Return gas temperature

[skyboy6142]

Hi friends,
What is effect of return gas temperature on compressor capacity ?

[frank]

Any incresae in temperature added to the suction gas after the evaporator will reduce system refrigerating capacity and increase the power required to run the compressor. The excess heat absorbed into the suction gas will also have to be rejected in the condenser before saturation can take place.

3K of suction gas superheat is considered 'useful' superheat as this ensures that no liquid refirgerant returns to the compressor, anything above 3K in considered 'non-useful' superheat.

[RANGER1]

https://www.achrnews.com/articles/143411-refrigerant-density-can-affect-compressor-capacity

This seems to explain things pretty well

[HwT]

Also having to low of an superheat can cause the oil in hermetic compressors to be washed/mixed with to much refrigerant and decrease its lubricating properties.