my plazmacluster is set to no a/c, windshield/floor, and recirc does not kick in when i turn fan on. recirc/ a/c kicks in only when windshield button is pressed on plazmacluster, even with that, i can manually shut a/c down. for long time, my plazmacluster used to go into recirc mode by itself, every time i had engine turned on. for some reason, it does not do it anymore. i am happy, i was always forgetting to turn recirc off.

The most efficient way to cool down the cabin during hot weather is for the AC to recirculate the air. My observation in summer is that recirculate is the default mode when AC is first turned on and when the cabin cools down it changes to fresh air mode.

Now that the weather is cold the system does not default to recirculate mode on.

Since it can easily prove hazardous to use recirculate mode in cool or cold climate maybe your system automatically switches into recirculate ONLY when the climate is warm. Recirculate mode most definitely improves cooling efficiency and thereby improves FE by lowering the amount of time the compressor needs to run.

Come next summer when you begin using the A/C my guess is that the system will go back to switching into recirculate mode on initial startup.

Not a Camry owner. But fogging is a simple factor of relative humidty and the temperature of your window surface. RainX and a few others make product which help by forming a microscopic layer on the window surface that seems to help. It works and use it in the EV as using the heater is rather wimpy and limits range. Don't use recirc when fogging is occuring. Put the fan on high and enjoy the cold air and fog free windows while waiting for the water temp to increase.

As there are anti-fogging products it is also MO that some window cleaners might make fogging more likely.

"...simple factor of relative humidity..."

"....simple matter of relative humidity INSIDE the vehicle..."

You are kidding, right? You risk unsafe driving due to fogged windows, and don't correct it because it might use a little gas? WOW!

There is also the hidden danger resulting from the use, or trying to use, the A/C for dehumidification in cold weather.

But no, you need not risk unsafe driving as a result of disabling the A/C. All you need do is use the heater to keep the windshield interior above the cabin atmosphere's dewpoint while keeping the cabin dewpoint fairly low via "fresh" airflow system mode, or even a slight lowering of the rear windows, in the extreme.

Many of us drove quite safety in wintertime conditions long before A/C became an option. As a matter of fact I believe that undue reliance on the A/C to prevent windshield fogging has likely resulted in more per capita accidents from windshield fogging than was the case before A/C was commonly available.

Heating the windshield to prevent fogging, or using heating to remove fogging will ALWAYS work. Whereas the successful use of the A/C for either purpose is left up to mother nature (outside air temperature and Rh) plus the after effects of A/C use are fraught with peril.

+1

FWIW, the car automatically defogs the window in under ten seconds. However, if you can't bear the thought of "wasting" gas, drive with the windows cracked about 1/4" open. It's old school but it works.

reading my WHOLE ENTIRE POST may shad some light on why I am not using a/c. I do not need to.

Fwiw, came back from gym last night in subfreezing snowy weather. Started car, within seconds window was fogged. Pressed auto and then defrost/defog button, windows clean within seconds. Once clean I flipped ECO to get better economy.
As far as I'm concerned,the TCH system runs perfectly.