R422d freon (refrigerant): characteristics (properties), tables, diagrams

R422d is a refrigerant that has become a popular replacement for R22, which is being phased out due to environmental concerns. The chemical composition of R422d makes it a suitable alternative to R22 as it has similar thermodynamic characteristics. In this article, we will look at the properties and characteristics of R422d, its applications, and the advantages and disadvantages of its use. We will also discuss the precautions that must be taken when working with this freon.

Characteristics and properties of R422d

Property	Value
Chemical names of components	pentafluoroethane, tetrafluoroethane, isobutane.
Chemical formulas of components	CF3CHF2, CF3CH2F, (CH3)3CH
Molecular mass	109.9
Boiling point (°C/°F)	-43.2 / -45.8
Critical temperature (°C/°F)	79.6 / 175.3
Critical pressure, bar	39.05
Critical density, kg/m3	528.7
Temperature slide at 1.013 bar, °C/°F	4.86 / 8.75
Liquid density at 0 °C, kg/m3	1250.5
Specific heat capacity of liquid at constant pressure at 25°C, kJ/(kg*K)	1.4429
Specific heat capacity of steam at constant pressure at 25°C, kJ/(kg*K)	1.0698
Steam density at 25°C, kg/m3	4.49
Vapor density at boiling point, kg/m3	5.954
Thermal conductivity of liquid at 25°C, W/(m*K)	0.067
Thermal conductivity of steam at 1.013 bar, W/(m*K)	0.014
Liquid viscosity at 25°C, mPa*s	0.155
Vapor viscosity at 1.013 bar, mPa*s	0.012
ATEL/ODL*, kg/m3	0.26
Flammability range, % vol. in the air	No
Global Warming Potential, GWP	2729
Ozone Depletion Potential, ODP	0

* ATEL/ODL – Acute toxicity exposure limit / Oxygen deprivation limit.

Composition of freon R422d

R422d refrigerant is a mixed freon. It consists of three separate refrigerants:

• R125 (difluoromethane) – 65%;
• R134a (1,1,1,2-tetrafluoroethane) – 31.5%;
• R600a (isobutane) – 3.5%.

Important!

Depending on the manufacturer and the quality of the raw materials, the ratio of components in freonR422d may vary. The error usually does not exceed 1% forR125 andR134a, and 0.5% forR600a. Due to this, the physical and chemical properties and thermodynamic characteristics of freon can change. When purchasing refrigerant, check how large the deviation in the proportions of the components can be.

Application of R422d

R422d refrigerant is commonly used as a replacement for R22 in air conditioning systems because it has similar cooling capacity and efficiency. It can be used in new systems or retrofit existing R22 systems. Freon R422d can also be used in industrial refrigeration units, for example, in cold storage warehouses and food processing plants.

Comparison of R422d and R22

Property	R422d	R22
Molecular weight, kg/kmol	109.94	86.5
Boiling point at 1013 bar, °C/°F	-43.2 / -45.8	-40.8 / -41.4
Steam pressure at 25 °C (bar abs.)	11.3	10.4
Critical temperature, °C/°F	79.56 / 175.21	96.2 / 205.16
Critical pressure, bar	39.03	49.8
Liquid density at 25 °C, kg/m3	1143	1193
Saturated vapor density at 1013 bar, kg/m3	5.9	4.7
Temperature slide, °C/°F	4.8 / 40.6	0 / 0
Specific heat capacity of liquid at 25 °C, KJ/kg*K,	1.44	1.26
Specific heat capacity of steam at 25 °C and 1 atm, kJ/kg*K	0.84	0.68
Flammability	No	No
Toxicity (ppm)	1000	1000
Ozone Depletion Potential, ODP	0	0.05
Global Warming Potential, GWP	2729	1810

Compatibility of R422d with compressor oils

• Mineral compressor oils (MN): Partially compatible with R422d.
• Alkylbenzene compressor oils (AB): Partially compatible with R422d freon.
• Polyolester compressor oils (POE): Fully compatible with R422d refrigerant.

When using mineral oils, alkylbenzene oils or mixtures thereof, return issues may arise. Most often this occurs when retrofitting systems from R22 to R422d. To solve the problem, you can add 5-10% polyol ether oil (POE) to the system. But it’s best to replace it entirely.

