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Material Research Institute for Sustainable Development
National Institute for Advanced Industrial Science and Technology (AIST) Anagahora Shimoshidami Moriyama-ku Nagoya, 463-8560, Japan
Abstract
Research status of energy efficient building materials as switchable mirror, wood-based material, humidity controlling material, and water retentive brick in our institute is introduced.
I. INTRODUCTION
In order to reduce CO2 emission from residential and commercial sector, it is important to develop energy efficient building materials which do not spoil comfortableness of the building. Our group has been investigating such materials as switchable mirror, wood-based material, humidity controlling material, and water retentive brick. Our group also has started the evaluation of energy saving performance of these materials in the newly constructed testing building.
II. SWITCHABLE MIRROR WINDOW
Switchable mirror is a new kind of film that can change its optical property reversibly between mirror state and transparent state. The switchable mirror window can make shade control of sunlight effectively by reflection, so it is expected to show good energy efficiency especially to cooling load. We prepare a prototype switchable mirror window, which is a double glazing with the size of 1.2m0.8m (Fig. 1). Pd capped Mg-Ni alloy thin film is deposited on inner surface of the double glazing glass by using DC magnetron sputtering. This double glazing can be switched to transparent state in a few minute by introducing 4%
H2 in Ar mixed gas into the inner space between two glasses.
By introducing O2 contained gas (air etc.) it can be switched to mirror state. This switchable window is installed to our testing
building, and the energy efficiency of cooling load is evaluated. The preliminary results show the switchable mirror window can save about 35% of cooling energy consumption compared with a normal double pane window in summer sunny day.
We are also developing a switchable mirror film that prepared on polymer film and switched by electricity.
III. ADVANCED WOOD-BASED MATERIAL
Improvement of insulating property of window frame is important for energy efficiency. We investigate high functional wood materials for window frame. Processes to strengthen wood material (impregnation of chemicals and compression), to add fire retardant property (impregnation of chemicals), and to give high durability are investigated. Process for preparation of advanced wood materials from low grade wood is also carried out. Because wood is carbon neutral material, we investigate the advanced wood-based material not only for window frame but also for other wide applications.
Fig. 1
Prototype switchable mirror window.
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IV. HUMIDITY CONTROLLING MATERIAL
High performance humidity controlling material keeps comfortable humid condition, and lowers the air conditioning load. We selected imogolite, clay with nanotube structure, as a candidate material, investigated large scale synthesis methods. In this investigation, we developed new adsorbent material (hydrated aluminum silicate) with interesting adsorption property. Water adsorption isotherm of the adsorbent is shown in Fig. 2. It means that large amount of water is adsorbed in any humidity area, and that adsorbed water is easily released by heating or lowering surrounding humidity. This property is best for adsorption heat pump or desiccant air conditioning. We are investigating these materials for building material and these applications etc.
V. WATER RETENTIVE BRICK
Water retentive brick set on a roof or balcony is effective for reducing heat island phenomenon. Water retained in the brick during rainfall or sprinkling with water, evaporates when heated by sunshine, and cools the surrounding. Our developed brick is environmental friendly, because it is manufactured from 100% recycled ceramics, and prepared without sintering process. This brick are installed on the roof of our testing building. Preliminary results shows max. 14C lowering the roof surface temperature in summer shiny day. Improvement of durability especially in winter season is carried out.
VI. TESTING BUILDING
We constructed the testing building for energy efficient building materials.
Each floor is divided to 4 rooms in 2nd and 3rd floor. The evaluation of energy saving of the developing energy efficient building materials is carried out by measuring the air conditioning load and room atmosphere
(temperature, humidity, and etc.).
Dr.Koji Tajiri is Deputy director of “Material Research Institute for Sustainable Development “ in AIST.
He has researched heat storage materials and transparent insulating materials
since 1982 in AIST.From 2007, he became present position, and adjusts energy efficient building material project carrying out his institute.
Fig. 2
Ction (Times New Roman / 10 point )
Fig. 3
Water retentive brick Fig. 2
Water adsorption isotherm of adsorbents.
Fig. 4
Constructed testing building
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Organizing Committee
Sukekatsu Ushioda (Chair) National Institute for Materials Science Masakazu Aono National Institute for Materials Science
Hiroyuki Akinaga National Institute of Advanced Industrial Science and Technology Yuichi Ikuhara The University of Tokyo
Tomoji Kawai Osaka University Hidetoshi Kotera Kyoto University Toyohiko Konno Tohoku University
Kazuo Furuya National Institute for Materials Science Kazuhito Furuya Tokyo Institute of Technology
Yasuhiro Horiike National Institute for Materials Science Takayuki Homma Waseda University
Syo Matsumura Kyushu University Hiroaki Misawa Hokkaido University
Junichiro Mizuki Japan Atomic Energy Agency
Toshihiko Yokoyama National Institutes of Natural Sciences Takamaro Kikkawa Hiroshima University
Supported by
Ministry of Education, Culture, Sports, Science and Technology Japan
Cooperating Organizations
IEEE Tokyo Section,
The Japan Society of Applied Physics, The Society of Polymer Science, Japan, The Institute of Electrical Engineers of Japan, The Institute of Electronics,
Information and Communication Engineers, Society of Nano Science and Technology, Nanotechnology Business Creation Initiative, The Chemical Society of Japan,
The Japan Institute of Metals,
The Japanese Society of Microscopy,
The Japanese Society for Regenerative Medicine, The Society of Materials Science, Japan,
Japanese Society for Artificial Organs,
Japanese Society for Medical and Biological Engineering, The Ceramic Society of Japan, The Japan Society of Drug Delivery System,
Japanese Society for Biomaterials, The Surface Science Society of Japan, The Physical Society of Japan,
一禁無断掲載一 Copyright (c)
Nanotechnology Researchers Network Center of Japan 文部科学省ナノテクノロジー総合支援プロジェクト
第 7 回ナノテクノロジー総合シンポジウム JAPANNANO2009
発 行 2009年（平成21年）２月
編集・発行 独立行政法人 物質・材料研究機構 NIMS テクノロジー拠点運営室
〒305-0047 茨城県つくば市千現 1-2-1 電話：029-859-2777