From my understanding it does this because if it's warmer outside and you have the ac on blowing cold with outside air mode on, it makes the air conditioner compressor work twice as hard. It has to cool the warm outside air coming in. So more wear and tear on the AC compressor. Takes longer for the cabin to feel cold. So it makes sense on why it would go to recirculate air mode above 75. You'll just have to get in the habit of pushing the button.
The problem with going back to outside air mode when it's gets cold enough in the cabin but still warm outside, your ac fan will start working again, work twice as hard.

 

For me, I actually prefer it to be on recirculate on ALL the time. I only use fresh air mode when it is on Defrost Mode (which is automatic) or times when I want to clear out Evaporator.

 

That’s precisely why I bought an LE. I‘ve got auto AC in my G37 and RX350 and that’s why I let my wife and daughter drive them.
At least the RX gives you a little more control over the system.

 

I never use it as I like full control.

 

Are you sure it's even outdoor temp related? I know there's times where its 60 outside but the midday sun has heated up the car to where the vinyl is hot, and I kick on the A/C getting in to cool it off fast - and it seems to default to recirc.
I guess I've never used recirc/max in any car I've owned - I'm all about the fresh air.

 

Yeah I think the system is smart enough to default to recirculation when the interior temp is too warm, regardless of the outside temp.

But I'm pretty sure it also defaults to recirculation when the outside temp is above a certain threshold. E.g., when I park in a covered garage in warm weather, the inside of the car is not very warm, but the system will still default to recirculation when I start the car.

Here's what it says in the owner's manual:

When the outside temperature exceeds 75°F (24°C) and the air conditioning system is on
-In order to reduce the air conditioning power consumption, the air condition-
ing system may switch to recirculated air mode automatically. This may also reduce fuel consumption.

-Vehicles without a smart key system:
Recirculated air mode is selected as a default mode when the engine switch is turned to the “ON” position.
Vehicles with a smart key system:
Recirculated air mode is selected as a default mode when the engine switch is turned to IGNITION ON mode.

 

I have a 2016 with manual HVAC and it does it too. I usually don’t have a problem with it since it’s on max A/C half of the year anyway. But where I live it can be 80+ degrees and very humid at midnight and recirculate causes the windshield to fog on outside at night. You have to have fresh air selected to avoid this.

It’s not just Toyota, my Ford F-150 does the same thing.

 

Years ago, on my older Toyotas, there was an option to eliminate the automatic suffocation feature.

Need to find a competent tech, or hacker with bootleg techstream, to see if the option is buried in one the interior or HVAC folders. Otherwise, you're stuck with the "Toyota knows more than you do and you have just been assimilated into the consensus foolishness". Resistance is futile.

 

My Volvo recirculate function has the option to switch off after about 15 minutes. I wish my Camry Hybrid XLE does that.

Giving the option is perfect because is satisfies both campus.

 

Yes, totally bothered by this Mode, seen on my 2021 Avalon hybrid.

The answers "works harder " from others is bunk. My other car, 17 yr old standard ICE Camry, does not default to Recirculation on the AC. It stays where I put it. I am totally disgusted by what the Toyota engineering has done, under extreme pressure by Toyota Marketing. I know the game, I was a beat-up engineer for 42 years, being told what feature to engage.

In my 2019 SE with auto climate control, I've noticed that whenever it's warmer than about 75F outside, the system defaults to recirculated air mode when I start the car and it never switches back to fresh air mode on its own. That eventually makes the air feel really dry and stuffy on longer trips. As a result, I have to manually switch the system to fresh air mode every time I drive the car.

I looked it up in the owners manual and it says that the system is designed this way to reduce power consumption. It doesn't seem like you can change the default setting anywhere on the infotainment screen or via Techstream.

Am I crazy, or does this seem like a problematic design, especially now with coronavirus concerns? Tons of Camrys are used as taxis/rideshares and I imagine a lot of people are driving around not knowing that they should switch the A/C to fresh air mode.

In all the older Toyotas and Lexuses I've driven, the the auto A/C system would start off in recirculation mode for max cooling, then automatically switch to fresh air mode after the cabin has cooled down, so you never had to think about it as long as you had the system in "auto" mode.

