Green roofs have been investigated as a bioclimatic strategy to improve the energy efficiency of buildings. Quantitative data on this subject are still needed for many specific climatic conditions. This paper deals with the investigation of the green roof thermal performance of an experimental single-family residence in Florianópolis (SC, Brazil), a southern city with a temperate climate. Field measurements during a warm period (01-March-2008–07-March-2008) and during a cold period (25-May-2008–31-May-2008) included internal air temperature of rooms, internal and external surface temperature of three types of roofs (green, ceramic and metallic), heat fluxes through these roofs, green roof's temperature profile, water volumetric content in substrate layer and meteorological data. During the warm period, the green roof reduced heat gain by 92–97% in comparison to ceramic and metallic roofs, respectively, and enhanced the heat loss to 49 and 20%. During the cold period, the green roof reduced heat gain by 70 and 84%, and reduced the heat loss by 44 and 52% in comparison to ceramic and metallic roofs, respectively. From the derived data it has been confirmed that green roof contributes to the thermal benefits and energy efficiency of the building in temperate climate conditions.

This paper reports the use of an internationally recognized validation and diagnostics procedure to test the fidelity of a simplified calculation method. The case study is the simplified model for calculation of energy performance of building envelopes, introduced by the Brazilian regulation for energy efficiency in commercial buildings. The first step of the assessment consisted on evaluating the simplified model results using the BESTEST. This paper presents a straightforward approach to apply the BESTEST in other climates than the original one (Denver, USA). The second step of the assessment consisted on applying the simplified model to evaluate four building typologies, and compare the results with those obtained using a state of the art building energy simulation (BES) program. For some BESTEST cases, the simplified model presented results inside of a confidence interval calculated by the authors. However, the simplified model was found to yield significant difference in the four building typologies analysed. Moreover, in all four building typologies analysed, the simplified model led to a lower energy efficiency label when compared to the label obtained using BES. The paper concludes that the simplified model may require improvements to properly indicate the actual energy performance of commercial building envelopes.

Este estudo tem por objetivo avaliar o procedimento indicado na NBR-15575-1 (ABNT, 2013a) para simulação do desempenho térmico de edificações residenciais. Para a análise, adotou-se uma edificação unifamiliar para os climas das cidades de Florianópolis, Curitiba e São Luís. A simulação computacional foi realizada através do programa EnergyPlus. A investigação analisou a influência das condições do piso da edificação em contato com o solo no resultado do desempenho térmico para verão e inverno, uma vez que a NBR 15575-1 (ABNT, 2013a) não especifica esse parâmetro. Foi também observada a influência dos parâmetros sombreamento e renovação de ar com base no procedimento simplificado da NBR 15575-1 (ABNT, 2013a). Por último, aplicou-se a proposta de um novo procedimento de simulação para avaliar o desempenho térmico de edificações residenciais, tendo-se comparado os resultados encontrados com os resultados do procedimento atual da NBR 15575-1 (ABNT, 2013a). As comparações entre os dois procedimentos indicaram, principalmente, que as modificações nas condições de contato com o solo exercem forte influência nos resultados das simulações do desempenho térmico da edificação e, consequentemente, na aprovação do sistema construtivo em análise.