Silica Aerogel-Filled Polycarbonate Planes: Innovative Energy-Efficient Daylighting Systems in Different Buildings

Windows have the most contribution to energy loss through the buildings envelope. One of the offered solutions to improve the energy efficiency of the windows and glazing units is the filling of the vacant space of the multilayer glazing systems with aerogel.  Aerogels are the lightest commercialized solids and have the lowest thermal conductivity among solid materials. Furthermore, their good acoustic insulation as well as daylight and solar energy transmittance properties, make them interesting insulation materials that can be used in the vacant space of multilayer glazing units. Multilaye r polycarbonate planes recently have found extensive applications in buildings. In this work, the vacant space, air gaps, of the polycarbonate planes were filled with silica aerogel and their thermal performance as an innovative glazing system was investigated. Polycarbonate planes with different thicknesses (5-15 mm) were filled with granular aerogels and the amount of reduction in the heat loss through the planes at different temperatures (40-70oC) was measured. Also, the effect of aerogel granule size on the thermal efficiency of the planes was investigated. Granule size in the range of 2-3 mm showed the best performance. Depending on the plane thickness, applied temperature, and aerogel granule size, the energy loss through aerogel-filled planed is reduced 21 to 66 % in comparison with conventional air-filled planes. Typically, the U-value of the 10 mm polycarbonate plane was reduced from 2.74 W/m2K in the air-filled plane to 1.1 W/m2K in the aerogel-filled plane.