The Refrigerant Compliance Glossary

The model code governing HVAC and refrigeration installation, including refrigerant charge limits by occupancy, machinery room requirements, and refrigerant detection. Adopted with amendments by state and local jurisdictions.

The manufacturer’s data plate listing model and serial number, refrigerant type, factory charge, and electrical data.

A refrigerant circuit closed by welding or brazing with no field-serviceable connections, factory-charged and factory-sealed.

An appliance using a refrigerant with a saturation pressure below 45 psia at 104°F — R-11, R-123, R-113, R-245fa. Typically large centrifugal chillers.

EPA’s grouping of appliances by refrigerant saturation pressure at 104°F: very high above 355 psia, high 170–355, medium 45–170, and low below 45.

A device on low-pressure chillers that removes air and moisture drawn in through sub-atmospheric leaks, logging its run time.

An inline component that removes moisture, acid, and particulate from circulating refrigerant. Replaced on any service that opens the system.

A vessel on the suction line that traps liquid refrigerant and returns it to the compressor as vapor, protecting against liquid floodback.

A vessel storing liquid refrigerant between condenser and metering device, buffering charge across varying load.

The metering device that drops refrigerant pressure entering the evaporator and controls flow — thermostatic (TXV), electronic (EEV), or a fixed orifice.