SAE Aerospace Applied Thermodynamics Manual Aerothermodynamic Systems Engineering and Design AIR1168/3A

This section presents methods and examples of computing the steady-state heating and cooling loads of aircraft compartments. In a steady-state process the flows of heat throughout the system are stabilized and thus do not change with time. In an aircraft compartment, several elements compose the steady-state air conditioning load. Transfer of heat occurs between these sources and sinks by the combined processes of convection, radiation, and conduction in the following manner:

The subsequent paragraphs discuss methods of determining each of the heat transfer rates listed above, as well as the physiological considerations involved in the selection of proper cabin conditions that are to be maintained.