Pressure-Temperature Charts

Saturation P-T data for common refrigerants

Select Refrigerant

R-404A

Zeotropic

GWP: 3,922

ODP: 0

Temperature Glide: 0.7°C

Quick P-T Lookup

Pressure → Temperature

psig

Temperature → Pressure

* Results are interpolated from the P-T table data

Zeotropic Blend

This refrigerant has a temperature glide of 0.7°C - use the correct saturation point!

Temperature Glide Visualization

Dew Point

100% Vapor

For Superheat

0.7°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-404A with 0.7°C glide, this error can significantly affect diagnosis and charging.

Dew Point (Vapor)

Used for suction line / evaporator

°C	°F	psig
-50	-58	-1.5
-45	-49	4.5
-40	-40	11.5
-35	-31	19.5
-30	-22	28.7
-25	-13	39.3
-20	-4	51.3
-15	5	65.0
-10	14	80.3
-5	23	97.5
0	32	116.5
5	41	137.5
10	50	160.7
15	59	186.2
20	68	214.1
25	77	244.6
30	86	277.7
35	95	313.7
40	104	352.6
45	113	394.7
50	122	440.0

Bubble Point (Liquid)

Used for liquid line / condenser

°C	°F	psig
-50	-58	-2.2
-45	-49	3.7
-40	-40	10.5
-35	-31	18.4
-30	-22	27.4
-25	-13	37.8
-20	-4	49.6
-15	5	63.0
-10	14	78.1
-5	23	95.0
0	32	113.7
5	41	134.4
10	50	157.2
15	59	182.2
20	68	209.6
25	77	239.5
30	86	272.0
35	95	307.2
40	104	345.3
45	113	386.3
50	122	430.5

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