Honeywell FC40R filters - help?
I've read the various posts on using the 4" MERV8 (or less) filters. I'm about to purchase them, but I have the cabinet that accepts 1" filters, but it does the metal tabs that can be bent/removed and hold a 4" filter.
However, Honeywell directions shows needing "7 inches total for a 4" filter". How important is having the extra 3 inches of space above the filter?