R422d advantages and disadvantages

Pros of R422d

1. In most cases, R422d can be used instead of R22 without changing the oil.
2. This freon has low global warming potential and ozone depletion potential.
3. In study R422d refrigerant showed a discharge temperature 20°C lower than R22. This provides longer compressor life. a>
4. To retrofit R22 systems, it is not necessary to make major changes to the equipment design.

Cons of R422d

1. R422d has 15-25% lower COP than R22.
2. The exergy efficiency of R422d refrigerant is 6-21% lower than that of R22.
3. Freon R422d is not an azeotropic mixture of substances. Therefore, in the event of a leak, the refrigeration equipment cannot be refilled.

R422d refrigerant pressure-temperature table

The table below uses the following abbreviations:

• t,°C – temperature in degrees Celsius.
• t,°F – temperature in degrees Fahrenheit.
• Pl, barA – absolute pressure of the liquid in bar.
• Pl, barg – excess liquid pressure in bar.
• Pl, psig – excess fluid pressure in pounds per square inch.
• Pv, barA – absolute steam pressure in bar.
• Pv, barg – excess steam pressure in bar.
• Pv, psig – excess steam pressure in pounds per square inch.

t,°C	t,°F	Pl, barA	Pl, barg	Pl, psig	Pv, barA	Pv, barg	Pv, psig
-70	-94	0.24	-0.78	-11.28	0.16	-0.85	-12.37
-68	-90.4	0.27	-0.75	-10.83	0.18	-0.83	-12.03
-66	-86.8	0.30	-0.71	-10.33	0.21	-0.80	-11.65
-64	-83.2	0.34	-0.67	-9.78	0.24	-0.77	-11.22
-62	-79.6	0.38	-0.63	-9.17	0.27	-0.74	-10.75
-60	-76	0.43	-0.59	-8.51	0.31	-0.70	-10.22
-58	-72.4	0.48	-0.54	-7.78	0.35	-0.66	-9.64
-56	-68.8	0.53	-0.48	-6.99	0.39	-0.62	-9.00
-54	-65.2	0.59	-0.42	-6.12	0.44	-0.57	-8.29
-52	-61.6	0.66	-0.36	-5.17	0.49	-0.52	-7.51
-50	-58	0.73	-0.29	-4.15	0.55	-0.46	-6.67
-48	-54.4	0.80	-0.21	-3.04	0.62	-0.40	-5.74
-46	-50.8	0.89	-0.13	-1.84	0.69	-0.33	-4.73
-44	-47.2	0.98	-0.04	-0.54	0.76	-0.25	-3.63
-42	-43.6	1.07	0.06	0.86	0.84	-0.17	-2.44
-40	-40	1.18	0.16	2.36	0.93	-0.08	-1.15
-38	-36.4	1.29	0.27	3.98	1.03	0.02	0.25
-36	-32.8	1.41	0.39	5.71	1.13	0.12	1.76
-34	-29.2	1.53	0.52	7.57	1.25	0.23	3.38
-32	-25.6	1.67	0.66	9.55	1.37	0.35	5.13
-30	-22	1.82	0.81	11.68	1.50	0.48	7.00
-28	-18.4	1.97	0.96	13.94	1.63	0.62	9.02
-26	-14.8	2.14	1.13	16.35	1.78	0.77	11.17
-24	-11.2	2.32	1.30	18.91	1.94	0.93	13.47
-22	-7.6	2.51	1.49	21.63	2.11	1.10	15.93
-20	-4	2.70	1.69	24.52	2.29	1.28	18.54
-18	-0.4	2.92	1.90	27.59	2.48	1.47	21.33
-16	3.2	3.14	2.13	30.83	2.69	1.68	24.29
-14	6.8	3.38	2.36	34.26	2.91	1.89	27.44
-12	10.4	3.63	2.61	37.88	3.14	2.12	30.77
-10	14	3.89	2.88	41.70	3.38	2.37	34.31
-8	17.6	4.17	3.15	45.73	3.64	2.62	38.05
-6	21.2	4.46	3.45	49.98	3.91	2.90	42.00
-4	24.8	4.77	3.75	54.44	4.20	3.18	46.17
-2	28.4	5.09	4.08	59.14	4.50	3.49	50.57
0	32	5.43	4.42	64.07	4.82	3.81	55.20
2	35.6	5.79	4.78	69.24	5.16	4.14	60.08
4	39.2	6.16	5.15	74.67	5.51	4.50	65.21
6	42.8	6.55	5.54	80.36	5.88	4.87	70.60
8	46.4	6.97	5.95	86.31	6.27	5.26	76.26
10	50	7.40	6.38	92.54	6.68	5.67	82.20
12	53.6	7.84	6.83	99.05	7.11	6.10	88.42
14	57.2	8.31	7.30	105.86	7.56	6.55	94.94
16	60.8	8.80	7.79	112.96	8.03	7.02	101.76
18	64.4	9.31	8.30	120.37	8.52	7.51	108.89
20	68	9.85	8.83	128.10	9.04	8.02	116.35
22	71.6	10.40	9.39	136.16	9.57	8.56	124.14
24	75.2	10.98	9.97	144.54	10.14	9.12	132.27
26	78.8	11.58	10.57	153.27	10.72	9.71	140.74
28	82.4	12.21	11.20	162.34	11.33	10.32	149.58
30	86	12.86	11.85	171.78	11.96	10.95	158.79
32	89.6	13.54	12.52	181.60	12.63	11.61	168.39
34	93.2	14.24	13.23	191.79	13.31	12.30	178.36
36	96.8	14.97	13.96	202.38	14.03	13.02	188.76
38	100.4	15.73	14.71	213.35	14.78	13.76	199.56
40	104	16.51	15.50	224.74	15.55	14.54	210.79
42	107.6	17.33	16.31	236.55	16.36	15.34	222.46
44	111.2	18.17	17.16	248.79	17.19	16.18	234.58
46	114.8	19.05	18.03	261.46	18.06	17.05	247.15
48	118.4	19.95	18.94	274.60	18.96	17.95	260.22
50	122	20.89	19.88	288.20	19.89	18.88	273.77
52	125.6	21.86	20.85	302.28	20.86	19.85	287.84
54	129.2	22.86	21.85	316.84	21.87	20.86	302.43
56	132.8	23.90	22.89	331.91	22.91	21.90	317.56
58	136.4	24.98	23.97	347.49	24.00	22.98	333.25
60	140	26.09	25.08	363.62	25.12	24.11	349.54
62	143.6	27.24	26.23	380.28	26.28	25.27	366.43
64	147.2	28.43	27.42	397.52	27.49	26.48	383.96
66	150.8	29.66	28.64	415.32	28.75	27.74	402.17
68	154.4	30.93	29.91	433.74	30.05	29.04	421.08
70	158	32.24	31.23	452.76	31.41	30.40	440.77

