An energy analysis of translucent concrete embedded with inclined optical fibers

Abstract

Translucent concrete (TC) is a kind of energy-efficient building envelope, which is able to transmit daylight into the interior of a building efficiently with improved thermal performance. Previous research shows that a kind of novel TC embedded with inclined optical fibers (OFs) is promising to achieve better climate-responsive transmittance and improved energy-saving potential compared with conventional TC. However, the newly proposed TC differs from traditional one in both light and heat transfer processes, and its distinctive optical and thermal performance have not been fully revealed. To bridge this knowledge gap, an improved optical and thermal model of the novel TC was developed and validated with experimental data. A parametric study was conducted to reveal the effects of optical fiber inclination angle and numerical aperture (NA) on the TC. The results show that the climate-responsive transmittance of TC can be improved by inclining OFs, and this can serve as a feasible method for TC transmittance adjustment especially when OFs with high NA values are not available or not cost-effective. The optimal optical fiber inclination angle is about 10° for a south-facing TC wall in Beijing, which is able to reduce building energy consumption by about 4.98% to 21.88% depending on the coefficient of performance (COP) of heating, ventilation and air conditioning systems.