September 26, 2000 "Energy-Saving Air Barrier System" Developed The blinds and exhaust system that were previously ignored have been redesigned. Takenaka Corporation Takenaka Corporation (Head Office: Osaka; Capital: 50 billion yen ; President: Toichi Takenaka) has developed an "energy saving air barrier system" that is perfect for the air conditioning of the perimeters(*) of "glass buildings" with glass on all sides. By combining newly developed, airtight blinds (jointly developed with Tachikawa Corporation) and an efficient exhaust system, an energy saving of around 32 percent can be achieved compared to contemporary air barrier systems. These advances are to be announced at the lecture series being sponsored by the Society of Heating, Air Conditioning & Sanitation starting from September 27. (*) Perimeter zone This phrase refers to the area from the exterior wall of a building to about five meters inside the building. Because this area is strongly influenced by sunlight and the outside air temperature, the area has different environmental properties compared to the center of a building, as in summer heat builds up, and in winter it gets too cold. In particular, if the external wall is glass, the characteristics of the glass material make it pervious to sunlight, and it conducts the heat of the outside air, thereby making big changes to the thermal environment. Background to the Development of the Energy-Saving Air Barrier System "Glass buildings" not only have advantages for the user, such as improving the work environment and making effective use of the outside light, but are also popular from a design point of view. Generally, there are three types of air-conditioning systems for the perimeters of buildings like these, which are easily affected by the outside air temperature: a fan coil system that blows up hot or cold air between the glass and the blind, an air-flow window system that uses double-layered windows and sucks out the air between them from the top and an air barrier system that creates the air flow between the glass and the blinds (by either blowing air up from the bottom and sucking it out at the top, or the reverse). Compared to the other two systems, the air barrier system had the advantage of having a low initial cost, but a problem remained with regard to hot air leaking out into the room. The newly-developed "Energy-Saving Air Barrier System" is an improvement on the conventional low cost air barrier system, and is designed to allow for effective air conditioning of the perimeter zone of a building that is imperative in order to reduce the load on the building's air-conditioning system. Types of Perimeter Air-Conditioning Systems (the air barrier system is the conventional system)

Energy-Saving Air Barrier System Configuration The "energy saving air barrier system" was developed with the idea that energy could be conserved by carefully and effectively blowing out the air caught between the glass surface and the blinds. The way it is configured is therefore by making the blinds airtight, and by placing the air input and output ducts in the most optimum positions. 1. Development of the Airtight Blinds With ordinary blinds, air is drawn in through the spaces between the slats at the bottom and leaks out at the top placing a load on the air conditioning inside the room. As a result, it is difficult to efficiently blow out just the air caught between the glass surface and the blinds. By making the slats wider and redesigning the vertical cords holding the slats, with the newly-developed airtight blinds there is a 64 percent reduction in the amount of air that leaks into the room from the spaces between the slats when they are closed as compared to contemporary blinds (as measured by Takenaka). 2. Optimizing the Air Input and Output Ducts With contemporary air barrier systems, not enough thought was put into the positions of the air input and output ducts, so Takenaka undertook tests to see how the amount of the airflow into the room changed during summer and winter with the ducts at different positions. These results showed that if the newly developed airtight blinds were used in summer, hot air could be efficiently blown out of the room by running an exhaust fan positioned at the top of the window. The other way around, in winter when the "cold draft phenomenon" can be felt around the leg area caused by cold air flowing down from the side of the window, this cold air could be effectively blown out of the room by simply running an exhaust fan installed at the bottom of the window. System Configuration

Merits of the Energy-Saving Air Barrier System By developing this Energy-Saving Air Barrier System made up of the airtight blind and exhaust fans for use in summer and winter, the following merits can be achieved: 1. An energy saving of 32 percent compared to contemporary air barrier systems (comparing the electric power cost of running the exhaust fan plus the electric power cost for air conditioning part of the parameter). 2. Improvement in the thermal environment of the parameter zone that is strongly affected by sunlight and the outside air temperature. 3. A reduction in the initial cost compared to fan coil or airflow window systems. Mechanism of the Airtight Blind

The Parameters of Contemporary Air Barriers and the Energy Saving Air Barrier Comparison of Annual Electric Power Costs