Research Project Summary Information
Develop Energy-efficient Smart Window Technology:New Smart Window Technology(ST4520-1)
Reveo and NYSERDA demonstrated in Phase I that cholesteric liquid crystal (CLC) materials can be used to produce switchable smart windows capable of reflecting visible light and infrared (IR) radiation, effectively blocking much of the thermal energy from the sun's rays responsible for heating buildings. Unfortunately, the economic benefits of the switchable IR reflecting window in commercial buildings were not very large. Reveo has determined that if a nonswitching, or passive IR reflecting, window made with CLCs were offered for commercial buildings, the energy savings would recover the incremental cost of the window within three years in New York State. The passive IR reflecting window would be different from other energy efficient windows because it decreases the solar radiation entering a building without reducing the amount of natural daylight entering through windows.
Under the project, Reveo was to determine the design specifications and building code requirements of glass curtain walls for commercial buildings. Reveo was to scale up existing fabrication equipment used to produce one-foot-by-one-foot panels to allow production of two-feet-by-three-feet panels that better represent a standard window size. Fabrication techniques were also to be determined that would be cost-effective and easily integratable into the typical operations of a glass manufacturer. Reveo was also to fabricate several two-feet-by-three-feet panels to establish the feasibility of producing standard size windows and have produced panels independently tested to determine the optical properties, energy benefits, and durability characteristics of CLC windows. Market research will be conducted to develop strategies for commercializing this technology in the building construction industry.
Preliminary estimates indicate air-conditioning energy usage could be reduced by 20% with the new smart window. The new product would also be more cost-effective than other available smart-window technologies. Manufacturing jobs in New York State could also be created if the new technology becomes commercialized.
Small prototype switching windows were produced and favorably tested with respect to performance and durability. A two-feet-by-three-feet sample for the passive IR reflecting film was produced and tested. The energy benefits for the switching window were determined using a computer simulation. Unfortunately, the economic analysis for the switching window determined that the energy savings were not sufficient to offset the incremental cost of the window. The performance of the passive IR reflecting sample was promising; its properties in the visible range were poor due to haziness and other optical distortions.
85 Executive Blvd.
Elmsford, NY 10523
NYSERDA Contact Information
R&D - Buildings Research