R134a, R407c & R410a have been presented as the main replacements for R22 in air conditioning applications. These referigerants have different physical properties comparied to R22:
R134a: has a considerably lower capacity than R22 (-33%) which means bigger & more expensive equipment is required.
R407C: has a wide glide of over 5°C which can cause operating problems including icing up & fractionation.
R410A: operating pressures more than 50% higher than R22 which requires a complete re-design of equipment & restricts its use to smaller systems. R410A can only be used in larger systems by adding more compressors which substantially increases system cost.
RS-45(R434A) has been formulated to avoid these problems and, in particular, to replace R22 in larger systems with a competitive total cost of equipment while matching the main thermodynamic properties of R22. RS-45 is unique in being able to mirror R22 at both high & low temperatures.
+7°C evap +45°C cond |
R22 | R134a | RS-45 R434A |
R410A | R407C | |
---|---|---|---|---|---|---|
Discharge pressure | Bar | 17.91 | 12.05 | 19.81 | 28.19 | 19.3 |
Discharge temperature | °C | 111 | 89 | 81 | 104 | 97 |
Capacity Capacity % R22 |
kJ/m3 | 3062 | 2049 67 |
3115 102 |
4467 146 |
3189 104 |
COP | System | 2.49 | 2.57 | 2.44 | 2.36 | 2.48 |
Compression ratio | 3.02 | 3.39 | 3.02 | 2.98 | 3.20 | |
Glide | °C | 0 | 0 | 1.5 | 0.1 | 5 |
-35°C evap +35°C cond |
R22 | R134a | RS-45 R434A |
R410A | R407C | |
---|---|---|---|---|---|---|
Discharge pressure | Bar | 14.07 | 9.25 | 15.55 | 22.15 | 15.02 |
Discharge temperature | °C | 197 | 140 | 120 | 180 | 160 |
Capacity Capacity % R22 |
kJ/m3 | 619 | 345 56 |
632 102 |
946 153 |
597 96 |
COP | System | 1.13 | 1.19 | 1.13 | 1.08 | 1.14 |
Compression ratio | 11.4 | 15.1 | 11.4 | 10.8 | 13 | |
Glide | °C | 0 | 0 | 1.5 | 0.1 | 5 |
RS-45 is suitable for use with mineral, alkylbenzene & polyol ester lubricants. R134a, R407C & R410A should not be used with MO & AB oils.
R22 compressors can be used with RS-45. The higher pressures of R410A restrict its use to smaller systems owing to the lack of availability of compressors. Larger systems using R410A require adding extra compressors at significant cost.
RS-45 has a glide of 1.5°C which compares to R407C with a glide exceeding 5°C. Consquently, RS-45 has a wider application range & avoids the problems of icing up, fractionation & reduced performance. R407C should not be used & tube evaporators where RS-45 is a suitable option to replace R22.
RS-45 has a COP which is 3% higher than R410A & similar to R22. Efficiencies can be optimized by installing a heat exchanger in the suction line which is often readily accomodated in bigger systems.
RS-45 has a cooling capacity which matches R22 at both high (+7%deg;C evap) & low temperatures (-35°C evap). RS-45 is, therefore, a single replacement for R22 across the temperature range.