Quote Originally Posted by SteinarN
It is however absolutely necessary to decrease the superheat when installing a system with a low TD evaporator.
That is a valid point and one not often considered. I forgot about this when posting my comments earlier (although I have mentioned this before in another thread somewhere). If the static superheat setting of the expansion avlve is less than the temperature difference of the evaporator you can have problems with loss of capacity or higher discharge temperatures.

You cannot get more superheat than you have temperature difference. This is a practical limit to recognize in my opinion.