Most domestic heating and automotive air conditioning requires a lot of energy. 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 five per cent of the vehicle fuel consumed annually. Within the UK it is responsible for over two million tonnes of CO2 emissions.
Stick with me!
Researchers have long been aware of a much more energy efficient way to drive heat pumps (or air conditioners) using adsorption technology. This uses heat from a gas flame or engine waste heat to power a closed system containing only active carbon and refrigerant.
When the carbon is at room temperature it adsorbs the refrigerant and when heated the refrigerant is driven out. A process which alternately heats and cools the carbon can be used to extract heat from the outside air and put it into radiators or hot water tanks. With air conditioning it extracts the heat from the inside of the car.
The major snag has been that adsorption technology to date would need to be roughly 300 litres in volume for a car air conditioner and larger for a heat pump to heat your house. Clearly that is not going to fit into a car and the volume of unit required for domestic heating probably couldn’t fit under your stairs at home either…
Now – I’ve got to the point – researchers at the University of Warwick 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 clever new arrangement that distributes thin (typically 0.7mm thick) 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 Warwick team to create adsorption based equipment that is up to 20 times smaller than was previously possible.
The researchers expect that their new adsorption technology can create domestic heat pumps that will produce a 30 per cent or more reduction in domestic fuel bills (and CO2 emissions) compared to even the best condensing boiler. In car air conditioning systems their new system can exploit waste heat from the engine, converting it into useful cooling.
Because no (or very little) mechanical power is then taken from the engine it will reduce both fuel consumption and CO2 emissions by nearly five per cent. The research team also anticipates that in new vehicle models the system can be integrated with little or no extra cost.
We’re told the UoW’s engineers have had significant interest in the new technology from a range of companies, and they have already entered into a technical partnership 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 market.
This significant commercial interest has led to a new spin-off company, Sorption Energy Limited, being set up by Warwick Ventures, the University’s technology transfer office, and H2O Venture Partners. Initially the company will use the new patent pending technology to focus on two high value markets: greener heating and hot water systems for houses and air conditioning for cars.