R-513A reads 39.9 psig at 40°F and 131.3 psig at 100°F, a few psi above R-134a at the same temperatures.
R-513A lookup
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R-513A at a glance
Safety group
A1
Type
HFO/HFC blend, azeotropic
Composition
R-1234yf / R-134a, 56 / 44 % by weight
GWP (100-yr)
630 (AR4) · 573 (AR5)
Lubricant
POE
Boiling point
-21.0°F at 1 atm
Critical temperature
203.7°F
Used in
Water chillers, including centrifugal and flooded chillers; Medium-temperature commercial and industrial refrigeration; Medium-temperature circuit of cascade systems; Ice rinks; Retrofit of R-134a systems
At an EPA GWP of 630, R-513A is under the 700 limit that EPA's Technology Transitions rule sets for new comfort-cooling chillers (from Jan 1, 2025) and process chillers with leaving fluid at or above -22°F (from Jan 1, 2026), and under the interim 1,400 limit for new supermarket systems (Jan 1, 2027 to Jan 1, 2032); it is above the 150 limit for new stand-alone retail units, household refrigerators and vending machines.
R-513A pressure-temperature table
Every 5°F shown. ″ Hg = inches of mercury vacuum.
R-513A saturation pressure, psig at sea level
°F
°C
psig
-40
-40.0
11.8″ Hg
-39
-39.4
11.3″ Hg
-38
-38.9
10.7″ Hg
-37
-38.3
10.2″ Hg
-36
-37.8
9.7″ Hg
-35
-37.2
9.1″ Hg
-34
-36.7
8.5″ Hg
-33
-36.1
8.0″ Hg
-32
-35.6
7.4″ Hg
-31
-35.0
6.8″ Hg
-30
-34.4
6.1″ Hg
-29
-33.9
5.5″ Hg
-28
-33.3
4.9″ Hg
-27
-32.8
4.2″ Hg
-26
-32.2
3.6″ Hg
-25
-31.7
2.9″ Hg
-24
-31.1
2.2″ Hg
-23
-30.6
1.5″ Hg
-22
-30.0
0.7″ Hg
-21
-29.4
0.0
-20
-28.9
0.4
-19
-28.3
0.8
-18
-27.8
1.1
-17
-27.2
1.5
-16
-26.7
1.9
-15
-26.1
2.3
-14
-25.6
2.8
-13
-25.0
3.2
-12
-24.4
3.6
-11
-23.9
4.0
-10
-23.3
4.5
-9
-22.8
5.0
-8
-22.2
5.4
-7
-21.7
5.9
-6
-21.1
6.4
-5
-20.6
6.9
-4
-20.0
7.4
-3
-19.4
7.9
-2
-18.9
8.4
-1
-18.3
8.9
0
-17.8
9.4
1
-17.2
10.0
2
-16.7
10.6
3
-16.1
11.1
4
-15.6
11.7
5
-15.0
12.3
6
-14.4
12.9
7
-13.9
13.5
8
-13.3
14.1
9
-12.8
14.7
10
-12.2
15.3
11
-11.7
16.0
12
-11.1
16.6
13
-10.6
17.3
14
-10.0
18.0
15
-9.4
18.7
16
-8.9
19.4
17
-8.3
20.1
18
-7.8
20.8
19
-7.2
21.6
20
-6.7
22.3
21
-6.1
23.1
22
-5.6
23.8
23
-5.0
24.6
24
-4.4
25.4
25
-3.9
26.2
26
-3.3
27.0
27
-2.8
27.9
28
-2.2
28.7
29
-1.7
29.6
30
-1.1
30.4
31
-0.6
31.3
32
0.0
32.2
33
0.6
33.1
34
1.1
34.0
35
1.7
35.0
36
2.2
35.9
37
2.8
36.9
38
3.3
37.9
39
3.9
38.9
40
4.4
39.9
41
5.0
40.9
42
5.6
41.9
43
6.1
43.0
44
6.7
44.0
45
7.2
45.1
46
7.8
46.2
47
8.3
47.3
48
8.9
48.4
49
9.4
49.6
50
10.0
50.7
51
10.6
51.9
52
11.1
53.1
53
11.7
54.3
54
12.2
55.5
55
12.8
56.7
56
13.3
58.0
57
13.9
59.3
58
14.4
60.5
59
15.0
61.8
60
15.6
63.1
61
16.1
64.5
62
16.7
65.8
63
17.2
67.2
64
17.8
68.6
65
18.3
70.0
66
18.9
71.4
67
19.4
72.8
68
20.0
74.3
69
20.6
75.8
70
21.1
77.3
71
21.7
78.8
72
22.2
80.3
73
22.8
81.9
74
23.3
83.4
75
23.9
85.0
76
24.4
86.6
77
25.0
88.3
78
25.6
89.9
79
26.1
91.6
80
26.7
93.3
81
27.2
95.0
82
27.8
96.7
83
28.3
98.4
84
28.9
100.2
85
29.4
102.0
86
30.0
103.8
87
30.6
105.6
88
31.1
107.5
89
31.7
109.3
90
32.2
111.2
91
32.8
113.1
92
33.3
115.1
93
33.9
117.0
94
34.4
119.0
95
35.0
121.0
96
35.6
123.0
97
36.1
125.1
98
36.7
127.1
99
37.2
129.2
100
37.8
131.3
101
38.3
133.5
102
38.9
135.6
103
39.4
137.8
104
40.0
140.0
105
40.6
142.3
106
41.1
144.5
107
41.7
146.8
108
42.2
149.1
109
42.8
151.4
110
43.3
153.8
111
43.9
156.1
112
44.4
158.5
113
45.0
161.0
114
45.6
163.4
115
46.1
165.9
116
46.7
168.4
117
47.2
170.9
118
47.8
173.5
119
48.3
176.1
120
48.9
178.7
121
49.4
181.3
122
50.0
184.0
123
50.6
186.7
124
51.1
189.4
125
51.7
192.1
126
52.2
194.9
127
52.8
197.7
128
53.3
200.5
129
53.9
203.4
130
54.4
206.3
131
55.0
209.2
132
55.6
212.1
133
56.1
215.1
134
56.7
218.1
135
57.2
221.1
136
57.8
224.2
137
58.3
227.2
138
58.9
230.4
139
59.4
233.5
140
60.0
236.7
141
60.6
239.9
142
61.1
243.1
143
61.7
246.4
144
62.2
249.7
145
62.8
253.0
146
63.3
