Not exactly, ducted fans are just air pumps, and if they cannot get air in the cannot pump it out the back. There are many models out there that have intakes too small for the flow needed for the fan, and cheater holes are the only way to get them to perform. Many will argue that once in the air the undersize "clean" inlet/s will be ok, but not in my experience. Covering cheaters has resulted in large performance dropoff in most models with undersize intakes.