Refrigerant PT charts and field calculators
Saturation pressures for 62 refrigerants computed from reference equations of state, with liquid (bubble) and vapor (dew) values for every blend. Type a gauge reading to get the saturation temperature, or open a chart.
- 319psig at 100°F
R-410A PT chart
A1 · GWP 2,088 · POE · Residential and light commercial split AC and heat pumps
- 303psig at 100°F
R-454B PT chart
A2L · GWP 466 · POE · New residential and light commercial split AC and heat pumps
- 326psig at 100°F
R-32 PT chart
A2L · GWP 675 · POE · New residential and light commercial AC and heat pumps, including ductless
- 196psig at 100°F
R-22 PT chart
A1 · GWP 1,810 · Mineral oil · Residential and commercial AC and heat pumps built before 2010
- 124psig at 100°F
R-134a PT chart
A1 · GWP 1,430 · PAG · Automotive A/C (vehicles before R-1234yf)
- 237psig at 100°F
R-404A PT chart
A1 · GWP 3,922 · POE · Low- and medium-temperature commercial refrigeration
- 225psig at 100°F
R-407C PT chart
A1 · GWP 1,774 · POE · R-22 retrofits in residential and commercial AC and heat pumps
- 244psig at 100°F
R-448A PT chart
A1 · GWP 1,387 · POE · Supermarket rack systems
Superheat calculator
Enter the suction pressure and the suction line temperature to get actual superheat.
Subcooling calculator
Enter the liquid line pressure and liquid line temperature to get actual subcooling.
Target superheat calculator
Enter the indoor return air wet bulb and the outdoor air temperature entering the condenser to get the target superheat from CEC Table RA3.2-2.
PT calculator
Pick a refrigerant and type a gauge pressure to get its saturation temperature, or type a temperature to get the pressure.
Temperature glide calculator
Pick a blend and enter a gauge pressure to get its bubble point, dew point, midpoint and the glide between them.
Duct sizing calculator
Enter the airflow in CFM and a design friction rate in inches of water per 100 ft.
Line set charge calculator
Enter the liquid line size, the actual line set length and the length the factory charge covers.
Airflow (CFM) calculator
Enter the sensible heat in BTU/h and the supply and return air temperatures to get airflow in CFM.
Pressure converter
Enter a value and pick its unit to see it in psig, psia, kPa and bar (gauge and absolute), MPa, inches of mercury vacuum and microns.
Psychrometric calculator
Enter the dry bulb and one second reading (wet bulb, relative humidity or dew point), plus elevation if you are well above sea level.
Static pressure calculator
Enter the supply and return static pressure readings in inches of water column and the rated external static from the nameplate.
R-410A vs R-454B
No. Can you put R-454B in an R-410A system?
R-410A vs R-32
No. Can you put R-32 in an R-410A system?
R-410A replacement: R-410A vs R-454B vs R-32
No. Is there a drop-in replacement for R-410A?
R-22 Replacement Refrigerants
It depends. What replaces R-22 in an existing system?
R-22 vs R-410A
No. Can you put R-410A in an R-22 system?
R-404A Replacement Refrigerants
It depends. What replaces R-404A in an existing system?
R-134a vs R-1234yf
No. Can you put R-1234yf in an R-134a system?
R-454B vs R-32
No. Can you put R-32 in an R-454B system, or the reverse?
A2L refrigerants guide
A2L is the ASHRAE 34 safety group for refrigerants with lower toxicity (A) and lower flammability (2L).
Refrigerant flammability and safety classes
Every refrigerant gets a two- or three-character ASHRAE 34 safety group: a letter for toxicity (A lower, B higher) and a number for flammability (1, 2L, 2, 3).
Recovery machine and cylinder compatibility for A2L refrigerants
Use a recovery machine certified for flammable refrigerants (EPA Appendix B4, which adds UL 1963 Supplement SB) and a recovery cylinder rated for the refrigerant on A2L systems.
AIM Act refrigerant rules for HVAC/R techs
The AIM Act works through three EPA programs: a cap on HFC production and import (down to 60% of baseline for 2024–2028), Technology Transitions limits on the GWP of refrigerant in new equipment, and emissions rules for leak repair, reclaimed refrigerant and cylinders.
R-410A phase-out
R-410A is not banned.
R-22 phase-out
R-22 production and import in the US ended on Jan 1, 2020, and new R-22 equipment stopped in 2010.
Refrigerant detection systems and leak mitigation
A refrigerant detection system is a sensor plus a control board that runs the indoor blower and locks out heating and cooling when it detects refrigerant, so a leak is mixed into the room air instead of pooling.
Refrigerant cylinder colors
Since Jan 1, 2020, AHRI Guideline N has called for every new refrigerant container to be painted light green-gray (RAL 7044), whatever it holds.
A2L charge limits and minimum room area
An A2L system's total charge sets the smallest room it can serve.
Installing and servicing A2L systems
A2L work uses the same brazing, pressure test and vacuum steps as R-410A, with extra rules on top: A2L-rated tools, no ignition sources near an open system, brazed or UL 207 joints only, an A2L-compatible leak check after charging, the total charge on the label and a working refrigerant detection system before you leave..
A2L building codes and state adoption
The 2024 International Mechanical, Residential, Building and Fire Codes contain the A2L provisions, and the 2024 Uniform Mechanical Code references ASHRAE 15 and 15.2 and UL 60335-2-40.
EPA refrigerant leak repair rules
Owners must repair leaks once an appliance's leak rate passes 10% (comfort cooling), 20% (commercial refrigeration) or 30% (industrial process refrigeration).
How to read a PT chart
Find the gauge pressure in the chart and read the saturation temperature next to it.
Refrigerant GWP chart
GWP compares how much heat a gas traps over 100 years against the same mass of CO2.
Refrigerant oil types
CFCs and HCFCs such as R-12 and R-22 run on mineral oil or alkylbenzene.
Evacuation and microns
Pull the system down to the manufacturer's micron target, isolate the pump, and watch the micron gauge.
Nitrogen pressure testing and purge brazing
Braze with a small flow of nitrogen, then pressurize the line set and indoor coil with dry nitrogen to the pressure the installation manual gives, never above it, and hold.
EPA Section 608 certification
Section 608 certification is required for anyone who opens a refrigerant circuit on stationary equipment.
How to recover refrigerant
Confirm the refrigerant, prepare an evacuated cylinder rated and labeled for it, recover liquid first and then vapor with a certified machine, and pull the system to the level in 40 CFR 82.156 Table 1.
How to identify an unknown refrigerant
Read the equipment nameplate and the cylinder label; cylinder paint and service ports tell you almost nothing.
Where the numbers come from
Every pressure on this site is calculated with CoolProp, the open-source implementation of the reference equations of state, and checked against the manufacturer's or NIST's published values at several points. The differences are shown on each chart. Regulatory pages cite the Federal Register, the eCFR and EPA, and each one shows when it was last reviewed. Data sources and method