Refrigerant Comparison Calculator
Put two refrigerants side by side at the same temperature: how their pressures compare, how their global warming potentials compare, and what a given charge amounts to in tonnes of CO₂-equivalent.
Method reviewed October 26, 2026. Version 1.0.0. How it works
Result
- R-410A saturation pressure (gauge)
- 118.4psi
- R-32 saturation pressure (gauge)
- 121psi
At 40 °F, R-410A saturates at 118.4 psig and R-32 at 121 psig. A 10 lb charge equals 9.47 t CO₂e of R-410A or 3.06 t CO₂e of R-32.
- R-410A is a blend; its dew-point (vapor) pressure is shown. The bubble point differs by under half a psi at 40 °F — see the PT calculator.
- Refrigerants are not interchangeable. Never put one refrigerant into equipment designed for another; equipment, oils and safety requirements differ. Only EPA-certified technicians may handle refrigerant.
- Pressure difference (R-32 − R-410A)
- 2.59psi
- Absolute pressure ratio (R-32 ÷ R-410A)
- 1.019
Climate impact
- R-410A global warming potential (100-year)
- 2,088
- R-32 global warming potential (100-year)
- 675
- R-410A charge as CO₂-equivalent
- 9.47t CO₂e
- R-32 charge as CO₂-equivalent
- 3.06t CO₂e
Show the working
- Saturation pressures from the validated CoolProp tables (absolute)R-410A: 133.1 psia; R-32: 135.6 psia at 40 °F
- Gauge = absolute − local atmosphereatmosphere 14.696 psia → 118.4 and 121 psig
- CO₂-equivalent = charge (kg) × GWP ÷ 1,0004.54 kg × 2088 ÷ 1,000 = 9.47 t; × 675 → 3.06 t
Where the numbers come from
Saturation pressures come from the same validated tables as our refrigerant PT charts, generated with the open-source CoolProp library and checked against independent published tables.
Global warming potentials (GWP) are the 100-year values EPA publishes: 2,088 for R-410A, 675 for R-32 (HFC-32), 1,430 for R-134a (HFC-134a) and 1,810 for R-22 (HCFC-22). They are based on the IPCC’s Fourth Assessment Report, and for regulated HFCs they equal the exchange values in the AIM Act regulations.
Reading the comparison
- Pressure: R-32 runs at slightly higher pressure than R-410A at the same temperature, while R-22 and R-134a run far lower. Equipment is designed for one refrigerant’s pressures.
- GWP: how much heat a kilogram of the gas traps over 100 years compared with a kilogram of CO₂.
- CO₂-equivalent: charge in kilograms × GWP ÷ 1,000 gives tonnes of CO₂e — the climate effect if the whole charge leaked.
Not a conversion guide
Refrigerants are not interchangeable. Each piece of equipment is designed, rated and listed for one refrigerant, with matching oil, controls and safety measures. Read the refrigerant and its safety class from the equipment nameplate and the refrigerant’s safety data sheet. Only EPA-certified technicians may handle refrigerant.
Worked example
These are the example values the calculator opens with, and the result the engine calculates for them.
Inputs
- First refrigerant
- R-410A
- Second refrigerant
- R-32
- Saturation temperature
- 40 °F
- Refrigerant charge
- 10 lb
- Site elevation
- 0 ft
Result
- R-410A saturation pressure (gauge)
- 118.4 psi
- R-32 saturation pressure (gauge)
- 121 psi
- Pressure difference (R-32 − R-410A)
- 2.59 psi
- Absolute pressure ratio (R-32 ÷ R-410A)
- 1.019
At 40 °F, R-410A saturates at 118.4 psig and R-32 at 121 psig. A 10 lb charge equals 9.47 t CO₂e of R-410A or 3.06 t CO₂e of R-32.
Assumptions
- Saturation pressures come from the same CoolProp tables as the site’s PT charts, each validated against at least two independent published tables. For R-410A the dew-point pressure is used.
- GWPs are the 100-year values EPA publishes (IPCC Fourth Assessment Report), which equal the AIM Act exchange values for regulated HFCs.
- CO₂-equivalent = refrigerant mass × GWP.
Limitations
- Safety (flammability and toxicity) classes are not shown: read them from the equipment label and the refrigerant’s safety data sheet.
- Pressures are saturation values. Operating pressures in a running system depend on the equipment and its charge; use the manufacturer’s data for charging.
Frequently asked questions
Why does R-410A show only one pressure?
R-410A is a blend whose dew-point and bubble-point pressures differ by less than half a psi at 40 °F. The comparison shows the dew-point (vapor) pressure. The PT calculator shows both.
Why is R-454B not included?
We only publish pressure data for a refrigerant when our tables agree with at least two independent sources, and the open-source model for R-454B does not yet. EPA lists its GWP as 465.
What does a tonne of CO₂-equivalent mean?
It is the amount of carbon dioxide that would have the same warming effect over 100 years. A 10 lb R-410A charge is about 9.5 tonnes CO₂e; the same mass of R-32 is about 3.1 tonnes.
Sources
- CoolProp — open-source thermophysical property library (version 8.0.0) — CoolProp developers (MIT licence). Equations of state for pure fluids and mixtures, incompressible fluids and brines, and IAPWS-IF97 water/steam; free for commercial use under its licence. Used here to generate the refrigerant saturation tables.
- Refrigerant PT charts and how they were validated — FreeHVACCalculators.com. Each published refrigerant’s generated table agrees with at least two independent published tables (worst differences and tolerances listed); R-454B is withheld because it does not.
- Technology Transitions GWP Reference Table — U.S. EPA. 100-year GWPs: R-410A 2,088; HFC-32 675; HFC-134a 1,430; R-454B 465. Exchange values for regulated HFCs are numerically identical to the 100-year AR4 GWPs (page updated April 2, 2026).
- Ozone-Depleting Substances (Class II list) — U.S. EPA. HCFC-22: GWP 1,810 (IPCC AR4, 100-year) and ODP 0.055 (Montreal Protocol) (page updated April 9, 2026).
- 40 CFR Part 84, Appendix A — Regulated Substances (exchange values) — Electronic Code of Federal Regulations (eCFR). Exchange values: HFC-32 675, HFC-125 3,500, HFC-134a 1,430, HFC-143a 4,470; §84.64 sets a regulated substance’s GWP equal to its exchange value.
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