Refrigerant Pressure-Temperature Reference
Look up saturation pressure for any refrigerant at any operating temperature. Data sourced from ASHRAE Fundamentals and manufacturer published data. Includes safety class, GWP, phase-out status, and diagnostic guidance for each data point.
Common Residential Refrigerants
R-410A and R-22 are the most common refrigerants in US residential HVAC systems.
- R-410A Pressure Charts — Current standard residential AC refrigerant, AIM Act phase-down by 2036
- R-22 Pressure Charts — Legacy refrigerant — production ended 2020, existing systems only
- R-32 Pressure Charts — Next-generation low-GWP alternative (GWP 675), A2L safety class
Commercial Refrigeration
R-404A, R-407C, and R-744 are common in commercial refrigeration applications.
- R-404A Pressure Charts — High-GWP commercial refrigerant facing priority phase-down
- R-407C Pressure Charts — R-22 replacement blend for new equipment
- R-744 (CO2) Pressure Charts — Natural refrigerant with near-zero GWP, transcritical applications
Natural Refrigerants
R-290 (propane) and R-717 (ammonia) offer ultra-low GWP for specialty applications.
- R-290 Pressure Charts — Propane — GWP 3, A3 flammable, growing in commercial vending and Europe
- R-717 Pressure Charts — Ammonia — industrial refrigeration workhorse, zero GWP
Refrigerant Comparisons
Side-by-side comparisons for system selection and retrofit decisions.
- R-22 vs R-410A — Legacy vs current standard — key differences for system upgrades
- R-410A vs R-32 — Current vs next-gen — GWP, pressure, and safety class comparison
- All Refrigerant Comparisons — Browse 10 head-to-head comparisons covering all major refrigerant transitions
Frequently Asked Questions
What is a pressure-temperature chart used for?
A pressure-temperature (P-T) chart shows the saturation pressure of a refrigerant at a given temperature. HVAC technicians use it to verify system charge: suction and discharge gauge pressures are converted to saturation temperatures, then compared to measured pipe temperatures to calculate superheat and subcooling.
What is the normal operating pressure of R-410A?
R-410A suction pressure at a 45°F evaporator saturation temperature is approximately 130 PSI. Discharge pressure at a 115°F condensing temperature is approximately 400 PSI. Actual pressures vary with ambient temperature and system load.
Why is R-22 no longer available in new systems?
R-22 is an HCFC refrigerant with an ozone depletion potential of 0.055. Under the Montreal Protocol and US EPA regulations, R-22 was banned for use in new equipment in 2010 and production/import ended in 2020. Reclaimed R-22 is still legal for servicing existing equipment but prices have risen significantly.
Is R-32 safe to use?
R-32 is classified A2L by ASHRAE — mildly flammable with a very low burning velocity. Equipment designed specifically for R-32 includes required safety features: leak detection, spark-proof electrical components, and ventilation. Do not charge R-32 into systems designed for other refrigerants.