DENSO Develops Refrigerator System for Light-duty Hybrid Trucks

DENSO Develops Refrigerator System for Light-duty Hybrid Trucks

― Improves fuel efficiency and keeps freezer/refrigerator temperature low―

KARIYA (Japan) ― DENSO Corporation has developed a refrigerator system for light-duty hybrid trucks that contributes to better fuel efficiency while maintaining low-level freezer/refrigerator temperatures when the vehicle is idling at a stop light or in other traffic situations.

“With the new refrigerator system, hybrid trucks can stop engines at a red light or other short stops and keeps the freezer/refrigerator temperature low,” said Akio Shikamura, senior executive director of DENSO’s Thermal Systems Business Group. “This significantly improves fuel efficiency of light-duty hybrid trucks.”

In addition to a conventional compressor driven by the engine via a belt, the new system uses an electric compressor powered by the battery unit of the hybrid vehicle. These two compressors are designed to automatically switch from one to the other while the engine is running or stopped: The conventional compressor is driven during engine operation, and the electric compressor is used during engine stop.

The new system is also approximately 25 percent* lighter compared to a conventional refrigerator system with external power supply units, which uses external electricity to keep the freezer/refrigerator temperature level low when the engine is stopped for a long period of time. The external power supply unit of conventional systems is relatively large and heavy, because it consists of a motor, a motor-driven compressor and a power-supply device for voltage conversion and other applications. In contrast, the new refrigerator system, which uses the built-in electric compressor when connected to an external power source, does not require a motor or motor-driven compressor and that’s why it is considerably smaller and lighter compared to a conventional system.

The new system will be introduced in Japan on July 6 with an annual sales target of 150 units. The new system can be installed on the Toyota DYNA and TOYOACE and the Hino DUTRO. DENSO will make the new refrigeration system available for a greater number of vehicle models and for electric delivery trucks in the future.

* Compared with DENSO’s previous product

About Refrigerator System

A refrigerator system consists mainly of a compressor, condenser, and evaporator, using the principle that a liquid absorbs heat from its surroundings when it evaporates. These three devices are connected to each other via a pipe and hose through which refrigerant circulates. The refrigerant is compressed and heated in the compressor and is cooled in the condenser by transferring its heat to the ambient air. The refrigerant is then cooled further as it decompresses while flowing through the evaporator to provide cold air to the freezer or refrigerator.

DENSO Corporation, headquartered in Kariya, Aichi prefecture, Japan, is a leading global automotive supplier of advanced technology, systems and components in the areas of thermal, powertrain control, electric, electronics and information and safety. Its customers include all the world’s major carmakers. Worldwide, the company has more than 200 subsidiaries and affiliates in 35 countries and regions (including Japan) and employs over 120,000 people. Consolidated global sales for the fiscal year ending March 31, 2012, totaled US$38.4 billion. Last fiscal year, DENSO spent 9.5 percent of its global consolidated sales on research and development. DENSO common stock is traded on the Tokyo and Nagoya stock exchanges. For more information, go to, or visit our media website at