What pressure should R-410A be at?

It depends on the temperature. R-410A's saturation pressure is 118 psig at 40°F and 317 psig at 100°F. The suction side follows the evaporator temperature and the liquid side the condenser; the equipment maker's charging chart gives the targets.

What is the R-22 pressure at 40 degrees?

68.5 psig, against 118 psig for R-410A at the same temperature.

How do I calculate superheat?

Read the suction pressure, find its saturation temperature on the chart, and subtract that from the suction line temperature measured near the service valve. 118 psig on R-410A is 40°F, so a 50°F suction line is 10°F of superheat.

How do I calculate subcooling?

Read the liquid line pressure, find its saturation temperature, and subtract the liquid line temperature from it. 317 psig on R-410A is 100°F, so a 90°F liquid line is 10°F of subcooling.

Is R-454B the same pressure as R-410A?

Close but lower: 111.9 psig against 118 at 40°F, and 300.8 against 317 at 100°F, about 5% less on the charts used here.

What is the difference between psig and psia?

psig is gauge pressure, above the atmosphere; psia is absolute, above a vacuum. psia = psig + 14.7 at sea level. PT charts and service gauges both use psig.

Home › HVAC › Refrigerant Pressure Temperature Chart

Refrigerant Pressure Temperature Chart

Hudson Technologies PT charts, checked against the Bonneville Power Administration R-410A chart

At 40°F, R-410A reads 118 psig and R-22 68.5: the same coil runs at 72% more pressure on the newer refrigerant. R-454B, its replacement, reads 111.9, about 5% below R-410A, and R-32 121, about 2.5% above. The chart below gives all four from -40 to 150°F, and the lookup turns a gauge reading and a line temperature into superheat or subcooling.

Read the chart

Refrigerant

I have a

Value

psig or °F

Line temperature (optional, for superheat or subcooling)

°F

Enter a pressure from the gauge or a temperature, and optionally the line temperature measured at the same place.

Specification summary

Generated from on . Reopen that address to reproduce these figures exactly.

Entered

Result

Worked example

R-410A suction at 118 psig, suction line measured at 50°F.

Saturation. 118.0 psig is 40°F on the chart.
Superheat. 50 − 40 = 10°F.

On the liquid line the same subtraction the other way round gives subcooling.

The formula

A chart lookup with straight-line interpolation between 5°F rows:

superheat = suction line temperature − saturation temperature subcooling = saturation temperature − liquid line temperature

saturation temperature: the chart's temperature at the gauge pressure
psia: psig + 14.7, the pressure above a vacuum

The target superheat or subcooling is the equipment maker's, not the chart's.

Where the numbers come from

The chart is Hudson Technologies' pressure temperature chart set, a refrigerant supplier's PDF dated May 2025, read on 30 September 2026. Hudson prints vapor pressure in psig at 5°F steps.

R-410A was checked against a second chart, the Bonneville Power Administration's, which gives the temperature for every 2 to 4 psig from 12 to 676 psig. The two agree within 1°F from 28 psig up and within 2°F below it, where the charts’ rounding and straight-line reading matter most, except for one printed cell, described below.

The chart

Saturation pressure, psig, from the Hudson Technologies PT charts
°F	°C	R-410A	R-22	R-32	R-454B
-40	-40.0	11.6	0.5	11.0	9.5
-35	-37.2	14.9	2.6	14.4	12.7
-30	-34.4	18.5	4.9	18.2	16.3
-25	-31.7	22.5	7.4	22.3	20.1
-20	-28.9	26.9	10.1	26.8	24.3
-15	-26.1	31.7	13.2	31.7	28.9
-10	-23.3	36.8	16.5	37.1	34.0
-5	-20.6	42.5	20.1	42.9	39.4
0	-17.8	48.6	24.0	49.3	45.3
5	-15.0	55.2	28.2	56.1	51.7
10	-12.2	62.3	32.8	63.5	58.6
15	-9.4	70.0	37.7	71.5	66.0
20	-6.7	78.3	43.0	80.0	74.0
25	-3.9	87.3	48.8	89.2	82.5
30	-1.1	96.8	54.9	99.1	91.7
35	1.7	107.0	61.5	109.7	101.5
40	4.4	118.0	68.5	121.0	111.9
45	7.2	130.0	76.0	133.0	123.1
50	10.0	142.0	84.0	145.9	135.0
55	12.8	155.0	92.6	159.5	147.6
60	15.6	170.0	102.0	174.1	161.0
65	18.3	185.0	111.0	189.5	175.3
70	21.1	201.0	121.0	205.8	190.4
75	23.9	217.0	132.0	223.2	206.4
80	26.7	235.0	144.0	241.5	223.3
85	29.4	254.0	156.0	260.9	241.1
90	32.2	274.0	168.0	281.3	260.0
95	35.0	295.0	182.0	302.9	279.9
100	37.8	317.0	196.0	325.7	300.8
105	40.6	340.0	211.0	349.6	322.8
110	43.3	365.0	226.0	374.9	346.0
115	46.1	391.0	243.0	401.4	370.4
120	48.9	418.0	260.0	429.3	395.9
125	51.7	446.0	278.0	458.6	422.8
130	54.4	476.0	297.0	489.4	450.9
135	57.2	507.0	317.0	521.8	480.4
140	60.0	539.0	337.0	555.7	511.3
145	62.8	573.0	359.0	591.4	543.6
150	65.6	608.0	382.0	628.8	577.4

