It's 80% recirculation (20% outside air). It does go to 100% recirculation for 3 minutes, along with higher fan speed. It's not just a lack of oxygen that's dangerous, but a potential small leak of the exhaust system leading to a buildup of carbon monoxide inside the car.
OK, so fifteen minutes for all of it. Did you subtract the volume of the passengers and cargo from the available air volume within the car? How long until the driver starts to notice a difference? I know I'm more alert with a steady supply of fresh air, especially on a long family trip in the Summer. Based on my experience, I'd say it's not safe to leave the system in recirculate for more than a few minutes - Toyota says three.
Doesn't anyone read their manuals? I know it's a point of pride not to read computer manuals and work it out for yourself and the prius has lots of little computers but the manual actually has important and informative stuff.
Believe it or not, the filter button is one of the things that isn't described in detail in the manual. IIRC, all it says is it's the "dust & pollen filter" button. This is confusing because it'll lead some people to believe that the filter isn't in use unless you press the button when in reality, all air that comes through the vents pass through the filter behind the glovebox.
Does any other Toyota have a "filter button"? If not, why was it decided this was a feature that would be appreciated by Prius drivers and not by everyone?
Lexus has it and I'm sure other flagship Toyota models have it as well but I don't know the specific models off the top of my head.
Lest anyone worry too much about oxygen depletion, the passenger and cargo volume (93.7 and 21.6, respectively) units are in cubic feet, not liters.
small but important correction: Prius volume (and all other EPA car volume #) is measured in cubic feet, not litters. One cubic feet contains ~28L.
Heat and humidity here in Texas makes the use of recirc especially effective. I keep it on nearly all the time in the summer. My longest non-stop drive with the a/c in recirc mode is 6 hours on I-10 (Van Horn to Kerrville) before my bladder finally said "give!". After the bio-break, got back in and drove another 3 hours home. By your count, I should have died/passed out hundreds of times. It's a car not a sealed spacecraft.
OK, you busted me! Yup, I pulled over every 3 minutes to lower the window since I didn't want to risk inhaling any exhaust fumes either. Trip actually took several days.....
LOL, no. I have used the air-recirc feature my whole life and lived to tell the tale. The "you'll run out of O2 if you leave the air-recir on" is a myth. I use "the air cleaner button" if I'm stuck in smelly traffic (diesels) or skunk, etc. It only functions for about 3 minutes and then returns to your previous settings (very convenient).
The ICON is not intuitive. I originally thought it was just a label for the air conditioning panel and not a button at all. It's the one located between the "mode" and "a/c" buttons and has a person sitting with an arrow pointing at the head.
The argument here is whether 100% recirc for too long is dangerous. Given that 20% fresh air is still let in when you're in normal recirc that's moot.
I feel the same way. I never had any clue that button was some filter button for the air in the car until I accidentally ran across this thread one day!
I never knew what that button was either, although I have pressed it before, until reading this thread. I have read and reread the manuals, guess it is just one of those things that you overlook. I continue to learn little unknown facts almost every day on this board.:rockon: Arkie
