That will work better for you I think. I had wondered if the compressor heating you were worried about was due to feeding a large compressor into 1/4 tubing - this may have less resistance but still 1/4". I am hooking up a similar system using about 20 ft of 1/4 tubing wrapped around and soldered to 3/4 tubing with all inside 5 ft of 1.5" tubing mounted vertically beside the water heater tank. I will use water from a solar tank up the center tube as and alternate heat in summer and thermosyphon or pump the dhw thru the annular space between the 3/4 and 1.5 " tubes as in the pics. I have a 7500 r22 compressor and wondered if it was too big for the 1/4 tubing as well.
I see you have your r290 entering and leaving at the top as I plan on doing but I wonder why Niohaomike advised in at the top and out at the bottom?
