Utilising the Earth's Natural Energy Resources

Energy produced in the skies above us does not disappear, it can be thought of as being stored in a global piggy (pls change this Eric) bank. While the atmosphere above it significantly affects the surface, the subterranean environment is not. In other words, a constant supply of energy is available for effective usage.

Geothermal heat "Cool Tube"


★Geothermal heat
The subterranean environment is a relatively long term stable environment, protected from the effects of the Sun and other surface influences. A casual walk in a tunnel during the summer months will confirm that the Sun does not greatly effect the chilly environment. During cooling, fresh air needs to be introduced from outside the building. However, it is easy to imagine how inefficient it is to introduce hot fresh air from outside for cooling. Naturally chilled subterranean air is far more efficient. Furthermore, as the temperature of the air introduced approaches the temperature of the air within the room, the efficiency improves further. Various uses can be envisaged for subterranean air tunneled up in ducts covered by earth.




kaga municipal kinjo junior high school

Structuer S


2floores above ground
Site Area 5,615.31㎡
Total floor space 7,514.89㎡
Purpose junior high school

In a Kanazawa prefecture school, supply air is drawn from an underground duct to provide cooled fresh air intake. A study into the above duct indicated that there would be an anticipated drop in the fresh air temperature of ℃ leading to a decrease in the current k plan of approximately x W.



Architectural Design KENGO KUMA & ASSOCIATE
Structuer wood


1 basement & 3floors above graund
Site Area 366.09㎡
Total floor space 927.99㎡
Purpose Traditional Japanese Inn

  The Ginzan Onsen (hot-spring) is naturally too hot for bathing as the water is around 60oC, so it is necessary to cool it down using the mains water supply. On the other hand, in this region the cold can be severe in winter with heavy snowfalls. Due to the accommodation, the energy required to provide heating and a hot water supply are considerable, therefore reductions in operation expenses and the environmental impact were sought and a system that made use of the valuable natural underground heat source was developed. The spring water is collected in a tank and cooled by a plate type heat exchanger with strong anti-corrosive properties and the bath is supplied by a run off, while the remaining heat is indirectly used as pre-heat for floor heating and the hot water supply. This makes for considerable savings in hot water and heating energy costs as well as in the water supply costs involved in cooling the hot-spring. Additionally, coiled pipes from the hot spring are fitted to the radiation fins of the air-conditioner outside units in order to defrost and melt snow in winter. Furthermore the waste water from the hot spring is not simply discarded but used to melt snow. In this way, by not wasting heat generated by the onsen and utilizing a cascade system this provides an excellent renewable energy source, which from the view point of lifecycle costs effectively kills two birds with one stone.


Rain water reuse


   Rainwater stored in a building's underground pit can be reused and purified for closet water. While not being suitable for potable water, rainwater sent to the building's sewage can be an effectively utilised natural resource.




Architectural Design Kiyonori Kikutake Architects
Location Tokyo
Completed 1993


2 basement & 7 floors above graund
Site Area 46,590㎡
Total heating capacity 626USRT

Transfomer capacity


The facility has a rainwater tank with the capacity of 2,500㎡ and coverage area is 10,000㎡. The rainwater usage rate achieved 37% in 1999. saving expensive treated main water.




Architectural Design Rafael  Vinoly ArchitectsP.C.
Location Tokyo
Completed 1996

Floors/Site Area

3 basement & 11 floors above graund 144,405㎡
Total cooling capacity 3,750USRT
Total heating capacity 12,000Mcal/h

Transfomer capacity

20,000 KVA

At Tokyo International Forum, cooling tower blow-down water, rainwater and waste water from the kitchen are recycled as raw water. Breakdowns of the rates of raw water usage and where is used are shown in the graph. Rain water is recycled and used effectively.



Structuer SRC, partial RC, S,
seismic isolation structuer


6 basement & 6 floors above graund
Site Area 5,030.76㎡
Total floor space 34,061.72㎡
Purpose shops, residences, parking, 
public amenities

At Omotesando hills rainwater from the building and premises (catchment area 5,500m2)is accumulated in a detention tank (370m3) beneath the building, and after filter sterilization has been carried out is stored in a reclaimed water tank, and along with grey water from the bathrooms, it runs from the glass monument at the east end of the site to create a small stream down a slope utilizing the natural gradient of Omotesando.