Einstein, along with Leo Szilard worked together to develop a new refrigerator after hearing a story about a family killed by the harsh chemicals leaking from their refrigerator. During that time chemicals such as methyl chloride, ammonia and sulfur dioxide, were used for refrigeration. These chemicals were poisonous and led to accidents. 

It was this reality that led Einstein and Szilard to develop a new way to refrigerate food. This refrigerator relied on concepts developed in Szilard’s dissertation work. Their new design included an electromagnetic pump and used pressurized ammonia, butane and water. It did not necessarily need electricity, just a heat source. 

This refrigerator design was not used because the toxic chemicals being used in refrigerators produced at the time had been replaced by the less toxic Freon, so there was little interest in Einstein and Szilard’s design. Despite little use of the design while Einstein was alive, modern scientists and graduate students have recreated Einstein’s refrigerator for its environmental advantages. With modification in the gases used and in the original design of Einstein and Szilard, the refrigerator may yet get use in modern times. Read more about how the refrigerator works at the source.