1. Joint FP5 ENERGIE Info-day and EnerBuild RTD Project Meeting JAPANESE BUILDING ENERGY RESEACH 7 September 2001, Malmo Ken-ichi Kimura Professor, Advanced Research Institute for Science and Engineering, Waseda University, Tokyo Fax:+81-3-3209-8316 E-mail: kkimura@mn.waseda.ac.jp

2. Climate of Japan Japanese archipelago ranges from cold to subtropical regions. In central mild areas, heating season: November-April in residential buildings January-March in office buildings.

3. Energy Use Trends in Japan Industrial Sector Residential and Commercial Sector Transportation Sector [PJ] - S. Ando

4. Residential Energy Breakdowns by District

5. 1/3 of CO 2 are related to buildings in Japan

6. Operation Energy of an Office Building

7. Energy Conservation and Natural Energy Utilisation are different.

8. Definition of Energy Conservation Minimisation of Energy Use while maintaining desire of people. Energy may be used as much as they want unless they think it wasteful. Energy conservation is not enough to meet the target of Kyoto protocol.

9. Natural Energy Utilisation Solar thermal Photovoltaics Wind power Geothermal power Ambient energy

10. Solar Hot Water Heaters Solar water heaters are installed in about 1/10 of total households. Forced circulation type of domestic solar water heating system can be seen in houses.

11. Solar Hot Water System Swimming pools Elderly people’s homes Hospitals Schools Apartments

12. Passive Solar Space Heating Traditionally common in residences. Insulation and air-tightness are prerequisites for passive solar heating

13. Passive Cooling in Residences Natural ventilation and sun shading are pre- requisites. Nocturnal ventilation Cool tube Earth contact floor Roof garden for evaporative cooling Nocturnal radiation

14. Improvement in Efficiency of Household Appliances Refrigerators Lighting bulbs (Compact lamps are not common in Japan.) Room Air- Conditioners Colour TV Air Conditioner Refrigerator Year

15. Energy Conservation in Buildings Energy Conscious Designs Energy Reduction in Lighting Energy Reduction in HVAC Energy Reduction in Office Machines

16. Energy Conservation in HVAC Heat Recovery System Variable Air/Water Volume System Free Cooling/ Night Purge Sun Shading Air Flow Windows Controls for Efficient Operation Set Point Temperature and Humidity

17. Thermal Comfort and Energy Conservation 1 degree of change in set point temperature makes 10% of energy saving in both heating and cooling. Slight increase in air movement substantially reduces cooling load.

18. Indoor Air Quality and Energy Conservation Displacement ventilation Occupied zone air conditioning Minimum allowable rate of ventilation

19. Occupied Zone Air Conditioning in Large Spaces

20. Direct Sunlight Introduction

21. Photovoltaics Integration in Architecture

22. Residential Photovoltaic System Installation

23. Residential Photovolaic Cost

24. PV Panels Backed with Air Collector Kyocera House

25. Natural Energy Utilisation in Vernacular Architecture

26. Massive House in Kawagoe

27. Modern Use of Vernacular Technologies

28. Earth Covered Building

29. Solar Architecture Heavy insulation and air-tightness natural ventilation and sun shading passive solar heating solar domestic hot water system PV for appliances

30. IEA Task 13 Advanced Japanese House-WISH House

31. Kimura Solar House - 1972 Movable collector panels Semi-basement with greenhouse Floor heating by heat pump Solar domestic hot water PV roof (2001)

32. Sagara Solar House - 1979 Hybrid solar Outside insulation No auxiliary for space heating 5028 kWh/a for total household

33. TEPCO Solar House - 1988 Earth contact floor Rock bed storage coupled with air collector and heat pump Sun space Heat pump for hot water from space cooling with off-peak electricity Phase change material floor 7800kWh/a for total household

34. Solar Chimney and PV Panels School building of Kitakyushu University, Faculty of Environmental Engineering

35. Carbon Emission from Buildings by Structural Types -100 -50 0 50 100 150 200 WOODENSTEEL REINFORCED CONCRETE REINFORCED CONCRETE STEELAVERAGE CARBON EMISSION PROM BUILDINGS FOR FLOOR AREA[ ｋｇ /m2] WOOD(-) OTHER MATERIALS TRANSPORTATION STEEL CERAMICS CONCRETE WOOD(+) Global Environment Committee, AIJ 1992

36. Conclusion-1 Energy conservation has a largest potential in reducing energy requirements in building sector. Different types of natural energy utilisation must be sought for different conditions.

37. Conclusion-2 A slight discomfort must be accepted for reducing energy use and warming gas emission. It can be regarded possible to meet the target level of Kyoto protocol as far as building sector is concerned in Japan.