# air recirculation question



## trumanlake (Aug 3, 2015)

I am new to this forum, and was wondering if someone could answer a question for me. To start, we have a 2014 Cruze LT (9000 miles), US made (Ohio). What I am curious about is the recirculation button. If anyone has a 2014 and could perform an experiment, I would greatly appreciate it.

First, start the car and then then turn on air conditioner, make sure recirculation is in the "inside only" (no outside air) max cooling, fan in high speed, upper and lower vents selected.

After it runs in this mode for approximately 30 seconds, then press the recirculation button to bring in the outside air.

Do you hear any change in the air flow? Do you feel any difference in your ears, as in pressure inside the vehicle?

The reason I am asking these questions, this is the first vehicle that I have not been able to tell any difference between the 2 modes.

I have taken the car to the dealer, they checked and said the actuator is moving, and everything is fine, and that "they are just made different now days".

My thought is, Ok the actuator is moving but is it moving the actual vent to change the air flow?

Thanks in advance.


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## Tomko (Jun 1, 2013)

Sounds like normal operation to me.


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## NickD (Dec 10, 2011)

In my 2012, blower speed is very very low, 2nd is very low, 3rd is low, but 4th is like a hurricane. Just saying difficult to tell the position of the recir door in the lower speeds. Typically hit the recir button in subzero weather, sure can feel the difference in air temperature when its on. But as the engine warms, have to switch it off or the windows will fog up.

Us people are the cause of this. Can also tell the difference in hot temperatures, can feel the compressor working a lot harder with the recir off. Can really tell the difference when passing a farm where they are open spreading liquid manure or past a paper mill. Just other signs of telling whether your recir door is working or not.

Took GM long enough to add that recir button.


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## Tomko (Jun 1, 2013)

It was always there. It was called MAX A/C. 

Round these parts it's the calling card of a skunk that gets me reaching for the recirc button.


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## EcoCruzer (Mar 4, 2011)

http://www.cruzetalk.com/forum/25-s...sive-moisture-condensation-frost-windows.html

A great write up and an answer to your issue.


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## NickD (Dec 10, 2011)

Cruze is kind of weird in this respect, can't get fresh air in unless the air can escape. For years would put an outlet vent at the rear door jam, front on two door cars. Weather strip was on the outside perimeter of the doors. Not on the inside like on the Cruze.

If you run your blower at the maximum speed you can feel air coming out between the front and rear side windows. And if you open the rear door, won't see a vent at the lower door jam. Have no idea why they did it this way. One way to get good air flow is to crack open your rear windows about a 1/4".

With driver side window noise, read about some dealers blocking that air flow, not a good idea.


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## Robby (Mar 1, 2013)

NickD said:


> Cruze is kind of weird in this respect, can't get fresh air in unless the air can escape. For years would put an outlet vent at the rear door jam, front on two door cars. Weather strip was on the outside perimeter of the doors. Not on the inside like on the Cruze.
> 
> If you run your blower at the maximum speed you can feel air coming out between the front and rear side windows. And if you open the rear door, won't see a vent at the lower door jam. Have no idea why they did it this way. One way to get good air flow is to crack open your rear windows about a 1/4".
> 
> With driver side window noise, read about some dealers blocking that air flow, not a good idea.


Nick and other readers,

The Cruze and all others do indeed have flow through ventilation.
In the case of the Cruze, cabin air is first exhausted into the trunk through the two vents located on the rear package shelf, either side of the third brake light housing.
They exhaust into the structure you see with the trunk open, below the package shelf and it is connected to both inner wheel housings.
From there, air moves into the quarter panel area where a vent with a one way flap on each side that is hidden by the sides of the rear facia…….this is a low pressure area and it draws air out at speed and prevents cabin pressurizing that would make door closing difficult if the windows are up.

This arrangement is almost too effective……in the cold weather, at speed, even with the blower operating, you can feel cold, outside air coming in from the door release handle area.

Anyways, the cabin is indeed, vented to atmosphere.

