9 September 2014 Light valve based on nonimaging optics with potential application in cold climate greenhouses
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We have evaluated a new concept for a variable light valve and thermal insulation system based on nonimaging optics. The system incorporates compound parabolic concentrators and can readily be switched between an open highly light transmissive state and a closed highly thermally insulating state. This variable light valve makes the transition between high thermal insulation and efficient light transmittance practical and may be useful in plant growth environments to provide both adequate sunlight illumination and thermal insulation as needed. We have measured light transmittance values exceeding 80% for the light valve design and achieved thermal insulation values substantially exceeding those of traditional energy efficient windows. The light valve system presented in this paper represents a potential solution for greenhouse food production in locations where greenhouses are not feasible economically due to high heating cost.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Angel A. Valerio, Angel A. Valerio, Michele A. Mossman, Michele A. Mossman, Lorne A. Whitehead, Lorne A. Whitehead, } "Light valve based on nonimaging optics with potential application in cold climate greenhouses", Proc. SPIE 9191, Nonimaging Optics: Efficient Design for Illumination and Solar Concentration XI, 91910K (9 September 2014); doi: 10.1117/12.2060412; https://doi.org/10.1117/12.2060412


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