As campus reopened to faculty, students and staff, there are questions about the role of building heating, ventilating (HVAC) and air-conditioning systems in either promoting transmission of the COVID-19 virus, or whether certain equipment, when added to HVAC systems, might help reduce transmission of the virus.
HVAC Operations Plans
The campus should be aware that Facilities Heating Ventilation and Air Conditioning engineers and operating staff strictly follow industry best practices, and will stay up-to-date on new developments with HVAC operations for the duration of this pandemic. However, social distancing, wearing of face masks and the use of recommended disinfection and hygiene practices, will remain by far, the most effective means for reducing risk of contracting or transmitting the virus.
Plan of Action
Early summer 2020, a committee was formed to develop an HVAC operation plan for campus as more information was provided from the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), Centers for Disease Control and Prevention and other resources on the concern for droplet and aerosol spread of COVID-19. The committee was made up of licensed professional engineers, the university’s HVAC foreman, safety and industrial hygienists, and a virologist researcher from the Department of Animal, Dairy & Veterinary Sciences.
The plan of action the committee came up with for the campus HVAC systems are as follows:
- Identify classrooms that have limited ventilation and use alternate resources for these classes.
- In classroom laboratory spaces with limited ventilation that cannot be relocated, provide HEPA air scrubbers in the space.
- Filtration efficiencies to exceed MERV 13 in fan systems where possible.
- Regular inspection of filters and outside air control equipment.
- Operate ventilation fan systems two hours after and two hours prior to occupancy for post- and pre-purge of building air.
- Dedicate outside air systems and systems without economizer and the capability of bringing in large volumes of air will be run 24/7.
- Increase outdoor ventilation to amounts that systems have capacity to maintain comfort in occupied spaces.
- Increase zone level air flows in areas with potential for high viral load (music practice rooms and etc.).
- Eliminate seating or waiting areas adjacent to or in the return path of large common areas (library, fieldhouse, etc.).
- Evaluated filter efficiencies across campus and identified systems capable and in need of improved filtration. MERV 13 filters were ordered and will be installed upon arrival.
- Preliminary testing of the operation of outside and return air dampers completed. This will be done on a regular and ongoing basis.
- Testing of air flow measuring stations and CO2 sensors has begun.
- Procurement of air scrubbers has taken place. Equipment scheduled to be delivered.
- Preparation being made to adjust ventilation rates and fan schedules across campus for campus re-population.
- COVID-19 may be transmitted between humans through three primary methods: via droplets containing the virus, through much smaller particles that can become airborne when suspended within an aerosol, or surface contact. The extent of which each of these three methods of transmission is still being investigated.
- The Center for Disease Control and Prevention (CDC) states that heavier virus-containing droplets, which are transmitted directly from one source to another, is the primary means for transmitting the virus. For more information on how the virus spreads, please click here.
- As larger droplets do not remain suspended in air for long periods of time, social distancing, masks, disinfection and good hygiene remain the primary defense for mitigating virus transmission.
- While the role of aerosol transmission of the virus is under debate, such transmission is known to be possible. However, aerosol transmission is generally not believed to be a major driver in the transmission of the virus.
- Because of the large distances that recirculated air travels in a building HVAC system, and with filtering of recirculated air, transmission of the virus from the larger and heavier droplets via HVAC is considered unlikely.
- The possibility of viral transmission from recirculating a small quantity of aerosol containing the COVID-19 virus through the HVAC system is considered less likely due to dilution and reduction in infectivity of the virus.
- While it cannot be discounted that an HVAC system can move virus-containing particles around within a room or building, the system does not appear to increase the risks of transmission beyond that of a failure to follow the recommended practices of social distancing, wearing of a mask, disinfection and good hygiene.
- While there are a number of filtering and disinfecting HVAC devices currently sold that are being represented as a means to mitigate COVID-19 transmission, none are presently being recommended under industry best-practices.
- Please keep in mind that information pertaining to COVID-19 transmission is continually changing. Please be assured that the Facilities department is monitoring and acting on developments regarding industry-best practices in the operations of HVAC systems throughout campus.
- The Facilities HVAC team is placing more effort than ever before to ensure HVAC ventilation systems are working properly, the most efficiency filtering possible is in place and in good condition, that more fresh air is being brought into buildings and HVAC systems are being operated in a manner to help mitigate the spread of COVID-19. All of these efforts are being done to ensure that those who work, study and visit our campus stay healthy and safe.
Do Your Part
While the Facilities HVAC team is following the recommended measures from the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) and CDC in how we operate and maintain our HVAC systems during this pandemic, these measures cannot compensate for the lack of individual responsibility to reduce the spread. The most effective way to reduce the spread is through mask wearing, social distancing, hygiene and following the other CDC and USU guidance while on campus, and while participating in other activities throughout the community.
Report Testing, Isolation, and Quarantine
If you have been tested for COVID-19 or asked to self-isolate or quarantine, please fill out the self-isolation questionnaire.