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I like to keep my climate control set on fresh air. Recently on my commute of approximately an hour, the system switches to recirculate. I looked through the owners manual and couldn’t find anything saying that the setting could be changed without driver pushing the button. Anyone else noticed this?
 

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I like to keep my climate control set on fresh air. Recently on my commute of approximately an hour, the system switches to recirculate. I looked through the owners manual and couldn’t find anything saying that the setting could be changed without driver pushing the button. Anyone else noticed this?
If you put it on Auto mode...it will switch it to recirculate. I put it on Auto mode inadvertently at times.
 

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I thought it does that automatically based on air quality. I have seen both AUTO and fresh air at the same time. I'll try to verify next time I drive it.
 

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I like to keep my climate control set on fresh air. Recently on my commute of approximately an hour, the system switches to recirculate. I looked through the owners manual and couldn’t find anything saying that the setting could be changed without driver pushing the button. Anyone else noticed this?
If I remember correctly it only automatically switches to recirculate in Econ mode. Recirculate is more efficient, both for AC and heat. I think it only runs recirculate until the set temperature is reached then it switches back to fresh, but I'm going from memory on that.

Note that there is still some fresh air coming in even with recirculate, just a smaller amount. But if you don't want it to ever turn on recirculate then you might try using Normal mode and see if that leaves it on fresh. Either that or don't use Auto mode. If you turn off Auto mode it will still regulate temperature as far as cycling AC compressor or heater, but you will have to control the fan speed yourself.

Auto mode shuts off if you change fan speed, change from recirculate to fresh or vice versa, or change which vent is used, i.e. face, feet etc. And Auto mode will remain off the next time you start the car.
 

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Today at local temp 67 F per car display, AUTO lit AND Fresh Air mode lit, car in ECO (green flower at top of display). control set at 72 F.
What was the cabin temperature? I realize that's not shown on the dash, but it is available in Car Scanner.
 

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I have a HDS clone so to speak (VXDiag MultiDiag with Honda add on) that I got after my near midnight TPMS ordeal. But I haven't tried it yet. It isn't rare to see it like that. I can say that it was this morning and I assume cabin temp was close to 72 F because very mild fan speed....
 

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I wonder if the car has a humidity sensor that dictates the switch to recirculation?
When learning about this type of system before it was based on air quality and differential between set temp and ambient, something along those lines. If you really crank the setting one way or the other you can probably get it to switch before your eyes. (I haven't tried)....

As far as I know you want fresh air if your windows are fogging up but I'm sure the engineers factor that setting/button in. It instantly turns off AUTO if pressed on ours, again if I recall correctly...
 

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This is cut & pasted directly from the Honda Clarity's owners manual:

If any buttons/icons are pressed while using the climate control system in auto, the function of the button/icon that was pressed will take priority. The AUTO indicator will go off, but functions unrelated to the button/icon that was pressed will be controlled automatically.

So that means that if you 1st put it in (AUTO), then if it changes to [Recirculate], you can press the [Fresh] button, & although the (AUTO) button light will go out, it will continue to operate in (AUTO) Mode, except for the spacific function that you changed. I had this same exact issue, until I read this in the manual.
 

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If it's much hotter outside the car than inside, then the AC system will use significantly less energy by cooling the cooler inside air than drawing it from outside. In fact it may not even have enough power to reach the target temperature when using outside air. I thought that's why these systems all switch to recirculating at some point (when in AUTO mode).

As jzchen said, some higher-end cars also switch to recirculate based on air quality. The particulate sensors probably have a BOM price of a few dollars, given the retail price of air quality sensors, so it's not a huge luxury. I don't think that the Clarity has one though.

In a lot of cases you're better off using recirculated air, because the filters will remove most of the particulate. Even if the outside air quality is good, you'll often end up behind a truck or a poorly-maintained car. Of course in the winter and/or on rainy days you'll need outside air to remove the humidity.

There: I've satisfied my male-answer syndrome for today!
 

