By Anonymous
Air infiltration (air leakages) is one of the leading causes of building energy losses, and the building sector was reported to consume more than 40% of the primary energy use in the United States (Goubran et al. 2018). Reducing energy usage of buildings has become a key achievement for nationwide energy savings. George Mason University has stated that academic buildings account for 40% of energy usage and spend close to $10 million in energy costs per year. Air conditioning is one of the largest contributors to the building’s total power consumption and it has been observed that the entrance(s) of these buildings play a significant role in energy consumption (Wang et al 2014).
George Mason University has multiple doors to each building and high door-usage frequencies which could cause large amounts of infiltration further increasing energy consumption. The Planetary Hall Building (alike other GMU buildings) has vestibule doors built for reducing energy loss. Vestibule doors have become a requirement in climate zones 3-8, minimizing energy loss (Strongin et al. 2021). In addition, vestibule could cost anywhere from $20,000 to $60,000 (Juszczak 2020). And are ineffective when both entrance doors open simultaneously during heavy traffic periods to allow cold outdoor air to penetrate (Wang, 2014).
To reduce infiltration through building entrances, an air curtain is an ideal solution compared to vestibule doors or single doors. Air curtain consists of a fan and casement with a jet outlet, the unit is often mounted above the doorway at a typical velocity and position for creating a seal of air. The effectiveness of an air curtain is 62% of the annual total air filtration in comparison to vestibule doors reducing 23% (Wang, 2014). The costs are often less than $6,000 and uses much less material in comparison to vestibule doors.
Thus, solutions for new George Mason University academic buildings would be to forget vestibule doors and install air doors. Added benefits prevent contaminants such as bugs, dirt, and debris from entering the indoor environment.
There is a prototype for energy harvesting from hinged doors that would supply the energy consumption of the air curtain. Applying a small battery to harvest energy from the frequencies of students opening and closing the doors (Dayal et al. 2017).
References
Dayal, V., & Lee, S. (2017). Air Curtain Development: An energy harvesting solution for hinged doors. SPIE Proceedings. https://doi.org/10.1117/12.2260157
Energy and buildings FAQ. University Sustainability. (n.d.). Retrieved November 9, 2022, from https://green.gmu.edu/energy-and-buildings-faq/
Goubran, Qi, D., & Wang, L. (Leon). (2018). Airflow and Energy Simulations to Assess Energy Savings from Vestibules and Air Curtains. ASHRAE TRANSACTIONS 2018, VOL 124, PT 2, 124(2), 79–91.
Juszczak, K. (2020, May 15). Air Curtains save more energy. Berner. Retrieved November 9, 2022, from https://berner.com/news/air-curtains-save-energy/
Strongin, A. S., & Zhivov, A. M. (2021). Energy Efficient Air Curtains for industrial gates in cold climates. E3S Web of Conferences, 246, 08005. https://doi.org/10.1051/e3sconf/202124608005
Wang, L. (Leon). (2018). Investigation of the Impact of Building Entrance Air Curtain on Whole Building Energy Use Executive Summary.