Evaluation of in-situ thermal transmittance of innovative building integrated photovoltaic modules: Application to thermal performance assessment for green mark certification in the tropics

Green buildings with adequate renewable energy penetration are fundamental pillars of global sustainability. Moreover, pertinent to ever-increasing impacts of cooling loads, air-conditioning systems, and elevated energy consumption in the tropics, building energy performance plays a crucial rule in achieving self sustainability. In this context, the proposed work experimentally evaluates the thermal performance of five innovative building integrated photovoltaic (BIPV) technologies, and assesses its feasibility to be integrated as building envelopes to attain the required green mark certification benchmarks in Singapore. For which, experiments are first performed using a state-of-art indoor laboratory equipped with a calibrated Calorimeter Hot Box for thermal transmittance (U − Value) measurements. Later, distinctive to existing works, this article extends the application of U − Values to obtain the Envelope Thermal Transfer Value (ETTV) by utilizing an analytical model for sensitivity analysis. In particular, this assessment is performed to provide an accurate quantification of the thermal characteristics of the tested BIPV technologies in compliance with the prevailing green building codes. Extensive case studies considering various window to wall (WWR) ratios have also been conducted to identify the optimal values that could guarantee successful BIPV deployment with green mark compliance. Altogether, this paper reports 720 benchmark test case results accounting for five cladding, and three fenestration systems considering various WWR ratios ranging from 0.1 to 0.9. It is foreseen that the ETTV sensitivity analysis carried out in this manuscript would assist researchers, and building professionals in abreast decision making for future adoption of BIPV facades at early design stages itself.