Japan Sustainable Building Database

Natural ventilation system

Conceptual diagram of natural ventilation in building A

A natural ventilation system was established to make the most use of cool weather. Ventilation windows are designed to automatically open and close according to the inside and outside temperatures and humidities and can be forced closed according to the outside air velocity or rainfall. We confirmed that this system functioned successfully for 970 hours throughout the year.

Cooling & heating trench system

Pattern diagram of large-scale cooling & heating trench system

Since this project is an experiment facility, it is subjected to large outside air load.

A large-scale cooling & heating trench system consisting of a 1-km-long trench for electric power intake was constructed, which precools and preheats outside air.

Cooling water heat recovery system

Schematic of heat source system

Heat is extracted from the cooling water for a highly efficient refrigerator by heat exchange to deal with dehumidification and reheat loads in summer and the intermediate seasons. Except in severe winter, the set temperature of warm water is low, and the heat recovery system is used as much as possible.

Light duct system

Sunlight tracking type daylighting system at the top of atrium

The site for this project is located in an area where the annual duration of sunshine is very long. For the daylighting unit to utilize this natural feature, we developed a sunlight tracking type light duct system. This system tracks the sun with a biaxial-controlled lens and introduces outside light into a room (dining space) on the northern side with a secondary mirror.