R-448A pressure-temperature chart

Gauge pressure at sea level. Liquid (bubble) pressure is the one to use for subcooling and vapor (dew) pressure for superheat.

°F and psig°C and kPa

R-448A saturation pressure by temperature, °F and psig
°F	Liquid (bubble) psig	Vapor (dew) psig
-40	4.9	0.0
-39	5.4	0.3
-38	5.9	0.7
-37	6.4	1.2
-36	7.0	1.6
-35	7.5	2.1
-34	8.1	2.6
-33	8.6	3.0
-32	9.2	3.5
-31	9.8	3.9
-30	10.4	4.4
-29	11.0	4.9
-28	11.6	5.4
-27	12.2	5.9
-26	12.9	6.5
-25	13.5	7.0
-24	14.2	7.5
-23	14.9	8.1
-22	15.6	8.6
-21	16.3	9.2
-20	17.0	9.8
-19	17.7	10.4
-18	18.5	11.0
-17	19.2	11.7
-16	20.0	12.3
-15	20.8	13.0
-14	21.6	13.7
-13	22.4	14.3
-12	23.2	15.0
-11	24.0	15.7
-10	24.9	16.4
-9	25.8	17.1
-8	26.7	17.9
-7	27.6	18.6
-6	28.5	19.4
-5	29.4	20.2
-4	30.3	21.0
-3	31.3	21.8
-2	32.2	22.6
-1	33.2	23.5
0	34.2	24.3
1	35.2	25.2
2	36.2	26.1
3	37.3	27.0
4	38.3	27.9
5	39.4	28.8
6	40.5	29.7
7	41.6	30.7
8	42.8	31.6
9	43.9	32.6
10	45.1	33.6
11	46.3	34.6
12	47.5	35.7
13	48.7	36.7
14	49.9	37.8
15	51.2	38.9
16	52.5	40.0
17	53.8	41.1
18	55.1	42.3
19	56.4	43.4
20	57.8	44.6
21	59.2	45.8
22	60.6	47.0
23	61.9	48.2
24	63.4	49.4
25	64.8	50.7
26	66.3	52.0
27	67.7	53.3
28	69.2	54.6
29	70.8	55.9
30	72.3	57.3
31	73.9	58.7
32	75.5	60.1
33	77.1	61.5
34	78.7	62.9
35	80.4	64.4
36	82.1	65.9
37	83.8	67.4
38	85.5	69.0
39	87.2	70.5
40	89.0	72.1
41	90.8	73.7
42	92.6	75.3
43	94.4	77.0
44	96.3	78.6
45	98.2	80.3
46	100.1	82.0
47	102.0	83.7
48	104.0	85.4
49	106.0	87.2
50	108.0	89.0
51	110.0	90.8
52	112.1	92.7
53	114.2	94.6
54	116.3	96.5
55	118.4	98.4
56	120.5	100.4
57	122.7	102.3
58	124.9	104.3
59	127.1	106.4
60	129.4	108.4
61	131.7	110.5
62	134.0	112.6
63	136.3	114.7
64	138.7	116.8
65	141.1	119.0
66	143.5	121.2
67	146.0	123.4
68	148.5	125.7
69	151.0	128.0
70	153.5	130.3
71	156.1	132.7
72	158.6	135.1
73	161.3	137.5
74	163.9	139.9
75	166.6	142.4
76	169.3	144.9
77	172.1	147.4
78	174.9	149.9
79	177.7	152.5
80	180.5	155.1
81	183.4	157.7
82	186.3	160.4
83	189.2	163.2
84	192.1	165.9
85	195.1	168.7
86	198.1	171.5
87	201.2	174.3
88	204.2	177.2
89	207.4	180.1
90	210.5	183.0
91	213.7	186.0
92	216.9	189.0
93	220.1	192.0
94	223.4	195.1
95	226.7	198.2
96	230.0	201.3
97	233.4	204.5
98	236.8	207.8
99	240.2	211.0
100	243.7	214.3
101	247.2	217.6
102	250.8	221.0
103	254.4	224.4
104	258.0	227.8
105	261.7	231.3
106	265.4	234.8
107	269.1	238.3
108	272.9	241.9
109	276.7	245.5
110	280.5	249.2
111	284.4	252.9
112	288.3	256.6
113	292.2	260.4
114	296.2	264.2
115	300.2	268.1
116	304.3	272.0
117	308.4	276.0
118	312.5	280.0
119	316.7	284.0
120	320.9	288.1
121	325.2	292.2
122	329.5	296.4
123	333.8	300.6
124	338.2	304.8
125	342.6	309.1
126	347.1	313.4
127	351.6	317.8
128	356.1	322.3
129	360.7	326.8
130	365.3	331.3
131	370.0	335.9
132	374.7	340.5
133	379.4	345.2
134	384.2	349.9
135	389.0	354.7
136	393.9	359.5
137	398.8	364.4
138	403.7	369.3
139	408.8	374.3
140	413.8	379.3
141	418.9	384.4
142	424.0	389.5
143	429.2	394.7
144	434.4	400.0
145	439.7	405.3
146	445.0	410.7
147	450.4	416.1
148	455.8	421.5
149	461.2	427.0
150	466.7	432.6

