hi guys, i seek technical advise for small capacity refrigeartion system. what is the minimum size for the compressor to have low temp application say -12 to -18 deg c. i got existing installation of +5 to 10 deg c but need to convert it to minus temp of -12 to -18 deg c. do i need to change the compressor, evaporator or just chage the expansion valve type or adjust the setting. im cluel]ess on this matter.thanks in advance. this is just use for provision on board the ship.