23 Oct 2021

Niwa working with Education Ministry to monitor CO2 in classrooms

8:10 pm on 23 October 2021

Air quality experts are working with officials on rolling out carbon dioxide monitoring in classrooms to help counter the threat of Covid-19.

Side view portrait of young man wearing mask while taking test or exam in school with diverse group of people, copy space

Photo: 123rf

Many classrooms have poor ventilation and when crowded could cause virus transmission.

The Education Ministry's main advice to schools is to keep their windows open as much as possible to allow fresh air to circulate.

Niwa said it was handy that it was warm enough to do that now. But it is advising the ministry on the options for winter.

Niwa principal air quality scientist Ian Longley said it was also working with the ministry on a plan to roll out more CO2 monitoring with strong safeguards around the data.

"What we want to avoid is really sort of rogue, poor quality instruments being brought into schools that are giving inaccurate data and leading to poor decision making."

The ministry was "in a big rush to get something out", Longley said.

Niwa had years of experience monitoring the air in schools and homes.

The ministry went to Niwa two weeks ago, and sought advice from other experts this past week, though measures to combat Covid at schools using ventilation or air purifiers have been debated internationally for the past year.

"Uncoordinated ad hoc monitoring could cause more problems than it solves by raising fears and causing panic," Longley said.

Outside CO2 levels sit at about 410 parts per million (ppm), while the current indoor standard is 1500 ppm. International studies show to reduce the risk of Covid-19 transmission, getting under 800 ppm is ideal.

While the air monitors might be a few hundred dollars, systematic monitoring that was consistent between schools and classrooms was crucial, Longley said.

"And it's how the data is going to be acted on. If you have a particularly high level of CO2, what is the school supposed to do about it?"

This required guidelines from the ministry, he said.

Opening windows and doors could be effective, he added.

"We are lucky it is spring now. Winter will be much more challenging and solutions are not simple."

Inexpensive innovations in much-colder Germany have included using simple plastic pipes above each desk, attached to a fan, that required occasional venting by opening a window.

The work being done in schools could be applied to other buildings like offices, Longley said.

The Education Ministry said in a statement that it is considering the use of air monitoring and treatment in classrooms.

"Niwa, who are a part of the advisory panel have also offered to use their sensors to collect CO2 data from a number of classrooms and from that model some ventilation options for us to consider," it said.

The ministry said no decisions have been made about the next steps yet, but advised it would keep the education sector updated.

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