Proposta de método para análise dinâmica de conforto térmico em espaços urbanos

Abstract

According to the UN's Intergovernmental Panel on Climate Change (IPCC) report, published in August 2021, the planet's average temperature is expected to rise by 1.5 °C by 2030. Given this new climate scenario, researchers around the world have been stepping up their research into thermal comfort in open urban environments and its effects on the health and well-being of the population. Assessing thermal sensation in open urban spaces is complex and requires various methodologies, such as field surveys and the interpretation of mathematical models. Research on thermal comfort varies in methods, situations analyzed, measurements, and times, making comparisons difficult, especially due to the different data collection protocols adopted according to the objectives of each study. Seeking to reduce these difficulties, this research aims to propose a method for evaluating dynamic thermal comfort by collecting microclimatic variables, subjective evaluation (application of questionnaires), and UTCI (Universal Thermal Climate Index) and PET (Physiologically Equivalent Temperature) thermal comfort indexes. The experiment was conducted in an urban park, which houses native vegetation from the Atlantic Forest, located in the city of João Pessoa, on the coast of Paraiba. In order to reduce the differences between equipment, the aim was to develop and evaluate the applicability of a prototype bioclimatic backpack for collecting environmental variables. The low-cost bioclimatic backpack prototype, called PLEMS (Portable Low-Cost Environmental Monitoring System), which was developed and tested, proved to be viable for application in thermal comfort studies in open urban spaces. A proposed questionnaire for subjective evaluation was also desenvolved. The questionnaire proved to be efficient in collecting biological information and assessing the thermal perception of those interviewed. It was found that, along the transect, the transients experienced significant variations in thermal conditions. It was found that, along the transect, thermal sensations were correlated with microclimate variables and with the UTCI and PET indexes. Both indexes overestimated the reported thermal sensation, especially during the dry period. The PET proved to be more sensitive to microclimatic variations, capturing discomfort in lower temperatures more accurately, while the UTCI showed stronger correlations with subjective variables. Both presented similar comfort ranges, but the PET was more closely aligned with air temperature. During the humid period, approximately 60% of the comfort sensation votes fall within the air temperature range of 27 °C to 30 °C, PET from 26 °C to 31 °C, and UTCI from 29 °C to 34 °C. In the dry season, about 37 % of the comfort sensation votes are concentrated within the air temperature range of 29 °C to 32 °C, PET from 29 °C to 35 °C, and UTCI from 33 °C to 38 °C.