Does the 2010 Prius automatically filter outside air?

I know there is a pollen filter that basically filters recirculated air but is there another filter that catches dust/debris from outside air?

All the air entering the cabin passes through that filter.

oh, didnt know that. do you know what the purpose of the pollen button is if it's the same filter all air passes through?

All cars have a general filter that all air entering the cabin passes through. The pollen filter is separate from that and that's what the button is for.

There's been some discussion of that pollen button in this thread:

http://priuschat.com/forums/gen-iii...discussion/66126-air-conditioning-filter.html

To my knowledge it just sets the a/c to recirc for up to 3 minutes. I don't know what else it does.

I'd beg to differ that we've even determined if there is another filter.

Some posters in that thread dispute this. How's this any different from the outside air/recirc button?

Marketing. 3 minute recirc timer marketed as a pollen remover.

I find that difficult to believe if pollen is a serious issue in Japan and it's marketed as "hay-fever prevention feature" there according to one poster.

So where's the filter? How do we get access to clean or replace it? I'm from Missouri on this issue.

And if you read that other thread front to back, there's no definitive answer there either.