Investigação do potencial de economia de energia com o uso de dispositivos de proteção solar nos Regulamento Técnico da Qualidade para o Nível de Eficiência Energética de Edificações Residenciais

Abstract

Supported by the CIE research project (Grant DTP ECV 002/2011), which intends to structure the development of researchs in the field of natural light for collaboration with the Buildings Energy Efficiency Labeling, this thesis aims to contribute to optimize shading devices evaluation in residential buildings. Launched in 2010, the Brazilian Energy Labeling Schemes for Residential Buildings (RTQ-R) presents scoring possibility in the rating system when using shading devices. The score ranges from 0 (zero) to 1 (one), being 0 when there is no shading device and 1 only when there are shutters. Other shading devices are scored based on two other methods and may receive scores of up to 0.2 (zero point two) or 0.5 (zero point five) points, depending of the method used. Nevertheless, the methods that assess the presence of devices other than shutters do not allow them to get higher scores, even though these devices show effective shading during sunlight periods and a consequent decrease in hour-degrees of disconfort. So this study intends to investigate the potential energy savings in addition to the thermal and luminic performance when are used different shading devices typologies, in order to compare and equalize the scores given by RTQ-R to the devices. For this purpose, analyses were made through integrated computer simulation using the software Daysim and EnergyPlus for the four main solar orientations and for seven cities in Brazil. The simulations were performed for two rooms with 128 variations using seven different shading devices and a model without any device. The results show that every method of shading device sizing has specific characteristics regarding its luminous, thermal and energy performance. The models in which the shading devices were designed using the solar chart showed the largest devices sizing, but a lower cooling hour-degrees demand for all Bioclimatic Zones. These models achieved up to 42% less hour-degrees than the model without shading devices. In other way, the models designed from RTQ-R evaluation and presence of shutters, only 26%. Concerning the energy performance, the potential saving by using shading devices was the highest for west-facing openings, achieving reduction of up to 14.7% when compared to the model without devices, while for south-facing openings it achieved up to 2.9%. The simulations results allowed the creation of a rating scale for the devices and showed an incompatibility between the simulations scores and the ones given by the RTQ-R. Frequently, the simulations results showed significantly higher scores than the maximum given to the shutters by the RTQ-R, achieving up to 4.21 points. It was also found that the scores are significantly different between the Bioclimatic Zones and solar orientations and therefore it is necessary to adopt zoned scores.