Quote Originally Posted by wdrzal
"Energy can be neither created nor destroyed", first law of thermodynamics.

If you put in 200 watts somehow 200 watts either comes out completely or part gets held my the mass as latent heat, but as 200 watts is feed continuously the latent heat will reaches a maximum for that substance and 200 watts will exit. minus small energy losses in other thermodynamic areas.
I hope everyone knows this... and I am pretty sure everyone does. By same token, if same amount of refrigerant is boiling inside evaporator, evaporator design shouldn't matter at holding same amount of load. Let's get bit more descriptive when we talk about this rather than in pure theory... Sometimes, this simplisitic fundamental talk will just get us no where...
My explanation (which I was writing on post and stopped when I thought about that it is about luke's idea of autocascade) was that due to the distance of subjected heat material through multiple medium (thermal interface material, copper, than thermal interface, evaporator) the surface area of such heat produced (resistor will have much less density per say in general due to size, shape of it and method of interface to the copper, and not the perfect world of perfect insulation gives this variances. In fact, at least few of us who used cartridge heater to be superior heating material in such case than typical load resistor being used for load tester. Not to mention safety aspect of it...
Anyways, let's try to keep subject to where it belongs.
In my all honesty, ethylene is bit of off child on autocascading due to some properties it has in my book. I've discussed this before...
#1 is that I don't know full checmical behavoir of gas with some potential other gases in mixture condition. And it can be rather violent gas.
#2 the boiling temp, critical pressure sits where I would consider it somewhat undesirable for effort involved in condensing it in auto cascade. Typical gas like R22 can't really condense it in safety zone. Which brings more exotic gas like R116 or R23 in it. At which point, it almost looks like wasting the system design when R14 becomes next acceptable jump. There might be another pure group of refrigerant that I am missing which can condense ethylene without going for another stage but I don't really think I have seen one yet.

Just my 2c on this matter.