Sorption Energy, a spin-off from Warwick University, is aiming to put a new spin on vehicle air conditioning systems.
Currently, air conditioning units in cars and light commercial vehicles burn more than five per cent of the vehicle fuel consumed annually throughout the EU. Indeed the UK alone emits about three million tonnes of carbon dioxide (CO2) a year by powering air conditioning units in vehicles.
That’s why Sorption Energy wants to commercialise systems that are based on waste heat-driven adsorption heat pump technology – this could eliminate both fuel consumption and the accompanying CO2 emissions.
Adsorption heat pumps and refrigerators can adsorb vapour when at low temperature and desorb it when heated. They therefore use an adsorbent chemical instead of a mechanical compressor and are driven by heat rather than mechanical work. The systems often also use natural refrigerants including ammonia, methanol and water.
In a basic system, there are two linked containers – one which contains the solid adsorbent and the other that combines an evaporator and condenser or receiver in which the refrigerant is evaporated and condensed. Even at low temperatures, the adsorbent contains a high level of refrigerant while the receiver only contains refrigerant gas. The refrigerant then condenses in the receiver, rejecting heat and producing a useful heat output if the system is used as a heat pump.
Even though these basic concepts are well known, the challenge has always been in the required size of the systems. So the University of Warwick researchers have developed an adsorption system that significantly shrinks these devices to make them small and light enough for use in both domestic heating and automotive air conditioning.
