Stay cool and save fuel

An intelligent air-conditioning system for hybrid cars could save drivers up to nine per cent of fuel in the summer months, according to its developers.

The system was developed through the Sentience project — a research collaboration led by Ricardo, the UK-based automotive technology and engineering consultancy.

The enhanced air-conditioning (EAC) control strategy was demonstrated in a Ford Escape Hybrid test vehicle at Ricardo Midlands Technical Centre's climatically controlled test facilities.

In the vehicle, the air-conditioning compressor is driven by the engine so that when the vehicle is stationary, as it would be at a red light, the hybrid powertrain operates in electric-only mode and the air-conditioning system shuts off.

Tom Robinson, Sentience project director for Ricardo, said that the intelligent part of the system is that it can tell when a car is about to become stationary. The system uses GPS data to determine whether a junction is up ahead.

'When we know we're approaching a point where the vehicle is likely to stop, we pre-cool the cabin by 1.5°C,' he said. 'It gives you a temperature buffer. So when the temperature starts to climb again in the cabin, you are not running the engine and you are, therefore, saving fuel.'

If a car was idle for a long time, added Robinson, the system would detect if the temperature was getting too high in the cabin. It would then alert the engine to turn back on again and provide extra air conditioning for a short period. A driver can override the system at any time with the touch of a button.

He said that EAC, which is about three years away from commercialisation, could be boosted with real-time traffic data and onboard vehicle sensors to detect whether a car is in traffic.

The Sentience project also involves Jaguar-Land Rover, TRL, Ordnance Survey and Orange Business Services, with part funding from innovITS, a UK centre for intelligent transport systems.

Siobhan Wagner