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If it's much hotter outside the car than inside, then the AC system will use significantly less energy by cooling the cooler inside air than drawing it from outside. In fact it may not even have enough power to reach the target temperature when using outside air. I thought that's why these systems all switch to recirculating at some point (when in AUTO mode).
In the old days climate systems had a MAX setting for the AC which you used when the car was hot, then you turned off MAX once the car was cooled down. Mostly all it did was switch into recirculate mode, as well as ramp up the fan speed independent of what level you had the fan set for. In later years the MAX button was replaced by the recirculate button, probably because that works with the heater also. Back in the old days I don't think it was possible to do recirculate for heat, at least on any car that I remember driving back then.

Of course back in the old days we were happy just to have a car with air conditioning at all, as it was considered a luxury item. Apparently going just a little farther back that was true with heaters also, as late as maybe the 1950's not all cars came with heaters.
 

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I always use the A/C in recirculation mode. It works best and it doesn't tax the battery as much.
Some people find recirculate to be stuffy if used for the entire drive. Could also depend on how many people are in the car. I don't notice the difference so I always use recirculate because it is more efficient.

It could also depend on the car, since even when you are in recirculate there is still some fresh air coming in. Maybe some cars use a higher percentage of fresh air than others when in recirculate mode.
 

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If it's much hotter outside the car than inside, then the AC system will use significantly less energy by cooling the cooler inside air than drawing it from outside. In fact it may not even have enough power to reach the target temperature when using outside air. I thought that's why these systems all switch to recirculating at some point (when in AUTO mode).

As jzchen said, some higher-end cars also switch to recirculate based on air quality. The particulate sensors probably have a BOM price of a few dollars, given the retail price of air quality sensors, so it's not a huge luxury. I don't think that the Clarity has one though.

In a lot of cases you're better off using recirculated air, because the filters will remove most of the particulate. Even if the outside air quality is good, you'll often end up behind a truck or a poorly-maintained car. Of course in the winter and/or on rainy days you'll need outside air to remove the humidity.

There: I've satisfied my male-answer syndrome for today!
And it sounds pretty logical!
 

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A tip that I learned years ago is to open the doors to let the heat out before turning on A/C. Probably most people have heard that but I don't think most people do it, at least from what I can observe. It's faster to just get in the car and start up AC, and people don't seem to mind if it takes a few minutes more for the interior to cool down since you at least get some cool air blowing on you immediately. But it's worth taking the extra 30-60 seconds or so to open a door on each side of the car which will immediately drop the cabin temperature at least 20 degrees, making the A/C's job so much easier.
 

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A tip that I learned years ago is to open the doors to let the heat out before turning on A/C. Probably most people have heard that but I don't think most people do it, at least from what I can observe. It's faster to just get in the car and start up AC, and people don't seem to mind if it takes a few minutes more for the interior to cool down since you at least get some cool air blowing on you immediately. But it's worth taking the extra 30-60 seconds or so to open a door on each side of the car which will immediately drop the cabin temperature at least 20 degrees, making the A/C's job so much easier.
I just hit the "down" buttons on both rear windows, and leave them down until I get the "thop, thop, thop" effect of the pressure oscillations at speed. Up they go, again, with a single two-fingered press. Hot air...ejected!

Edit to add: Funny! I had to edit my onomatopoeia describing the air pressure oscillations. The "objectionable words algorithm" didn't like my use of w-o-p, so I had to go with "thop".
 

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I just hit the "down" buttons on both rear windows, and leave them down until I get the "thop, thop, thop" effect of the pressure oscillations at speed. Up they go, again, with a single two-fingered press. Hot air...ejected!
I do that too sometimes when I am in a hurry, but I really hate that w-o-p, w-o-p, w-o-p effect.
 

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I do that too sometimes when I am in a hurry, but I really hate that w-o-p, w-o-p, w-o-p effect.
I used that effect as an instructional tool when I taught the high school physics unit on resonance. I also had them do a frequency sweep with their voices while in the shower, to find the resonance points within that cavity. Resonance is everywhere!
 
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