- Refrigerant type / safety class
- HCFC (legacy)
- 100-year GWP (EPA reference)
- 1,810
- Charging and P-T guidance
- Use the R-22 P-T chart and the equipment manufacturer's charging method.
- Handling and field notes
- Production and import of newly manufactured R-22 ended in the United States in 2020. Service rules still apply; do not mix it with replacement refrigerants.
Refrigerant reference
Useful notes without pressure shortcuts
Use these notes for context, not as fixed charging targets. Pressure depends on saturation temperature, load, airflow or water flow, and the equipment.
25 of 25 refrigerants
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- Refrigerant type / safety class
- HFC (single component, A2L)
- 100-year GWP (EPA reference)
- 675
- Charging and P-T guidance
- Use R-32 P-T data and the OEM charging procedure; never set charge from pressure alone.
- Handling and field notes
- Mildly flammable (A2L). Follow the unit's refrigerant-specific safety, leak-detection, ventilation, and charge-limit requirements.
- Refrigerant type / safety class
- HFC (single component, A1)
- 100-year GWP (EPA reference)
- 1,430
- Charging and P-T guidance
- Use R-134a P-T data and the OEM procedure; verify application and equipment design.
- Handling and field notes
- Found in some older refrigeration and chiller equipment. Not interchangeable with R-513A or other proposed alternatives without OEM approval.
- Refrigerant type / safety class
- Hydrocarbon / propane (A3)
- 100-year GWP (EPA reference)
- 3.3
- Charging and P-T guidance
- Use only in equipment expressly designed and labeled for R-290; follow its specified charge weight.
- Handling and field notes
- Highly flammable (A3). Specialized service procedures, ignition-source controls, ventilation, and charge limits are critical.
- Refrigerant type / safety class
- HFC blend (A1)
- 100-year GWP (EPA reference)
- 3,922
- Charging and P-T guidance
- Follow the OEM charging procedure and the R-404A P-T chart.
- Handling and field notes
- Legacy commercial refrigeration refrigerant. High GWP; do not assume a proposed replacement is a direct drop-in.
- Refrigerant type / safety class
- HFC zeotropic blend (A1)
- 100-year GWP (EPA reference)
- 1,774
- Charging and P-T guidance
- Use dew-point saturation for superheat and bubble-point saturation for subcooling.
- Handling and field notes
- Temperature glide matters. Follow the manufacturer's liquid-withdrawal and charging instructions; do not mix with other refrigerants.
- Refrigerant type / safety class
- HFC blend (A1)
- 100-year GWP (EPA reference)
- 2,088
- Charging and P-T guidance
- Use R-410A P-T data and the equipment-specific charging method.
- Handling and field notes
- Common in legacy comfort cooling and heat pumps. Higher operating pressures than R-22; never substitute R-32 or R-454B into equipment not approved for it.
- Refrigerant type / safety class
- HFO/HFC blend (A1)
- 100-year GWP (EPA reference)
- 1,386
- Charging and P-T guidance
- Use the correct dew/bubble P-T data and OEM charging method.
- Handling and field notes
- Used in certain commercial refrigeration systems. Has temperature glide; check compressor, controls, and oil requirements for the actual equipment.
- Refrigerant type / safety class
- HFO/HFC blend (A1)
- 100-year GWP (EPA reference)
- 1,396
- Charging and P-T guidance
- Use the correct dew/bubble P-T data and OEM charging method.
- Handling and field notes
- Used in certain commercial refrigeration applications. Glide and equipment-specific capacity/valve settings matter; not a universal R-404A replacement.
- Refrigerant type / safety class
- HFO/HFC blend (A1)
- 100-year GWP (EPA reference)
- 601
- Charging and P-T guidance
- Follow the manufacturer charge weight and applicable P-T data.
- Handling and field notes
- Lower-GWP option in some medium-temperature refrigeration and chiller designs. Confirm the exact approved equipment and charge procedure.
- Refrigerant type / safety class
- HFO/HFC blend (A1)
- 100-year GWP (EPA reference)
- 2,140
- Charging and P-T guidance
- Use R-452A-specific P-T data and the equipment procedure.
- Handling and field notes
- Used in some transport and low-temperature refrigeration applications. Follow manufacturer-approved retrofit or new-equipment instructions.
- Refrigerant type / safety class
- HFO/HFC blend (A2L)
- 100-year GWP (EPA reference)
- 698
- Charging and P-T guidance
- Use R-452B-specific P-T data and the OEM charge method.
- Handling and field notes
- Mildly flammable (A2L). Handling requirements differ from A1 refrigerants; never charge it into R-410A equipment unless expressly approved.
- Refrigerant type / safety class
- HFO/HFC blend (A2L)
- 100-year GWP (EPA reference)
- 237
- Charging and P-T guidance
- Use the correct dew/bubble data where applicable and the OEM instructions.
- Handling and field notes
- Low-GWP A2L blend for certain refrigeration designs. Observe blend-handling, ventilation, detection, and charge-limit requirements.
- Refrigerant type / safety class
- HFO/HFC blend (A2L)
- 100-year GWP (EPA reference)
- 465
- Charging and P-T guidance
- Use R-454B-specific P-T data and the OEM charging procedure.
- Handling and field notes
- Used in newer comfort-cooling equipment. Mildly flammable (A2L); follow unit nameplate, detection, airflow, and charge restrictions.
- Refrigerant type / safety class
- HFO/HFC blend (A2L)
- 100-year GWP (EPA reference)
- 146
- Charging and P-T guidance
- Use the correct R-454C P-T data and manufacturer instructions.
