An HVAC refrigerant chart is a critical field reference for HVAC technicians and engineers. It shows pressure-temperature (PT) relationships for common refrigerants, environmental data (GWP, ODP), safety classifications, and phase-out status — everything needed to verify system charge, compare refrigerant options, and stay current with EPA and international regulations.
Professional reference only. EPA Section 608 certification is required to purchase and handle refrigerants. Always verify pressures with manufacturer data sheets. PT values are typical saturation pressures and may vary slightly by source.
Pressure-Temperature Lookup
Pressure-Temperature Reference Chart
Saturation pressures shown are approximate typical values. Use manufacturer data sheets for precision work. psia = absolute pressure (includes 14.7 psi atmospheric).
Refrigerant Comparison Chart
GWP = 100-year Global Warming Potential relative to CO₂. ODP = Ozone Depletion Potential relative to R-11. Safety class per ASHRAE Standard 34.
ASHRAE 34 Safety Classifications
Refrigerant Phase-Out Timeline
Sources: Montreal Protocol, EPA AIM Act (2020), EU F-Gas Regulation. Timelines are for the United States unless noted. Consult EPA.gov for the latest regulatory guidance.
EPA Section 608 Certification
Under EPA regulations (40 CFR Part 82, Subpart F), technicians who maintain, service, repair, or dispose of appliances that contain refrigerants must be certified under Section 608. There are four certification types:
- Type I — Small appliances (hermetically sealed, ≤5 lb charge)
- Type II — High-pressure systems (R-410A, R-22, R-134a, R-32)
- Type III — Low-pressure systems (R-11, R-113, R-123)
- Universal — All three categories above
Purchasing refrigerant containers over 2 lbs also requires Section 608 certification. Contact EPA or an approved testing organization (ESCO Institute, NATE) for certification information.
How to Use the HVAC Refrigerant Chart
This HVAC refrigerant chart gives technicians and engineers three reference tools in one: a pressure-temperature (PT) lookup, a full refrigerant comparison table, and a phase-out regulation timeline. Use the tabs at the top to switch views and the unit toggle to switch between imperial (°F/psi) and metric (°C/bar).
PT Lookup — verify system charge
Select a refrigerant (R-410A, R-22, R-32, or R-134a), enter a temperature, and click Look Up to get the corresponding saturation pressure. This is the core diagnostic step: on a running system, the low-side gauge pressure should match the saturation temperature of the refrigerant at the suction line temperature for normal operation. Compare your actual gauge readings to the chart values to identify overcharge, undercharge, or airflow restrictions.
The full PT reference table below the lookup shows pressures across the common operating range (20°F to 120°F / -7°C to 49°C) for all four refrigerants simultaneously, so you can compare them side by side at a glance.
Refrigerant Comparison — choose the right refrigerant
The comparison table lists all major refrigerants — including natural refrigerants like R-290 (propane) and R-717 (ammonia) — with their type, GWP, ODP, ASHRAE safety class, status, and primary application. Click the column headers to sort. Use this view when evaluating a system retrofit or comparing options for a new installation. The safety classification legend below the table explains what each ASHRAE 34 class means for flammability and toxicity.
Phase-Out Timeline — stay current with regulations
The refrigerant industry is in a period of rapid change driven by environmental regulation. The Montreal Protocol phased out CFCs and HCFCs (including R-22) globally. The AIM Act (2020) in the U.S. is now driving a phase-down of high-GWP HFCs like R-410A. This timeline view shows key regulatory milestones for each refrigerant so you can plan system decisions — new equipment purchases, retrofit timing, and refrigerant inventory — accordingly.
Reading the pressure-temperature chart correctly
PT chart values show saturation pressures — the pressure at which a refrigerant boils or condenses at a given temperature. These are absolute pressures (psia), so to read them on a standard gauge (which reads psig, or gauge pressure), subtract 14.7 psi from the psia value. For example, R-410A at 40°F has a saturation pressure of about 83 psia, which is approximately 68 psig on a manifold gauge set. When working in bar, the values are already absolute (bara); subtract 1.013 bar for gauge readings.
