Why don't my filters ever get dirty. My house is very dusty

When your A/C is on do you feel a strong pull of air going through the vent? If not you may have an issue. The only way it is going to filter is by passing air through the filter. You may have holes or something missing in your ductwork.

Yes there is a fair amount of pull

Its hard to judge fair. So lets try it this way. Is there enough air passing through it to make it difficult to remove a filter when it is "on" and pull it back into place on its own ?

There are no grille filters only filters are in the down flo filter in plenum. But, if there were filters in the 3 central return points one for sure would pull it back into place on its own. I will check the other 2 to see how strong the pull is there. Thx

Ok I checked and they too have a strong pull

Then maybe this is normal for where you live. Consider yourself lucky that they don't clog up fast. On average filters should be changed or cleaned if reusable about once a month.

It's almost like the air is bypassing the filters. Could that happen if the blower is installed wrong? It is not normal for Oklahoma and my brother lives down the street and his get plenty dirty. Mine could go indefinitely without getting dirty. Something is wrong, but I can't figure it out and the repair people don't seem to be concerned.

What is the airflow like at the registers (supply air)? Any chance of a duct leak if you are getting a lot of dust?

you can try this door trick (http://phxheatpump.blogspot.com/2012/02/how-do-i-know-i-have-duct-leak-old-door.html)


A return leak would still pull in air at the return but would also suck in a lot of junk in the attic, crawl space etc where you are. If that is the case and you do the door trick the air should be trying to close the door or air blowing out because the fan motor has less resistance on the return side and is pulling in excess attic air, etc...

I've caught a lot of ductleaks this way and they may not be that bad, just near a dusty spot or cellulose insolation or something.

Why don't my filters ever get dirty. My house is very dusty ?
Older homes have more drafts than newer homes and will let in more dust in. The same with duct systems. The air ducts of older homes are not sealed as well as the newer ones. The type of air filter you use may make the difference. If its one of those old blue ones that you can hold up in front of your eyes and read the news paper good luck catching dust or a small bird with it. You may need to get a better filter. Have a blower door test ran on your home it will show all air leaks in your home and duct system.