Properties of R-407A
R-407A is a zeotropic hydrofluorocarbon refrigerant blend composed of 20% R-32 (difluoromethane), 40% R-125 (Pentafluoroethane), and 40% R-134a (1,1,1,2 – Tetrafluoroethane). More properties for R-407A can be found in the table below.
| R-407A Properties |
| Formula | R-32 (20%) R-125 (40%) R-134a (40%) |
| Molecular weight (g/mol) | 90.1 |
| Boiling temperature °F (°C) | -49 (-45) |
| Critical temperature °F (°C) | 180 (82.3) |
| Critical pressure, PSI, (Bar) | 655 (45.1) |
| Gas heat capacity Btu/lb·°F, (kJ/(kg·°C)) | 0.198 (0.829) |
| Liquid heat capacity @ 1 atm, 30°C Btu/lb·°F (kJ/(kg·°C)) | 0.363 (1.52) |
| Temperature Glide °F (°C) | 8 (-4.4) |
| Global Warming Potential | 2100 |
| Ozone Depletion Potential | 0 |
| ASHRAE Safety Group | A1 |
Performance Comparison of R-407A vs. R-404A & R-22
To compare their performance, we’ve designed a theoretical coil and run it through Enterprise, our coil selection software.
We’ll use a 40” x 80” 4-row, 9FPI copper/aluminum evaporator coil designed for a refrigerated display case application. It features 0.375” OD copper tubes with a wall thickness of 0.19” and rifled walls. The fins are .0075” aluminum with a corrugated enhancement for added air turbulence.
The design conditions are shown below along with the performance rating for that coil using R-22, R-404A, and R-407A.
| Inputs |
| Airside | Tube-side |
| Air flow | 4,000 SCFM | Degrees superheat | 6°F |
| Target capacity | 312,212 Btu./hr. | Liquid temperature | 100°F |
| Entering air temp. | 85°F/78°F (WB) | Refrigerant suction temp. | 35°F |
| Leaving air temp. | 55°F/45°F (WB) | | |
| Air pressure | 14.696 PSIG | | |
| Performance Comparison: R-404A vs. R-407A |
| | R-404A | R-407A | Difference (%) | Difference (abs.) |
| Coil capacity | 408,937 Btu/hr. | 397,971 Btu/hr. | -2.7% | 10,966 Btu/hr. |
| Leaving air temp. | 46.1°F | 47.3°F | 2.6% | 1.2°F |
| Refrigerant inlet temperature | 18.6°F | 24°F | 29% | 5.4°F |
| Refrigerant pressure drop | 0.620 PSI/coil | 0.346 PSI/coil | -44% | 0.274 PSI/coil |
| Refrigerant mass flow | 9,384 lb./hr. | 6,426 lb./hr. | -31% | 2,958 lb./hr. |
| Circuit loading | 6,390 Btu/hr. | 6,281 Btu/hr. | -1.7% | 109 Btu/hr. |
| Performance Comparison: R-22 vs. R-407A |
| | R-22 | R-407A | Difference (%) | Difference (abs.) |
| Coil capacity | 391,531 Btu/hr. | 397,971 Btu/hr. | -1.6% | 6,440 Btu/hr. |
| Leaving air temp. (WB) | 47.9°F | 47.3°F | -1.25% | 0.6°F |
| Refrigerant inlet temperature | 18.6°F | 24°F | 29% | 5.4°F |
| Refrigerant pressure drop | 0.282 PSI/coil | 0.346 PSI/coil | 23% | 0.064 PSI/coil |
| Refrigerant mass flow | 5,646 lb./hr. | 6,426 lb./hr. | 14% | 780 lb./hr. |
| Circuit loading | 6,118 Btu/hr. | 6,281 Btu/hr. | 2.6% | 163 Btu/hr. |
*Note: the same circuiting was used for all three coils
Applications for R-407A
R-407A is primarily used for medium to low temperature refrigeration applications.
R-407A: Pros
The main benefits of R-407A are:
- Lower GWP (~2100) than R-404 (~3900)
- Similar performance profile as both R-22 and R-404
