Researchers from the Western Cooling Efficiency Center have published a new study evaluating a low-cost ventilation control strategy designed to reduce energy use and improve indoor air quality in school buildings.
The study, published in Science and Technology for the Built Environment, tested the IAQ-Energy Controller in two occupied classrooms in California’s Central Valley. The controller adjusts outdoor air intake based on indoor carbon dioxide levels, outdoor fine particulate matter, and temperature. When outdoor air pollution is elevated, the system reduces outdoor air intake and uses an internet-connected portable air cleaner to help maintain clean airflow indoors.
The field test found that the controller reduced classroom carbon dioxide concentrations by 16% to 18% compared with fixed-rate ventilation. It also maintained or improved clean airflow for infectious aerosol removal, delivered comparable thermal comfort, and did not increase energy use.
The findings point to a practical retrofit approach for schools and other buildings that need to balance ventilation, outdoor air pollution, energy use, and occupant health. This is especially important in regions where wildfire smoke and other air quality events can make outdoor air less safe to bring indoors.