- Handling and field notes
- A2L blend used in selected low-GWP refrigeration designs. Account for glide and use the required refrigerant-safe tools and procedures.
- Refrigerant type / safety class
- HFO/HFC/CO₂ blend (A2L)
- 100-year GWP (EPA reference)
- 146
- Charging and P-T guidance
- Use manufacturer-specified P-T data and procedures for this blend.
- Handling and field notes
- Used in certain refrigeration equipment; its blend behavior and operating conditions are equipment-specific. Follow all A2L precautions.
- Refrigerant type / safety class
- HFC blend (A1)
- 100-year GWP (EPA reference)
- 3,985
- Charging and P-T guidance
- Use R-507A P-T data and the equipment-specific charge procedure.
- Handling and field notes
- Legacy commercial refrigeration refrigerant with high GWP. Do not assume another blend can be substituted without component and OEM review.
- Refrigerant type / safety class
- HFO/HFC blend (A1)
- 100-year GWP (EPA reference)
- 630
- Charging and P-T guidance
- Use R-513A P-T data and the OEM charging procedure.
- Handling and field notes
- Used in selected chillers and refrigeration systems. Confirm compressor, oil, performance, and control compatibility before any conversion.
- Refrigerant type / safety class
- HFO/HFC blend (A1)
- 100-year GWP (EPA reference)
- 287
- Charging and P-T guidance
- Follow R-515B equipment documentation and refrigerant-specific data.
- Handling and field notes
- Low-GWP A1 choice for certain chiller applications. Use only in approved equipment; do not assume direct interchangeability.
- Refrigerant type / safety class
- Hydrocarbon / isobutane (A3)
- 100-year GWP (EPA reference)
- 1
- Charging and P-T guidance
- Use only the charge weight and service procedure for equipment labeled R-600a.
- Handling and field notes
- Highly flammable (A3). Common in sealed domestic/light commercial units; ignition-source control and exact charge quantity are crucial.
- Refrigerant type / safety class
- Ammonia (B2L)
- 100-year GWP (EPA reference)
- 1
- Charging and P-T guidance
- Use ammonia-system procedures and suitable instruments; do not use HFC service assumptions.
- Handling and field notes
- Toxic and mildly flammable. Industrial systems require dedicated safety training, protective equipment, and emergency procedures.
- Refrigerant type / safety class
- Carbon dioxide / CO₂ (A1)
- 100-year GWP (EPA reference)
- 1
- Charging and P-T guidance
- Use R-744-specific high-pressure procedures and operating-mode data.
- Handling and field notes
- High operating/standstill pressures; transcritical systems need different diagnostics than conventional HFC systems. Follow rated pressure and relief-system requirements.
- Refrigerant type / safety class
- HCFO (single component, A1)
- 100-year GWP (EPA reference)
- 4
- Charging and P-T guidance
- Use R-1233zd(E)-specific chiller data and manufacturer procedures.
- Handling and field notes
- Used in certain low-pressure centrifugal chillers. Service, leak checks, and evacuation requirements differ from common comfort-cooling systems.
- Refrigerant type / safety class
- HFO (single component, A2L)
- 100-year GWP (EPA reference)
- 1
- Charging and P-T guidance
- Use R-1234yf service equipment and the OEM instructions.
- Handling and field notes
- Mildly flammable refrigerant common in automotive A/C. Never connect incompatible refrigerant recovery/charging equipment.
- Refrigerant type / safety class
- HFO (single component, A2L)
- 100-year GWP (EPA reference)
- 1
- Charging and P-T guidance
- Use R-1234ze(E) P-T data and equipment-specific procedures.
- Handling and field notes
- Low-GWP refrigerant used in some chillers and specialty applications. Follow manufacturer flammability and service guidance.
Charge by the procedure for the equipment in front of you. Use current pressure-temperature data and measured superheat/subcooling where the method calls for them. Do not use a pressure by itself as the charge test.
GWP values shown use the U.S. EPA Technology Transitions reference table. Regulatory values and assessment bases can differ by rule or source.
Diagnostic patterns
Read the whole refrigeration pattern
These combinations are clues, not diagnoses. Verify airflow or water flow, load, sensor accuracy, and the OEM charging method before changing the refrigerant charge.
Possible undercharge
High superheat + low subcooling after airflow/load are verified
Check first
Airflow, evaporator load, metering-device operation, and measurement accuracy
This pattern can support low refrigerant mass, but it should lead to a leak search and the OEM charging procedure. Do not top off by pressure alone.
Possible feed restriction
High superheat + normal/high subcooling
Check first
Filter-drier temperature drop, TXV/EEV command, sensing inputs, liquid-line condition, and charge history
Liquid can be backed up in the condenser/receiver while the evaporator is starved. Prove the restriction or metering-control fault before replacing a valve.
Possible overcharge / poor heat rejection
High condensing temperature/pressure with elevated subcooling
Check first
Condenser airflow or water flow, fan/pump staging, coil condition, ambient/entering-water temperature, and noncondensables
High head pressure is not automatically overcharge. Restore heat rejection and verify the complete operating pattern before recovering refrigerant.
Low superheat / floodback risk
Low superheat or evidence of liquid returning to the compressor
Check first
Airflow/load, EEV/TXV control, sensing bulb/thermistors, overfeeding, defrost/reheat sequence, and accumulator condition
Protect the compressor first. Determine why the evaporator is not fully boiling the refrigerant before extended operation.