ayonnebay

I just replaced the cabin AC filter (2004 CL). The replacement filter had an arrow indicating "Air Flow". The plastic filter holder has an arrow indicating "Top". I installed the new filter so that it's arrow pointed in the same direction as the arrow on the holder, but now I'm thinking I did it wrong.

I think it's wrong because the old dirty filter I removed had all the dirt & debris on the Top. That would indicate that the air flows Downward through the filter, meaning the new filter air flow arrow should point Down - just the opposite of the arrow on the black plastic filter holder in the car.

Am i right ? - Should the Air Flow arrow on the new filter point down ?

Walt

AlexusAnja

I just checked and the arrows are indicating which sides should be "UP" not airflow direction. As long as you lined the two up and the arrow is going up, you're fine.

ayonnebay

Yeah, but not quite. The black plastic holder reads "TOP" with an arrow, but the new filter clearly reads "AIR FLOW" with an arrow (It's a WIX filter) - That's what makes it not seen right ......

I have a new OEM Toyota filter also, and that reads "UP" with an arrow, like you said, so installing the Toyota filter is pretty clear. I think in the case of a cabin filter it's not anything to be really concerned about, so I'm just going to leave the WIX filter as it is. Just for the record, though, it appears the actual air flow is DOWN - just the opposite of the (UP) arrows.

Thanks for looking at it. I appreciate that.

Walt

Jabberwock

yea I agree it is confusing - the air flow onto the filter surface is certainly coming from the top onto the filter surface and then going down. So if the arrow on the filter is suggesting airflow orientation than the arrow on the filter itself should be facing downwards.

AlexusAnja

Agree, the flow is top to bottom. When I checked, the dirt was on the top. You did not mentioned you had none OEM...

The cabin filter I would not worry too much about performance. I only got OEM because the price difference was like $2 or so between what I could get OEM for and like a "Purolator" filter.

You should be fine.

PapaCat

I've had the same question for over a year, and thought after reading these posts I had the answer. However, let me add my two cents. Regarding my 2011 IS250, I mistakenly thought the air flow was up, coming from the engine compartment. I now agree with you guys that is is actually down. Here's the catch. I saved the original cabin air filter - the one that was factory installed. On the filter itself, it has the words "UP" clearly printed in two location. Right next to the two locations where the word "UP" is printed an up arrow also appears. Just to made make sure you guys understand what I'm saying, let me repeat - there is an arrow pointing up right next to the word "UP."
Doesn't this indicate that the the filter should have been installed with the up arrow pointing to the top of the filter, the direction from which the air is flowing?

I don't remember how the original filter was installed, but I can assure you, the dirty side of the original filter is on the side that would be considered the bottom, assuming the guys at the factory installed it with the arrow pointing up. So, now that we all agree the air flow is from inside the cabin and down through the top of the cabin filter, I'm assuming they installed the filter incorrectly at the factory. (The "UP" arrow is pointing to the clean side, and the other side of the filter, the one that I would imagine should have been on the bottom, is filthy.)

Bocatrip

After all is said, what would happen if the filter was installed incorrectly? Would it not be doing it's job? The last time the reminder light came on for the cabin filter replacement, all I saw on the filter were a few pieces of twigs etc and the rest of the filter looked good. Should the filter be replaced regardless every 15,000 miles?

jayclapp

I think it should be changed yearly at least to prevent the dreaded mold smell. $25 to prevent that once year is a good investment in my opinion.

Natey2

The Denso cabin air filter I had said "UP" with a direction arrow that matched the direction on the plastic filter housing.
The new filter I bought says "Air Flow" with a direction arrow that now needs to point in the opposite direction as the filter housing.
I suspect direction wouldn't matter if there was no charcoal coating (for odor elimination) on the filter, but it looks like one side has more charcoal particles than the other.
As others have mentioned, air flow is top to bottom on the LS430.
I also see what looks like a cylindrical filter inside the compartment after you remove the square cabin air filter. Does that need to be cleaned too?

Lavrishevo

iTrader: (1)

The arrow does not indicate air flow. Filter arrow should be facing upwards towards the top of the dash.

Edit: I am referencing oem Denso

Natey2

Why would a filter manufacturer print "Air Flow" on the side of a disposable filter, with arrows next to the words? Most people would interpret that to mean the direction of the air flow.
The Denso filter did not have the words "Air Flow"; just an arrow that said "UP".

NickTee

The aftermarket filters do a terrible job of indicating which direction to install it. Even calling them and asking will only reveal very confused workers who have no clue, they will simply repeat the phrasing from the installation guide. There is no agreed-on way to install the filter.

If you're using an aftermarket carbon air filter, I found it greatly inhibits airflow and I would recommend against it. It's an extra $25($40~ total) for the OEM carbon version, an expense you only have to pay once a year. That's less than $4 a month for clean air without the same restriction that the FRAM and STP version give you.

Lavrishevo

iTrader: (1)

Denso is only $17 on Amazon. I order my Denso Cabin and engine filter from Amazon. The only filter I don't run oem is my rear AC. It's like $150 from the dealer. Ridiculous. I run the Beck Arnley.

http://www.amazon.com/gp/aw/d/B000CJ...AKL&ref=plSrch

jimbosr1

$150 for a filter!
man they are might proud of that.

iToaster

To be fair, the rear filter in 04+ models is coated with a special photocatalyst that works with the ultraviolet light in the updated air purifier to better purify the air or something along those lines. Not that it's really worth the money, but they can ask more for it.