In response to COVID-19, health experts, including those at the Centers for Disease Control and Prevention (CDC), have made recommendations to higher education on indoor air circulation and ventilation, as well as guidelines about fans, filters, and other equipment needed to meet new standards for reducing exposure to infection.
Based on this guidance, University Facilities and Services has been working this summer and into the fall to evaluate and update the air circulation in residential, administrative, and academic buildings on River Campus and at the Eastman School of Music, making improvements for occupant comfort and safety.
The team identified the HVAC (heating ventilating and air conditioning) requirements for facilities as identified by the CDC and has been using the guidance for institutions of higher education and office buildings.
Specifically, the team worked to:
- Increase total airflow supply to occupied spaces, wherever possible, and ensure ventilation systems are operating properly.
- Use natural ventilation (i.e., opening windows if possible and safe to do so) to increase outdoor air dilution of indoor air when environmental conditions and building requirements allow.
- Increase the percentage of outdoor air entering buildings (e.g., using economizer modes of HVAC operations), potentially as high as 100 percent.
- Disable demand-control ventilation (DCV) controls, including economizers, which are used to reduce ventilation air based on CO2, temperature, or occupancy. Since the CDC’s guidance is to increase outside air volume to the greatest extent possible, the HVAC systems were modified to allow the systems to run continuously (on a 24-hour schedule) and increase the percent of outside air brought indoors. This change increases energy costs, but maximizes the amount of ventilation air into the buildings, thereby increasing the number of outside air changes before, during, and after building occupancy.
- Increase air filtration to as high a volume as possible (MERV 13 or 14) without significantly diminishing design airflow.
The team also worked closely with University research leaders to ensure that no air circulation adjustments take place in any building where research is performed, without formal approval.
Additionally, experts agree that fans placed inside open windows can increase fresh airflow into interior spaces. Therefore, Facilities installed fans in many classroom windows in order to maximize dilution ventilation. Where possible, instructors and staff have been asked to open windows at each end of the room, turn on the fan, and keep the door to the hallway closed—signage with these instructions is in close proximity to each fan.
All of these strategies for maximizing fresh air in indoor spaces will be adjusted for each building this fall and winter to ensure that the incoming air temperatures are not so low that they cause freezing in the systems. A few of the older buildings do not have controls that allow for adjustments to the outside air volume. Therefore, it is important that all faculty, staff, and students follow the CDC and New York State recommendations to reduce exposure to COVID-19, including wearing a mask, washing hands frequently, and maintaining a physical distance of six feet.
If University community members have any questions about indoor air circulation on campus, they can be directed to FacCust@facilities.rochester.edu.