Tom Chalko built this low-energy refrigerator out of a chest freezer. He rigged it with a SparOmeter that measures power consumption (bottom left) and a $40 external thermometer (top right) with a battery-operated internal relay that cuts the power at a set temp.
In the first 24 hours my new chest fridge took 103 Wh (0.103 kWh) of energy. About 30% of this energy was consumed during the initial power up and re-arranging of the fridge content. The room temperature varied from 21oC during the day to 15oC at night. The fridge interior temperature was kept between +4o and +7o C. The fridge compressor was working only for about 90 seconds per hour. When the thermostat intervened - the fridge consumed ZERO power. The only active part was a battery powered temperature display.
Results of my experiment exceeded all my expectations. My chest fridge consumes as much energy in 24 hours as a 100W light bulb does in just an hour. Not only it is energy efficient. I have never seen a fridge that was SO quiet. It only works 90 seconds or so every hour. At all other times it is perfectly quiet and consumes no power whatsoever. My wind/solar system batteries and the power sensing inverter simply love it. With my new chest fridge I have power to spare and I can use it to warm up my house in winter with a heat pump. I wonder why no one has ever thought of a chest fridge controlled by a digital thermostat...
Instructions are available at Build It Solar (links to PDF).
[via Home Design Find]