RS-45 (R434A) The answer to replacing R22 in larger systems for OEMs

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.

Table 1 - Comparative properties: Air Conditioning
+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
Table 2 - Comparative properties: Refrigeration
-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
  • Particularly suited to larger systems where R410A is not a practical option, R407C has a high glide, & R134a requires much larger equipment.
  • A single replacement for R22 mirroring its performance across the application range of air conditioning & refrigeration.
  • Near azeotropic with glide 70% lower than R407C
  • Avoids costly re-tooling to high pressure R410A
  • Same compressors for RS-45 as R22. No need to "bank" compressors like R410A to increase system capacity. As a result RS-45 is a considerably lower cost option.
  • Same compression ration as R22
  • Similar Coefficient of Performance to R22 & 3% higher than R410A
  • Similar pressures to R22 & considerably lower pressures than R410A
  • Compatible with traditional as well as synthetic lubricants

Lubricants

RS-45 is suitable for use with mineral, alkylbenzene & polyol ester lubricants. R134a, R407C & R410A should not be used with MO & AB oils.

Compressors

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.

Glide

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.

Coefficient of Performance

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.

Capacity

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.