Opaque envelope parameters energy consumption in commercial buildings in Brazil

This article presents an analysis of the energy performance of commercial buildings as a function of the influence of the overall heat transfer coefficient of the external walls and roof. Cases with different internal load densities, exterior absorptance, patterns of use, window-to-wall ratios and other parameters were simulated to analyse their influence on the annual energy consumption. The analysis was carried out through computer simulation using the EnergyPlus program and weather files for Florianopolis, Curitiba and Sao Luis. Two building typologies were adopted: a five-storey office building and a one-storey commercial store. These results show that the limits adopted by ASHRAE Standard 90.1 can be exceeded, depending on the case and climate analysed, as using high values of overall heat transfer coefficient in the walls can help to dissipate the internal heat gain to the exterior, minimizing the air conditioning energy consumption.