isoenthalpic vs isoentropy refrigeration process ?

[Doug30293]

But I don't know what's the theory behind that, in order to choose an isoentropic and not an isoenthalpic there. Maybe is not theory but experimental data.

Correct. The models are often an attempt to align theory with experimental data. The compression line roughly follows an isotrope so it is called an isoentropic process.

Some areas of thermodynamics, such as the saturation tables and heat transfer analysis, are entirely based on experimental data. The equations are nothing more than curve fit functions.