5. Machine features and operation

The operating characteristics of a single-stage compression refrigeration machine or heat pump (cooling or heating capacity, coefficients of performance, power input, compressor discharge temperature, etc.) depend, to a greater or lesser extent, on the following parameters:

• evaporation temperature (or pressure) ;

• condensation temperature (or pressure) ;

• overheating of suctioned vapors;

• liquid subcooling.

The values of these parameters determine what we call the machine's operating conditions.

Let's examine in turn the influence of the first two parameters on cooling or heating capacity and coefficients of performance, with the other parameters remaining constant.