R-410A (saturated liquid)
R-410A saturated liquid from −40 to 60 °C — the high-pressure blend in most modern split systems and heat pumps, running roughly 60 % above R-134a pressures.
| Phase | Liquid — saturated state |
| Temperature range | -40 to 60 °C |
| Source | NIST REFPROP / ASHRAE Handbook—Fundamentals, Ch. 30, saturated liquid line |
Validated from -40 to 60 °C along the saturation curve.
| Density | 1,046 kg/m³ |
| Dynamic viscosity | 0.14 mPa·s |
| Specific heat | 1.6 kJ/(kg·K) |
| Thermal conductivity | 0.099 W/(m·K) |
| Vapour pressure | 1,444.2 kPa |
| Latent heat of vaporisation | 202.9 kJ/kg |
| Kinematic viscosity ν = µ/ρ | 0.13384 mm²/s |
| Prandtl number Pr = cpµ/k | 2.263 |
Saturated state only. On the saturation curve temperature and pressure are locked together, so one input fixes everything — but sub-cooled liquid and superheated vapour need two, and these values do not describe them.
Every fluid property in these opens already filled, all from the same state — so a density and a viscosity in one calculation always describe the same fluid at the same temperature.
Reynolds Number
ρ = 1,046μ = 0.14
Poiseuille's Law
μ = 0.14
Learning zone
R-410A is a near-azeotropic blend of R-32 and R-125 in equal parts by mass. "Near-azeotropic" means its temperature glide is about 0.1 K — small enough that it can be treated as a pure substance for field work, unlike genuinely zeotropic blends such as R-407C with 6 K of glide where evaporator inlet and outlet saturation temperatures genuinely differ. One consequence does survive: R-410A must be charged as a LIQUID from the cylinder, because drawing vapour would preferentially remove the more volatile component and shift the mixture.
The defining characteristic is pressure. At 40 °C its saturation pressure is 2413 kPa against R-134a's 1017 — nearly two and a half times — and a hot-day condensing pressure of 3000 kPa (about 420 psig) is routine. That is why R-410A equipment uses heavier tubing, different service gauges and 800 psi rated hoses, and why R-22 systems could never simply be retrofitted with it.
The payoff is capacity. Latent heat is markedly higher than R-134a's — 233 kJ/kg at 0 °C against 199 — and the higher pressure means higher vapour density, so a given compressor displacement moves substantially more heat. That is what allowed the compact high-efficiency split systems and heat pumps of the last two decades.
Watch the top of the range. Its critical point is 71.4 °C, so the properties change violently above about 50 °C: density falls off a cliff, latent heat collapses from 137 kJ/kg at 50 °C to 102 at 60, and specific heat spikes. A heat pump asked to make hot water on a hot day is operating uncomfortably close to that, which is a real limit on air-to-water heat pump leaving temperatures. Its GWP of 2088 is now driving replacement by R-32 and R-454B.