Hello guys, I have a question about the design of a system which uses an evaporator made out a coil of copper tubing as opposed to a normal evaporator made with copper plates and fins. I've made some measurements with my R290 blast chiller and it's evaporator consists in 3 meters of 10mm tubing in the shape of a normal evaporator, and a fan which blows air through the fins for improved thermal exchange. However, let's say that I replace just the evaporator with a copper tubing wound around a metal pot to cool it down, I reckon that the length should be way higher because the coild would only contact with the external steel of the pot, and steel is not an extremely efficient heat conductor and also the surface contact between the copper tubing and the steel would have gaps in between, so I think I should compensate for this by using a longer tube, maybe even 20 meters, so I ensure that all of the liquid refrigerant has the chance to change state and prevent compressor flooding. However, my question is: should the refrigerant charge be increased to accomodate for a "bigger" evaporator, not "bigger" as in greater heat capacity but as in more volume of gas that can fit inside?