How important is good air quality?

Teachers' refusal to work highlights issue, expert reveals what technologies are most effective

How important is good air quality?

COVID-19 has changed the world in the past couple of years, and we’re still dealing with the health crisis. But it did shine a lot on the quality of air people breathe at the workplace.

“The COVID 19 virus, prior to that, people had some idea as to air ventilation and systems and fresh air supply into buildings, but there wasn't a lot of attention to it,” Konrad Seemann, of PL Energy Services, told Canadian Occupational Safety (COS).

“Now, there is a lot of attention on the air quality in buildings, because they realize there's a direct relation between the air quality in the building and health of its occupants. And so, because of this, there's been a lot of movement in this industry.”

Read more: Air quality huge concern among employees returning to work

While a lot of workers in different industries are concerned about the virus, teachers in schools were among the most vocal. For the week of January 17 this year alone, there were 11 documented work refusals in Ontario’s education sector, according to the Labour Ministry. Maintaining good air quality in schools is vital, said Seemann.

“In school settings, it's really important because we have large concentrations of people in those rooms. [It’s really important] for us to be looking at how can we effectively deactivate bacteria or any viruses that are moving through our air handling system, so that we're sure that the air that we're providing to the space is the best quality possible.”

HVAC systems

In a ventilation system, there's a certain amount of air that gets pulled back from the various spaces in the building, that goes through an air filtration, and then a heating or cooling coil, and that’s then redistributed into the building, explains Seemann.

However, some air quality managers are just using the wrong technology at times, he says.

“Early on… most people were installing MERV 8 filters which aren’t as effective at stopping bacteria or sneeze nuclide. So, when those systems pull back from a space that may have sneeze nuclide from someone that’s sick, there’s potential for that to be redistributed into the air system throughout the building and possibly infect people or possibly cause issues because of low air quality.”

Read more: Some teachers refusing to work because of COVID-19 concerns

Handling air quality in a school setup, said Seemann, is pretty much similar to handling it in an office setup.

“The same types of methods of filtering that air are going to work in the various scenarios,” he said.

And there are technologies that people can turn to, he said, with UV lighting being one of them. “UVC wavelength is able to attack the microorganisms on a molecular level, deactivating and destroying the contaminants in the air.”

MERV 13 or higher filters are also able to filter down to the 0.3 to one micron particle size, “which allows it to remove the various dusts, bacteria, sneeze nuclide out of that air distribution system.”

And maintaining the amount of fresh air. “It's important to measure the CO2 level and CO2, it's a good measure in a building as to when additional fresh air needs to be supplied to the space. So, typically, we're trying to keep CO2 levels in a space around 800 parts per million or less.”

Read more: Return to Work: Why employers must ensure high air quality


Air quality managers, however, must also not forget to observe proper maintenance of these technologies. Air filters, Seemann said, must typically be replaced quarterly, for example.

“One of the measures that they've done before with air filters is how much airflow are you getting across that filter. And when that air filter starts to become plugged, that's when it's time to change.

“When you get to the MERV 13 level filters, you are filtering down to a much higher level, so it's catching a lot more in the air. Meaning that replacements of those filters are going to have to happen more frequently. And typically, that's happening right now on a quarterly basis.”

This however, still depends on a lot of factors, he said.

Building occupants

Maintaining air quality is really the job of air quality manager, building managers and employers. But workers can also do their part.

“Keeping your workspace clean of dust, dirt and debris is one method” that workers can help with, said Seemann. Raising concerns is another.

“As an individual that's working at your desk in the space, there's not a ton that you can do to change the air that's coming out of the diffuser in the ceiling above you. But again, bringing that to the attention of the people that are operating your building… and asking the questions [about] what are we doing in the building to address these issues [is important]. It's really key that these conversations happen because these conversations are what drives the industry to move in those directions.”