The help and encouragement has been a huge boost for me. Good to see you chiming in, Bob.
My water cooling/power consumption target is 12000 BTU which calculates to a bit over 10F degrees of water cooling at 2GPM. Slowing the flow in this sort of closed loop system would help if a lower target water temperature was needed, but otherwise, no help with actual BTUs of cooling delivered. The water temps I'm getting are OK at 2 GPM. I don't want to go below 58F water, or I may get condensation at the PEX manifolds. Another reason to not just through lots of BTUs at this system.
The suction temp at the compressor was 72F, I'll have to measure it at the heat exchanger. If it's about 10 degrees colder there (as normal for remote compressor/condenser setup), it's very close to the outgoing water temp...so the exhanger is doing as it should, but I'd like a few more BTUs.
I'll see what water chilling performance I can get tomorrow. My pressures are a little low for R410a, and my superheat is quite high, both pointing to needed a bit more refrigerant needed, though superheat targets may not be the same for a water chiller. Still, I hope it may give me some performance improvement.
Normal use is with an air evaporator, with a colder return, thus lower superheat value. The water exhanger throws a wrench in the normal values- I haven't been able to find a good tech reference for that part of the design, so I am just going to measure the delta water temperature as I add a bit of refrigerant, watching pressures and monitoring amperes.
The capillary tube adjustment for the brazed flat plate exchanger/evaporator is another performance impacting issue I don't understand well enough to do, yet.
I will take a liquid line temperature tomorrow. I didn't today because it's not needed for superheat calculation and supercooling isn't recommended for capillary tube systems.
I'm hoping for sunny and hot tomorrow!