Air Handling and Ventilation in CLAS Buildings

To: Departmental Executive Officers
From: Joshua Weiner, Associate Dean for Research
RE: Air Handling and Ventilation in CLAS Buildings

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I know that many faculty are concerned about air handling in the buildings in which they work and teach, especially about the possibility that viral particles could be transmitted through a building’s air handling unit (AHU). The UI’s Steps Forward document contains a section on ventilation that lists steps Facilities Management will take to ensure that our AHUs are functioning optimally so that risks are reduced. Given faculty concerns, CLAS Facilities director Eugene Buck and I recently met with FM personnel to get details. I am summarizing what we learned here, and I hope this extra information will be useful to you and any of your faculty who may have concerns.

  • CIMT had a ventilation sub-committee that featured an Engineering professor and student, a professor from Public Health, a representative from EHS, and 4 members of FM. They worked out the steps to take and consulted information from sources such as the CDC and ASHRAE, the industry group for air handling.
  • FM are making classrooms their #1 priority to ensure safety during instruction.
  • They are assessing every AHU on campus on a 6 point scale based on ASHRAE guidelines for factors protective against COVID-19 transmission. I saw an example of the checklist for a building where an FM employee assessed whether filters were properly installed and clean, air intakes were not blocked, system was operating within guidelines, etc.
  • Most buildings have had filters with a MERV rating of 8. This is a common industry standard, and is estimated to block 40% of viral particles in air. The new ASHRAE recommendation against COVID-19 is a MERV rating of 13, which blocks 70% of viral particles. This is what UIHC uses, and there has been no transmission through AHUs there.  FM got approval June 26 to purchase and install MERV 13 filters in all buildings where the AHUs can handle it (there may be a very few buildings that can’t because the better filter slows air flow too much). I did ask, and buildings of concern such as EPB and MLH should be able to handle MERV 13 filters.
  • They are examining every AHU for the extent to which they can increase fresh air vs. recirculation. In all cases where fresh air intake can be increased it will be.
  • In several older buildings they are conducting experiments to measure and ensure that the proper volume of air is being exchanged in a given amount of time.
  • Every morning, FM staff analyze overnight data from a fault dynamics system with 90,000 data points taken at 5 minute intervals to ensure all AHUs are functioning within guidelines.
  • Finally, at FM@YourService, they will soon be adding a “COVID-19” button that will lead to FAQ’s specifically related to preventing viral transmission and through which you can ask COVID-related questions. As always, questions related to building ventilation should be addressed directly to FM through this portal. Should you not quickly receive an answer, Eugene Buck and I stand ready to help as intermediaries on behalf of CLAS.