... Heat Pump, Water to Water Screw Compressor Heat Pump, Ground Source Heat PumpMain Parts:1.Compressor: Semi-hermetic Screw Type, Brand Bitzer, Hanbell ... heater and a thermal overload cut-out; the screw compressor is also complete with a built-in electronic protection ... microprocessor system.8. For the units with semi-hermetic screw compressor, an infinitely variable capacity control system that is ...