Carbon could prove the 'good guy' for better heating, cooling

Carbon could go from villain to hero, according to researchers who have developed a better way to use “adsorption technology” to drive more efficient heaters and air conditioners.

The process involves using carbon to adsorb a refrigerant — essentially causing it to cling to the carbon’s surface, rather than absorbing it — depending on the surrounding temperature. When heated, the carbon would release the refrigerant and cool the surrounding area, storing the extracted heat in a radiator or hot water tank.

Because they operate as closed systems, such adsorption technologies are more efficient than conventional condensing boilers or electric heat pumps. Up until now, though, the problem has been the technology’s size: it would have to take up roughly 300 litres for a car air conditioner and even more space for a home heat pump.

Researchers at the University of Warwick, however, have made a breakthrough that could dramatically shrink such devices, making them small and light enough to use in both cars and homes. Their new design uses very thin sheets of metal distributed through the carbon; each sheet contains 100-plus tiny water channels that help make the heat transfer more efficient. This has enabled the research team to shrink the required size of adsorption technologies by up to 20 times.

Eventually, the researchers hope, such improved adsorption technologies could create domestic heat pumps that could reduce both fuel bills and carbon dioxide emissions by more than 30 per cent. Used in car air conditioning systems, the technology could lead to fuel consumption and emissions reductions of nearly 5 per cent.

The innovation has already attracted interest from commercial developers, prompting the research team to spin out a new company, Sorption Energy Ltd.

“The technology is now ready for commercialisation and we are very excited by the opportunities which are developing,” said lead researcher Bob Critoph. “It is particularly pleasing that the technology will significantly help reduce CO2 emissions.”

“This is exciting stuff,” added David Auty, CEO of Sorption Energy. “The technology has been proven in the University’s laboratories at the sizes needed for vehicles and domestic systems, and there are several other large markets.  The ability to provide products which make significant reductions in both energy consumption and CO2 emissions at a similar price to existing products will make Sorption Energy very attractive to customers, and is very satisfying for the team.”