Which Way Does the Wind Blow?

Yes. If you will check your Owner's Manual it will show you the air flow as being UP.

 

Actually it blows down through the filter, to the blower motor area then out to the vents.

 

Suck or blow?


The dirt on the top of the filter tells me the air flows down.

 

The Owner's Manual for the 2010 shows the filter with the letters UP pointing in the UP direction. This is the way that I found my original filter.

I would "assume" that the UP would indicate air flow. I will have to check the next time I have the filter out.

Maybe the Gen III is different than the Gen II ??

 

Where does it say that?

My owners manual says the following:
The “↑UP†marks shown on
the filter should be pointing up.

And:
If the filter is dirty, clean by
blowing compressed air
through the filter from the
downward side.

Which leads me to believe that during operation the air flows downward through the filter.

 

Not necessarily. It indicates there's a right way and a wrong way to put the filter in, but there's no particular reason for 'this way up' to indicate air flow direction.

Possibly, though I've changed cabin filters in both and they seem very similar. All the parts were in the same place, as far as I remember. I'm perfectly willing to be corrected by facts and admit I'm wrong, but until then, this is my story and I'm sticking to it.

 

Which makes perfect sense - If the air flowed UP, replacing the filter would result in some of the captured debris falling on to the floor.

 

Is it possible, just possible, that Cabin Air Filters don't really need to be changed? I've not changed mine after 20,000 miles and I'm still getting 53MPG, and there seems to be plenty of hot and cold air when I need it.

 

Stream,

You are exactly right. I did not read the part right below the UP mark about blowing compressed air. So the airflow will be down as Owner's Manual, hyo silver, and you indicate. I stand corrected.

Most filters label the "air flow" direction but Toyota chooses the UP to indicate which way the filter goes in .

This is what I love about this site, you learn something new every day.

Thanks,

Dwight

 

As Stream pointed out in the manual, you are correct, this is just an indication of the right way to put the filter in.

You are correct again. I was wrong in my "assumption". One more time, that is what I get for assuming

 

... and besides, if you changed the filter, you might disrupt that mouse family living in the debris accumulated over the past 20k miles.

 

I suppose one could argue that you never need to worry about the cabin air filter, or the filter for your home HVAC system, but I believe it's important from a health perspective.

I checked mine after 15K miles, and it was very dirty (I posted some pics if you're interested). Did changing it affect MPG? No (changing a dirty engine air filter would). Did it affect the quality of the cabin air that I breathe? Yes.

 

Which is exactly what it's there for. The 'wind' will still blow hot and cold, but the air will be cleaner if the filter is. As an alternative to the recommended 'blowing compressed air', a vacuum works perfectly well. Washing works, too, so long as the filter's completely dry before you put it back in - you absolutely do not want mould in your hvac system.

Speaking of which, mould formation in the ac has been a problem with the earlier models. I don't know what or if changes have been made for the next generation, but the same trick of turning off the ac and running warm air through will probably help. When you use defrost or cooling, turn it off just before you get home and let the fan blow. If it's hot out, vented outside air will work fine. If it's cold and wet, run some heat through to help remove moisture from the condensor.

 

The air definitely flows down through the filter as there is a hatch that opens above the filter when in filter mode that sucks air from the cabin down through the filter. I took a little video of it if it’ll attach - but it’s too large. You can see for yourself when you go to change it.

 

When I saw this (old) thread title, I really thought it would philosophy, lyrical, maybe weather related, lol.

I think you're right that the air's flowing down, but from the air inlets, beside the wipers?

As far as filter direction, I wonder if it matters, with these aftermarket ones that indicate air-flow direction, rather than Toyota's less ambigious "this side up" instruction?

Maybe the key is to never use it in one orientation, then flip it later on?