Análise da eficiência energética da envoltória de um projeto padrão de uma agência bancária em diferentes zonas bioclimáticas brasileiras

Abstract

Some public and private organizations that operate throughout Brazil have standardized their building projects. These projects have been developed to achieve a common approach to the implementation of technical, economic and service networks. Buildings are constructed by repeating the same standard design in different locations often without considering regional bioclimatic conditions. This study analyzed and rated the energy performance of a standard project undertaken by a bank to build new branches using the Prescriptive Method of RTQ-C in different bioclimatic zones in Brazil. In situations where the building presented opportunities for improvement, bioclimatic strategies were tested, such as shading fenestration areas or changing the solar heat gain coefficient (SHGC) of the windows. In order to evaluate the potential of saving electricity, computer simulation software (EnergyPlus) was used. Simulations were run for the original standard design and the optimized design taking into consideration each bioclimatic zone. In only six cases the envelope of the original standard building design did not reach Level A (best) by Prescriptive Method of RTQ-C. For these cases, changes to the shading devices (overhangs and fins) were tested as well as the SHGC of windows. The equations for the Prescriptive Method were recalculated to obtain a value of the envelope’s consumption (ICEnv) below the maximum value for classification with Level A. For the original standard building design implemented in Bioclimatic Zone ZB-1 having its main façade to the West, the value of ICEnv for the Level A could only be achieved with the removal of all its windows vertical shading protections (reduced AHS), increasing the SHGC of some windows and increasing the width of the overhang at the entrance of the agency (increased AVS). This proposed amendment was simulated for the city of Curitiba/PR, indicating a potential energy saving of 25.97% over the original project. When the original project was deployed in Bioclimatic Zones ZB-4 and ZB-5 having the main façade to the West, the only viable alternative according to the equations of the Prescriptive Method was to reduce the value of the SHGC of some windows. In the case of the city of Brasilia/DF (located in ZB-4), the simulation showed savings of up to 30.53% when compared to the original standard project. There have been no simulations of the optimized project for the ZB-5 due to lack of climate data files for cities located in that zone. The original project did not attain Level A when deployed in Bioclimatic Zone ZB-7 having the main façade to the North, East and South. Changing values in the equation of Prescriptive Method for the ZB-7 indicated three possibilities for improving original project (increasing the average value of SHGC, increasing AVS or reducing AHS). Computer simulations validating the equations of ZB-7 were made for the city of Cuiabá/MT. With the amendment of the SHGC, the simulation showed that the savings potential is practically nil (0.04 to 0.50%). Increasing AVS gave savings of 0.68% for the Southern façade, 2.80% for the Eastern façade and 3.90% for the Northern façade. The reduction of AHS has not been confirmed by the simulation, due to there being an increase in energy consumption of 1.43% for the Northern façade, 1.74% for the Eastern façade and 3.23% for the Southern façade.