Suitable water temperatures entering and leaving the supercooler are crucial for higher COP and effectively used energy in a given super cooling type ice-making system. There are three ways to raise the water temperature entering the supercooler: (1) by a special heater; (2) by the environment; (3) using the returning water in the air conditioning system.. The variation of the effectively used energy and COP according to the water temperatures entering and leaving the supercooler was achieved and suitable temperatures were chosen.