Another AC question

By default, AC is set to recirculate the air. I leave it on recirculate since I subscribe to the theory that you described.

 

There's an even more important reason for recirculating:

The Most Unhealthy Commutes in America

 

<div class='quotetop'>QUOTE(Angel Flight Pilot @ Aug 6 2007, 12:40 PM) [snapback]491351[/snapback]</div>

I may be way off here, but back in the "old days" when in recirculate mode it meant the compressor ran continually and, of course, recirculated the cabin air not letting outside air in. If that is the case still, then running the compressor all the time will take more power than with it running off and on on the normal setting. Perhaps one of the techs could chime in as to whether the AC compressor runs all the time when on recirculate...

 

If you use "auto" A/C, which is the default, BTW, my observations indicate the system uses recirc and fresh air, according to its' own desires (programming, actually).

Use "auto" and let it do its' thing. It appears to be smarter than we.

 

Yea, leave it on auto. It'll set the recirc on if it needs it. Usually to help cool the interior quickly then go to fresh air. Using fresh air is adviced so the condensers don't grow mold and on the very very rare chance that carbon monoxide gets trapped inside your car.

 

"I may be way off here, but back in the "old days" when in recirculate mode it meant the compressor ran continually and, of course, recirculated the cabin air not letting outside air in. "

GM systems sort of used to work that way. They labeled the switch position "MAX COLD" and it really meant RECIRC. Older systems ran the compresser all the time and blended hot air to get the set temperature output. This wasteful practice was changed in the mid-late 70s as gas prices hit the (don't laugh) astronomical price of $1 per gallon. ;-)

 

In the Prius recirc does not run the compressor continuously. Recirc at will. I recirc continuously, except sometimes if needed during defrost, to keep the cabin and my lungs cleaner.