Integrated analysis of hygrothermal performance, CO2 concentration, and filamentous fungi growth in social housing in Bioclimatic Zone 2R

The study evaluates indoor air quality in social housing units located in Pelotas/RS, considering the proliferation of filamentous fungi and the concentration of carbon dioxide in two indoor environments of a building with cast-in-place concrete walls. The research was developed through computational simulations using the EnergyPlus, WUFI - 2Pro, and WUFI - Bio software, with the thermal properties of the concrete obtained from laboratory tests. The building’s solar orientation was considered to define the most critical internal walls in terms of radiation incidence and indoor hygrothermal conditions. The results indicated differences in the hygrothermal performance of the analyzed internal surfaces, with a greater propensity for the occurrence of internal surface condensation and moisture-related degradation processes, such as the promotion of fungal growth. The isopleth analysis showed relevant variations in surface moisture levels throughout the simulated period, indicating favorable conditions for the growth of filamentous fungi and reinforcing the need for strategies such as adequate ventilation and the use of materials and coatings with better hygrothermal performance. It was also observed that increasing the temperature setpoint from 19 °C to 25 °C intensifies the risk of fungal proliferation and CO2 concentration, especially in scenarios without ventilation.