Pretty simple really, the basic laws of physics show that a warm liquid will rise. The Egg uses this premise and operates with a copper refrigerant system that doesn’t have a pump. This saves energy spent and boosts the efficiency from 12 to 57 percent.
While the refrigerant is warmed during the AC process it is pushed into the hot water vessel above. The same refrigerant is cooled while warming the water through heat transfer and the process repeats itself and reduces energy waste.