Innovative Mechanical Ventilation Control for Enhanced Indoor Air Quality and Energy Efficiency

Indoor air quality (IAQ) is often overlooked, yet a poorly maintained environment can lead to significant health issues and reduced concentration and productivity in work or educational settings. This study presents an innovative control system for mechanical ventilation specifically designed for university classrooms, with the dual goal of enhancing IAQ and increasing energy efficiency. Two classrooms with distinct construction characteristics were analyzed: one with exterior walls and windows, and the other completely underground. For each classroom, a model was developed using DesignBuilder software, which was calibrated with experimental data regarding CO2 concentration, temperature, and relative humidity levels. The proposed ventilation system operates based on CO2 concentration, relative humidity, and potential for free heating and cooling. In addition, the analysis was conducted for other locations, demonstrating consistent energy savings across different climates and environments, always showing an annual reduction in energy consumption. Results demonstrate that mechanical ventilation, when integrated with heat recovery and free cooling strategies, significantly reduces energy consumption by up to 25%, while also maintaining optimal CO2 levels to enhance comfort and air quality. These findings emphasize the essential need for well-designed mechanical ventilation systems to ensure both psychophysical well-being and IAQ in enclosed spaces, particularly in environments intended for extended occupancy, such as classrooms. Furthermore, this approach has broad applicability, as it could be adapted to various building types, thereby contributing to sustainable energy management practices and promoting healthier indoor spaces. This study serves as a model for future designs aiming to balance energy efficiency with indoor air quality, especially relevant in the post-COVID era, where the importance of indoor air quality has become more widely recognized. © 2025 The Authors.