EPA lists R-32 as acceptable, subject to use conditions, in new residential and light commercial AC and heat pumps under its SNAP program. Its AR4 GWP of 675 is under the 700 limit that EPA's Technology Transitions rule applies to that equipment from January 1, 2025.
R-32 pressure-temperature table
Every 5°F shown. ″ Hg = inches of mercury vacuum.
R-32 saturation pressure, psig at sea level
°F
°C
psig
-40
-40.0
11.0
-39
-39.4
11.7
-38
-38.9
12.4
-37
-38.3
13.0
-36
-37.8
13.7
-35
-37.2
14.4
-34
-36.7
15.2
-33
-36.1
15.9
-32
-35.6
16.6
-31
-35.0
17.4
-30
-34.4
18.2
-29
-33.9
19.0
-28
-33.3
19.8
-27
-32.8
20.6
-26
-32.2
21.4
-25
-31.7
22.3
-24
-31.1
23.2
-23
-30.6
24.1
-22
-30.0
25.0
-21
-29.4
25.9
-20
-28.9
26.8
-19
-28.3
27.8
-18
-27.8
28.7
-17
-27.2
29.7
-16
-26.7
30.7
-15
-26.1
31.7
-14
-25.6
32.8
-13
-25.0
33.8
-12
-24.4
34.9
-11
-23.9
36.0
-10
-23.3
37.1
-9
-22.8
38.2
-8
-22.2
39.4
-7
-21.7
40.5
-6
-21.1
41.7
-5
-20.6
42.9
-4
-20.0
44.1
-3
-19.4
45.4
-2
-18.9
46.7
-1
-18.3
48.0
0
-17.8
49.3
1
-17.2
50.6
2
-16.7
51.9
3
-16.1
53.3
4
-15.6
54.7
5
-15.0
56.1
6
-14.4
57.5
7
-13.9
59.0
8
-13.3
60.5
9
-12.8
62.0
10
-12.2
63.5
11
-11.7
65.0
12
-11.1
66.6
13
-10.6
68.2
14
-10.0
69.8
15
-9.4
71.5
16
-8.9
73.1
17
-8.3
74.8
18
-7.8
76.5
19
-7.2
78.3
20
-6.7
80.0
21
-6.1
81.8
22
-5.6
83.6
23
-5.0
85.5
24
-4.4
87.3
25
-3.9
89.2
26
-3.3
91.1
27
-2.8
93.1
28
-2.2
95.1
29
-1.7
97.1
30
-1.1
99.1
31
-0.6
101.2
32
0.0
103.2
33
0.6
105.3
34
1.1
107.5
35
1.7
109.7
36
2.2
111.9
37
2.8
114.1
38
3.3
116.3
39
3.9
118.6
40
4.4
121.0
41
5.0
123.3
42
5.6
125.7
43
6.1
128.1
44
6.7
130.5
45
7.2
133.0
46
7.8
135.5
47
8.3
138.0
48
8.9
140.6
49
9.4
143.2
50
10.0
145.8
51
10.6
148.5
52
11.1
151.2
53
11.7
153.9
54
12.2
156.7
55
12.8
159.5
56
13.3
162.3
57
13.9
165.2
58
14.4
168.1
59
15.0
171.1
60
15.6
174.1
61
16.1
177.1
62
16.7
180.1
63
17.2
183.2
64
17.8
186.3
65
18.3
189.5
66
18.9
192.7
67
19.4
195.9
68
20.0
199.2
69
20.6
202.5
70
21.1
205.8
71
21.7
209.2
72
22.2
212.6
73
22.8
216.1
74
23.3
219.6
75
23.9
223.2
76
24.4
226.7
77
25.0
230.4
78
25.6
234.0
79
26.1
237.7
80
26.7
241.5
81
27.2
245.3
82
27.8
249.1
83
28.3
253.0
84
28.9
256.9
85
29.4
260.9
86
30.0
264.9
87
30.6
268.9
88
31.1
273.0
89
31.7
277.1
90
32.2
281.3
91
32.8
285.6
92
33.3
289.8
93
33.9
294.1
94
34.4
298.5
95
35.0
302.9
96
35.6
307.4
97
36.1
311.9
98
36.7
316.4
99
37.2
321.0
100
37.8
325.7
101
38.3
330.4
102
38.9
335.1
103
39.4
339.9
104
40.0
344.8
105
40.6
349.6
106
41.1
354.6
107
41.7
359.6
108
42.2
364.6
109
42.8
369.7
110
43.3
374.9
111
43.9
380.1
112
44.4
385.3
113
45.0
390.6
114
45.6
396.0
115
46.1
401.4
116
46.7
406.9
117
47.2
412.4
118
47.8
418.0
119
48.3
423.6
120
48.9
429.3
121
49.4
435.1
122
50.0
440.9
123
50.6
446.8
124
51.1
452.7
125
51.7
458.7
126
52.2
464.7
127
52.8
470.8
128
53.3
477.0
129
53.9
483.2
130
54.4
489.5
131
55.0
495.8
132
55.6
502.2
133
56.1
508.7
134
56.7
515.2
135
57.2
521.8
136
57.8
528.5
137
58.3
535.2
138
58.9
542.0
139
59.4
548.9
140
60.0
555.8
141
60.6
562.8
142
61.1
569.8
143
61.7
577.0
144
62.2
584.1
145
62.8
591.4
146
63.3
598.7
147
63.9
606.1
148
64.4
613.6
149
65.0
621.2
150
65.6
628.8
151
66.1
636.5
152
66.7
644.3
153
67.2
652.2
154
67.8
660.1
155
68.3
668.1
156
68.9
676.2
157
69.4
684.4
158
70.0
692.6
159
70.6
701.0
160
71.1
709.4
