[NiHaoMike]

My friend Brittany Benzaia experimented with a low side float in her hybrid A/C that uses water as a refrigerant. I remember her saying that it worked just as well as or better than the high tech alternatives (electronically controlled expansion valves of various types) she tried and thus would most likely be what would be used in production. As an added benefit, it was easy to make it pose little resistance to flow when fully open which, when combined with the free-flowing centrifugal compressor, allowed it to have a very efficient bypass mode (turn off the compressor and let the refrigerant flow by gravity) that transitions smoothly to and from normal operation.

So amongst all the microchips, high voltage transistors, and an extremely fast and precise spinning wheel inside the compressor, there's that rather important part of the machine that operates exactly like the mechanism in a toilet tank...