The two numbers you reuse constantly Specific heat of air, cp: about 1.006 kJ/kg.K (or 1006 J/kg.K). Density of air, rho: about 1.2 kg/m3 at 20 degC and 1 atm. Together they give a volumetric heat capacity of roughly 1200 J/m3.K - the energy stored in each cubic metre of air per degree of temperature. […]