Ventilation and filtration practices during COVID-19

In 2020 as a result of the pandemic, Metropolitan State University reviewed and implemented ventilation strategies in accordance with CDC guidelines. This included flushing buildings with fresh air for extended operating hours. he buildings are ventilated for two hours prior and after normal occupied hours with fresh air.

Filtration ratings and preventative maintenance schedules were reviewed and existing maintenance practices confirmed. Filtration levels in our St Paul campus buildings are at recommended levels.

Additionally, we conducted an independent mechanical review by TKDA engineering to document ventilation in spaces and review air handling practices, outdoor airflow rates and occupant density in campus spaces. The engineering review used Minnesota Mechanical code and ASHRAE Standard 62.1 Ventilation for Acceptable Indoor Air Quality standards for specifying the minimum outdoor air (ventilation) rates of circulation through various occupancy classifications. The review included guidance for SARS-COV-2 which addressed transmission through the air of various pathogens in office and education environments.

Five site visits to document building automation system values and filtration levels were conducted. Two site visits to verify missing information on existing conditions and use of spaces. These site visits included the St Paul campus buildings, Midway Technology Center and the Dental Clinic.

The Minneapolis College (Old and New Harmon) office and classroom spaces were not included in this mechanical assessment. That building is planned for extensive renovation as part of a Capital bonding initiative. Design work is beginning in summer 2021 for this project. Construction work which includes extensive HVAC and electrical work as well as interior spaces renovation is scheduled to begin in late summer 2022.

• Test and balancing at MSU owned facilities should focus on increasing minimum ventilation rates during heating season, specifically in Variable Air Volume HVAC systems. This is the biggest opportunity for improvement. (Work to adjust building controls systems to increase fresh air supply during winter season will be completed this fall).
• Overall, mechanical ventilation systems maintained by MSU full-time facilities staff are in excellent working condition and regular maintenance efforts and system upkeep is commendable. Filters have been upgraded to meet current MERV rating recommendations.
• Midway’s ventilation systems are currently undergoing a renovation from pneumatic controls to Direct Digital Controls (DDC). Select HVAC zones with updated controls were identified by MSU for ventilation and airflow verification. Campus Operations staff is meeting with the landlord to obtain confirmation of code compliance and get regular updates on progress towards completing the mechanical work.
• The Dental clinic space had lower levels of minimum air supply levels in the space than would be recommended. Filtration levels for the building are MERV 8. A recommendation to add larger commercial grade HEPA filtration units in this space is recommended to provide air cleansing in this clinical space. Staff is working on sizing and purchasing equipment is in progress.