HVAC Toolkit

Pressure-Temperature Charts

Saturation P-T data for common refrigerants

Select Refrigerant

HFC / HCFC

R-22 R-32 R-125 R-134a R-143a R-404A Z R-407C Z R-410A R-507A

Low GWP (HFO)

R-449A Z R-454B Z Low GWP R-513A R-1234yf Low GWP R-1234ze(E) Low GWP

Natural

R-290 (Propane) Low GWP R-600a (Isobutane) Low GWP R-744 (CO2) Low GWP R-717 (NH3) Low GWP

Pressure Unit

psig kPa bar kgf/cm²

R-454B

Zeotropic
GWP: 466
ODP: 0
Safety Class: A2L
Temperature Glide: 1.3°C

Low GWP alternative to R-410A. Also known as Opteon XL41. Mildly flammable (A2L), requires proper handling and equipment rated for A2L refrigerants.

A2L Mildly Flammable - Use equipment rated for A2L refrigerants. Follow local safety codes.

Quick P-T Lookup

bar

* Results are interpolated from the P-T table data

Z

Zeotropic Blend

This refrigerant has a temperature glide of 1.3°C - use the correct saturation point!

Temperature Glide Visualization

Dew Point
100% Vapor
For Superheat
1.3°C Glide
Higher Temp Lower Temp
Bubble Point
100% Liquid
For Subcooling

DEW Suction Side / Superheat

  • • Superheat = Suction Temp - Dew Point Temp
  • • Use at evaporator outlet
  • • Low pressure gauge reading
  • • Temperature where last liquid evaporates

BUBBLE Liquid Side / Subcooling

  • • Subcooling = Bubble Point Temp - Liquid Temp
  • • Use at condenser outlet
  • • High pressure gauge reading
  • • Temperature where first bubble forms

Important: Using the wrong saturation point will give incorrect superheat/subcooling readings. For R-454B with 1.3°C glide, this error can significantly affect diagnosis and charging.

Dew Point (Vapor)

Used for suction line / evaporator

°C °F bar
-50 -58 0.7
-45 -49 1.0
-40 -40 1.3
-35 -31 1.8
-30 -22 2.3
-25 -13 2.8
-20 -4 3.5
-15 5 4.2
-10 14 5.1
-5 23 6.0
0 32 7.0
5 41 8.2
10 50 9.5
15 59 10.9
20 68 12.4
25 77 14.1
30 86 16.0
35 95 18.0
40 104 20.2
45 113 22.6
50 122 25.1
55 131 27.9
60 140 30.9
65 149 34.0
70 158 37.5

Bubble Point (Liquid)

Used for liquid line / condenser

°C °F bar
-50 -58 0.6
-45 -49 0.9
-40 -40 1.2
-35 -31 1.7
-30 -22 2.1
-25 -13 2.7
-20 -4 3.3
-15 5 4.1
-10 14 4.9
-5 23 5.8
0 32 6.8
5 41 7.9
10 50 9.2
15 59 10.5
20 68 12.0
25 77 13.7
30 86 15.5
35 95 17.4
40 104 19.6
45 113 21.9
50 122 24.4
55 131 27.0
60 140 29.9
65 149 33.0
70 158 36.3

Pressure Units: psig = Gauge pressure (relative to atmosphere) kPa / bar / kgf/cm² = Absolute pressure