Air (R729) Thermodynamic properties

Saturation tables by temperature and by pressure, superheated vapor table, p–h and T–s diagrams and constants of Air, computed with CoolProp. Any other state of Air, from any two properties, in the State Explorer or the Worksheet.

Calculate a state of Air Open it in the Worksheet

Constants

Also known as: air, AIR, R729
CAS: AIR.PPF
Molar mass: 28.965 g/mol
Bubble and dew points at 1 atm: -194.25 °C, -191.43 °C
Critical temperature: -140.62 °C (132.53 K)
Critical pressure: 3.786 MPa
Critical density: 342.69 kg/m³
Triple point: -213.4 °C, 5.2642 kPa
Acentric factor: 0.0335
Valid up to: 1726.9 °C, 2000 MPa

Saturation table

Air is a mixture: at a temperature, it starts boiling (bubble) and ends (dew) at different pressures.

Saturated Air, by temperature
T °C	P bubble kPa	P dew kPa	vf m³/kg	vg m³/kg	hf kJ/kg	hfg kJ/kg	hg kJ/kg	sf kJ/(kg·K)	sg kJ/(kg·K)
-210	10.276	5.2874	0.0010597	3.4129	-30.188	218.97	188.78	-0.42524	3.17
-205	24.08	14.088	0.0010839	1.3755	-20.663	214.13	193.47	-0.28032	2.962
-200	49.727	32.171	0.00111	0.6414	-11.098	209.02	197.92	-0.14527	2.7912
-195	92.905	65.074	0.0011381	0.33479	-1.4599	203.53	202.07	-0.018469	2.6485
-190	160.19	119.53	0.0011689	0.1908	8.2884	197.55	205.84	0.10147	2.5269
-185	258.8	203.2	0.0012028	0.11648	18.193	190.95	209.14	0.21577	2.4214
-180	396.44	324.38	0.0012407	0.075055	28.311	183.58	211.89	0.32555	2.3278
-175	581.17	491.88	0.0012836	0.050439	38.713	175.28	213.99	0.43188	2.2427
-170	821.39	714.91	0.0013334	0.035005	49.492	165.83	215.32	0.53585	2.1632
-165	1125.8	1003.1	0.0013923	0.024874	60.772	154.93	215.7	0.63869	2.0866
-160	1503.2	1366.6	0.0014645	0.017946	72.734	142.14	214.87	0.74193	2.0099
-155	1963	1816.2	0.0015572	0.013021	85.672	126.73	212.41	0.84778	1.9293
-150	2514	2364.2	0.001686	0.0093673	100.16	107.29	207.45	0.96046	1.838
-145	3164	3027.3	0.0019017	0.0064705	117.93	79.89	197.82	1.0925	1.7202

Saturation table by pressure

At a pressure, Air starts boiling (bubble) and ends (dew) at different temperatures.

Saturated Air, by pressure
P kPa	T bubble °C	T dew °C	vf m³/kg	vg m³/kg	hf kJ/kg	hfg kJ/kg	hg kJ/kg	sf kJ/(kg·K)	sg kJ/(kg·K)
10	-210.15	-206.85	0.001059	1.8892	-30.467	222.22	191.75	-0.42967	3.0341
20	-206.16	-202.98	0.0010781	0.99485	-22.881	218.18	195.3	-0.31308	2.889
30	-203.56	-200.46	0.0010912	0.68412	-17.923	215.45	197.53	-0.24061	2.8055
50	-199.96	-196.96	0.0011102	0.42697	-11.019	211.51	200.49	-0.1442	2.7016
100	-194.36	-191.54	0.0011419	0.22508	-0.22363	204.95	204.72	-0.0028166	2.5625
200	-187.76	-185.16	0.0011836	0.11822	12.699	196.34	209.04	0.15326	2.4246
300	-183.33	-180.88	0.0012149	0.080806	21.543	189.91	211.45	0.25286	2.3435
500	-177.03	-174.79	0.0012655	0.049648	34.453	179.61	214.06	0.38908	2.2393
1000	-166.93	-165.05	0.0013682	0.024953	56.345	159.36	215.7	0.59901	2.0873
2000	-154.64	-153.21	0.0015651	0.011599	86.667	124.32	210.99	0.8557	1.8984
3000	-146.19	-145.19	0.0018355	0.0065719	113.18	85.151	198.33	1.0576	1.7255

Diagrams

p–h diagram of Air, with isotherms

T–s diagram of Air, with isobars

Superheated vapor table

At each pressure, from its saturated vapor (Sat.) to higher temperatures.

