[mr337]

I have been told a different take. The amount of airflow over the coils is important as the compressor system also expects a certain thermal exchange (think air conditioning) and thus a certain pressure on the return.

Less air over the coils can inhibit the cooling properties, this was conveyed to me as high "head" compression pressure that can lead to premature compressor failure in the outdoor AC part, the expensive part. This is more important as the higher the SEER level, generally newer the system, the more sensitive they are to this issue. HVAC tech sold me with high head pressure expect failure of compressor in a few years.

Also you are running as efficient since the AC has to work longer burning electricity.