Only 1/4 of A/C Filter being used

[caswelld]

I pulled out the air conditioning filter and noticed that only about the forward 1/4 of the filter had any dust on it. The rest of the filter looked new, not a bit of dust.

It looks like air is only passing through about a quarter of the filter....is that normal?

Dave

[ScottBrownstein]

Originally Posted by caswelld

I pulled out the air conditioning filter and noticed that only about the forward 1/4 of the filter had any dust on it. The rest of the filter looked new, not a bit of dust.

It looks like air is only passing through about a quarter of the filter....is that normal?

Dave

Most AC units have a "dump valve" which is a slider that bypasses the ducts and allows air to go straight down into the living space. On my unit it covers/opens the back half of the grille. With that closed the air will only go over part of the foam filter, not sure about the percentage, but the filter is for the intake and not the outlet.

[hook47]

I have I have noticed the same thing on mine.

[caswelld]

Ours has that as well, it's open most of the time.

[redneck 92]

Ours is the same on both.

[halla]

Yep, same

[FOURWHL]

That’s the intake.

The rest of the filter covers what would be the exhaust except for we have ducts so I don’t believe much air flows over it unless you open it up and don’t use the ducts

[Iwannacamp]

One mine... that is where the return air is. The cavity is larger, but the return air opening is behind the dirty spot. Least restriction is the path in passage for just about anything.