THERMAL AND OPTICAL ANALYSIS OF A NOVEL GLAZING FAÇADE SYSTEM WITH PARALLEL SLATS TRANSPARENT INSULATION MATERIAL (PS-TIM)

Abstract

With the increase of the awareness of sustainability in the built environment, it has never been stopped to continuously improve the performance of glazing facade systems leading to indoor comfortable a nd building energy conservation. An innovative facade system where parallel transparent plastic slats are sandwiched in between two glass panes to form a Transparent Insulation Material (PS-TIM) structure is proposed to effectively reduce the coupled convective and radiative heat transfer, therefore increasing the thermal resistance of the facade, meanwhile keep sufficient sunlight penetrating into rooms. A numerical investigation of the thermal and optical performance of this PS-TIM facade were conducted and presented in this paper. The detailed modelling of the thermal characteristics of the PS-TIMs was undertaken using a finite volume Computational Fluid Dynamic (CFD) package FLUENT while the optical simulation is realised by a commercial ray-tracing tool TracyPro. The thermal numerica l model was validated with previously published experimental measurements. The CFD predictions show that: an aspect ratio of A=0.35 can provide full suppression in convection; the PS-TIM structure can reach 35%-46% reduction of thermal conductance compared with standard double glazing at the same size with no slat installed in the air cavity; In addition, the trade-off analysis between U-value and light transmittance at various solar incidence angles have also been investigated. The results provide a better understanding of the benefits of parallel plastic slats Transparent Insulation Material (PSTIM) in energy saving and also leads to better designs of glazing facade systems.