Sorry for another filter question but this is tough. With my old furnace it had a opening in the wall for a 20 by 25 filter. With the new one they installed another intake in a room that needed it that is about the same size as a register. The unit has a Honeywell 16 by 25 5 inch filter mounted in the unit. The problem is where my larger intake is, it is now getting covered inside on the material that lines it with dust and is really looking bad.
Can I take out the Honeywell and put something like a merv 8 disposable in the grill again and get one of the merv 4 cutaway filters to size it and out it in the register intake. Less filtering but at least my larger intake will not get filty. Thank you.