Achieving Sustainable Buildings: Balancing Energy Efficiency and Comfort through Ventilation Management
Abstract
Proper ventilation management is essential for balancing energy requirements and limiting indoor CO2 concentration. A high continuous ventilation rate ensures safe indoor CO2 levels but significantly increases energy consumption. The high energy demand often leads building owners and occupants to prioritize meeting thermal requirements while neglecting the importance of indoor air quality. To optimize energy demand while maintaining thermal comfort and safe CO2 limits, intermittent ventilation or reduced ventilation rates must be employed. Based on this study, different occupant densities provide varying ventilation time gaps to maintain CO2 concentration within safe limits and offer an opportunity to save energy. For occupant densities higher than 50 m3/person, a maximum ventilation gap of 250 minutes can be utilized, and the ventilation gap depends on the outdoor CO2 level. For safe CO2 levels at occupant densities above 20 m3/person, continuous ventilation of 1.0 ACH suffices, while higher densities necessitate intermittent ventilation to cut energy demand. Energy use increases with higher ventilation rates and occupant densities, ranging from 1.25 to 2.28 times compared to the base case for 10 m3/person to 90 m3/person, respectively. Continuous ventilation at 2.0 and 3.0 ACH is required for lower occupant densities of 20 m3/person and 10 m3/person, which escalates energy use. So, it is recommended that lower occupant densities be avoided in indoor spaces. Tailored ventilation strategies can achieve approximately 50% energy savings in building operations.