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. […]
The epsilon-NTU Method: Predicting Heat Exchanger Performance
Effectiveness, the practical metric Effectiveness (epsilon) is the ratio of actual heat transferred to the maximum thermodynamically possible: epsilon = actual_heat_transfer / (Cmin x (Thot_in - Tcold_in)) It is the number you see quoted as "70% efficient" for a recovery core, and it is directly related to the efficiency metrics reported for air-to-air units. NTU: […]