I recently called our HVAC installer to ask about putting a 4" or 5" airfilter at the air handler (I think right term) after reading about the problems with the 1" filter we have now.
He told me we could also get a 4" filter that he could install where our 1" filter is now (behind the grate in the walls or ceiling). I looked around but did not see any mention of that here. Are there any opinions about these?
We have several different size intakes, anywhere from a 12x12 to a 16x25, so I assume they come in all different types of sizes.
From what he said the installation is much less expensive, but since you have to buy more of them the cost adds up.
Are there any opinions about these?