Recirculatatory vs. A/C?

Hi Folks.  I'm new to the forum.  Recent '06 H3 owner, black, adventure, nerf bars, inilex, security, chrome.  2nd day of owning (brand new), Stab Sys/4X4 Service light comes on, took it in, had to replace the Actuator Motor (Transfer Case).  Been reading alot about the head problems.  My Step-Father is the Service Manager at a Cadillac/Hummer dealership and told me that it is a problem with a poorly built Cylinder Head and the new head is re-designed and corrects the issue.  He said it usually happens between 6K and 11K miles, but can happen at any time.  Does not hurt the vehicle to drive, don't worry about it, check engine light should come on, and take to the dealership.  Can I get it replaced in advance?  He told me If they are a high volume dealership, then they should already have them in stock by now because this problem is VERY common and large hummer dealerships are being stocked.  He told me the 2 biggest problems with the 06 H3 is that head replacement issue, and the Actuator Motor (TXFR Case).  So, I'm 1 for 2.  Love the H3 though, its a beautiful vehicle.  Had it for about a month now, no problems.

I did have one operating question, not sure if this is normal, but it doesn't appear to be operating correctly per it's use and design.  When I turn on the fan only WITH the recirculator button ON, cold air comes out, even when the A/C button is NOT depressed.  Huh?  Why is this?  When I turn the recirc. button off, normal hot air from the outside blows in like it should, but if I depress the recir. button, it should just recirculate the air in the car, right, no A/C?  I had a loner '07 when I was having the actuator motor replaced, and it ALSO did the SAME thing.  Comments?  Cheers.

Hi I'm also a new Hummer owner and noticed the same thing but since no one had posted about it I figured oh well it's just me. Glad to see it's not... LOL
I live in Texas and it's already gotten hot down here but I have yet found the need to turn on the ac like you said the recirculator keeps it plenty cool. I'm sure someone will post pretty quickly with your answer, I look forward to seeing what everyone says.

Jenn

I noticed the exact same thing this week driving back from Moab. The temps have been mild, I bought my H3 back in November of last year, an 07 model. Never used the AC much until yesterday when driving back home and noticed that when the recirculator light is on it feels like AC. When I turn it off and bring in outside air it really gets warm in a hurry, back on and it gets cold again. I'm thinking that with the recirculator light on it kicks on the compressor, I even toyed with it on cruise control on a flat section of highway and tried to tell if I could sense any change when pressing the AC btton on the left knob and/or the recirculator on the midle knob. Temp wise, I couldn't tell any different and I really couldn't feel the compressor lugging the motor going from on to off on either know or any combo of the settings. The air was plenty cold so I have to believe that the imddle button also kicks on the compressor, wierd...

The compressor turns on with the recirculation button to prevent the windows from fogging up. I too thought I was crazy with cold air coming in in traffic, 85F, in Hawaii.  While driving with the circulation off and it saves about 2mpg.  Currently I average 15mpg with 35" Claws.  On and it drops to 13mpg

Yup.  That's how it's designed.  There is no way around it.  The recirculate button automatically turns the AC on whether you have the AC button turned on or not.  Now it's possible that the AC button does what the MAX AC setting does in the other GM cars, but I haven't noticed a different in the temperature of the air either way.  You can just automatically assume that if Recirculate is on, so is your AC, and that's GM Design for ya

Thanks for clearing that up.  That is what I assumed.  Honestly, that is a pretty crappy design job there.  That really sucks that they didn't make it work like is supposed to.  I noticed it right away.  There are times when I would like to run the fan from the air inside the car only (on days that it is brisk outside but warm enough inside the car), but now I know you cannot EVER with my H3.  You would definitely save $$ in mpg because if you run the a/c to cool the car down, then when the car is at a temp that you like, all you should have to do is turn off the a/c and keep the recirc. air going, and you are recir. cold air until it heats up again and then turn the a/c button back on.  We also have a Jetta and that is what we do, and it really saves us mpg.  Oh well.

It's not just a GM thing, newer HVAC systems from many brands also operate the same way.  The only work around is to turn off the recirc mode and just run the fan with the temp set a bit higher on colder days.
 
On some non-GM cars that I've owned, the recirc mode even had a time-out function that automatically shut off recirc after about 20 minutes.  Does Hummer do this too?  I've never noticed with our H3 because I only use recirc when something smells bad outside.

sooo  either  way  the a/c  is on?   which is better?

I'm not sure it's a matter of which is better, it's more about options, I suppose.  Being able to recircualate the air inside the car without having to run the a/c (MPG) when you don't want to.  It makes the actual A/C button almost useless.  I can't see any circumstance when I would actually press the A/C button, only if I want the A/C on, and fresh air coming in from the outside, otherwise I'll just recirculate the nice smell of my interior because the a/c is already on.  You have no choice.  Oh well, I'm glad I know that it wasn't something wrong with the vehicle.  Cheers.