Ventilation is one of many strategies that can be used to mitigate the spread of COVID-19. UC Berkeley is complying with all applicable guidelines and recommendations regarding the use of ventilation during the pandemic. In accordance with CDC recommendations and Cal/OSHA guidelines, the following measures have been taken:

  • Buildings with mechanical ventilation systems have been configured to maximize the introduction of outside air and to minimize recirculation of inside air.
  • Instructors are encouraged to open windows in rooms without mechanical ventilation and the ability to open windows is being assessed in rooms where this functionality has been disabled.
  • Facilities Services has been performing additional maintenance and repairs and has increased staffing to be able to more quickly respond to any problems that may arise.
  • Engineers have been reviewing building systems and identifying measures to improve performance.
  • Demand-controlled ventilation systems that reduce air supply based on occupancy or temperature during occupied hours have been overridden where possible to maximize the flow of air.
  • Filters are being inspected and maintained to ensure optimal performance and maximum MERV rating allowed by the building’s HVAC system.

After thorough analysis, the campus has decided to not move forward with some ventilation-related strategies:

  • Placing fans in rooms to increase airflow. Improperly placed fans may create undesirable airflow within a room — possibly increasing the risk of transmission.
  • The use of portable high-efficiency particulate air (HEPA) fan/filtration systems.  A number of concerns were reviewed, including proper positioning of the unit within shared spaces to maximize effectiveness and reduce the risk of increased transmission, noise levels, ability to maintain filters, and stresses on a building’s electrical systems that weren’t designed to support a large number of HEPA filter units. While HEPA filters can be an effective strategy to reduce airborne spread of the coronavirus in some situations, UC Berkeley is not currently in a position to support the maintenance of a large number of portable HEPA filter units across campus.  EH&S and Facilities Services are working collaboratively to prioritize the use of portable HEPA filter units and to identify rooms where this type of intervention may be appropriate while accommodating the aforementioned concerns.

There is currently no public health guidance to suggest that in-person instruction should be curtailed as long as we are following CDC, CDPH, and Cal/OSHA guidelines for ventilation, which we are. As is the case with some other COVID-19 mitigation strategies such as social distancing, it would not be possible to return to primarily in-person instruction while only using buildings equipped with the most modern ventilation systems. The Public Health Committee has determined that vaccination is the best way for members of the campus community to protect themselves and prevent the spread of COVID-19. This is why the campus has prioritized its vaccination efforts and is requiring vaccination of all students, staff and faculty. The campus has been incredibly successful in this effort, achieving a greater than 90% vaccination rate prior to the start of instruction for the fall 2021 semester. The second most effective strategy is face coverings. In response to the increased transmissibility of the delta variant, the city of Berkeley imposed an indoor face-covering mandate in August 2021. The campus will continue to comply with any applicable face-covering mandates. The campus is also requiring testing for certain groups and will continue to assess other mitigation strategies. The Public Health Committee has determined that UC Berkeley’s incredibly high vaccination rate combined with the city of Berkeley’s indoor face-covering mandate minimizes the need for additional mitigation measures. Where feasible, UC Berkeley will continue to prioritize ventilation improvements and encourages outdoor activities over indoor activities whenever possible.


To report a possible ventilation issue, please contact EH&S or by phone 510-642-3073.