The model sequence starts by guessing the fraction of the tube
length required to de-superheat the refrigerant, FSH (FSH (FSH < 1).
To calculate the resistance over the superheated zone, each full
resistance, that is the each of the five resistances over the full tube
length (Rfull), is divided by the fraction of the tube length (FSH) used
for that particular section,
The total resistance is the sum of the individual resistances. The
conductance of the superheat zone, as calculated by the model, is
given by: