Enhancing indoor air quality and occupant well-being in Split Air-conditioned bedrooms through integrated ventilation

Maintaining Indoor Air Quality (IAQ) and ensuring the well-being of individuals in split air-conditioned indoor spaces such as bedrooms can be challenging, primarily due to the increased risk of airborne infection transmission and high CO2 concentration. To address these issues, pertinent guidelines recommend ensuring adequate ventilation with fresh air, as it effectively mitigates the spread of indoor pollutants. However, split air-conditioned spaces often lack a continuous supply of fresh air. The resulting indoor air quality deterioration can cause occupants to resort to opening doors and windows. This, in turn, can result in an unnecessary increase in heating or cooling energy use. The objective of this study is to address the limitations of existing air cleaning and air- conditioning systems, which may include insufficient ventilation, excessive recirculation of indoor air, limited effectiveness, and the inability to dynamically respond to indoor pollutants in an energy-efficient manner. It has been observed that occupant’s open doors and windows for fresh air ventilation in response to a feeling of stuffiness for a considerable fraction of the total operational hours of a split AC in a bedroom. The present study suggests that by integrating ventilation and air-conditioning in a coordinated manner, IAQ and hence occupants' well-being in bedrooms can be enhanced in an energy-efficient manner.