April 24: Denso Corporation has developed the world’s first automotive air conditioning (AC) system that is capable of heating/cooling the driver’s area only. The new system can separately control the climate in three different cabin zones, the driver, front passenger and rear seat areas, which can help improve overall fuel economy when the AC is on.

“With Denso’s new AC system, the heating/cooling can be off in unoccupied areas, and temperature can be individually adjusted according to personal preferences when more than one area is heated or cooled,” said Akio Shikamura, senior executive director of Denso's Thermal Systems Business Group. “When the driver side AC is being used only, the AC system can save up to approximately 20 percent energy consumption on an annual basis compared with conventional models, which helps improve the vehicle’s fuel efficiency.”

How it works

As in-dash space is limited, it is important for the new system to maintain the same size level as a conventional AC system. With this in mind, the company developed a new internal structure for the heating, ventilation and air-conditioning (HVAC) unit. To separately control the climate of each area, the internal structure was divided into five compartments with each compartment connected to specific air vents: the driver’s dashboard and the driver side front window, the driver’s legs; the front passenger’s dashboard and front passenger side front window; the front passenger’s legs; and, the rear seat. Denso conducted repeated tests and simulations in various conditions to provide the optimum climate control and maintain occupants’ comfort even in severely hot and cold temperatures.



When an AC system is in heat mode, it uses a large amount of outside low-humidity air to ventilate the cabin and to prevent window condensation. Previously, the same amount of cabin air was lost externally. However, the new system only uses outside air for the driver and front passenger’s dashboard and front window vents. Compared to conventional products, this reduces the amount of warm cabin air lost by half, which also helps to reduce the amount of energy needed to operate the AC.

The new AC system has been launched in the Japanese market and in other regions of the world earlier this year.