ctemkin

While reading through the manual, I noticed that there is a thumbwheel in the middle of the front air control unit which is identified as providing cool air. But I didn't see any explanation of it.

Does this override the thermostat settings? Does it just let in outside air, assuming that is cooler than the vehicle? Any guesses?

bmw2mb

this feature is to allow cooler air to be blow out from the dash...however, you will only notice it in a cold climate because it's mainly used with the heating system since a/c air is blown out the dash as well.

it does not change the temp in the cabin, however, when the heat is on, you can have adjustable cool air out of the dash while the heated air is blown on the floor.

i have not experienced this as of yet since i have not yet driven the car in winter. my x bmw had this feature and is a must feature in winter driving.

jim256

As I read the manual, and in checking how the blue wheel actually works this past winter:
1. The AC system must be in one of the manual override positions (using the buttons to select the airflow outlets) with or without the compressor on (AC OFF button)
2. Cool outside air does come out of only the center outlet while other outlets may be heating
3. It is operating on a servo, it is not a manual control for a door, so give it time to open or close.

bmw2mb

so in winter when the heat is on auto, does any cool air come from the center vents or does the cooler wheel have no affect?

jim256

I could not observe any effect when the system was in Auto.

e500

jim256 is correct. When full auto is selected no cool air will come from the center vents. All you have to do is turn the silver ring (air flow direction) one notch in either direction and then the thumbwheel can be adjusted to allow the amount of cooler air you desire. This only applies to the heat mode.

Damian L

my understanding is that instead of having to roll down a window, in the winter, to alleviate fatique you can open this fresh air vent. especially effective with rear passsengers.

ctemkin

Guys, thanks a lot for the info. I finally tracked down the reference to the thumbwheel in the manual. I had missed it earlier because it is under, of all things, heating. The above info is much more complete than the manual, too. One thing I noticed while testing it is that if you shut off the auto on one side but not the other, it appears to affect only the side where the auto is shut off. This lets you get cool air without protest from the passenger. A great feature.