Assessment of the impacts of balconies on indoor environmental quality in mild climate conditions, Portugal

The configuration of balconies can affect the indoor environmental performance of dwellings, but there is not enough knowledge regarding how a balcony simultaneously impacts all the parameters of indoor environmental quality (IEQ). Therefore, this study aims to evaluate, for the first time, the impacts of different balcony configurations on IEQ. A comprehensive in-situ campaign was carried out on ten balconies and their contiguous rooms in a building in Porto. Air temperature, relative humidity, CO2, PM2.5 and TVOCs concentration, illuminance and sound pressure level were simultaneously monitored. The results show that an open balcony has a positive impact on hygrothermal conditions, controlled daylight illuminance, and reduced traffic noise by up to 10 dBa. The presence of a glazed balcony improved hygrothermal conditions in winter and increased the noise reduction by up to 15 dBA, but caused a reduction in the daylight of up to 64%. The rooms, in which the balcony was eliminated presented the worst hygrothermal conditions, lost the benefits of noise reduction and had an increase in daylight illuminance of up to 136%. It was also found that the impacts are interrelated and that a balcony influences the occupants' behaviour by enhancing window opening.