 

Recirculate is much less energy costly and it certainly is not "bunk" to say that. My Echo has a lever that chooses either one or anywhere in between, cable operated slider.
I can tell you exactly what it costs to run the compressor. Coasting with engine idling at 272 MPG instant, hit the AC button and it drops below 200 MPG AND I can cool down the cabin on recirculate and keep cooling the car for a minute with the COLD evaporator, where if it was on fresh air it would last 15 seconds.
Anytime I have to slow down, I downshift and hit the compressor. The engine is using no fuel ( DFCO instant MPG 999.9) and the compressor is still running with no fuel consumed, so the inertia is being traded for AC without using any fuel.
That is scientific PROOF recirculate is better and in my case AC is free as far as fuel consumption.
I never use fresh air AC unless I want instant window defogging, which is automatic when you choose maximum cool and max defrost, even though the light is NOT on indicating the compressor is working (only at those settings).
Not meant as an argument but your position is not supported by factual evidence.

 

I don’t really have an issue with the auto circulation because I like how the A/C blows colder and harder while it’s active. However, how often should I run fresh air through it to prevent mildew and mold build-up on the evaporator? I usually turn off the recirculation before I park the car so it can be in fresh air mode while the car is sitting there, but I don’t know if the car will default it back to recirculation while it’s off.

 

This is my concern as well. Even if I let the AC stay on recirculate, I always switch to fresh air several minutes before I get where I'm going if I can remember.

I use recirculate when it's really hot outside and i need to cool the cabin quickly. I rarely run it that way all the time.

And don't get me started on forcing the AC on while the defogger is selected. There are times you want a little WARM air blowing on the windsheld.

 

It annoys me. My other annoyance with the climate system is not being able to adjust temperature with the fan off.

 

My 14 Tacoma turns recirc on as soon as you turn the temp adjust all the way to cold. I get it why they do it, but it’s always annoyed me. I’ve see others that took the temp control apart and disabled it.

 

Putting it in simple terms, your home central A/C system only runs on recirculate. It's a lot more efficient and less work to cool already cooled cabin air rather than hot outside air.

As a test, on a warm sunny day with the cabin cooled off and running on recirculate get out and take listen to the cooling fans. Most likely they will be running on a low speed. Then switch recirculate off to go to fresh air and listen to the fans again. After a couple of minutes the fans will ramp up to high speed. When hot outside air is brought in it warms the evaporator and this heat increases the pressure in the system. The computer commands the fans to high speed to try to draw the heat out of the condenser.

The system performs best on recirculate but I do override it sometimes. I live in the gulf south and it's very hot and humid here so most of the summer it's running on Max A/C anyway. But it can still be 85 degrees and very humid at 10:00 at night. In these conditions if it runs on recirculate the outside of the windshield can start to have condensation build up and you would have to use the wipers to clear it. This is when I override it to use fresh air after the cabin has cooled off.

When it runs on fresh air in humid conditions water pours out of it. Not a drip, drip but a steady stream of water. A sign of a well performing system but it also means the evaporator is soaking wet with condensation. If you have the moldy smell I would stick with recirculate as much as possible. On recirculate, the dehumidified cooled cabin air doesn't form nearly as much condensation as fresh air.

 

I thought it’s recommended to use fresh air (non recirculate) setting to prevent mold/mildew growth because you can dry out the evaporator. But you’re suggesting the opposite?

 

Yes that's what I'm saying. Think about how it works; the evaporator is cold and if you run fresh air, warm humid air will pass over the evaporator. This will create condensation. The humidity is the main factor. If you're running recirculate the cabin air has already been dehumidified so the amount of condensation is significantly reduced.

Test it yourself. After taking a drive where the cabin has cooled to a comfortable temperature while running on recirculate check under the car and see how much water is dripping out. Then switch to fresh air and take another 15-20 minute drive and check again. .

Now if you switch to fresh air AND turn off the A/C then the evaporator will dry out.

 

On my 76 Z car the AC vacuum line cracked driving down the interstate, which made it go to fresh air. I didn't think about it until fog started coming out of the dash then the evaporator turned into a block of ice and it stopped cooling. Stopped for lunch, let it melt and then reconnected the vacuum line after clipping the end off the hose. Worked perfectly after that.

 

When I get in my hot car that's about 140 degrees, I need it cooled as quickly as possible. If the outside temp is 90 degrees, that's 50 degrees lower than the inside air that will be running through the evaporator. So I switch to fresh right away until the cabin starts to cool down and the inside temp is noticeably cooler. Then I switch it to recirculate to finish the cool down. When the car is nice and cool, I switch it back to fresh. Sorry, but I don't want to be re-breathing the same air all the time. Keep the cabin filter changed too.

