That's a lot to type out here, I'd be happy to email you the details. It's a "home made" inverter setup, meaning I just bought a 3 phase compressor unit and put a VFD on it. I have custom control software that I wrote to maximize whichever thing is most important based on situation like; max efficiency, minimum running kw, maximum humidity removal, maximum hot water production, etc. I run it all closed loop with pressure and temperature sensors as well as controlling the condenser fan. The controller in the evaporator fan still works so my system just switches between the 5 torque choices on there for indoor fan control. it's a 410a system. I was going to use one heat exchanger for house hot water and the other one for an outdoor hot tub but just ended up plumbing them in series for house water. I think the small one was 30k BTU ad the big one was 60k BTU. The way I end up using it is actually on demand hot water. It will heat up my water heater tank in normal daily use but 60 gallons or whatever doesn't go very far. I set up my software where you just push a button before taking a shower and it fires up in maximum hot water production mode for a timed duration and then switches to humidity removal for a timed duration before shutting off. With all that junk, it can make the water plenty hot for a high flow shower in real time. There are a LOT of aspects to this I'd be happy to share but I could go on for days. Thanks for your interest.

@@RickBaconsAdventures What! So many disciplines right there! (low/high voltage, embedded logic/controllers (esp32/arduino/plc?) I wanted to spare me (and I don't have the expertise anyways) from having to build the outdoor part, still think I could use inverter based 3-ton R410A unit (gree flexx/mrcool universal) and implement a very basic 24vac logic (compressor + reversing valve signaling). The outdoor unit would maintain liquid/gas line delta-T and take care of not exceeding the safe pressure (667psi on gas side based on their service manual), while ecm pump (grundfos alpha2) would pull water through a bphe and into 119gallon tank where the heat would be stratified. I'm now researching which bphe I need to get (pressure ratings, size vs plate count). I'd be using this for radiant heating, with several in-concrete-floor zones (low temp 80-85F supply) and supplemental radiators and towel warmers (hi temp 110-115F), so would need the tank to get upto 125-130 or more and then use mixing valves to get the target temp. "Tankless" heat pump water heater? nice! I suppose it you have a low-flow shower head and temp raise from from 50F to 100F you could get away with about ~25k BTUs.... and at high COP you are definitely saving on electricity...

@@elyor2008 I have an illegal modified extremely high flow shower head. I'm in florida so the incoming water is basically always 73 degrees F. I can get 120-130 degree water coming from the heat exchanger. The effects that this has on the air conditioner definitely have to be compensated for. If you don't have control over the rest of the system, you can only really take some of the heat coming directly out of the compressor and not actually condensing the refrigerant. All of my software is embedded C on boards I designed. Arduino is a great starting point for new people though. Some of the other popular platforms these days get too far away from proper programming. What are you air conditioning that you also need heat at the same time? Are you just trying to build a heat pump radiant heating system and not cooling at all?

it's still holding 450 psi almost 3 years later so it can't be that bad haha. I don't get to practice this type of soldering/ brazing much so I just got the job done. I was mainly surprised how well the flux worked

@@RickBaconsAdventures j

at the time I was using regulators that didn't work right and would drift

Yes, I bought a small tip for my torch for this job. I believe it was a #0. Did not take very much heat at all. I have tried MAPP gas when in a remote location once and it wasn't really hot enough.

first of all it's held 450 psi for about 5 years with no issues