Evaluating the performance of shading devices and glazing types to promote energy efficiency of residential buildings

This study presents a novel residential envelope transmittance value (RETV) performance-based approach for determining the suitable external shading devices and glazing types to improve energy efficiency in residential buildings. The approach is applied to two residential buildings types, namely, point block and slab block, for any given orientation in an entire year. In this approach, a RETV equation for residential buildings was first developed. Employing this equation, we demonstrated how the design of shading devices and the selection of glazing type impact the cooling load of high-rise residential buildings. Comparing results from the model simulations, the half egg-crate louver was found to be the most suitable shading device for residential buildings facing the north and south orientations, whereas a horizontal projection with 30° downward tilt was appropriate for facade facing the east and west orientations to reduce cooling load. In addition, simulations also indicated low-E single clear glazing to be a suitable glazing since it results in relatively economical short payback periods.