Walk-in cooler owners have often asked if it is really a good idea to switch off the evaporator fans inside their coolers. Intelligently shutting down your evaporators does not compromise the system’s ability to keep the cooler at the desired temperature, nor does it create potential to damage the compressor system.
...well, not quite free, but as close to free as any of us are going to get. One satisfied customer in upstate New York has used its compressors and evaporators for a total of 45 minutes through the first two months of 2015!!! It has been keeping its 400,000 cubic foot beer warehouse at a cool 38 degrees using only four industrial Polar Power Packages.