Refrigerant circuit with reduced environmental impact

A method of cooling a walk-in refrigeration unit, the method comprising:

• providing one or more refrigeration systems, wherein each refrigeration system comprises:
• a condenser;
• a plurality of compressors, wherein each of the plurality of compressors comprises a compressor input and a compressor output and wherein each compressor output is communicably coupled to the condenser;
• and
• propane refrigerant with a maximum charge of 5.3 ounces per each of the plurality of compressors;
• an evaporator;
• wherein the one or more refrigeration systems provides cooling to the walk-in refrigeration unit.

A walk-in refrigeration unit comprising:

• one or more refrigeration systems configured to receive power from a single source, wherein each refrigeration system comprises:
• a single condenser coupled to the power source;
• a plurality of compressors, wherein each of the plurality of compressors comprises a compressor input and a compressor output and wherein each compressor output is communicably coupled to the condenser;
• an A3 refrigerant with a maximum charge of 5.3 ounces per each of the plurality of compressors;
• a plurality of expansion devices communicably coupled to the condenser;
• and
• a single evaporator communicably coupled to the plurality of expansion devices.