Log p-h diagrams for R422d freon

Safety precautions

• Always use personal protective equipment such as gloves, goggles and respiratory protection when working with R422d.
• Avoid inhalation, ingestion or contact with refrigerant. If on skin, wash affected area with soap and water for at least 20 minutes.
• Handle R422d refrigerant in a well-ventilated area to avoid vapor buildup.
• Keep refrigerant away from heat and open flames as it is under pressure and may cause an explosion.
• Store refrigerant in a cool, dry and well-ventilated area. Keep it away from incompatible materials such as acids and oxidizing agents.
• If there is a refrigerant leak, leave the area immediately and seek medical attention if necessary.

Thermodynamic properties of R422d freon, table

Below are the thermodynamic properties of R422d refrigerant at the saturation line. The following abbreviations are used in the table:

• t,°C – temperature in degrees Celsius.
• t,°F – temperature in degrees Fahrenheit.
• Pl – liquid pressure, bar.
• Pv – steam pressure, bar.
• Dv – vapor density, kg/m3 or g/l.
• Dl – liquid density, kg/m3 or g/l.
• Hl – liquid enthalpy kJ/kg.
• Hv – steam enthalpy kJ/kg.
• Sl – entropy of liquid J/(kg*K).
• Sv – entropy of steam J/(kg*K).