Superheated Air at 20 kPa (Tsat -202.98 °C)
T °C	v m³/kg	u kJ/kg	h kJ/kg	s kJ/(kg·K)
Sat.	0.99485	175.4	195.3	2.889
-200	1.0387	177.59	198.36	2.9318
-180	1.3301	192.1	218.71	3.1777
-160	1.6194	206.5	238.88	3.3739
-140	1.9077	220.85	259	3.5376
-120	2.1956	235.18	279.09	3.6782
-100	2.4832	249.5	299.17	3.8014
-80	2.7707	263.82	319.23	3.9111

Superheated Air at 50 kPa (Tsat -196.96 °C)
T °C	v m³/kg	u kJ/kg	h kJ/kg	s kJ/(kg·K)
Sat.	0.42697	179.14	200.49	2.7016
-180	0.52794	191.69	218.09	2.9103
-160	0.64496	206.22	238.47	3.1085
-140	0.76106	220.65	258.7	3.2731
-120	0.87672	235.02	278.86	3.4141
-100	0.99213	249.37	298.98	3.5376
-80	1.1074	263.71	319.08	3.6475

Superheated Air at 100 kPa (Tsat -191.54 °C)
T °C	v m³/kg	u kJ/kg	h kJ/kg	s kJ/(kg·K)
Sat.	0.22508	182.22	204.72	2.5625
-180	0.26047	191	217.04	2.7037
-160	0.32013	205.77	237.78	2.9054
-140	0.37884	220.31	258.19	3.0716
-120	0.4371	234.75	278.46	3.2134
-100	0.4951	249.15	298.66	3.3374
-80	0.55295	263.52	318.82	3.4476

Superheated Air at 200 kPa (Tsat -185.16 °C)
T °C	v m³/kg	u kJ/kg	h kJ/kg	s kJ/(kg·K)
Sat.	0.11822	185.4	209.04	2.4246
-180	0.12659	189.53	214.85	2.4887
-160	0.15768	204.83	236.36	2.6981
-140	0.18772	219.62	257.17	2.8675
-120	0.21728	234.22	277.67	3.011
-100	0.24659	248.71	298.03	3.1359
-80	0.27574	263.15	318.3	3.2467

Superheated Air at 500 kPa (Tsat -174.79 °C)
T °C	v m³/kg	u kJ/kg	h kJ/kg	s kJ/(kg·K)
Sat.	0.049648	189.24	214.06	2.2393
-160	0.060049	201.82	231.85	2.4079
-140	0.072991	217.49	253.99	2.5883
-120	0.085375	232.57	275.26	2.7371
-100	0.097476	247.37	296.11	2.8651
-80	0.10941	262.02	316.73	2.9778

Superheated Air at 1 MPa (Tsat -165.05 °C)
T °C	v m³/kg	u kJ/kg	h kJ/kg	s kJ/(kg·K)
Sat.	0.024953	190.75	215.7	2.0873
-160	0.027139	195.93	223.07	2.1539
-140	0.034645	213.66	248.31	2.3598
-120	0.041374	229.7	271.07	2.5192
-100	0.047765	245.07	292.84	2.6528
-80	0.053971	260.11	314.08	2.7689

Superheated Air at 2 MPa (Tsat -153.21 °C)
T °C	v m³/kg	u kJ/kg	h kJ/kg	s kJ/(kg·K)
Sat.	0.011599	187.79	210.99	1.8984
-140	0.015196	204.46	234.86	2.0879
-120	0.0193	223.42	262.02	2.2783
-100	0.022895	240.23	286.02	2.4257
-80	0.026259	256.15	308.66	2.5496

Enthalpy and entropy are measured from Air's own reference state (CoolProp's default). The textbooks' refrigerant tables use ASHRAE's: in the Worksheet, write reference ASHRAE.