People's subjective response to any thermal environment is commonly investigated by using rating scales describing the degree of thermal sensation, comfort, and acceptability. Subsequent analyses of results collected in this way rely on the assumption that specific distances between verbal anchors placed on the scale exist and that relationships between verbal anchors from different dimensions that are assessed (e.g. thermal sensation and comfort) do not change. Another inherent assumption is that such scales are independent of the context in which they are used (climate zone, season, etc.). Despite their use worldwide, there is indication that contextual differences influence the way the scales are perceived and therefore question the reliability of the scales’ interpretation. To address this issue, a large international collaborative questionnaire study was conducted in 26 countries, using 21 different languages, which led to a dataset of 8225 questionnaires. Results, analysed by means of robust statistical techniques, revealed that only a subset of the responses are in accordance with the mentioned assumptions. Significant differences appeared between groups of participants in their perception of the scales, both in relation to distances of the anchors and relationships between scales. It was also found that respondents’ interpretations of scales changed with contextual factors, such as climate, season, and language. These findings highlight the need to carefully consider context-dependent factors in interpreting and reporting results from thermal comfort studies or post-occupancy evaluations, as well as to revisit the use of rating scales and the analysis methods used in thermal comfort studies to improve their reliability.

The adoption of air-conditioning as a cooling strategy in hot and humid climates is common practice. In such locations, the overcooling of buildings in a concern as this leads to the dissatisfaction of the occupants and unnecessary cooling energy consumption. In this regard, a field study was carried out in the Brazilian city of São Luis (hot and humid equatorial climate) to evaluate the preferred and most comfortable thermal conditions in this context. The investigation took place in air-conditioned and naturally-ventilated classrooms, in which the environmental parameters were measured concomitantly with the application of questionnaires to the undergraduate students for thermal assessment purposes. There was a difference between the preferred thermal sensations (noticeably the “slightly cool”) and the ones considered most comfortable/acceptable (“slightly cool” and “neutral”, equally), which reflected in the preferred and most comfortable temperatures. Thermal comfort in naturally-ventilated classrooms was limited due to high air temperatures and low air speeds. The best thermal conditions in air-conditioned classrooms were found to be between 23–24 °C standard effective temperature, and more than 20% of the students were uncomfortable below 22 °C because of excessive cold when clothing insulation values were close to 0.3 clo. The results also showed that indoor air temperatures can be set as high as 26 °C without impairing thermal comfort, which could aid attempts to minimize the cooling energy consumption in this year-round hot and humid climate.

Thermal discomfort is one of the main triggers for occupants’ interactions with components of the built environment such as adjustments of thermostats and/or opening windows and strongly related to the energy use in buildings. Understanding causes for thermal (dis-)comfort is crucial for design and operation of any type of building. The assessment of human thermal perception through rating scales, for example in post-occupancy studies, has been applied for several decades; however, long-existing assumptions related to these rating scales had been questioned by several researchers. The aim of this study was to gain deeper knowledge on contextual influences on the interpretation of thermal perception scales and their verbal anchors by survey participants. A questionnaire was designed and consequently applied in 21 language versions. These surveys were conducted in 57 cities in 30 countries resulting in a dataset containing responses from 8225 participants. The database offers potential for further analysis in the areas of building design and operation, psycho-physical relationships between human perception and the built environment, and linguistic analyses.

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.

In this study, thermal and optical properties (emittance and reflectance of solar radiation) of different colors ceramic tiles for use in outside surfaces were measured. Although widely used in the brazilian residential market, these materials are not properly characterized with respect to these properties. The thermal emittance measures were performed using an emissometer (D&S pattern SA1) and the solar reflectance using a spectrophotometer UV-Vis-NIR (model Lambda 1050). These properties are important for the determination of Solar Reflectance Index, SRI, that may help designers and consumers to choose the appropriate materials to make their buildings more energy efficient and comfortable. The SRI indicates the ability of a surface to reflect solar radiation and mitigate the temperature rise of surfaces, being used in LEED certification (Leadership in Energy and Environmental Design) to evaluate the performance of some opaque elements in constructions. The studies revealed a wide variation of SRI (values are between 72 and 22) in the same product with different colors. In particular two samples showed SRI lower than 29, which place them even below the minimum requirement of LEED for application in some types of outside surfaces, as steep roofs and pavement materials (LEED v. 2009 used in Brazil).

