R32 Pressure Temperature Chart UK: Complete Reference for HVAC Engineers
R32’s operating pressures are one of its most important characteristics for UK HVAC engineers. Similar to R410A in pressure profile, R32 is compatible with existing copper pipework and pressure ratings on most modern systems. This PT reference covers the full range of temperatures relevant to UK split AC and heat pump installations.
R32 Saturation Pressure-Temperature Data
Pressures in bar absolute (bara) and bar gauge (barg). At sea level, atmospheric pressure = 1.013 bara = 0 barg.
- -30°C: 2.75 bara / 1.74 barg
- -20°C: 3.82 bara / 2.81 barg
- -10°C: 5.83 bara / 4.82 barg (suction typical, cold climate)
- -5°C: 7.10 bara / 6.09 barg
- 0°C: 8.00 bara / 6.99 barg (typical UK evaporating condition)
- 5°C: 9.22 bara / 8.21 barg
- 10°C: 10.6 bara / 9.6 barg
- 15°C: 12.1 bara / 11.1 barg
- 20°C: 13.8 bara / 12.8 barg
- 30°C: 17.8 bara / 16.8 barg
- 40°C: 22.6 bara / 21.6 barg (typical condensing)
- 50°C: 28.4 bara / 27.4 barg (high ambient condensing)
- 55°C: 31.9 bara / 30.9 barg (hot climate, high ambient)
How to Use This PT Chart
When reading R32 manifold gauges: the low-side (suction) pressure gives the evaporating saturation temperature. For a system with suction pressure of 6.99 barg (8.0 bara), the evaporating temperature is 0°C. Compare this to the actual suction line temperature to calculate superheat. The high-side pressure gives the condensing temperature. For 21.6 barg (22.6 bara), condensing temperature = 40°C.
R32 Operating Envelope: Typical UK Values
- Typical UK evaporating temperature (summer AC): 2–8°C (suction pressure 8.1–9.8 barg)
- Typical UK condensing temperature (summer): 35–45°C (high-side 19–23 barg)
- Heat pump heating mode (UK winter): Evaporating -10 to -3°C, Condensing 45–55°C
- Maximum high-side pressure: ~45 bar — check equipment ratings before commissioning in high-ambient areas
R32 vs R410A: Pressure Comparison
R32 operating pressures are very similar to R410A — typically within 2–5% at the same temperature. This is why R32 is largely compatible with copper pipework and components designed for R410A systems. Key difference: R32 has a slightly higher discharge temperature at the same conditions, which can affect compressor selection.
Servicing an R32 system? Source your refrigerant from Refrigerant Gas Supplies Ltd — R32 9 kg cylinders, UK F-Gas compliant, next-day delivery. See our complete R32 guide.
Frequently Asked Questions
What is the suction pressure for R32 at typical UK AC evaporating conditions?
At 0–5°C evaporating temperature (typical UK summer AC), suction pressure is approximately 7.0–8.2 barg. In heat pump heating mode at -5°C evaporating, suction pressure is approximately 6.1 barg.
What is the condensing pressure for R32 at 40°C?
Approximately 21.6 barg (22.6 bara absolute). At 45°C condensing: approximately 24.8 barg. These are similar to R410A values at the same temperature.
Can I use an R410A manifold gauge on R32?
Only if the gauge has an R32 PT scale — R32 and R410A pressures are close but not identical. Always use the correct refrigerant selection on your digital manifold to ensure accurate superheat and subcooling calculations.