Saturation pressures computed with CoolProp 8.0.0 (R32) on October 10, 2026, gauge pressure at sea level. Checked against Arkema published chart at 8 points; largest difference 0.05 psi. How these numbers are made.
What R-32 is and where it is used
R-32 is difluoromethane, a single-component HFC. It is half of R-410A by weight and 68.9% of R-454B. Arkema says it was developed to replace R-410A in many air conditioning applications, and lists new residential and commercial air conditioners, heat pumps, dehumidifiers and small chillers as its uses. Its 100-year GWP is 675 (AR4) or 677 (AR5), about a third of R-410A's 2088.
R-32 is ASHRAE safety group A2L: lower toxicity and mild flammability. Arkema says that because of its mild flammability and higher operating pressures, R-32 should never be used to retrofit an existing R-410A system. Read what A2L refrigerants change for techs before working on it.
How to read the R-32 chart
R-32 is a single compound, so the bubble and dew pressures are the same and the chart has one pressure per temperature. Use the same column for superheat and subcooling.
Superheat: a suction reading of 121 psig converts to 40.0°F. Subtract that from the suction line temperature.
Subcooling: a liquid line reading of 400 psig converts to 114.7°F. Subtract the liquid line temperature from it.
The figures below are worked examples at assumed coil temperatures, not targets for any unit:
Suction: at a 40°F evaporator saturation temperature, R-32 reads about 121.0 psig, compared with 118.4 psig for R-410A.
Head: at 115°F and 125°F condensing temperatures, R-32 reads 401.4 psig and 458.7 psig. R-410A would read 392.3 psig and 448.0 psig.
Arkema puts typical R-32 operating pressures 5 to 10% above R-410A at comparable conditions. It tells users to check the equipment manufacturer's guidelines for charging instructions, so charge to the method and values in the installation manual.
Service notes
Oil: Arkema says R-32 is typically used with POE oil, since it does not mix with mineral oil or alkylbenzene. It warns that POE is hygroscopic and readily absorbs moisture from the air, and that high moisture levels can lead to oil degradation and system failure.
Charging: R-32 is a single compound, and Arkema says it can be charged as vapor or liquid. Follow the manufacturer's instructions.
Discharge temperature: Arkema notes R-32 runs higher discharge temperatures than R-410A, which the equipment design must accommodate. It also has a higher volumetric capacity than R-410A and needs a smaller charge.
Tools: Chemours says some service equipment, because of its electrical components and motors, should be designed for mildly flammable A2L refrigerants such as R-32. Its A2L tool list calls for 2L-certified recovery machines and leak detectors and recovery cylinders labeled flammable with left-hand threads.
R-32 among the R-410A replacements
EPA's Technology Transitions rule set a GWP limit of 700 for new residential and light commercial AC and heat pumps from January 1, 2025. R-32 (675) and R-454B (465) both meet it, and EPA lists both under SNAP for that equipment. At 40°F, R-32 reads 121.0 psig, R-410A dew reads 118.4 psig and R-454B dew reads 107.0 psig. Chemours says not to mix refrigerants, so charge only the refrigerant on the unit's nameplate. Compare them in R-410A vs R-32 and R-454B vs R-32.