Cool thinking

It is hardly news to hear that car air-conditioning is a clear offender when it comes to raised fuel consumption and exhaust emissions.

But it is news to hear from British researchers that an "intelligent" Enhanced Air Conditioning (EAC) system currently under development is capable of reducing urban-cycle fuel consumption in a hybrid vehicle by as much as 9 per cent.

The system works with the car's electronics to monitor the electric motor and petrol engine. It controls the operation of the air-conditioning compressor so that, in electric only mode or if the vehicle is stationary, the air-conditioning system does not operate.

According to the team that developed EAC, "By linking the EAC and powertrain control strategies, knowledge of when the combustion engine may be stopped allows the system to plan an appropriate and more efficient cooling strategy.  Cabin air temperature can thus be maintained within a narrow range while maximising the opportunities for the gasoline engine to switch off -- and hence minimising the time that the engine is run solely to drive the air-conditioning."

The research was conducted by Sentience, a research team headed by technology provider Ricardo and involving Jaguar-Land Rover, the UK's Transport Research Laboratory, Ordnance Survey and Orange Business Services. Part-funding is provided by innovITS, the UK centre of excellence for intelligent transport systems and sustainable mobility. The Ford Escape Hybrid based Sentience test vehicle was revealed to the press in March 2009.

The vehicle was a showcase for various technologies, including Enhanced Acceleration/Deceleration (EAD) control, in which the vehicle speed is controlled to meet actual and virtual speed limits using an advanced form of adaptive cruise control linked to the hybrid powertrain.  Virtual speed limits are calculated using GPS and mapping data, including features such as bends and speed bumps, roundabouts and traffic lights. Once EAD is operating, the driver simply steers the vehicle. It can, at any time, be manually over-ridden.

According to Tom Robinson, who is the Sentience project director for Ricardo, the EAC system is the subject of a Ricardo patent application and is claimed to be applicable to "all types of hybrid vehicles, including the stop-start systems which are becoming increasingly common."

The 9 per cent reduction in fuel consumption sounds welcome but, as the initial research was conducted in mild UK summer weather, it still needs to be proven in harsher climatic conditions -- Australia, for example.

Sitting in Melbourne or Sydney traffic on a 40 degree day with no air-conditioning is something this generation of car users would be unable to even contemplate.