Another factor that influences the choice of the compressor is the evaporation temperature range that the system requires. We can point out two extremes:
- Freezers operating at very low temperatures ranging from -25°C to -35°C.
- Dehumidifier that works with an evaporation temperature above 0°C.
The heat absorption by the refrigerant will depend on the evaporation temperature.
A certain temperature in the evaporator corresponds to a certain pressure. The gas density is low at low temperatures and therefore only a small amount of heat can be absorbed during evaporation. If the evaporation occurs at a higher temperature, for example, 0 ° C, the pressure and density increase and the amount of heat will be greater.
For this reason, we can conclude that the work done by a compressor motor will be higher than that achieved by the same compressor at a low evaporation temperature.
Consequently, motors for application in high-pressure evaporation systems should have a higher operational torque.
Compressors can be classified according to their application:
- LBP - Low Back Pressure - Low evaporation temperature.
- MBP - Medium Back Pressure - Average evaporation temperature.
- HBP - High Back Pressure (High Back Pressure) - High evaporation temperature.
Depending on the compressor model, its application may extend from the LBP to the BPH classification (see table below).