We all know Einstein as the man who invented E=MC2. He also used experiments to find Avogadro’s Number, proposed that light was not just a wave but also a particle (a photon), created the General Theory of Relativity, and among all his accomplishments, designed a fridge without a single moving part. As with all things in our industry, this relied on cheating the laws of physics into doing our bidding.
The first refrigerators were deadly machines. They used a similar compression system to what we have today, but there was a catch. The new technology had a short lifetime before failure and when it did fail, it failed deadly. At the time, there were three major refrigerants: methyl chloride, ammonia, and sulfur dioxide. Methyl Chloride can disrupt the central nervous system, starting with drunken symptoms and ending at paralysis, coma, and death. Ammonia is incredibly corrosive and will cause irritation of the skin, eyes, and lungs before more severe symptoms such as blindness and death by lung failure set in. Sulfur Dioxide is similar to ammonia, it attacks the skin and mucous membranes, and with the right circumstances can damage and destroy the lungs, and even interfere in the heart. The seals on early fridges would fail at random due to the newness of the technology, variations in product quality, and perhaps even outright design flaws. When such a failure occurred, toxic gasses got into the air, and nothing good came of it. Making matters worse was the lack of education. People viewed their new machines as being almost magical, with no understanding of how it worked. They didn’t know to run in terror if it stopped working or made a hissing sound.
These failures were entirely too common. Newspapers would run stories every few weeks of another tragic death. It was possible for an entire family to literally drop dead in their sleep from the exposure, none the wiser. At the time however, there was nothing to stop the growing crisis. More families were ditching their ice boxes in favor of theoretically better fridges. Guaranteed temperature control was essential to public health, preventing people from eating rotten food and cutting down the preservatives it took to keep food fresh.
For Einstein and his co-creator Leo Szilard, the last straw is believed to have come in 1926. A whole family in Berlin killed by a leaking seal.
The Team Up
Szilard started his career with an engineering degree before working on his Doctorate in Physics at the Institute of Technology in Berlin. By all accounts, he was brilliant, filing for patents on X-Ray cells, mercury vapor lamps, and would eventually work on electron microscopes and particle accelerators. He was no second fiddle, even working with Einstein.
Einstein and Szilard would meet at the Institute of Technology, rapidly becoming close friends and opening the way for their future collaboration.
To fix the existing designs, a new fridge would have to have no seals. Every pipe and part of the system would have to be a welded and soldered mass of metal. There could be no seals or lose fittings. No seals means no motors, compressors, or moving parts. Anything that moved would need a gasket around it, and that gasket would eventually fail. If the gasket failed, it’d leak poison into the world and defeat the whole purpose of the project.
Their design would build on an existing concept: An absorption fridge. An absorption fridge needs only a heat source to operate. At the time, that was often an open flame. In The Einstein-Szilard design, it could come form anything. They would use Ammonia, Butane, and Water to create pressure and state changes inside the system. The state changes would, as in modern fridges, allow for the transfer of energy.
This lead to dozens of patents being filed in multiple countries, but there was a problem: the refrigerant industry had solved their deadly problem.
The End of an Idea
The Einstein-Szilard fridge never quite took off. The team was always at odds, Einstein trying to create a simple, elegant device while Szilard was trying to add complexity to improve it’s performance, efficiency, or any of a dozen other factors. Before they could ever get a feasible product built or coerce any company into licensing the technology, a new refrigerant had come along.
The industry was shifting to Freon. Today, we know Freon is an awful, awful choice for a refrigerant. In the 1930s however, Freon was viewed as a relatively safe chemical. It wouldn’t melt lungs, destroy your brain, or induce any immediately deadly side effects. You certainly wouldn’t have it with your morning coffee, but if your fridge failed, you’d live to see the repair bill.
Without any real need for their absorption fridge, the two moved on. The great depression was in full swing and Germany was building towards World War II. Szilard would flee for the United States in 1933 around the same time as Einstein.
Back from the Idea-Graveyard
In recent years, the Absorption Fridge, and particularly the Einstein-Szilard approach have been getting a second chance at life. Engineers and scientists have been looking to the design as an efficient alternative to the modern fridge. Humanitarian groups have been considering the design for bringing refrigeration to the most remote parts of the world, where there is no electricity, but plenty of sunlight or gas. Even doctors have looked to the technology as a possible way to chill vaccines when working in third world countries.
The Wrap Up
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