Effectiveness of Reducing Heating and Cooling Load by Using Double-skin Facade Coupling the Earth-to-air Heat Exchanger

A double-skin facade was adopted in the Izumi Media Building of Meiji University located in Tokyo in order to reduce the noise and dust emanating from an expressway which runs by the south side of the building, as well as for energy conservation purposes. For similar reasons, the bottom of the double-skin facade of the south side was connected to a subterranean pit for seismic isolation, which allowed for the introduction of outside air from the north side. In this paper, field measurements were performed in order to study the effectiveness of reducing the thermal load on the double-skin. Furthermore, the improvement of the performance of the thermal load reduction by combining the use of the double-skin with an earth-to-air heat exchanger was studied by numerical simulation. Compared to other window systems (single skin), the double-skin was confirmed to be highly effective with respect to reducing the thermal load due to its superior ability to shade solar radiation in summer and to reduce heat loss caused by thermal transmission in winter. Compared to the case where only a double-skin was used, the combined use of the double-skin and the earth-to-air heat exchanger improved the effectiveness of reducing thermal load by about 33%, owing to the fact that air which is cooler than outside air in summer or warmer than outside air in winter can be introduced into the double-skin. In summary, it was demonstrated that the combined use of a double-skin façade and an earth-to-air heat exchanger utilized the subterranean pit efficiently and improved the effectiveness of reducing thermal load on the double-skin.