The federal chart has a typo at 20 psig

The Bonneville Power Administration publishes an R-410A chart with 304 pressure readings. Laid against Hudson's chart, every one agrees within 2°F, most within 1°F, except one.

At 20 psig it prints −36.9°F. Its own neighbors are −29.4°F at 18 psig and −24.5°F at 22, and a refrigerant's temperature cannot fall as its pressure rises. Hudson's chart puts 20 psig at about −28°F. The printed figure is almost certainly −26.9 with one digit wrong.

Four refrigerants at the same temperature

Saturation pressure at two working temperatures, psig
Refrigerant	At 40°F, a typical evaporator	At 100°F
R-410A	118.0	317.0
R-22	68.5	196.0
R-32	121.0	325.7
R-454B	111.9	300.8

R-410A runs about 1.6 to 1.7 times R-22's pressure, which is why the two never share a system or a set of gauges. R-454B runs about 5% below R-410A at both temperatures and R-32 about 2.5 to 2.7% above. Close, but not interchangeable: each refrigerant is read from its own column.

Frequently asked questions

What pressure should R-410A be at?: It depends on the temperature. R-410A's saturation pressure is 118 psig at 40°F and 317 psig at 100°F. The suction side follows the evaporator temperature and the liquid side the condenser; the equipment maker's charging chart gives the targets.
What is the R-22 pressure at 40 degrees?: 68.5 psig, against 118 psig for R-410A at the same temperature.
How do I calculate superheat?: Read the suction pressure, find its saturation temperature on the chart, and subtract that from the suction line temperature measured near the service valve. 118 psig on R-410A is 40°F, so a 50°F suction line is 10°F of superheat.
How do I calculate subcooling?: Read the liquid line pressure, find its saturation temperature, and subtract the liquid line temperature from it. 317 psig on R-410A is 100°F, so a 90°F liquid line is 10°F of subcooling.
Is R-454B the same pressure as R-410A?: Close but lower: 111.9 psig against 118 at 40°F, and 300.8 against 317 at 100°F, about 5% less on the charts used here.
What is the difference between psig and psia?: psig is gauge pressure, above the atmosphere; psia is absolute, above a vacuum. psia = psig + 14.7 at sea level. PT charts and service gauges both use psig.

Check these numbers yourself

Hudson Technologies, Pressure Temperature Charts, R-410A, R-22, R-32 and R-454BHudson Technologies, refrigerant supplier; PDF set titled R-11 to R-448A Pressure Temperature Charts, created May 2025. The same URL pattern serves each refrigerant. Vapor pressure in psig at 5 F steps. Read 2026-09-30.
Bonneville Power Administration, R-410A Pressure-Temperature ChartBonneville Power Administration, US Department of Energy, 2012. Saturation temperature at every 2 to 4 psig from 12 to 676 psig, used as the cross-check. Read 2026-09-30.

How every figure here is verified: Sources & Method. Who builds this: Lucas Pradella, and the method is on About. Found something wrong? Tell us and it gets fixed or removed.

Figures on this page last checked against the source documents on 2026-09-30. Codes are amended locally; confirm against the edition your jurisdiction enforces.

Related calculators

Saturation values for pure refrigerant. Charging targets come from the equipment maker's data, not from a PT chart alone.