Thermal bridges modeling in South Brazil climate: Three different approaches

The impact of thermal bridges and their consideration in walls thermal transmittance calculations is a subject that has been discussed for a long time in several countries in the world, and for a few years in regions of cold climates in Brazil. The presence of vulnerable points in the envelope of the building may influence the energy performance, and may also have consequences for the building maintenance, such as favoring conditions for the filamentous fungi formation. Globally, several countries already have standards or regulations on the subject. In Brazil, none of the regulations deals with this problem. This work aims to evaluate the impact of thermal bridges of reinforced concrete structure on the thermal energy performance of a residential building in southern Brazil, considering three different possibilities to model the thermal bridge in Energy Plus software. The results show that the type of modeling influences the values of energy consumption and the thermal comfort indexes in the building. The different models can reach a consumption difference of up to 20% depending on the level of the building insulation.