Ran across a 6' hill phoenix seafood case that had a pump and water going to it. It had plastic hoses going into the evaporator coils. It had what appeared to be a condenser coil with a fan but no compressor maybe some kind heat exchanger. Can sombody explain how this works mechanically and the control stategy. There is a board with sensors and a timer ant t/stat There is also solenoids om the water lines.