Os materiais utilizados na construção civil absorvem radiação solar e dissipam parte do calor acumulado, influenciando no equilíbrio térmico das cidades. Este fenômeno é conhecido como Ilha de Calor Urbano. Este trabalho apresenta resultados da caracterização de propriedades óticas e térmicas (refletância e emitância) de telhas cerâmicas esmaltadas e telha de material reciclável comercializadas na região do Médio Vale do Itajaí - SC, bem como a determinação do Índice de Refletância Solar (SRI) para verificação do atendimento aos critérios estabelecidos pela certificação LEED (Leadership in Energy and Environmental Design). Foram selecionadas amostras de telhas produzidas com tecnologias não convencionais, tais como, telhas cerâmicas do tipo grés e telhas produzidas a partir de embalagens longa vida. Os resultados evidenciaram que três das telhas cerâmicas analisadas não atenderam aos critérios da certificação LEED para uso em telhados com alta inclinação, ou seja, possuem SRI inferior a 39. A refletância solar da telha de embalagem longa vida é relativamente próxima a das telhas cerâmicas de coloração clara e atende aos critérios da certificação. Na análise dos parâmetros colorimétricos das telhas cerâmicas foi observado uma relação linear entre a luminosidade (L*) e SRI, o que permitiu identificar que L* deve ter um valor maior do que 50 para que essa tipologia de telha atenda os critérios exigidos pela certificação LEED. Desta forma, apenas com o valor do parâmetro L* pode-se identificar qualitativamente quais cores estariam a risco de atender os critérios dessa certificação, simplificando e agilizando o processo de análise

This paper presents the results for the solar reflectance and temperature of 20 types of pavements used in Brazil for roads, parking lots, squares and sidewalks. New and aged pavement samples were tested. Some asphalt mixtures and Portland concrete mixtures were developed in the laboratory, with the addition of colored pigments in different percentages. The standard method ASTM E1918 and the procedure E1918A were used to measure solar reflectance of the pavements in the field. The difference between the surface reflectance values for surfaces with a lighter (white Portuguese mosaic) and darker (Reference CPA asphalt mixture) appearance was approximately 48%, and the corresponding difference in the measure surface temperature was 18.4 °C. A correlation between the solar reflectance and the temperature measured in the field is reported. The results obtained can be used as a reference to design public spaces, contributing to reducing the urban heat island (UHI) and improving the thermal comfort of the users.

A normatização brasileira relacionada ao desempenho termoenergético de edificações tem procurado inserir a refletância ou a absortância solar em seus critérios de análise. O objetivo deste artigo é analisar a exatidão e a repetibilidade de medições de refletância com o espectrômetro Alta II, bem como a influência da luminosidade do ambiente e da rugosidade da superfície sobre os valores medidos. Foram realizadas três séries de medições, variando os espectrômetros utilizados, a exposição à luz, e a rugosidade da superfície avaliada. Medições com o espectrofotômetro Lambda 1050 serviram de referência. A análise demonstrou que os resultados podem apresentar imprecisão elevada, com incerteza de ±0,10 nos valores absolutos de refletância solar. Sendo assim, o usuário do espectrômetro Alta II deve utilizá-lo com precaução, considerando tal erro. Também foi possível observar neste estudo que o Alta II pode ser usado especialmente para análise de superfícies planas e lisas. Além disso, deve-se garantir que as medições sejam realizadas com o cuidado de evitar a infiltração de luz através da superfície de contato entre o equipamento e a amostra.