Trickier HVAC question than it sounds.

[TXAVy]

Ok, I know someone is going to say that this has already been asked and answered but I'm not sure that we have the whole answer yet, so here goes.


What is the small round vent over the driver's head?


The popular and well accepted answer is that it's the temperature sensor for the HVAC system and includes a small fan that pulls the air in over the sensor.

If that's true, then were is the passenger side air sensor for Dual Zone HVAC equipped models? There isn't a similar vent over the front passenger's head, so I guess it's elsewhere? So I guess my real question is...


If the vent over the driver's head is the HVAC temperature sensor, then where's the complimentary sensor for the front passenger located on a Dual Zone HVAC equipped AV?

 

[pktwatch]

I would see no need for one. The way I understand the dual HVAC system is that it works by setting the diference in temps between the settings. If the driver wants 72 degrees then the passanger wants 76 degrees it just adjusts up 4 degrees from what is set and what the reader is saying...make any sence?

Butch

 

[TXAVy]

That does make sense, but it doesn't account for which side of the vehicle the sun is on which this system claims to account for. On top of that, you don't make the driver 72 degrees by blowing 72 degree air, so I'm not sure knowing the difference between the two sides would allow you to know how warm/cold to blow on the passenger.

According to the initial reviews of the system when it first came out in the TrailBlazer it's possible to get and maintain almost 20 degrees difference between the two front seats. I'd hate to drive like that for very long though.

 

[ygmn]

I think it knows where the sun is by using the light sensors in the dash.....thos little black button thingys....

And man what a great question.....in original post.,....

 

[MongoRanger]

I agree, I think for the system to function properly it should have two sensors, one for each side. I'm glad I read this post. I was getting ready to find a new spot to mount that sensor closer to the floor. I figured that would help to keep my legs stay warm while not making my head feel like it is in a sauna, since heat rises. I did not know that it had a fan with it so maybe I will rethink this for now. At least until I can get a picture of the sensor or see one up close.