6. Thermal power adjustment modes

The values for the cooling capacity of a refrigeration machine, or the heating capacity of a heat pump, used to calculate and select the required equipment, generally correspond to the machine's maximum thermal load. This is because the system must be able to satisfy cooling or heating requirements under the most difficult conditions. When, under the influence of various factors, these requirements are reduced, the machine's cooling or heating output must be lowered to adapt to the new load conditions.

We must therefore consider the various methods that can be used to reduce the thermal power produced by these machines. We will confine ourselves here to presenting the principles.