The Performance Evaluation of Ventilated Windows in the Simultaneous Improvement of Energy Efficiency and Indoor Air Quality in Office Buildings: A Case Study

Energy efficiency and indoor air quality (IAQ) are two crucial required features in a building. Simultaneous improvement of energy efficiency and IAQ in a building can pave the way for obtaining a green building certification. This paper examined the performance of the airflow windows’ supply and exhaust operating modes in energy-saving and providing IAQ criteria. The analytical zonal model coupled with the airflow network model was used to evaluate the system’s thermal performance and the induced airflow. The simulation was done for an office building located in Shiraz, Iran. The results showed that the energy performance of ventilated windows is positive in nine months of the year. Compared to a conventional double-glazed window, the maximum energy savings is about 10%, which occurs in August. It is predicted that using ventilated windows in office buildings in Shiraz can improve the window’s thermal performance by an average of about 5%. The results also showed that ventilated windows could provide the fresh air needed for the building in 250 days of the year to achieve the desired IAQ index (based on ASHRAE 62.1 standard). Furthermore, the effects of glass aspect ratio, airflow channel thickness, and the size of inlet/outlet openings on energy efficiency and IAQ of the suggested window were studied. Results indicated that in the climatic conditions of Shiraz, the exhaust operating mode is much more efficient than the supply mode.