IN-24-C041 - Indoor Air Conditions Multicriteria Optimization: Finely Instrumented and In-Situ Experimental Based Investigations of Mechanical Ventilation Systems Potential

Heating, ventilation, and air conditioning (HVAC) systems emerge as the main contributor of energy demand in buildings. Reducing their energy consumption while maintaining acceptable indoor air quality and thermal comfort holds the promise of substantial environmental and financial benefits. This paper explores optimal mechanical ventilation strategies for an office space environment within the experimental setting of "HYBCELL," an advanced laboratory facility at ENTPE, France. “HYBCELL” characterizes building level environmental conditions, encompassing thermal comfort, air quality, and heating and ventilation management strategies. The study rigorously examines various levels of control strategies—manual control and simple control based on PID control, to assess their effectiveness in simultaneously enhancing occupant comfort and reducing electrical energy consumption. Emphasizing the pivotal role of thermal comfort and indoor air quality in HVAC design, double-flow ventilation is used as an energy-efficient method to improve air quality and thermal comfort. Several control scenarios are implemented to assess proper ventilation rates. These include the Demand-based Ventilation Control strategy, which adjusts ventilation rates based on occupancy levels and pollutant concentrations, and the Dynamic Setpoint Control Strategy, which adjusts the temperature and humidity setpoints of HVAC systems based on external conditions, occupancy, and IAQ measurements. The testing involved three different scenarios including observing humidity and CO2 levels without mechanical ventilation, while the second scenario employed PID control to activate mechanical ventilation, maintaining temperature and specific CO2 levels for optimal comfort. The last scenario involved manual control for ventilation to regulate temperature and fan speeds for effective humidity and ventilation rate management. The experimental setup in "HYBCELL" meticulously monitors critical indoor parameters, exploring diverse scenarios to evaluate the impact of ventilation strategies on occupant well-being and energy consumption in real-world building conditions. The scenarios also encompass testing environmental parameters at different heights within the room. Data acquisition is conducted using LABVIEW environment through collecting real-time data from sensors. In conclusion, the paper provided valuable insights into the selection and application of ventilation control strategies, which can improve ventilation conditions, guiding the design and operation of energy-efficient, comfortable indoor environments.