Cabin Filters...what's the deal?

[dx92beater]

On all of my new to me vehicles I am seeing cabin filters being marketed as important elements to fresh air. I'd really enjoy fresh air during my no longer too often commutes due to covid. However, I know that generally the dirtier a filter is the better it filters correct?

Doesn't the same apply to automotive HVAC systems? I spend coin and time to replace my cabin filter but I am actually allowing more particulates to flow in the cabin than if I did not replace it right?

I am sure that the cabin filter has to be replaced sooner or later but I am not too eager to replace the cabin filter on all of my vehicles too frequently.

I have also cut up higher MERV home HVAC filters of odd sizes that I got for cheap in the past and shaped them like the factory filter but the cost benefit doesn't seem to be there. I admit I am a bit lazy sometimes and things are starting to become a chore as I get older. Some of the hvac filters are not uber easy to replace either.

Thank you.

 

[JHZR2]

Funny situation, isn’t it.

I always attributed filter change to higher delta P resulting in higher energy use moving air/slower velocity across the coils.

I agree filtering is superior as it builds up a “cake” or equivalent. Up to the point at least that pressure drop starts to increase fast.

Never underestimate the ability of marketing folks to make up stuff to sell product. I’m sure someone can come up with a speck of rationale as to why it’s right and real... just enough to be “truthful”.

Now, the one thing I’d wonder is if since cabin filters aren’t exactly tightlay sealed, perhaps a clogged filter can allow a lot of bypass air, and that would be full of pollen or whatnot...

 

[dx92beater]

Great take. Thank you. I didn't notice that there was a filtration forum perhaps even a cabin filtration subfolder. Would it be possible to move it?

Mehhhh...probably lots of traffic by leaving it here too.

Either way as you say, other pros will be arriving soon. Pressure drop is a big deal. I don't want to hurt my HVAC system is about all.

I have never changed the cabin filters on my VW TDI or Tribeca. I am starting to wonder. I suffer from allergies to dust for starters. Those are larger particles. I guess any cheapo filter should catch that. I'd put more faith into a deep cleaning of the vehicle interiors which I admit I rarely do. It's discouraging living off of a gravel road to "half clean" a vehicle.

 

[Cripes]

Ive changed my cabin air filter twice on an 07 Pilot. The first time, the filter was very wet and gross. I was glad I did. Perhaps take a peak at yours and see how it looks.

 

[pezzy84]

IMO the cabin filters primary function is to keep all that crap from getting into your evap coil and/or heater core where it will stay forever until you need to replace the heater core or evaporator. Side benefit is it does filter a little bit of smaller bits from blowing into the cabin, just like your HVAC filter its mainly to keep the system clean.

 

[JeffKeryk]

I have changed cabin air filters numerous times and experienced better air flow outta the vents.
Sometimes they come out very well used...

On a similar note, many people changed their cabin air filters in many areas of California after the wild fires.
Everyone was coughing.

 

[meep]

Slower air flow in automotive HVAC due to restricted filters would be no different than running a lower fan speed, as seen by the coils. The compressor will cycle normally. Im not an aggressive filter changer, but every 2 years seems good to me with these. I don’t think the activated charcoal elements last very long, but as black as these things come out, I appreciate that it’s not my lungs. Note- in our newest vehicles, recirc bypasses the filter, and the ac defaults to recirc most of the time, so they may not be as deeply used.

 

[Justus1]

I change my cabin air filter once a year. Usually in May or June.

 

[Eddie]

~ 24,000 miles or two years is my method.

 

[oldhp]

A mechanical air pump (engine) is going to suck some air one way or the other. So the "caking" thing isn't going to hurt it as much as a electric blower wheel fan. A fresh cabin air filter will insure proper air flow to the HAVC car systems. Pretty simple to change and if you saved your change, you would have more than enough to buy a filter yearly. My thoughts. . .

 

[Artem]

I know this is a 6 month old thread but I just gotta chime in real quick…

I don’t understand the standardization of air filter changes based on a set mileage or time frame. Everyone operates in different conditions (dust, parking under trees and your AC usage in general) and from experience, these parameters effect the condition of the filter.

My wife parks in the garage. Her cabin filter stays WAY CLEANER then mine, which is parked under our big ass tree. I always pick out leaves from my filter whereas hers is nothing but a fine layer of dust.

Plus the design of the cowl and the overall design of the ac system plays a role in how much dirt gets shoved directly on the filter.
I’ve seen vehicles that have huge openings to the point that very large bugs can easily get in and I’ve seen others that have OEM very fine mesh or guards in the cowl opening which acts as a pre-filter so the cabin filter stays cleaner for LONGER.


Thankfully all my recent vehicles have easy access to cabin filters and I frequently take 30 - 40 second to peek in there and tap out the loose stuff it collected and shove it back in there. I splurge for the high end filters and try to make them last as long as possible.

 

[JustinH]

Changed the cabin filter in my wifes 17 Sonata with 18k miles on it. It was trashed.

Also it was a napa filter, so it has been changed by a previous owner at least once.

Once a year makes sense.

 

[mightymousetech]

I change my cabin air filter once a year. Usually in May or June.

Same here.

 

[Sparky16]

I've seen dead rodent there . . . reason enough to change every so often.

 

[ryster]

When I had my Hyundai, the dealer tried to upsell me a $80 cabin air filter replacement every single time I went in for an oil change (every 5,000 miles.) It was bone simple to replace, so I did them myself for 1/8th the price as needed. I finally had a terse discussion with the service advisor as to why the car seems to need a cabin filter every single time I come in, and my previous Chevrolet only needed 2 in the 60,000 miles I owned it. He tried to claim that the roads around where we live are very dirty/dusty and the filter gets dirty very quickly. I told him that I drive the same exact roads with the Hyundai that I did with the Chevy, and it sounds like the Hyundai is letting in too much dirt. He shrugged and literally turned around and walked away.

 

[Bud_One]

A/C air flow is all about flow vs filtration in my book .
Anything that's inhibiting cold air flow from the vents when it's 100 degrees F outside is not my friend.

 

[Krieg]

I wouldn't own a Hyundai based on these forums and NHTSA.

 

[Bud]

Same here.

I do the same, every year once the main spring pollen season lets up.

 

[TheLawnRanger]

Every 30k mine get checked. Doesn't always need to be changed. Of course my truck doesn't have one. Danger danger.

 

[wemay]

Same here.

Here as well. Once a year.