Bangalore: Can a refrigerator work without power? Scientists at Oxford University may soon find an answer for this question as they are on the experiment on a 1930 invention by renowned scientist Albert Einstein to develop an eco-friendly refrigerator which will run without electricity.

While modern refrigerators emit greenhouse gases called freons which damages the environment, Oxford team claims that the product under development can work without power and thereby reduce the gas.

A prototype of a type of Einstein fridge has already been developed by the scientists. The design was partly used in the first domestic refrigerators before more efficient compressors became popular in the 1950s. It uses ammonia, butane and water instead of freons and takes advantage of fact that liquid boil at lower temperatures when air pressure is lower.

Malcolm McCulloch, the lead scientist said, "If you go to the top of Mount Everest, water boils at a much lower temperature than it does when you're at sea level and that's because the pressure is much lower up there."
At one side is the evaporator, a flask that contains butane. "If you introduce a new vapour above the butane, the liquid boiling temperature decreases and, as it boils off, it takes energy from the surroundings to do so. That's what makes it cold," he added.

Einstein's Pressurised gas fridges replaced by Freon-compressor fridges partly as they were not very sufficient. However, British scientists say that by tweaking the design and replacing the types of gases used it would be possible to quadruple the efficiency of the refrigerators that could well be the GenNext appliances.