Abstract: An electrical energy use saving system for the sales of purchasable amounts of beer, soda, bottled water, meat, vegetables, fruit, dairy, eggs or seafood products kept in a walk-in cooler, reach-in cooler or display case whose temperature is to be maintained includes a compressor, a thermostat, a suction fan and a thermometer in a network by which the cooler or case is cooled by outdoors ambient air when outside temperatures are cold and where the cooler or case is cooled by the compressor when outside temperatures are warm.