 

Unfortunately many of the issues in modern cars is a result of CAFE standards.
Engineers have to constantly figure ways to squeeze more out of each gallon of fuel.
The fact is that when you recirculate the air in any space, Co2 levels and natural contaminants rise.
A car is worse case. Its bad enough recirculating the air of 1 person, but add a few more and the co2, perfume, deodorant etc levels steadily climb.

Unfortunately whatever the car makers do to obtain fuel efficiency has to be defaulted to be certified for the MPG rating.
If they started at recirc and switched to outside air after 10 minutes for instance, that is what they would have to have in place when obtaining certification. This is the reason
for things like the ridiculous 0W-16 oil. It is also why many cars default to ECO mode when you start the car with an option to switch to sport etc.

Ideally an in-between setting should be available. Open the outside damper say 20 to 50% and replace a fixed portion and recirculate the rest. That would freshen the air and obtain some efficiency.

 

The car doesn't default to recirculation. If the outside temperature is above a certain point the HVAC system will automatically select recirculate.

I've come to realize most people now have little to no knowledge of how systems in cars work. They don't ever read the owner's manual, don't open the hood and if they did have no idea what they're looking at. They're to used of automation and the fact most cars are now very reliable.

I'm sure one of the reasons it automatically turns on recirc is because people have been coming back to dealerships complaining of poor A/C performance and the problem was recirc not being turned on. The A/C makes much colder air on recirc rather than fresh air. So now it turns by itself and if that's not enough they put in a Max A/C position that also turns it on and forces you to move the selector to the coldest position.

They made it idiot proof.

 

I'm driving a RAV4 2006 2.0 vvti (EU modell). It had thr same problem (running the ac on recirculate). I found the solution on a forum. You can acces some hidden functions through long pressing a couple of radio or dasbhoard buttons. I don't remember. But it is possible. Cause mine worked out. No recirc anymore.

 

Sorry. But I did it 15yrs ago, when I had just bought the car. I got the solution from a guy who worked at Toyota USA, so they must know at Toyota. Maybe they just don't want people to know?

 

Saw your old post. Yes , as a 2021 Avalon hybrid owner Jan 2021, this auto recirculation by default is a problematic design. I have also owned 2 conventional Camrys before hybrid, and I never had this situation. The software engineers should have left the choice ( always Recirc in AUTO mode, or Outside air default on AUTO.), but they did not, because we owners are stupid and need our hands held.
That is what irritates me the most.

As other postings have mentioned, on a hot summer day, the cabin interior may be wellover 100degF, solar heating we all know. So bring in outside air much cooler than interior air! Why try to cool that
But Toyota marketing said "don't do anything that reduced MPG rating by running down the traction battery causing the ICE to recharge it"

Please Toyota, let me program my car for MY preferences!!

 

on a hot summer day, the cabin interior may be wellover 100degF, solar heating we all know. So bring in outside air much cooler than interior air!

This is why it automatically goes to recirculate. Turning on outside air is the wrong setting, it needs to be on recirculate for the coldest air. On a hot summer day if you want it to cool down quicker roll the windows down for a minute when you first get in and drive to let the hot air out.

Maybe we need to go back to the days when American cars didn't have a fresh air/recirc selector. Back then they had a Max A/C and Normal A/C setting. In reality Max A/C was recirculate and Normal A/C was outside air. I guess they knew Americans couldn't figure out how to use fresh air and recirculate correctly, so they simplified it in a way that was easier to understand.

 

If it automatically selects recirc it will usually switch to fresh air once the outside temperature drops below 70. Recirculate is also more fuel efficient because the compressor doesn’t have to work as hard which is another reason it’s automatically turned on.

Recirculate is also cleaner air. Your home A/C and all buildings use recirculate exclusively.

 

2018 Camry Hybrid XLE owner here, I think the way it should work (if I was Toyota CEO) is: if the temperature (and humidity/dew point) in the car are above what it is outside that the Auto A/C function should switch to fresh outside air until the inside air is below that of the outside temp/humidity and then switch to recirc. It should then only switch to fresh air occasionally depending on how many occupants are in the car based on input from the seat/safety belt sensor which it already has. How much it does this should also depend on the load on the system with more recirc % time on the hottest/most humid times with feedback from the following 4 sensors: inside temp, outside temp, inside humidity and sunlight/solar sensors. I believe the above could be done in software.