The effects of different ventilation types on IAQ and occupants' health in residential buildings

Nowadays, the importance to ensure adequate Indoor Air Quality (IAQ) in non-industrial buildings requires both qualitative and quantitative assessments on health risks for occupants, who spend about 90% of their time in indoor environments, due to air pollution. In fact, exposure to indoor pollutants has a negative effect not only on occupants’ well-being and comfort, but also on their health and productivity. In this context, ventilation represents the most effective strategy in order to control sources of pollutants and to reduce emissions, as well as to consequently minimize health risks. The present paper aims to provide information about the effects of ventilation on health symptoms, such as asthma, allergies, chronic obstructive pulmonary disease, cardiovascular diseases, and lung cancer. In detail, the literature review focuses on the research of existing relationship, both direct and indirect, and qualitative and quantitative, between different ventilation types and occupants’ health in residential buildings. The analysis carried out show the potential benefits of mechanically ventilated building in terms of decrease in occupants’ health symptoms and complaints, compared to natural ventilation systems. In fact, the review highlights the difficulty to assess health benefits of naturally ventilated buildings due to their dependence on several non-controllable factors, such as geometry of windows, wind direction and speed, and occupant window opening behaviour. In this way, although natural ventilation is more economically convenient, the benefits rising from the installation of mechanical ventilation, in terms of reduction of health symptoms, are higher and might counterbalance the higher investment and maintenance cost