(Tandem compressor)water heater update.

[Bobinater33]

Here’s the gist of it:

-1x 10k btu r22 rotary comp in tandem with a 5k btu R32 rotary. (Yes I know ,diff oils , but at-least I scaled the suction line flow washer in size relative to Copelands discus specs.

-Johnson controls v46 head pressure water flow regulating valve at the HX inlet

-Home-brew condensor refrigerant-water tube-in-tube HX (1/2” L copper pipe inside for water 3/4” outer jacket for the refrigerant)

-24kBtu trane mini split outdoor coil for the evaporator

-1-1/2 to 3 ton r22 TXV, filter drier and site glass.

-Fried a teco 3hp VFD trying to drive a 2 ton twin rotary BLDC compressor so I’ve defaulted to an inkbird PID / mechanical contactors for controlling this experiment) (wiring In pic is incomplete)

-800 CFM 10 speed 10” inline fan (super quiet and ductable)


A slew of various temperature/ pressure / amperage sensors with displays consolidated in the door of the control box


Any input questions or concerns are very welcome. This is more of an experiment and I’m positive there are many potential problems as it stands currently.

The random tandem window comps were just what I had on hand…