We have a handful of things that we use to run efficiently at those temps. We start with the compressor itself. The compressor is a two stage semi-hermetic reciprocating compressor that can handle the wide pressure differential required to get down to these temperatures. We also implement within that compressor an economizer sub-cooler that helps the compressor run more efficiently at that place. We also use increased amounts of insulation, which you can see here, and special pumps and things like that to make the unit run more efficiently at those temperatures. Contact Us