hello RE,
I'm a mechanical/thermal engineer. I have a task to evaluate a "low pressure" R134a system. The system is like that inside Liebert XDP models. There doesn't seem to be an expansion valve, the liguid gets heat and expands to a gas in the "evaporator". Where should I post questions/etc. on this?

I want to compare to using water for the same application and performance.

Thanks.
-Henry