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

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.