I'm thinking just keep everything equal and get the same txv i'm using on the water and indoor coils.
So my brain has been in high gear today and here is what I'm thinking on.
Why not have 2 solenoids? One on the water coil and one on the outside air coil. Have audiuno taking temps and which ever has the high temp gets used? This to me seems simple and 100% all the time. The txvs are not going to work right 100% of the time due to changing temps.
Been thinking on the programming as well. Since I'm taking a temp reading anyway I can tell the compressor to start up at a certain % based on how cold/hot it is inside vs outside and the ramp up if more is needed.
Also in cooling mode I could be measuring indoor humidity and have the indoor fan start up and run slower to increase condensation and dehumidification if the humidity gets over around 50%.
http://www.fancollectors.org/info/speed.htm
Would something like this work to control the fan speeds? I would need 2 per fan, indoor and out. One for 50% and one for 75%.
AC Motor Fan Dimmer Speed Control 1000W 220 240V Triac Assembled Kit | eBay
Here is a drawing I have so far, without solenoids.
I really like finding/building from scratch the outdoor unit that way I can build everything and simply swap out the txv inside and some electric work and swap out the outside unit. Instead of 2-3 days of running line sets and brazing TONS to use the unit I have now.