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In this paper, an economic analysis of replacing a single phase motors with a three phase motors and an inverter is carried out for the domestic water cooler. Considering the importance of saving energy, the enormous contributions being made by electrical motor in the residential loads, and the ever-increasing prices of energy carriers necessitate using technology to optimize energy consumption. In this study, we evaluated replacement of a three phase motor with an inverter instead of the conventional single phase motor being used in a specific timeframe in a hot and dry climate such as Kashan, where a great number of such cooler are used. Offering such technology, would lead to a softer starting in electrical motors, less breakdown owing to reduced mechanical stress on parts, reduced electric power generation and cost and less power losses in transmission lines. In all these cases energy savings can be achieved having a payback period of less of two years for the investment incurred, making this technique a superior one for such applications