R-448A saturation pressure by temperature, °C and kPa
°C	Liquid (bubble) kPa	Vapor (dew) kPa
-40	34	0
-39	40	4
-38	47	10
-37	53	16
-36	60	21
-35	68	27
-34	75	33
-33	83	39
-32	90	46
-31	99	53
-30	107	60
-29	116	67
-28	125	74
-27	135	82
-26	144	91
-25	154	99
-24	165	107
-23	175	116
-22	186	125
-21	198	135
-20	209	145
-19	221	155
-18	233	165
-17	246	176
-16	258	187
-15	272	199
-14	285	210
-13	300	222
-12	314	234
-11	329	247
-10	344	261
-9	360	274
-8	376	288
-7	393	303
-6	410	317
-5	427	332
-4	445	348
-3	463	364
-2	481	380
-1	501	397
0	520	414
1	541	432
2	561	450
3	582	469
4	604	488
5	626	508
6	649	528
7	672	549
8	696	570
9	720	592
10	745	614
11	770	636
12	796	660
13	822	684
14	849	708
15	877	733
16	905	759
17	934	785
18	963	811
19	993	839
20	1,024	867
21	1,055	895
22	1,087	925
23	1,119	955
24	1,152	985
25	1,186	1,016
26	1,221	1,048
27	1,256	1,080
28	1,292	1,114
29	1,329	1,148
30	1,366	1,182
31	1,404	1,218
32	1,443	1,254
33	1,482	1,290
34	1,522	1,328
35	1,563	1,367
36	1,605	1,406
37	1,647	1,446
38	1,690	1,487
39	1,734	1,528
40	1,779	1,571
41	1,825	1,614
42	1,871	1,658
43	1,918	1,703
44	1,966	1,749
45	2,015	1,795
46	2,064	1,843
47	2,115	1,892
48	2,166	1,941
49	2,218	1,992
50	2,272	2,043
51	2,326	2,096
52	2,381	2,149
53	2,436	2,204
54	2,493	2,259
55	2,551	2,316
56	2,609	2,374
57	2,669	2,432
58	2,729	2,492
59	2,791	2,553
60	2,853	2,615
61	2,916	2,679
62	2,981	2,743
63	3,046	2,809
64	3,113	2,876
65	3,180	2,944

You're free to reuse this chart's numbers under CC BY 4.0. Just credit Pocket HVAC and link back to this page.

From pockethvac.com/r448a-pt-chart/. Rows every 5°F are from Arkema's Forane PT chart, and the rows between are filled in from them. Free to reuse under CC BY 4.0.

What is an R-448A PT chart?

An R-448A PT chart lists the pressure R-448A boils and condenses at for each temperature. At 40°F that's 72.1 psig on the vapor (dew) side and 89.0 psig on the liquid (bubble) side, 17 psi apart, because R-448A has about 10°F of glide. It's sold as Solstice N40 and Forane 448A.

Anywhere liquid and vapor are together in a system, like inside the evaporator and condenser coils, the pressure and temperature are locked together, so one tells you the other. On the job, the chart turns gauge readings into saturation temperatures: the suction pressure gives the temperature the evaporator is boiling at, and the liquid line pressure gives the temperature the condenser is condensing at. Compare those with your line temperatures and you have superheat and subcooling.

R-448A is a blend of R-32, R-125, R-1234yf, R-134a and R-1234ze(E) (safety class A1) made to replace R-404A, R-507A, R-22 and the R-407 blends in low and medium temperature refrigeration, in new equipment and as a retrofit. Its global warming potential (GWP) is about 1,390.

How it's calculated

Absolute pressure = gauge pressure + 14.696 psi (101.325 kPa, one standard atmosphere)
Saturation data: R-448A: Arkema, Forane Refrigerants Pressure Temperature Chart, 2025 (NIST REFPROP 10), every 5 °F from -50 to 150 °F
Between the published table's rows: ln(pressure) follows a cubic spline (not-a-knot) in 1 ÷ absolute temperature, through every printed row
Between table points (every 0.5 °F): ln(pressure) is interpolated linearly in 1 ÷ absolute temperature
Blends have separate liquid (bubble) and vapor (dew) curves
Glide = dew temperature − bubble temperature at the same pressure
Printed rows every 5 °F are the published table's own; the others come from the spline

Sources

If a number doesn't match your chart, email me what you entered and what you expected, and I'll check it against the source. You can also read how the numbers are checked.

Checked by Paul Williams · Updated October 31, 2026

Questions

What is the R-448A pressure at 40°F?

At 40°F, R-448A saturates at 72.1 psig on the vapor (dew) side and 89.0 psig on the liquid (bubble) side. At 100°F it's 214.3 psig vapor and 243.7 psig liquid.

Which column do I use for superheat and subcooling?

Vapor (dew) for superheat and liquid (bubble) for subcooling. R-448A is a blend of five refrigerants (26/26/20/21/7 by weight) with about 10 to 11°F of glide at evaporator pressures and about 8°F at condenser pressures, so reading the wrong column throws the answer off by that much.

Can I use an R-404A chart on an R-448A system?

No. The liquid side is close, but R-448A's vapor (dew) pressure runs well below R-404A's: at 40°F it's 72.1 psig against 85.4. Read a 72.1 psig suction off an R-404A chart and you get about 32°F instead of 40°F, so superheat comes out about 8°F too high. After a retrofit, use this chart.

How accurate is this chart?

Every 5°F row is Arkema's own number, from its Forane pressure-temperature chart (NIST REFPROP 10), and the rows between are filled in along a smooth curve through them. It agrees with Solstice's own N40 chart to within 0.15°F at every pressure that chart lists.

R-448A PT Chart