Specific heat capacity of dry air

c_{p,\mathrm{air}} = 1,006\ \text{J/(kg}{\cdot}\text{K)}

Value	1.006 kJ/(kg·K) (1,006 J/(kg·K)) Use in the calculator →
Status	Reference value; the source states no uncertainty
Source	Lemmon, Jacobsen, Penoncello and Friend (2000) equation of state for air, computed with CoolProp: 1006.4 J/(kg·K) at 300 K and 1 atm (1004.8 as an ideal gas)
Categories	Thermodynamic Engineering & Trade

Specific heat capacity of dry air in every specific heat capacity unit

Unit	Value
kilojoule per kilogram-kelvin	1.006 kJ/(kg·K)
joule per kilogram-kelvin	1,006 J/(kg·K)
BTU per pound-Fahrenheit	0.24027897 BTU/(lb·°F)
joule per kilogram-Celsius	1,006 J/(kg·°C)
foot pound-force per pound-Rankine	186.97771 ft·lbf/(lb·°R)
kilojoule per kilogram-Celsius	1.006 kJ/(kg·°C)
joule per gram-kelvin	1.006 J/(g·K)
calorie per gram-Celsius	0.24043977 cal/(g·°C)
kilocalorie per kilogram-Celsius	0.24043977 kcal/(kg·°C)
BTU per pound-Rankine	0.24027897 BTU/(lb·°R)

Learning zone

This is the constant behind every air-side heat calculation. Combined with a density of 1.2 kg/m³ it produces the familiar shortcuts: 1.2 kW per m³/s per kelvin in SI, or the North American sensible heat factor of 1.08 in Q = 1.08 × cfm × ΔT BTU/h, which quietly bundles specific heat, standard air density and the minutes-to-hours conversion into one number.

Dry air's c_p is nearly constant near ambient (1006 J/(kg·K) at 300 K, rising only to about 1014 at 400 K) so treating it as fixed is safe for HVAC. Moist air is different: because water vapour's c_p is roughly 1.86 kJ/(kg·K), psychrometric work uses the moist-air value c_p + 1.86W per kilogram of dry air, and at typical humidity ratios that adds one to two percent.

Used by 4 solvers

Air Sensible Heat (1.08 Rule)

\dot{Q}_s = \rho_a c_a \dot{V} \, \Delta T

Air Total Heat (4.5 Rule)

\dot{Q}_t = \rho_a \dot{V} \, \Delta h

Mixed Air Temperature

T_m = f \, T_{oa} + (1-f) \, T_{ra}

Sensible Heat (Q = mcΔT)

Q = m c \Delta T

Revised 1 November 2026

Cite this page

formula.expert. (2026, November 1). Specific heat capacity of dry air. https://formula.expert/constants/specific-heat-dry-air