Another theoretical question thats bugging me.
On the Daikin vrv's ive been installing it seems that the expansion devices are at the indoor unit. I havent really taken an indoor apart to have a look as I never have the time but i assume there is some kind of electronic expansion valve at the indoor unit that allows refrigerant to flow when the unit is calling for duty.
Thats pretty obvious and all fine and dandy etc but what i want to know is this. When you are pressure testing or evacuating the system with no power to the units this expansion device restricts the flow of gas but does not shut of completely.
So why is it that when the condenser is running but you may have a particular unit or group of units turned off that there is not refrigerant passing through those expansion devices causing the refrigeration effect.
I.e. if you turned the power off to one particular unit and left the system running, why does this unit not start to ice up?