The Compressor takes low pressure refrigerant gas and squeezes it, raising the pressure and temperature in the process. This hot gas then condenses at the high pressure giving off large amounts of heat for a relatively small amount of electricity to power the Compressor's motor.
The more efficiently the gas is compressed, the higher the COP of the heat pump. Both piston and scroll Compressor designs have some leaks and because they can't compress 100% of the gas, there are efficiency losses. Heat Siphon Scroll Compressor models are about 12% more efficient than competitor piston models.
In a SCROLL Compressor the gas is continuously squeezed and theoretically come close to 100% compression, something a piston Compressor can't do because the valves get in the way.
Unlike reciprocating piston Compressors with many moving parts, SCROLL Compressors have only two moving parts - one scroll or spiral orbits a matching fixed scroll. The orbiting motion creates a series of gas pockets traveling between the two scrolls. On the outer portion of the scroll the pocket draws in gas, then moves it to center of the scroll where it’s discharged.
The SCROLL design allows more than one pocket of gas to be compressed at the same time providing a smooth, nearly continuous compression cycle. This enables the SCROLL Compressor to operate more smoothly and quietly, with less vibration. The rating for noise is 3 to 5 decibels less than a piston Compressor but our experience indicates for the HEAT SIPHON MODELS overall they are more like 1 to 3 dB quieter.
In either case - PISTON OR SCROLL - QUIETER THAN A POOL PUMP.