The following components of an HVAC system are considered refrigerant containing components: condensing coil, compressor, evaporator coil, metering device (TXV, EXV), filter/drier, and refrigerant piping (line-set).

Alterations or repairs to any of these components that would require the removal and/or replacement of refrigerant to the system may trigger a requirement to verify that the system is correctly charged after all work is completed.