To meet new health and safety guidelines, the University of Waterloo’s mechanical design teams and trade staff have been inspecting the heating, ventilation and air conditioning (HVAC) units on campus over the past year. The school reports that retrofits were made to support higher levels of filtration and reprogram building automation systems.
“We’ve had more than 350 trades, custodial and grounds staff on our campuses daily to ensure that our campus spaces remain safe and functional,” Stepanka Elias, executive director of plant operations, said in a recent media release from the university. “Buildings require a lot of upkeep whether people are in them or not, from temperature control and ventilation to electrical and plumbing.
“Based on the advice of public health officials and other professional associations, we’ve been modifying cleaning priorities, making upgrades to our HVAC systems and focusing on preventative maintenance measures.”
Waterloo’s campuses have 63 major buildings with 398 HVAC units, supporting a variety of research, teaching and staff and student activities. Since November 2020, every building has been retrofitted to accommodate MERV13 filters. MERV13 filters are recommended by the American Society of Heating, Refrigeration and Air-Conditioning Engineers and over the pandemic have become standard across the industry because they are more effective at filtering small droplets and particles that travel through the air (at least 85 per cent efficient at capturing particles in the 1 µm to 3 µm size range).
Elias said that MERV14 may provide slightly better performance, but are physically too large for the school’s ventilation systems. HEPA filters, although very efficient, may strain ventilation systems and reduce air flow.
Air exchange rates in campus buildings vary, for example, wet science and engineering labs are typically supplied with 100 per cent outside air and have high air exchange rates to limit exposure to various chemical and biological agents. This makes lab environments inherently safe when it comes to filtration of virus particles. Other spaces such as dry labs and classrooms have been designed with comfort in mind and therefore have lower air exchange rates. The mechanical engineering team is reviewing the air flow for all classrooms in preparation for fall.
“Everybody has worked hard through the stress of the pandemic and many employees have taken on new COVID-related tasks” said Elias. “There’s a feeling of UWaterloo pride and community spirit as we all band together to maintain our campuses, keep people safe and prepare for the gradual return of our students, faculty and staff in the fall.”