to eliminate the particular refrigerant as a valid choice for conversion. Note that the capacity losses become more magnified as the evaporating temperature becomes lower. For example choose a refrigerant that has a capacity loss of approximately six per cent in an air conditioning application. On systems that are barely maintaining temperature with R-22, this would not be a good choice. However, if the sys-
(Air Conditioning) show the comparative values for these four system parameters. Capacity relative to R-22 is fairly self explanatory. Assuming that the R-22 capacity is 100 per cent, a value less than that means you will be suffering a capacity loss when using the particular refrigerant that capacity loss is attached to. The numbers in red are losses that are substantial and likely
• Cooling capacity of the system • Discharge temperature • Required refrigerant mass flow rate (which will determine whether flow controls will need replacement) In most cases it would be desirable to use an R-22 replacement that will provide performance and capacity close to that of R-22. The charts in Table 3 (Low Temperature), Table 4 (Medium Temperature) and Table 5
continued on p.24 Table 2 – Chemical Composition of Common R-22 Replacements Blend Component
Refrigerant (ASHRAE Designation Number) R-407A
R-407C
R-407F
R-417A
R-421A
R-422A
R-422B
R-422D
R-424A
R-427A
R-32
20%
23%
30%
R-125
40%
25%
30%
47%
58%
85.1%
55%
65.1%
50.5%
25%
R-134A
40%
52%
40%
50%
42%
11.5%
52%
31.5%
47.0%
50%
R-428A
R-434A
R-404A
R-507
R-438A
8.5%
50%
77.5%
63.2%
44%
50%
45%
50%
16%
4%
18%
52%
15%
R-143A
10%
R-290 Propane
20%
R-410A
44.2% 50%
0.6%
R-600 N-Butane
1.0%
R-600A IsoButane
3.4%
3.4%
3%
R-601A IsoPentane
3.4%
0.9%
1.7% 1.9%
2.8%
0.9%
0.6%
Table 3 – Comparative Performance of R-22 Replacements in AC Applications Refrigerant R-404A
Trade Name
Capacity Relative to R-22
Mass Flow Relative to R-22
Efficiency (COP) Relative to R-22
Recommended Lubricant Type
HP62, FX-70
103%
142%
91%
POE
R-407A
Klea 60
106%
114%
96%
POE
R-407C
Suva 9000
102%
101%
97%
POE
R-407F
Performax LT
112%
109%
96%
POE
R-417A
MO59, NU22
86%
107%
96%
MO, AB, POE
R-421A
Choice
88%
120%
95%
MO, AB, POE
R-422A
MO79, OneShot
102%
164%
90%
MO, AB, POE
R-422B
NU22B
89%
118%
95%
MO, AB, POE
R-422C
One Shot B
100%
158%
91%
MO, AB, POE
R-422D
MO79
93%
131%
93%
MO, AB, POE
R-424A
RS-44
86%
130%
96%
MO, AB, POE
R-427A
FX-100
98%
103%
97%
POE
R-428A
RS-52
107%
170%
89%
MO, AB, POE
R-434A
RS-45
99%
144%
93%
MO, AB, POE
R-438A
MO99
94%
111%
96%
MO, AB, POE
R-507A
AZ-50
104%
148%
90%
POE
hpacmag.com
december 2013 | HPAC
23