How to design a custom cabin filter

[toyotafan113]

I live in a metropolitan area, and when I turn on the AC, there are black powders, or smokes from other automobiles, entering my cabin and nostrils. This ain't healthy.

Has anyone tried to cut and glue a custom-trimmed filter for 8th gen Corolla? Is there enough space near the blower motor to be creative with an AC filter used at home?

Thx.

[all2baka]

Only when the AC is on or when you turn on the entire air system?

[fishexpo101]

I've seen some people put filters inside the vent tubes (i.e., remove the cabin vents, stuff in a register filter (the stuff that you insert behind a floor vent on most homes). There isn't any clearance between the blower an the main trunk of the HVAC registers - but that doesn't mean you couldn't add a spacer to make enough room.

While ago, I was planning to measure the mounting locations and check clearances to see if I could retro a cabin air filter into the HVAC from a 9th gen blower assembly. But that sort of fell of the table due to time constraints.

[toyotafan113]

Whether it is in A/C button light on or off, whenever air comes in or the internal air circulates, I get the black powder accumulating between the vent silts or grills, whatever you may call it.

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Idea: I am thinking of placing a 3in x 4in custom cut square filters *behind* the vent holes which are behind to the dashboard.

1 on the far-left side of driver
2 central vents or on top of the radio
1 on the passenger, far-right side

I expect 4 filters for these grills will do. I may velcro-tape the filter pieces behind the grills.

What worries me is the noise may increase due to the obstruction of the air flow due to the filter. But I would rather have clean air and a noisy AC than a quiet AC with dirty air.

I need to know how to disassemble or pull the far-right and far-left vents. Are they "pliable" like the center grill set?

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Thanks for continuous thought and brainstorms.

[fishexpo101]

Those outside vents will pull out the same way as the center ones - but if the car has been garaged outside all the time, I'd be worried about brittleness of the plastic. Just go slowly and work at it a little at a time to help reduce the chance of breaking those vents.

As for the black stuff out near the vents - might be worthwhile to pull the blower fan out and taking a peek at it. If it was anything like mine, would probably shock you as how much crap there is on the fan. Same goes for the vent tubes themselves, probably can't clean the whole length, but try and get to as much as you can without damaging anything. Lot of stuff might get dislodged and shot out the vents when you first run the fan, but should be cleaner afterwards.

Try wiping an interior section with a damp cloth and see if there is any black residue on it. Could be from debris from the road, could be the gasket material and tubing itself is breaking down and ejected through the vents, or be mold and/or mildew broken up and shot out the vents.

You will decrease the amount of airflow through the vents, but I haven't heard anything "bad" about doing this, fan blower health wise. If you have allergies or just doing it for peace of mind, IMP, worth the trade-off of overall air flow for cleaner air.

[toyotafan113]

fishexpo101 and others: Thanks for your input.

I forgot to mention that I replaced the blower motor 5 days ago. So the circular, vertical blade is white and clean.

And yes, I almost vomited when I pulled the previous blower motor with fans. It was blackish gray with dry leaves inside the fan, dancing like a circus when I turned on the AC. That is how I discovered the feasting noise.

Q: But where is the main entrance (?) of air from the front (?) of the car into the blower motor chamber? I want to put the filter on the "master air-intake hole or tube", and I am very cautious to use this phrase to prevent the confusion with "air-intake manifold" or similar engine air-intake parts. I believe once I filter that master-air-intake-hole-for-the-cabin, the rest of air splitter-tubes for the cabin air-grills may stay cleaner.

Again, here I am not talking about the engine part but the cabin air quality.

Any comment from anyone is appreciated.

[old-corolla]

i would go that route instead of the indiviual filters for each vent. for one it sounds like they would be visible, and for two if your vents are brittle, having to take them in and out to change the filter might just do them in after enough in-and-out.
let us know how it works out

[fishexpo101]

Originally Posted by toyotafan113

Q: But where is the main entrance (?) of air from the front (?) of the car into the blower motor chamber? I want to put the filter on the "master air-intake hole or tube", and I am very cautious to use this phrase to prevent the confusion with "air-intake manifold" or similar engine air-intake parts. I believe once I filter that master-air-intake-hole-for-the-cabin, the rest of air splitter-tubes for the cabin air-grills may stay cleaner.

Again, here I am not talking about the engine part but the cabin air quality.

Any comment from anyone is appreciated.

The air enters the cabin via the cowl - that black plastic panel that sits right below the windshield, on the outside of the car - right below that air runs to the cabin. You'll have to find some way to get to that main trunk - may not be very easy, hence why the OEM tapped into the line right on top of the blower on the 9th gen Corollas - as that filter can get pretty nasty very quickly, depending on the conditions - also need a quick, easy access for filter replacement.

Placing it in front of the blower will also protect the blower as well - though that implies that you have to check on the filter on a regular basis. In any case, any type of filter is better than nothing at this point.