owners Manual, I google for the same info about BMWs. Here's a BMW forum thread about the recirculation button shutting off when it feels like it. Unfortunately, there is no solution described, just confirmation that BMW designed it that way.

 

I believe you can change this behavior using Bimmercode. I haven't personally done so on my car, but I did see it and it appears to do what you want - "Automatic Air Recirculation" - enables/disables the Automatic Air Recirculation function.

EDIT: There appears to be a companion setting called "Air circulation setting memory" - "Enable/disable storing of the air circulation setting. If this function is active, the last used air circulation setting will be restored during the next start of the car."

So you'd probably have to set that one to Active and set the Automatic Air Recirculation to Not Active to make sure the car doesn't change anything.

 

That's what I read too - but it NEVER kicked on or stayed on, even when the outside air was terrible. In my car recirc stays on for 5-10 minutes in the winter time, and a lot longer for summer and fall. Not sure what's guiding the decision making (temperature, humidity?).

 

In an SE, seriously? Mine won't stay on for more than 15 seconds.

 

Its been talked about here, maybe two months ago, in terms of following a smokey diesel truck. There wasn't anyway to extend recirc besides hitting the button again and again. Annoying when following that truck. Someone was going to look at Bimmercode but the thread just died, I think, without resolution. My 2022 is 5 to 10 minutes more or less.

 

I would put a little poop emoji sticker on the button and call it "pedestrian fart defense mode."

Over the past couple days I monitored my recirc and it has not turned off on its own. I wonder if your sensor is broken?

 

Brrr. 40F on September 1st. Lol. I've been living in Texas for too long. I grew up in Virginia but even 40F in September was unthinkable there.

 

I tested yesterday with temperatures in the high 60s, shuts off after 15 seconds or so.

 

Mine was set about the same, slightly higher fan speed.

 

I did another test on my home commute, the recirculation stayed on the entire trip (40+ miles, over an hour). I don't know what magic is behind it, maybe it has to run for short periods for a number of times before it works normally?

Here are the environmental conditions during my test:

Temperature: 80 ºF
Dew Point: 54 ºF
AQI: 32
A/C: Automatic, 74 ºF, fan speed medium low​

 

Its possible the AC goes into max mode when the difference in indicated interior temperature is much more than the desired set point. Or when the outside temp is high, or when there is a lot of sun. AC max modes typically use recirculate and, in some conditions, don't increase fan speeds. If BMW uses the same fresh air strategy as other car makers, recirculate will cycle off now and then to let fresh air in, the change in vent temperatures that result seems to annoy drivers.

Long term recirculate when its cold enough out tends to lead to condensation and frost on interior windows. I dunno how effective the Mini is in keeping the interior of windows free of condensation and frost. If its weak I could understand a recirc limit, but 15 seconds seems too short.

 

There's a separate AC Max control. When I did my test that was off, but my recirculation stayed on until I stopped the car. @Carsten Haase I suggest trying it a few more times (maybe separate drives) and see if it eventually stays on. Every time I tried my recirculation it would shut off after 15 seconds or so, until this last time when it stayed on indefinitely. Maybe there's a "burn-in" period of some sort after being newly-built? Could there be some sort of residue inside that's causing it to shut off until that's eventually blown out?