It seems as if the default setting is 'recirculating' for the A/C setting. I prefer the straight through setting and when I restart the Prius the A/C is back at recirculating. How can I defeat the recirculating setting?

Allen

 

Hi allen,

Yeah I've got some issues with the A/C system as a whole as well. However, the re-circ isn't usually one of them. I managed to get it to come on without re-circ, but I generally use it with re-circ because it stays colder that way. Of course, I use the A/C sparingly to begin with. If you have package #6, you can use the Voice Activation to turn the A/C on or off, re-circ on or off, I believe. I just discovered this today and I've had my Black Prius 8 days longer than you've had yours! (got mine from Ventura Toyota, btw.)

Rick

P.S. Sorry I rambled and didn't really answer your question!

 

When you say you managed to get it to come on without recirculating, I assume you mean with voice command. Is that so?
You're doing good on your mpg, good for you. I've 400 miles with only 45mpg.
I got mine at Manhattan Toyota, live Hermosa beach, retired and need gas savings.
Allen

 

The auto climate in the Prius operates the same as auto climate in just about any other vehicle. The system makes decisions based upon logic which is hard programmed into the a/c control system.

There is an ongoing debate about recirc when the vehicle starts up. It helps to understand how it makes these decisions based upon what it us sensing.

If you have the a/c set somewhere between 73 and 76 degrees, which I would consider normal interior temperatures, then the system bases its output parameters based upon this set point. It then takes into account the actual interior temperature of the vehicle, and it takes into account solar energy which is entering the cabin. So, if your car has been sitting out in the sun and you start it up, the interior temperature is way above your set point, and if the sun is still out and the sun sensor on the dash is sensing direct light entering the cabin, the system will take that into consideration. So, hot interior, combined with direct sunlight on the sun sensor and the system puts itself into a Max cooling mode at the very start, which usually puts fan on max, a/c compressor on and recirc mode on.

As the cabin cools down fan speed will drop, and eventually recirc mode will turn off. If the sun goes down, or your car is pointing in a direction which minimizes solar energy, the sun sensor will communicate that change to the a/c controller and further automatic adjustments will occur, usually further lowing fan speed, changing vent placement and turning off recirc.

In addition to the changes you can feel and see in the cabin, the vehicle also will adjust the speed of the a/c compressor to maximize efficiency and reduce usage of HV power.

The other thing you need to be aware of is that the a/c system on the Prius uses a split air system. Typically, even with recirc off, the system will put recirculated air on the floor, while fresh air is drawn in and placed on dash vents. The vehicle does this because retaining some recirculated air in the vehicle at a temperature close to the set point helps reduce the load on the a/c system, which makes the system even more efficient.

The vehicle is truly a set it and forget it car. Find a temperature set point which you feel is comfortable and leave it there. The car will make the adjustments to the cabin it needs to and will do it more efficiently than you could. On top of that, the battery needs room temperature air to run most efficiently. So, the car is relying on you to choose a comfortable set point so that the battery is also comfortable and working in its most optimum temperature range.

 

Very good explaination. I'll play around with my set point to find the one I'm comfortable with.

 

I just discovered that you may be able to activate or deactivate AUTO A/C, it's a feature that hides in the 'secret' diagnostic menu (the 'secret' menu) so... if you are brave you'll end up at this menu:



Follow instructions at the top and midway down this page to get to that menu:
http://www.vassfamily.net/ToyotaPrius/Custommenus.html

 

Thanks for the 'secret' menu information. But, I wouldn't do that much fooling around with settings to my home computer let alone my new $25,000 computer on wheels. I love knowing these things but will pass for now. I have put my set point at a good number and can toggle the recycle on and off from the steering wheel. That works for me. The only thing I changed via code changes is to turn off the back up beep. That drove me nuts.

Allen