Recently had two of these installed to match two Lennox Air Handlers. I noticed the opening where the power plug goes into the unit pulls a good amount of air, theoretically pulling the dirty attic air into the unit. From an IAQ standpoint, isn't that a significant defect?
Since I live in the desert, I unplugged the UV lights and taped over the openings, choosing to run it as a normal MERV16 filter.
I have installed a few of those and they are nice units. If I remember correctly the MERV filter is closest to the furnace and the doors have changed in the last 2-3 years, but I could swear there was a rubber grommet/ seal were that plug goes through the door. If not then I would us foil tape to seal hole after plugging it back in. I typically use that same foil tape to seal any and all seams that I may see on the filter, furnace, coil and plenums to reduce air leaks. Don't use mastic on the filter door (I say that because I've seen it done).
Tape it up after you plug it in. Otherwise those are just some really expensive filter cabinets. If you don't care about the odor reduction then remove the bulbs and catalyst cuz they're just adding static pressure. On a side note, if you don't want to spend a small fortune for the replacement kits every couple years(or every year from what I hear the new models are going to), get a UV/ozone purifier. They sterilize germs unlike the Lennox pure air and the ozone does a better job on odors.