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.