Experimental study of the thermal performance of a large institutional building with mixed-mode cooling and hybrid ventilation

The paper explores mixed-mode cooling strategies in buildings with hybrid ventilation and high levels of exposed thermal mass and presents data collected over an extensive period of time using a full-scale experimental set-up in an occupied institutional building with motorized façade openings integrated with an atrium. Night cooling strategies for thermal mass pre-cooling, with variable low temperature setpoint for control of airflow through operation of motorized grilles or a possible variable speed fan, are evaluated. Results for the thermal conditions in the highly-glazed atrium zone and the wind and buoyancy-driven airflow rates show that free cooling covers a significant portion of the buildingʹs cooling requirements while maintaining a comfortable indoor environment. The heat removal from concrete floor slabs is 2–5 times higher with the inlet air stream at an average temperature of 12 °C, compared to that with an air stream at 15 °C or 18 °C respectively. These findings provide insights for space conditioning using hybrid ventilation that can support the development of model-predictive control strategies.