Indoor Air Quality, Thermal Environment and Mental Health: Ventilation with Heat Recovery to Improve Satisfaction with Low-Energy Impacts

The paper analyses the connections among indoor air quality, concentrations of pollutants and VOCs, poor ventilation, presence of carbon dioxide in thermal environments and then evaluates the potential role that mechanical ventilation can have in improving indoor conditions, in terms of purity of air. Therefore, the investigation concerns the indoor environment not only in terms of thermodynamics but also in terms of cognitive capabilities and mental satisfaction of hosted persons. After a deep review of the state of the art, the installation of decentralized mechanical ventilation is evaluated, by analyzing the effects of reduction of indoor pollutants, reduction of vapor concentration in humid environments, and improvement of indoor air quality without significantly affecting the energy consumption. Real measurements were provided, with reference to significant days in February 2024, by revealing great potential in the improved well-being in indoor spaces beyond the known performance in terms of energy efficiency. Indeed, the energy recovery ventilator has caused a reduction, at temperatures of 19-20 °C, of approximately 6-8% in relative humidity, a strong reduction in the concentration of carbon dioxide, and an energy saving which implies a cost-saving of around 5,18 €/day.