Optimization of the passive house concept for residential buildings in the South-Brazilian region

Abstract

This paper is focused on the optimization of the Passive House concept for single-family houses in the climatic context of the Southern Brazilian region, using two approaches: 1) Analysing the buildings’ energy performance through the simulation method presented in the Technical Regulation of Quality for the Level of Energy Efficiency of Residential Buildings (RTQ-R); 2) Analysing the buildings’ energy performance according to the Passive House concept approach, with optimization using a multi-objective evolutionary algorithm. Three single-family houses built with basic passive strategies were selected as the case studies for the Bioclimatic Zones BZ1, BZ2 and BZ3 of the Southern Brazilian region. These buildings were geometrically modeled and each profile for usage and occupation were defined. Posteriorly, the thermal and energy performance of the buildings have been performed through the classification of the energy efficiency level of the envelope, according to the RTQ-R standard. Then, the Passive House concept was applied to the three reference buildings and the optimization process has been performed using the multi-objective algorithm to instruct the dynamic simulation software. In the models with the Passive House concept, it has been observed a reduction in energy demand of 83.5%, 56.3% and 55.1%, and a reduction in thermal discomfort, on an annual comfort basis established between 20 and 26 °C, from 83.5%, 73.7% and 86.2% for buildings located in Bioclimatic Zones BZ1, BZ2 and BZ3 respectively. To improve the buildings’ thermal and energy performance in the climates corresponding to Bioclimatic Zones BZ2 and BZ3, it was necessary to adopt the windows opening strategy in order to increase the system's air renewal rate through natural ventilation, combined with the MVHR system. It has been concluded that through the use of the Passive House concept optimized to the Southern Brazilian climate region, a significant increase in terms of thermal comfort was attained whilst drastically decreasing the energy demand of buildings.