Rob


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## Robby (Mar 1, 2013)

trumanlake said:


> I am new to this forum, and was wondering if someone could answer a question for me. To start, we have a 2014 Cruze LT (9000 miles), US made (Ohio). What I am curious about is the recirculation button. If anyone has a 2014 and could perform an experiment, I would greatly appreciate it.
> 
> First, start the car and then then turn on air conditioner, make sure recirculation is in the "inside only" (no outside air) max cooling, fan in high speed, upper and lower vents selected.
> 
> ...


OP,
Notice on the temp knob, when rotated to the coldest position, the knob has a detent you can feel.
When at the full end of travel, beyond the detent, the system is in a 'Partial' recirculate mode for maximum cooling.

When the knob is turned just to the point of the detent, but not past it, the car is only pulling outside air across the evaporator core with no cabin air mixed.
If you then press the recirculate button, the system goes into a full recirculate…..it only draws cabin air across the evap. and then cools already cooled air.
When the controls are in this position, if the air is at all humid, like not crossing the desert, the potential of the evaporator core freezing over and blocking airflow presents itself…….so, recirc., beyond short term or desert usage, should be avoided.

When in the partial recirc., maximum cooling temp mode, enough outside air is admitted to prevent the freezup, but does not exchange cabin air at the same rate……..this can be a problem if you have a smoke (I do) while driving…..gets a bit stinky.
So, in my case, a cracked window with the temp control at, but not beyond the detent is necessary for air exchange purposes.
Once done with my smoky treat, after a couple of minutes, I go back to the lowest, (beyond detent) setting and close the window.

Regarding the question about sound change……if you are at max cooling (partial recirc.) and press the recirc (full recirculate) button there is hardly any perceptible change in sound……partial and full are too similar air paths to differentiate.

However, if you put the temp control up to, but not beyond the detent, and toggle from recirculate to outside there is a clear difference in sound…..you can tell the muted sound of it pulling outside air from the louder sound of it drawing cabin air.

Help any?

Rob


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## Tomko (Jun 1, 2013)

When on A/C I run it exclusively on Recirc and usually at fan speed one or maybe two. 

During the 10 hour drive to Lordstown last year I believe the HVAC system was able to sense when the evaporator froze over and automatically changed itself into outside air so as to thaw the evaporator. During that particular drive I noticed this happening every 15 minutes or so. My indicator was the volume of air movement which increases when set to outside air. 

There was no other indication. Neither the button light nor the my link display indicated any change.


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## obermd (Mar 3, 2012)

Tomko said:


> It was always there. It was called MAX A/C.
> 
> Round these parts it's the calling card of a skunk that gets me reaching for the recirc button.


Must not be any feed lots in your area. They're worse than skunks.


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## jblackburn (Apr 14, 2012)

Can confirm - Max A/C engages recirculate without the light being on!

Actually my recirculate didn't work at all when I first got the car. Then I couldn't figure out why it wouldn't go out of recirculate once they fixed it!


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## NickD (Dec 10, 2011)

GM was going into recir mode for years, in the so called Max AC position. Only way to go into recir mode, 82 Pace Arrow, a Chevy is this way. Not a good idea for colder days.

Best car if my memory serves me right, owned so many different vehicles, hard to remember. Was a 1986 Nissan Maxim, had a lever for the recir door door, cable driven and you could set it wherever you wanted it to. Got this thing about having the ability to do my own controlling.

Okay with a home thermostat, don't want to get up every couple of hours to switch on the heat or the cooling. But in a vehicle, strapped in that seat like a mummy, and don't have much else to do. Except play with the radio and the climate controls.

Liked the 04 Cavalier, temperature, mode, and recir were all cabled controlled. Cruze runs all this stuff through the BCM. Like going from Chicago to New York via China with a lot more problems and firmware stored in flashram. 

Ha, 30 Olds/Ford, and 33 Buick never had MVAC problems, didn't have this stuff, suppose to be tough. But if you weren't would carry blankets in the winter and hand fans in the summer. But really liked cables and real switches for MVAC, and that includes a cable operated recir door. But just couldn't stop here, really maintenance free, just had to slap in a microcontroller, more problems.


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