e34 heating / ac controls

[gymkata]

I just read the owner's manual on how to use the AC / heating. The instructions don't explain it well in my opinion.
The 2 dials on the bottom control the dual zone setting.
What does the dial on top next to the middle vents that goes from red marks to blue marks on it depending on how you rotate it do?
Can anyone clarify?
:D

[Paul in NZ]

is this the thumb wheel in the middle of the vents?

[KenB]

You can mix heat into the air from the vents by pushing the wheel up towards red if the left main control is dialed to heat also.

[Yiorgos]

The dial at the upper middle are to change the temperature of the air coming out of those vents only.

This way, you can have heat going through the vents for your feet, and air coming through the top vents being cool for your face.

This is clearly explained in the user manual.

[gymkata]

The dial at the upper middle are to change the temperature of the air coming out of those vents only.

This way, you can have heat going through the vents for your feet, and air coming through the top vents being cool for your face.

This is clearly explained in the user manual.

I don't see how it's clear, but I'll doublecheck the manual about what you're saying. I've attached a photo to clarify what I'm talking about.
Supposedly if the dial on the left is turned all the way cool (left), it's off and you can control it from the top.

[Qsilver7]

I don't see how it's clear, but I'll doublecheck the manual about what you're saying. I've attached a photo to clarify what I'm talking about.
Supposedly if the dial on the left is turned all the way cool (left), it's off and you can control it from the top.
NO..that is not what the instructions from the manual is saying. The far left and far right DIALS control the temperature (that's all)...the middle DIAL controls the fan speed. The LEVERS control the air distribution...if they are pushed to the far left...then all of the air flaps are closed off.

Read the following link that has the instructions from the manual: http://www.bimmer.info/forum/showpost.php?p=111897&postcount=1

The upper ctr vents have a knurled temp dial in the ctr that controls the air temperature that blows from those vents ONLY. This is what BMW call stratified air. This system allows you to vary the temperature of the air from those ctr vents so that the driver can have cooler/fresh air blow in their direction to help keep them alert...and have warmer air blow from the floor vents or to the windshield to keep the cabin warmer for other passengers or to keep the windshield from fogging up. This "stratified" air circulation is great for long trips. It keeps the driver from having to roll the windows down and stick their head out the window to keep them awake.

Stratified Air is explained in the far right column from this page from the owners manual:

http://luuk.xs4all.nl/bmwboeken/bmwe34manual/pg33.jpg

Might as well throw this tibbit in too....HEAT never comes from the rear ctr vent (see last 2 paragraph in far right column in image above)...it only blows fresh ouside air or cooled "conditioned" air when the AC button has been intiated. So in the WINTER...please shut the dial to prevent from blowing cold air on the rear passengers. The HEAT for the rear passengers comes from the floor vents under the front seats!