Warwick spins out Sorption Energy

Researchers at Warwick University have devised a way to miniaturise adsorption technology, a move they say paves the way for carbon to become a key material in low-energy heating and air conditioning systems.

Domestic space heating and hot water account for 25 per cent of energy consumption in the UK, across the EU, vehicle air conditioning uses about 5 per cent of the vehicle fuel consumed annually.

Researchers have long been aware of an energy efficient way to drive heat pumps and air conditioners using adsorption technology. This uses heat from a gas flame or waste heat from a car engine to power a closed system containing active carbon and a refrigerant.

When the carbon is at room temperature it adsorbs the refrigerant and when heated the refrigerant is driven out. This alternate heating and cooling of the carbon can be used to extract heat from the outside air to warm radiators or hot water tanks, or, in the case of air conditioning, to extract heat from inside a car.

However, current devices for doing this are too large for practical application, at around 300 litres in volume for a car air conditioner and larger for a domestic heat pump.  

The Warwick researchers have made a breakthrough in adsorption systems design that dramatically shrinks these devices, making them small and light enough for use in both domestic heating and automotive air conditioning. They have devised and filed a patent on a new arrangement that distributes thin (typically 0.7mm) sheets of metal throughout the active carbon in the heat exchanger. Each of these sheets contains more than a hundred tiny water channels (typically 0.3mm in diameter) designed to make the heat transfer much more efficient.

This has enabled the researchers to create adsorption-based equipment that is up to 20 times smaller than was previously possible. They claim this can be used to build domestic heat pumps that will produce a 30 per cent or more reduction in domestic fuel bills and CO2 emissions compared to the best condensing boiler available currently.

In car air conditioning systems the new system can exploit waste heat from the engine. Because no, or very little, mechanical power is then taken from the engine it will reduce both fuel consumption and CO2 emissions by nearly 5 per cent.

There is significant interest in the new technology from a range of companies and a technical partnership has been agreed with a major global vehicle manufacturer to develop and demonstrate the technology. There has also been considerable interest from the domestic heating and hot water manufacturers.

A new spin-out company, Sorption Energy Ltd, has been set up by Warwick Ventures, the university’s technology transfer office, and H2O Venture Partners to commercialise the technology.

The lead researcher Bob Critoph said, “My team has been working on these developments for several years, supported by grants from EPSRC and the EU totalling over £2.5million. The technology is now ready for commercialisation and we are very excited by the opportunities which are developing. It is particularly pleasing that the technology will significantly help reduce CO2 emissions.”

David Auty, Chief Executive of Sorption Energy, said, “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.”

Sorption Energy Ltd is currently building its management team and will shortly be seeking funding to take the technology forward.