Common diagnostic use cases
A normal R-410A residential system at peak cooling typically shows around 118–125 psig (about 135 psia) on the low side, corresponding to roughly 48–51°F saturation temperature, and 400–425 psig on the high side. If your low-side pressure corresponds to a saturation temperature much higher than the design evaporator temperature, the system is undercharged or has a restriction. If it is much lower, the system may be overcharged or the expansion device is malfunctioning. Always cross-reference PT data with superheat and subcooling measurements for a complete diagnosis.
FAQ
Is this refrigerant chart free to use?
Yes, this HVAC refrigerant chart is completely free. It runs entirely in your browser — no signup, no account, and no data sent to any server. You can bookmark it for quick field reference.
Is my data private when using this tool?
Yes, everything runs locally in your browser. No inputs, searches, or lookups are sent to any server. Your data never leaves your device.
What is the difference between R-410A and R-32 refrigerants?
R-410A is a blend of R-32 and R-125 with a GWP of 2088, currently the standard refrigerant in most residential AC and heat pumps. R-32 is a single-component refrigerant with a GWP of 675 — about 68% lower — and higher energy efficiency. R-32 is increasingly used in new systems and is expected to become the dominant refrigerant as R-410A is phased down under HFC regulations.
Why was R-22 phased out?
R-22 (Freon) is an HCFC refrigerant with an ozone depletion potential (ODP) of 0.05 and a GWP of 1810. Under the Montreal Protocol, the U.S. banned production and import of R-22 after January 1, 2020. Systems using R-22 can still operate on reclaimed refrigerant, but it is increasingly scarce and expensive. Replacement options include drop-in substitutes like R-422D or system conversions to R-410A.
What do ASHRAE safety classifications like A1 and A2L mean?
ASHRAE 34 safety classifications have two parts: a letter (A = lower toxicity, B = higher toxicity) and a number (1 = no flame propagation, 2L = mildly flammable, 2 = flammable, 3 = highly flammable). A1 refrigerants like R-410A and R-22 are non-toxic and non-flammable. A2L refrigerants like R-32 and R-1234yf are mildly flammable but have very low burning velocity, requiring special installation practices.
What is GWP and why does it matter for refrigerants?
GWP (Global Warming Potential) measures how much heat a gas traps in the atmosphere over 100 years relative to carbon dioxide (CO2 = 1). High-GWP refrigerants like R-404A (GWP 3922) contribute significantly more to climate change if leaked than low-GWP alternatives like R-1234yf (GWP 4) or natural refrigerants like R-290 propane (GWP 3). Regulations under the EPA AIM Act and EU F-Gas regulation are driving a phase-down of high-GWP HFCs.
What does the pressure-temperature chart tell a technician?
The pressure-temperature (PT) chart shows the saturation pressure of a refrigerant at a given temperature. Technicians use it to verify system charge: the low-side (suction) and high-side (discharge) pressures on their gauges correspond to specific saturated temperatures. Comparing those saturation temperatures to design targets helps diagnose overcharge, undercharge, restrictions, or airflow problems.
Do I need EPA Section 608 certification to work with refrigerants?
Yes. Under EPA Section 608 regulations, technicians who maintain, service, repair, or dispose of equipment that uses refrigerants must be certified. There are four certification types: Type I (small appliances), Type II (high-pressure systems like R-410A/R-22), Type III (low-pressure systems), and Universal (all categories). Purchasing refrigerants in containers over 2 lbs also requires certification.
Can R-410A be used in older R-22 systems?
No. R-410A operates at much higher pressures than R-22 (roughly 50–70% higher), so it cannot be used as a drop-in replacement in equipment designed for R-22. The compressor, metering device, and other components are rated for different pressure ranges. Installing R-410A in an R-22 system risks catastrophic failure. Instead, use retrofit refrigerants designed for R-22 systems (like R-422D or R-407C) or replace the system.