Thermal comfort analysis of a representative multi-story social housing unit with wood as an alternative construction material in Brazil

Abstract

This research intends to link thermal comfort as an important part of achieving energy efficiency in the operational phase of a building with the use of wood as a low embodied energy and carbon efficient construction material. The thermal performance of a representative multi-story social housing unit with common construction materials is evaluated in contrast to wood-based construction systems in Brazil. A project located in São Carlos, Brazil was selected. The construction system for walls consists of concrete blocks while roofs are composed of a fiber cement sheet and a concrete slab ceiling. As alternative wood-based wall systems, plywood panels with an air chamber or three different insulation materials (expanded polystyrene, cellulose and mineralized wood fiber) were tested while two alternative roof systems were analyzed (plywood lining with air chamber or insulation material). The project with common construction materials as well as the wood-based alternatives were evaluated through the Brazilian standard NBR 15575 and the European Standard ISO 13786. Furthermore, a transient simulation was conducted following the procedure established by NBR 15575 and using the adaptive comfort model ASHRAE 55-2013. The analysis evidenced the neglection of the recommended passive design strategies according to the Brazilian Standard 15220 and the psychometric chart of Givoni. In regard to the wood-based constructions, results showed that insulation of mineralized wood fiber in panels performed better than cellulose and expanded polystyrene. The transient simulation also demonstrated better thermal comfort conditions with a hybrid wood-based model compared to the construction typology of the representative project.