Ventilation

Most buildings on campus have HVAC systems that are designed with air re-circulation. However, considering COVID-19 safety, we have deviated from what the systems are originally designed for and have changed our operations to maximize outside fresh air and minimize return air in all our campus HVAC systems. Where air re-circulation exists, McMaster installed MERV-13 filters and will replace these filters more frequently. Some indoor areas, for example some laboratories, have 100 per cent fresh air as per original design.

McMaster has installed high standard air filters (called MERV-13 air filters) in all buildings where air is recirculated prior to the fall 2022 term. A MERV-13 filter has a higher capture efficiency than a normal filter and can help remove finer particles from the air that recirculates through the system. Filters will also be replaced more frequently.

All McMaster classrooms and lecture halls have been assessed to ensure they meet ventilation requirements as outlined in ASHRAE 62.1. Standard 62.1 outlines minimum ventilation rates and other measures intended to provide indoor air quality that is acceptable to human occupants and that minimize adverse health effects.

Though all of our current operational classroom inventory meets or exceeds Public Health guidelines, McMaster further enhanced our ventilation plan to ensure all lecture theatres and classrooms on campus meet a minimum six equivalent air changes per hour (eACH), a standard considered ideal by Harvard T.H. Chan School of Public Health’s Healthy Buildings for Health guidelines.

This list  indicates which classrooms and lecture halls on campus meet 6 eACH and actions taken. For classrooms do not meet our minimum standard of six equivalent air changes per hour (eACH), McMaster is:

• Changing operations or equipment to increase air flow.
• Equipping the space with appropriate standalone high efficiency particulate air (HEPA) filter units to increase equivalent air changes. The number of HEPA units and sizes were selected for each room in order to meet 6 eACH.

The vast majority of McMaster’s buildings on campus have mechanical heating, ventilation and air conditioning (HVAC) systems. McMaster has created a list of all buildings on campus, indicating if they have mechanical ventilation systems or are naturally ventilated (do not have mechanical ventilation).

There are five out of 56 buildings on campus that do not have a mechanical ventilation system.  There are plans to install standalone high efficiency particulate air (HEPA) filter units in each of these five buildings:

• University Hall (bldg. 1)
• Edwards’ Hall Residence (bldg 5)
• Alumni House (bldg 7)
• Refectory (bldg 4) – 2nd floor only
• Alumni Memorial Hall (bldg 8) – Great Hall (Room 102) and the 2nd floor

Installing standalone high-efficiency particulate air (HEPA) filter units in buildings that do not have a mechanical ventilation system is what the government of Ontario has recommended for learning environments and what ASHRAE has advised for the reopening of colleges and universities.

See the next accordion for more information about installing standalone HEPA filter units in administrative or academic office spaces in the five buildings that are not mechanically ventilated.  

Only offices in the five buildings on campus that do not have mechanical ventilation can be fitted with standalone high-efficiency particulate air (HEPA) filter unit.

Find a full list of campus buildings by ventilation type here.

Supervisors must contact Facility Services by emailing FSUtilitiesClerk@mcmaster.ca to inform them about plans to occupy the offices or meeting spaces in these buildings. Utility Services will then install standalone high efficiency particulate air (HEPA) filter units. Please allow for 10 days for installation in administrative or academic offices in these buildings.