Pressure-Temperature Relationship of R-134a
PRESSURE-TEMPERATURE RELATIONSHIP OF R-134A
| Temperature °C (°F)(1) | Pressure kPa (psi)(1) | Temperature °C (°F)(1) | Pressure kPa (psi)(1) | ||
|---|---|---|---|---|---|
| -8 (17.6) | 113.1 (16.4) | 9 (48.2) | 296.2 (43.0) | ||
| -7 (19.4) | 121.5 (17.6) | 10 (50.0) | 309.6 (44.9) | ||
| -6 (21.2) | 130.2 (18.9) | 15 (59.0) | 383.7 (55.7) | ||
| -5 (23.0) | 139.1 (20.2) | 20 (68.0) | 467.7 (67.8) | ||
| -4 (24.8) | 148.4 (21.5) | 25 (77.0) | 567.5 (82.3) | ||
| -3 (26.6) | 157.9 (22.9) | 30 (86.0) | 667.8 (96.9) | ||
| -2 (28.4) | 167.6 (24.3) | 35 (95.0) | 785.6 (113.9) | ||
| -1 (30.2) | 177.8 (25.8) | 40 (104.0) | 916.4 (133.0) | ||
| 0 (32.0) | 188.2 (27.3) | 45 (113.0) | 1,062.2 (154.0) | ||
| 1 (33.8) | 198.8 (28.8) | 50 (122.0) | 1,222.1 (177.2) | ||
| 2 (35.6) | 209.9 (30.4) | 55 (131.0) | 1,398.2 (202.8) | ||
| 3 (37.4) | 221.2 (32.1) | 60 (140.0) | 1,589.6 (230.5) | ||
| 4 (39.2) | 232.9 (33.8) | 65 (149.0) | 1,799.0 (260.9) | ||
| 5 (41.0) | 245.0 (35.5) | 70 (158.0) | 2,026.6 (293.9) | ||
| 6 (42.8) | 257.4 (37.3) | 75 (167.0) | 2,272.2 (329.5) | ||
| 7 (44.6) | 269.8 (39.1) | 80 (176.0) | 2,544.0 (369.0) | ||
| 8 (46.4) | 282.9 (41.0) | - | - | ||
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Evaporator Range: From -7 to 7 °C (19.4 to 44.6 °F), the temperatures represent the gas temperatures inside the coil and not on the coil surfaces. Add 2 to 6 °C (36 to 43 °F) to the coil and air-off temperatures.
Condenser Range: From 45 to 70 °C (113 to 158 °F), the temperatures are not ambient. Add 19 to 22 °C (66 to 72 °F) to the ambient temperatures for proper heat transfer. Then refer to the pressure chart.
Example:
32 °C (90 °F) Ambient temperature + 22 °C (40 °F) = 54 °C (130 °F)
Condenser temperature, which yields 1,379 kPa (200 psi), based on 50 km/h (31 mph) airflow.