Air Conditioning - What Size Filter for 3 Ton Unit?

What size Filter should I have for a 3 Ton Heat Pump A/C System? I'm getting quotes about putting in a new 3 Ton System & the Tech told me I had to cut out a wall in my Closet (next to Unit) and put in a bigger Air Filter. My Air Filter is a 25"X16"X1" Is this too small for a 3 Ton Unit. It worked for 13 years with my old 3 Ton Unit 10 Seer. The old unit is being replaced by another 3 Ton 13 Seer. Thanks in advance!

The installation manual of the new unit should have the manufacturer's recommended size. Shouldn't the tech give you "qualified" advice on this? You as the homeowner should not have to worry about the technical aspects of this installation.

Again, the Tech is telling me I need a bigger Filter and is saying he would go through my Closet to put an additional Filter to compensate for the size of my Filter. This is not a new house. Filter size was cut when it was built in '95. We would like to avoid doing any modification of my closet. Someone on here must know Filter Sizes for a 3 Ton 13 Seer System. Is my Tech right about this ? Or is he just giving himself more work?

I agree with your a/c tech. 16x25 is a little bit too small for a 3 ton system (probably a builder install). While it may work, it is not ideal. 20x25 is what I would consider the absolute minimum.

Or is he just giving himself more work?

It appears you may not trust your technician. If you don't value his opinion, find another technician. But be careful, you may find someone who will tell you exactly what you want to hear.

You mention the absolute Minimum, but what is the ideal size for a 3 Ton ? Thanks for the help !

At a recommended filter surface area of 200 square inches per ton your current filter is sized for a 2 ton system this does not mean that your setup won't work it does mean that the system was improperly installed meaning you are not getting the air conditioning you were paying for equalling higher energy costs and shortening the life of the system and increasing repair costs

Dumb Question but here goes:
If for a 3 Ton I need 600 Sq. Inches, what dimension Air Filter do you suggest? Thanks. I just
can't do the math. Sorry.

Dino...cause the other guys don't seem to be on.

Based on what they said...you'd need a 20 x 30 (600 sq in)filter if it was just going to be one filter. If he's adding to what you already have, it could be smaller. Your filter now is 16 x 25 = 400 sq in. So if he's adding on, you would need at least 200 sq in more. 10 x 20 ( 200 sq in), 14 x 14 (196 sq in), 15 x 15 (225 sq in), etc , etc.

But what pflor and J-C said really applies. What is the required return size per the manufacturer and why wouldn't you believe what the guy is telling you. He could just slap a new unit in the never return your call when it was noisy or didn't work right. It sounds like he's trying to do it right to me. Although it seems putting a return in a closet (I presume it has a door on it) would pretty much defeat the purpose, since it will have little to no air flow with the door closed.

Thank you & everyone for your time. It's not that I don't believe the Tech. I'm getting estimates right now and so I'm getting different opinions. A bit confused since the first company I called never mentioned the small air filter. Your explanation is very helpful, accurate & detailed. Thank you. Forums like these are very helpful for people like myself, who just don't know. :)