05/21/2021
By Jean Robinson

To address questions raised regarding the extensive efforts made to mitigate the risk of the spread of COVID-19 through UMass Lowell ventilation systems, answers to frequently asked questions have been posted on the Facilities website and are also listed below. 

What role does HVAC play in the transmission of COVID-19?

The primary means of COVID-19 transmission is through face-to-face contact within six feet for more than 15 minutes. Small respiratory particles suspended in the air are removed by the ventilation system, while larger respiratory particle drop to solid surfaces. To date there have been no documented cases of this virus traveling through the HVAC system to infect a person in a different room. Experts across all industries recommend the wearing of face coverings and social distancing to be the most effective mitigation strategies for reducing the spread of COVID-19. Adjusted ventilation systems to optimize fresh air and exhaust will further dilute the smaller particles for reduced risk of transmission.

Can ventilation eliminate the transmission of COVID-19?

All industry leaders have agreed that ventilation alone will not eliminate the transmission of COVID-19. Rather, ventilation should be viewed as an additional layer to the multiple layers of campus mitigation strategies listed below. 

Is my building ventilated well enough?

Most of the academic and administrative buildings have HVAC systems that either use 100% outside air with no recirculation or are able to adjust to a desired mix of outside/return air. In the latter, we have maximized the outside air with only a small portion of return air used to avoid freezing or overheating of equipment. Buildings without these systems have windows that can be opened. We are currently looking into portable air filters/purifiers for the more heavily used classrooms with natural ventilation.

What steps have been taken to enhance the efficiency of ventilation on campus?

To maximize ventilation effectiveness in all spaces our mechanical department has continuously monitored and followed the guidance from state/local public health agencies including Center for Disease Control, World Health Organization, Occupational Health and Safety Administration, ventilation industry experts (ASHRAE) and infectious disease control industry experts (AHIA and ACGIH). Guidelines are based upon current information and will be updated as advisories are adjusted and information changes. We have implemented the following best practices as recommended by leaders across all industries: 

  • maximize the supply of outside air when the temperature is between 25-80 degrees,
  • maintain minimum outdoor air flow rates by code,
  • upgrade HVAC filters to the highest levels possible, and
  • flush buildings two hours before and after occupancy to exchange all air with fresh air.

Can UML increase the air-exchange rate in offices and other rooms?

Air exchange rates are governed by ASHRAE standards. Increasing airflow beyond system designs can damage equipment.

Was the HVAC system shut down in unoccupied areas?

Despite low occupancy in some areas across campus, all ventilation systems remained operable and well maintained. In those areas of low occupancy, the ventilation systems continued to operate in an “unoccupied” mode which reduces airflow and temperature settings without shutting down the system. As UML resumes normal operations, the ventilation systems will be adjusted to normal occupancy. All systems will be flushed two hours before and after occupancy to purge potential contaminants suspended in the air. Laboratories that require constant ventilation may continue to operate at a reduced air flow during unoccupied modes (4 ACH).

What temperature and humidity set points are needed to reduce the risks of COVID-19?

It remains unproven that changing the temperature and relative humidity of a space will have a measured reduction of risk for the transmission of COVID-19. To maximize the outside air and minimize recirculated air in buildings temperature set points in the summer are set at 77 degrees and during the winter at 68 degrees. During power savings curtailments the temperature settings are adjusted to achieve the desired results.

How does room density reduce the potential spread of COVID-19?

By reducing the density of a room below its original occupancy limits there is more fresh air and less potential contaminants to be shared between people. This is referred to as the dilution rate and is an effective way of reducing risk. The most effective strategy remains for all people to wear face coverings to significantly reduce the respiratory particles released into the air.

Is the University going to install enhanced ventilation in classrooms?

The university currently maintains the highest rated filters available in each building system. To support an anticipated increase in density during the fall semester, we are currently reviewing options to install enhanced filtration in some areas and classrooms.