Evaluation of performance of energy efficient hybrid ventilation system and analysis of occupants’ behavior to control windows

Abstract Hybrid ventilation systems have become increasingly attractive, because they are considered to provide good indoor air quality (IAQ) with low energy consumption. In this study, we evaluate the performance of a hybrid ventilation system (operating on both mechanical and natural ventilation mode) by monitoring the IAQ (e.g. temperature, humidity, CO2 levels) and the energy consumption of a multifamily building. We then investigate occupants' window-opening behavior during the heating season by means of window sensors. The results show that the hybrid ventilation system maintains a good level of IAQ while being energy efficient. We also find that occupants’ window-opening behavior is significantly affected by indoor temperature and CO2 concentration. We therefore recommend adopting them as input parameters when designing ventilation control strategies to enhance the performance.