FRANKFURT, Germany --- TRW Automotive Holdings Corp. is introducing its Efficient Comfort Control (ECC) system, which uses sophisticated algorithms to monitor vehicle cabin comfort and to minimize the energy draw resulting from a vehicle's heating, ventilation and air conditioning (HVAC) system. ECC concentrates on balancing three major goals --- maintaining occupant comfort, keeping the windshield clear of fog and optimizing fuel use. TRW said that years of ECC research have focused on gaining a better understanding of the dynamics of occupant comfort within the vehicle cabin and using this knowledge to employ the most efficient methods within the HVAC system through proprietary control algorithms. This leads to occupant comfort and reduced draw of energy on the engine, which in turn leads to improved fuel economy and lower emissions. "The motivation behind the ECC system is clear --- when air conditioning is switched on it is the number one source of ancillary energy draw on the engine," explained TRW Director of Business Development Victor Peltola. "The TRW Body Control Systems business has been developing algorithms and control technologies that look at all of the variables that make up comfort within the vehicle cabin and how best to ensure these variables are addressed while creating as little draw as possible on engine power." The ECC system factors in humidity in addition to the three major causes of heat in the vehicle cabin. These include 1) heat conduction via seats, steering wheel or arm rest; 2) heat convection via the discharge air of the HVAC or open windows; and 3) heat radiation from the sun or interior surfaces. Studying the interaction of these factors has helped lead to the development of the ECC control algorithms. "By understanding the basic physics relating to comfort and the factors required to control it, TRW can avoid the situation-based control strategy typically used for HVAC control that must be re-engineered with every new vehicle," said Peltola. "This dramatically improves development time, potentially leads to a reduction in costs, and results in a system that provides a numerical measure of the occupant's comfort level in real time and can be tuned to various vehicle cabins." The ECC system is already being used to develop HVAC control systems in current vehicles, and TRW plans to continue to refine ECC for future product generations and for compatibility with alternative powertrains. For example, TRW has developed a fuel-efficient control application that uses humidity sensing and efficient compressor management. The result is a higher level of fuel efficiency on a hybrid electric vehicle set to launch in the 2009 model year.