Publications

Phase Change Materials (PCMs) increase the building's thermal inertia comparably to materials traditionally associated with high thermal capacity. Incorporating Phase Change Materials (PCMs) in indoor environments can increase users' thermal comfort and the building's energy efficiency. Many investigations have proven the performance of PCMs in temperate climates and at high latitudes. However, in the Brazilian climatic context, research is relatively limited. This thesis aims to contextualize the application of PCMs in the built space and analyze their influence on the thermal comfort of office users in Brazilian climates. An integrative literature review was conducted to define the state-of-the-art and thermoenergetic simulations using EnergyPlus. The review presented the most relevant and current examination parameters in research with PCMs: climate, environmental conditioning, solar orientation, the type/characteristics of the PCM, the layer in which the material is installed, and its thickness. After the survey, simulations were conducted using organic PCMs with phase-change temperatures between 18°C and 44°C, installed in a naturally conditioned, low thermal capacity office model. The simulations were divided into two groups, the first contemplated 5 cities and focused on installation parameters and boundary conditions and the second assessed 95 cities and focused on climate parameters. The first simulations revealed that the phase-change temperature, the climate (temperature and radiation), and the installation layer were the most influential parameters, resulting in 20% variations in adaptive thermal comfort. Solar orientation had a moderate impact, with up to 10% comfort variation, followed by layer thickness and type of ventilation, with 2% thermal comfort alteration. In the second group of simulations, the highest impact parameters in the first group were fixed. The climatic parameters were adopted as independent variables and analyzed according to adaptive thermal comfort variation between the PCM-incorporated and base cases. Dry bulb and dew point temperatures, direct and diffuse infrared radiation, relative humidity, wind direction, and wind speed were evaluated. The results indicated that the incorporation of PCMs has the potential to increase comfort in part of Brazil, with improvements between 20% and 36% compared to cases without PCMs. Consistently, the best results occurred in Bioclimatic Zones (BZs) 1 to 4, with the best effects in cities with average annual temperatures at or below 21°C. Cities with annual average temperatures between 21°C and 23°C in ZB3, ZB4, ZB5, and ZB8 also performed satisfactorily, demanding further evaluation. For the best circumstances, dry bulb temperature, relative humidity, and wind direction were the most representative climatic parameters and, therefore, most significant for increasing users' thermal comfort in environments with PCM.

Keywords: Phase Change Materials. PCMs. Thermoenergetic simulation. EnergyPlus. Brazilian climates. Adaptive thermal comfort. Climatic parameters.

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