FAQs about Heating, Ventilation and Air Conditioning (HVAC) Systems
As preparations for the fall 2020 semester are underway and campus buildings reopen, the facilities department has issued answers to frequently asked questions regarding HVAC systems, in light of the COVID-19 pandemic. The FAQs address how HVAC systems work and measures being taken to reduce COVID-19 transmission through those systems.
Those FAQs are as follows:
What COVID-19 related guidelines are utilized to determine best practices for HVAC?
UMass Amherst is utilizing COIVD-19 related guidelines developed by the Centers for Disease Control and Prevention (DCD) and American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) to inform HVAC-related measures on campus.
How do HVAC systems work in campus buildings?
Air is mechanically supplied to building spaces by air handler units or by natural ventilation (open windows). Air handlers serving laboratory buildings provide 100 percent outside air. This means that all of the air delivered to the space from the air handler comes directly from outside and is 100 percent exhausted, with no recirculation. Many non-lab buildings recirculate a portion of the air from the space and mix it with a portion of outdoor air. In these buildings, the campus will optimize the system to bring in maximum fresh air, whenever possible, and exhaust it entirely.
What measures are being taken to reduce COVID-19 transmission through the university’s heating, air conditioning and ventilation (HVAC) systems?
Air handler units will maximize outside air into the system to flush the building two hours prior to occupancy and again for two hours after scheduled occupancy. Air handlers will increase air flow rates as much as possible during occupancy given equipment and ambient temperature and humidity conditions. The campus is also implementing reduced public health occupancy limits for spaces. This will allow more outside air available per occupant.
HVAC air filtration is rated by Minimum Efficiency Reporting Values, known as MERV ratings. ASHRAE recommends filters with MERV13 rating or higher as part of their COVID-19 guidelines. UMass is utilizing MERV13 and MERV14 rated filters.
Spaces with more limited or no mechanical ventilation will have operable windows left open.
Facilities maintenance staff continue to perform scheduled preventive maintenance on HVAC systems.
The campus also continues to maintain reduced levels of density of persons in spaces, requires face coverings and social distancing in buildings.
What other measures are being taken in face-to-face instructional locations?
Class lab spaces will have increased air changes per hour during occupancy, which will increase the amount of outdoor air exchange, and there will be two hour pre- and post-occupancy flushes of the buildings.
HVAC systems in non-lab spaces vary by building. During classes, the HVAC system will maximize the amount of fresh air that the system can deliver to and from the space, and there will be two hour pre- and post- occupancy flushes of the buildings. For limited spaces with no mechanical ventilation, the windows can remain open.
How do I report stagnant conditions in my classroom or office building?
For all academic and administrative spaces, you can contact the Facilities Solutions Center at 413-545-6401.