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© 2020 Informa UK Limited, trading as Taylor & Francis Group. Airtightness refers to the amount of air leakage through a building’s envelope. This uncontrolled exchange of air between inside and outside, either infiltration or exfiltration, may lead to thermal discomfort. Nevertheless, little or no attention has been given to airtightness in some countries including Brazil. In Brazil, a range of different strategies are suitable to achieve thermal comfort depending on the several climatic regions. In those regions where winter conditions are noticeable, such as in São Paulo, airtightness is a key parameter, but it has been historically overlooked. In this work, the authors deployed the innovative Pulse test methodology to determine airtightness levels for the first time in Brazil, in the city of São Paulo. Three representative multifamily residential buildings dating from the 1970s, 1980s and 2000s were measured, and the results’ values widely ranged from 1 to 5.7 h−1, at 4 Pa. Next, dynamic building simulations were conducted using measured and representative airtightness values (converted to infiltration) to understand the contribution of this variable on the thermal comfort. The results suggested that up to 9% improvement in the thermal comfort levels could be achieved by adopting 1 h−1 as maximum infiltration, and up to 14% by adopting 0.5 h−1.

A pesquisa analisa o desempenho térmico de duas edificações escolares distintas, o Centro de Educação Profissional do Vale do Caí e a Escola de Ensino Fundamental Frei Pacífico, localizados em municipalidades também distintas e compostos por tipologia arquitetônica e orientação solar similares. Método: Os dois casos estudados tiveram o seu desempenho analisado pelo método de medição in loco, com coleta horária das variáveis de temperatura e umidade relativa do ar, fazendo uso de data loggers. A amostra foi composta por uma sala de aula, em cada ambiente de ensino. Objetivos: Foram objetivos desta pesquisa: caracterizar os estudos de caso; calcular as propriedades térmicas dos fechamentos; apontar distinções no procedimento de coleta de dados; analisar o desempenho térmico das salas estudadas, considerando o período de medições e o período de ocupação; e comparar dados climáticos das municipalidades com os dados climáticos de Porto Alegre. As análises foram estruturadas por estações do ano, com análise de temperatura (incluindo atraso e amortecimento térmico) e umidade relativa do ar. Auxiliaram nas análises de dados, a metodologia de análise de graus-hora e a carta bioclimática proposta por Givoni. Foram realizadas análises considerando o período de medições e o período de ocupação das escolas. Resultados: Os resultados apontaram um desempenho mais satisfatório para o Centro de Educação Profissional do Vale do Caí, o que pode ser atribuído à inércia térmica e às propriedades térmicas dos fechamentos deste edifício, mesmo tendo apresentado oscilações maiores de temperatura e umidade relativa. A análise dos dados climáticos das municipalidades permitiu identificar algumas similaridades com os do município de Porto Alegre, embora a proximidade deste com massas d’água tenham demonstrado interferência considerável na amplitude térmica e na umidade relativa do ar. The research examines the thermal performance of two different school buildings, Vale do Caí Professional Education Center and Frei Pacífico Elementary School, located in different municipalities and also composed of similar architectural style and solar orientation. Method: The two cases studied had their performance evaluated by the in situ measurement method, with hourly collected hourly rate of the variables of temperature and relative humidity, using data loggers. The sample consisted of one classroom in each teaching environment. Objectives: The objectives of this research: were to characterize the case studies; to calculate the thermal properties of the elements; to point out distinctions in the procedure of collecting data; to analyze the thermal performance of the classrooms studied, considering the measurement period and the period of occupation; and comparing climatic data of municipalities to the climate data from Porto Alegre. The analysis was structured by seasons, with analysis of temperature (including thermal delay and thermal damping) and relative humidity, to help the data analysis methodology degree-hours and bioclimatic chart proposed by Givoni. There were analyses considering the measurement period and the period of school occupation. Results: The results showed a more satisfactory performance for Vale do Caí Professional Education Center, which can be attributed to thermal inertia and thermal properties of the closures of the building, though it had the highest swings in temperature and relative humidity. The analysis of climate data of the municipalities identified some similarities with that of the city of Porto Alegre, although the proximity of masses of water to the later, demonstrated considerable interference in the temperature and relative humidity ranges.