AIST Develops Solar-Heat Reflective Film Sheet

The National Institute of Advanced Industrial Science and Technology (AIST) announced that it has developed a flexible film which selectively reflects near-infrared rays, a main factor in solar heat gain. AIST unveiled the film during its open laboratory event held on October 20, and 21, 2008. By applying this film on the inside of windows, it significantly reduces solar heat flow through windows while assuring a visible light transmittance.

The study of this spectrally selective film sheet, the results of which were announced on September 17, 2008, evolved from the technology used to develop a reflective glass which is able to block particular near-infrared rays. The sheet, using polycarbonate as a base material, has nano-laminated coatings of different refraction indices, which achieves a high heat reflection and yet permits sufficient transmission of visible light.

The sheet transmits 78 percent of visible light (percentage of visible light passing through the window), thereby minimizing the disruption to natural lighting. It reduces transmission of solar energy to 47 percent, thereby allowing for energy savings in terms of indoor temperature control.

According to the Japanese government's New Energy-Saving Standards in 1992, 71 percent of heat intake into buildings comes through windows during the summer season when demand of air conditioning is highest. Applying this technology on building windows is expected to reduce air conditioning use, thereby saving large amounts of energy.

- New Flexible, Switchable Mirror Film on Windows Boosts Energy Efficiency (Related JFS article)
http://www.japanfs.org/en/pages/026969.html
- Solar Heat-Reflective Glass to Reduce Cooling Loads (Related JFS article)
http://www.japanfs.org/en/pages/026826.html
- National Institute of Advanced Industrial Science and Technology (AIST)
http://www.aist.go.jp/index_en.html

Posted: 2009/03/29 06:00:15 AM