256.4
147
63.9
259.8
148
64.4
263.2
149
65.0
266.7
150
65.6
270.2
151
66.1
273.7
152
66.7
277.3
153
67.2
280.9
154
67.8
284.5
155
68.3
288.1
156
68.9
291.9
157
69.4
295.6
158
70.0
299.3
159
70.6
303.1
160
71.1
307.0
Saturation pressures computed with CoolProp 8.0.0 (R513A.mix) on October 10, 2026, gauge pressure at sea level. Checked against Chemours published chart at 10 points; largest difference 0.62 psi. How these numbers are made.
What R-513A is and where it is used
R-513A is a blend of 56% R-1234yf and 44% R-134a by weight, sold by Chemours as Opteon XP10. It is an azeotrope with essentially no glide and an ASHRAE A1 (nonflammable) rating. Chemours designed it to replace R-134a with a close capacity and efficiency match. It is used in new equipment and for retrofits.
Typical uses are water chillers (positive displacement, flooded and centrifugal), medium-temperature commercial and industrial refrigeration, the medium-temperature side of cascade systems, and ice rinks. Chemours lists an AR5 GWP of 573, about 56% below R-134a.
How to read the R-513A chart
Chemours lists R-513A as an azeotrope with zero glide. In the computed table its bubble and dew pressures stay within about a tenth of a psi of each other, so the chart shows one column and the glide rounds to 0.0°F. Chemours still calls it good practice to use dew for superheat and bubble for subcooling.
Superheat: at 40 psig suction the saturation temperature is 40.2°F. Use the superheat calculator.
Subcooling: at 140 psig liquid pressure the saturation temperature is 104.0°F. Use the subcooling calculator.
Do not read an R-134a chart on an R-513A system. At 40°F R-513A is 39.9 psig and R-134a is 35.0 psig. Read the other way, 40 psig is 40.2°F on R-513A but 45.0°F on R-134a, and that difference goes straight into the superheat figure. R-513A boils at -21.0°F at atmospheric pressure, so low-temperature suction readings near that point will be close to 0 psig or in vacuum.
Typical R-513A pressures
Chemours compares R-513A with R-134a at a 14°F evaporator and a 104°F condenser, the medium-temperature conditions in its retrofit guide. At those temperatures:
Suction: R-513A 17.9 psig, R-134a 14.4 psig
Condensing: R-513A 140.0 psig, R-134a 132.8 psig
For a chiller example, assume a 40°F evaporator and a 100°F condenser. R-513A reads 39.8 psig and 131.3 psig, against 35.0 psig and 124.2 psig for R-134a. These are saturation values at assumed temperatures. Chiller set points and limits come from the manufacturer.
Service and retrofit notes
Oil. The POE already in an R-134a system is usually suitable. Systems on HCFC service blends such as R-401A, R-401B or R-409A need an oil change and new seals.
Charging. Remove liquid from the cylinder. Chemours warns that liquid charged into the suction line can cause irreversible compressor damage, so flash it to vapor through the manifold or a throttling valve first. Chemours suggests starting at about 85% of the R-134a charge. The final charge is usually near 97%.
Expect slightly higher mass flow, slightly higher discharge pressure and a lower discharge temperature than R-134a. Chemours says EPRs and pressure cutouts may need resetting, and controllers should be updated with R-513A properties.
Leak testing. R-513A can become combustible when mixed with high concentrations of air under pressure. Pressure test with dry nitrogen only.
Regulatory context
R-513A sits under the 700 GWP limit for new chillers in EPA's Technology Transitions rule, so it remains an option for new chiller designs. It is above the 150 limit for new self-contained products such as household refrigerators, stand-alone retail units and vending machines. EPA's rule does not restrict servicing and repair of existing R-134a and R-513A equipment. Compare with R-1234yf, its HFO component.