Scientists at Oxford University are all set to take the legend of Einstein a step forward by working upon the 1930 invention by Albert Einstein to develop an environmentally friendly refrigerator which they claim will run without electricity. Determined to fight the repercussions of modern fridges that emit greenhouse gases called freons and as a result damage the environment, the Oxford team is developing appliances that can work without electricity and thereby reduce the gases. Motivated by contemporary newspaper reports of a Berlin family who had been killed when a seal in their refrigerator broke and leaked toxic fumes into their home, Einstein and his colleague, the Hungarian physicist Leo Szilard patented an absorption-type refrigerator which has no moving parts and requires only a heat source to operate.

The machine is a single-pressure absorption refrigerator, similar in design to a gas absorption refrigerator. The refrigeration cycle uses ammonia, butane and water, has no moving parts, and does not require electricity to operate, needing only a heat source, e.g. a small gas burner besides taking advantage of the fact that liquids boil at lower temperatures when air pressure is lower.

The forgotten fridge alongside being greener also is better fit for rural areas where there is no electricity. The modus operandi is that by introducing a new vapors above the butane, the liquid boiling temperature decreases and, as it boils off, it takes energy from the surroundings to do so which in turn makes it cold. Pressurized gas fridges based around Einstein’s design were replaced by freon-compressor fridges partly as they were not very efficient.

Electrical engineer Malcolm McCulloch at the University of Oxford is reviving the design and is looking into solar energy to kick start the process, though in future the team will also experiment with different types of gases to improve the mechanism’s efficiency.

Via popsci