t,⁰C	t,⁰F	Pl	Pv	Dl	Dv	Hl	Hv	Sl	Sv
-18	-0.4	2,916	2,484	1317.1	13.97	176.75	347.85	0.9127	1.5895
-16	3.2	3.139	2,688	1310	15.07	179.28	349.01	0.9225	1.5886
-14	6.8	3.376	2,905	1302.9	16.24	181.83	350.16	0.9323	1.5877
-12	10.4	3.625	3.135	1295.6	17.48	184.39	351.31	0.9421	1.5868
-10	14	3,889	3,379	1288.3	18.79	186.96	352.45	0.9518	1.5861
-8	17.6	4,167	3.637	1280.9	20.19	189.54	353.57	0.9615	1.5853
-6	21.2	4.46	3,909	1273.4	21.66	192.14	354.69	0.9712	1.5846
-4	24.8	4,768	4,197	1265.9	23.22	194.74	355.8	0.9808	1,584
-2	28.4	5,091	4.5	1258.2	24.87	197.36	356.9	0.9904	1.5834
0	32	5.432	4.82	1250.5	26.61	200	357.98	1	1.5828
2	35.6	5,788	5.156	1242.7	28.45	202.65	359.05	1.0096	1.5822
4	39.2	6,163	5.51	1234.7	30.4	205.31	360.11	1.0191	1.5817
6	42.8	6,555	5,882	1226.7	32.45	207.99	361.15	1.0286	1.5812
8	46.4	6,966	6,272	1218.5	34.62	210.69	362.18	1.0381	1.5807
10	50	7,395	6,682	1210.2	36.9	213.4	363.19	1.0476	1.5802
12	53.6	7,844	7.111	1201.8	39.31	216.13	364.19	1.0571	1.5798
14	57.2	8,313	7.56	1193.2	41.86	218.87	365.17	1.0665	1.5793
16	60.8	8,803	8,031	1184.5	44.54	221.64	366.12	1.076	1.5789
18	64.4	9,314	8,523	1175.7	47.38	224.42	367.06	1.0854	1.5784
20	68	9,847	9,037	1166.7	50.36	227.23	367.98	1.0949	1.5779
22	71.6	10.4	9,574	1157.5	53.52	230.05	368.87	1.1043	1.5774
24	75.2	10.98	10.14	1148.2	56.85	232.9	369.74	1.1137	1.5769
26	78.8	11.58	10.72	1138.6	60.36	235.76	370.58	1.1232	1.5764
28	82.4	12.21	11.33	1128.9	64.08	238.66	371.39	1.1326	1.5759
30	86	12.86	11.96	1119	68	241.57	372.17	1.1421	1.5753
32	89.6	13.54	12.63	1108.8	72.16	244.52	372.92	1.1516	1.5746
34	93.2	14.24	13.31	1098.3	76.55	247.49	373.64	1.1611	1.5739
36	96.8	14.97	14.03	1087.6	81.21	250.49	374.32	1.1706	1.5732
38	100.4	15.73	14.78	1076.6	86.14	253.53	374.96	1.1802	1.5724
40	104	16.51	15.55	1065.3	91.38	256.59	375.56	1.1898	1.5715
42	107.6	17.33	16.36	1053.7	96.95	259.7	376.11	1.1994	1.5706
44	111.2	18.17	17.19	1041.7	102.9	262.84	376.62	1.2091	1.5695
46	114.8	19.05	18.06	1029.2	109.2	266.02	377.06	1.2188	1.5683
48	118.4	19.95	18.96	1016.4	116	269.26	377.45	1.2286	1.5671
50	122	20.89	19.89	1003	123.2	272.54	377.78	1.2385	1.5656
52	125.6	21.86	20.86	989.08	131	275.87	378.03	1.2485	1.5641
54	129.2	22.86	21.87	974.52	139.3	279.27	378.2	1.2586	1.5623
56	132.8	23.9	22.91	959.25	148.4	282.73	378.28	1.2689	1.5603
58	136.4	24.98	24	943.16	158.2	286.28	378.25	1.2792	1.5581
60	140	26.09	25.12	926.11	169	289.91	378.1	1.2898	1.5556
62	143.6	27.24	26.28	907.92	180.8	293.65	377.8	1.3006	1.5527
64	147.2	28.43	27.49	888.36	193.9	297.51	377.33	1.3117	1.5494
66	150.8	29.66	28.75	867.08	208.7	301.52	376.64	1.3232	1.5455
68	154.4	30.93	30.05	843.61	225.5	305.73	375.69	1.3351	1.5409
70	158	32.24	31.41	817.17	245.1	310.2	374.37	1.3477	1.5354
72	161.6	33.59	32.83	786.45	268.6	315.05	372.54	1.3613	1.5284
74	165.2	34.99	34.31	748.76	298.4	320.49	369.9	1.3765	1.5193
76	168.8	36.43	35.88	696.79	340.7	327.18	365.71	1.3952	1.5058
78	172.4	37.85	37.61	578.64	433.8	339.93	355.45	1.4309	1.4752