By Jean Robinson

In just a few weeks faculty and staff will begin returning to campus for the fall semester. As part of our planning I would like to provide an update on steps that have been taken to maximize the effectiveness of the building ventilation systems as one of several COVID-19 mitigation strategies for our campus.

Our partners in Environmental Health & Safety, Emergency Management, and Health and Wellness continue to constantly monitor guidance from the CDC and the Mass. Department of Public Health while our facilities department stays on top of best practices from ventilation and infectious disease leaders. Across the board, industry leaders and public health experts have reinforced that no single mitigation strategy, including ventilation, can eliminate COVID-19. The best strategy is a multi-layered approach, just as we have adopted at UML.

The university’s multi-layered approach for mitigating risk includes mandatory vaccinations and face coverings, daily self-health assessments and surveillance testing for asymptomatic faculty, staff and students that have a medical or religious exemption from receiving the vaccine. These mitigation strategies, in combination with the proactive steps we have taken to optimize our building ventilation systems as described below, will help us maintain the vibrant campus our UMass Lowell community deserves.

Below is a short list of FAQ we have compiled in response to recent questions about ventilation. A complete list of these and other facilities related questions can be found on the Facilities website. Welcome back and know your Facilities team is here to do our part in making this a successful semester.

Q: What role does the HVAC system play in the transmission of COVID-19?
A: 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 particles 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 and there is very low risk of surface transmission. Likewise, there has been little evidence of viral transmission from surface transmission. We have adjusted ventilation systems to optimize fresh air and exhaust to further dilute the smaller particles for reduced risk of transmission. Experts across all industries recommend vaccination and the wearing of face coverings to be the most effective mitigation strategies for reducing the spread of COVID-19.

Q: Is my building ventilated well enough?
A: Most of the academic and administrative buildings have HVAC systems that either use 100% outside air with no recirculation or are able to be adjusted to a desired mix of outside/return air. 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 have also upgraded air handler filters to the highest level possible. Classrooms with natural ventilation or cabinet unit ventilators are being equipped with additional HEPA filters for enhanced ventilation.

Q: What steps have been taken to enhance the efficiency of ventilation on campus?
A: To maximize ventilation effectiveness in all spaces, our mechanical department has continuously monitored and followed the guidance from state/local public health agencies including CDC, WHO, OSHA, 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:

  • maximized the supply of outside air when the temperature is between 25-80 degrees
  • maintained minimum outdoor air flow rates by code
  • upgraded HVAC filters to the highest levels possible
  • flushed buildings 2 hours before and after occupancy to exchange all air with fresh air
  • installed portable HEPA filters in classrooms where recommended by industry guidance

Q: Can UML increase the air-exchange rate and amount of fresh air introduced in offices and other rooms?
A: Air exchange rates are governed by ASHRAE standards and have been set to the maximum allowable rate per equipment specifications. Increasing airflow beyond system designs can damage equipment. UML has evaluated and adjusted the settings for ventilation systems to ensure that the maximum amount of fresh air is introduced into all spaces in compliance with Massachusetts Building code and the ASHRAE Standard 62.1 (Ventilation for Acceptable Indoor Air Quality) to optimize our building systems. This will improve general indoor air quality by reducing the amount of carbon dioxide and other internal air pollutants in supply air.

Q: What type of ventilation do I have in my building?
A: UMass Lowell has six different types of mechanical systems used to provide ventilation in our buildings. Many of our buildings use multiple systems in different sections of the building, which makes it difficult to categorize each building into a single ventilation type. The Facilities department has used automated controls, when available, and the most efficient filtration available to optimize ventilation in each building. The six types of ventilation used on our campus are:

  • 100% Outside Air: Ventilation is supplied by a mechanical air handling unit using only outside air. This system is not designed to recirculate return air within a space.
  • Outside Air/Return Air Mix: The air source for ventilation can be controlled and balanced between outside air and return air. The system is set to draw 100% outside air when air temperatures are between 25 and 85 degrees Fahrenheit, with modest return air added outside this range to prevent freezing or overheating
  • Cabinet Unit Ventilation: This ventilation equipment is located inside each room and cannot transfer air between rooms. The ventilation unit balances a combination of outside air and return air in a manner similar to the Outside Air/Return Air Mix in centralized systems.
  • AHU split systems: These are air handlers that use a fixed Outside Air percentage and use return air to balance the ventilation in given space.
  • PTAC units: This ventilation equipment is located inside each room and cannot transfer air between rooms. Windows and a small damper provide the ventilation source for these rooms.
  • Window Ventilation: The only source of ventilation in these spaces is from outside air coming in from windows. This system does not transfer air between rooms and is not supplemented by any mechanical ventilation.

Q: Is the university planning to install enhanced ventilation in buildings?
A: The university has upgraded the filters in all centrally controlled ventilation systems to the highest level possible. In addition, we are installing portable HEPA filters for enhanced ventilation in classrooms with PTAC units and/or window ventilation as recommended by industry guidance.

The university prohibits personal HEPA air purifiers as a COVID risk mitigation strategy unless reviewed and approved by EHS/EOO. If you wish to request a reasonable accommodation for your health-related conditions, please contact Equal Opportunity and Outreach at 978-934-3565.