I have a 2008 UK Prius TSpirit I have noticed that now the "Summer" is here in the UK the car sometimes starts up with the Climate Control in recirculate mode (I leave it in Auto mode all the time and adjust the tempreature up or down to suite). Is this design intent such that when you start the car up and the inside temprature is above a certain value, the Climate Control sets itself to recirculate in order to cool the inside down quicker? If yes then a "BIG UP" to Toyota design for a realy "cool" feature (sorry couldn't resist). If it is design intent and I leave it long enough will it go back to non-recirculate mode automatically when the tempreature reaches the set value, or do I have to switch it to non-recirculate manually? If not is it a bug, has anyone else experienced it, is there a fix? Martin.
It is designed that way.... A number of features on the AC/Heater system are programmable... the one related to your post is the "Air Inlet Mode" which defaults to automatic.. Any time the temperature inside the car exceeds the set value by a certain amount, it will go to recirc mode to more quickly bring the temperature down.. Then it goes back to external air mode... You can re-program it to "manual" if you don't care for this feature...
The reason why it recirculates is to help cool the interior down faster. Of course you can help by opening the windows and letting the hot air out too. It will switch back to fresh air when it's cooled down enough. That's the brilliant thing about automatic climate control. Of course, if you have a manual A/C unit in your other cars, switching to recirc on those cars will also help you cool the interior down faster but you'll have to open it yourself.
On the left of your dashboard there's a light sensor. The automatic AC-system uses information from this sensor too.
Based on my observation, I think it's a bit smarter than that. This seems to work based on the difference between outside temperature and the target temperature. Let's say you set your climate control to 72 and the outside temperature is 73 and your inside temperature is 85. Then bringing in outside air is more efficient than trying to cool the air inside. But if the outside temperature itself is 85 or so then it's better to recirculate. I haven't checked this in the manual but I think this is how it works. Probably more of an efficiency feature than comfort. But great either way.
the most cool feature is the humidity Sensor.... when you drive long distances in recirc the air can become very dry, below the comfort of most poeple. The Prius than open back to fresh air a ammont of time to make the atmosphere more human comfortable.... This feature you find normally only in the S-Class or the BMW 7 series Andreas
