Air quality can affect outcomes

Improved ventilation and air quality in NSW classrooms is needed to meet building standards, with research showing it could improve student health and educational productivity.

A team from the University of NSW’s School of Built Environment found that due to a lack of proper ventilation, concentrations of carbon dioxide (CO₂) in classrooms reached levels that were significantly higher than the 850-ppm threshold prescribed by the National Construction Code.

The UNSW research found that air quality in classrooms was vital to a healthy learning environment.

“Improving indoor thermal and environmental quality is as important as improving the teaching material in the classroom,” the researchers said.

“The study also showed that low ventilation rates raise the concentration of other contaminants in a classroom environment, such as emissions from the building materials and furniture and particulate matter from indoor/outdoor sources. Poor indoor air quality and high indoor air temperatures in classrooms are critical problems worldwide. This is only worsened when ventilation rates are insufficient to remove excessive heat or pollutants.”

The lead author of the study, Associate Lecturer Dr Shamila Haddad, said children are particularly vulnerable to the impacts of poor air quality.

“Poor indoor air quality in classrooms is a critical problem given that students spend a substantial amount of their daytime in the classroom,” Dr Haddad said. “Pollutant exposure during developmental stages may produce lifelong issues such as respiratory infections and upper and lower airways disorders.”

Poor air quality doesn’t just affect student health and wellbeing but also learning capacity through concentration loss, tiredness and fatigue.

“High concentrations of CO₂ released by the occupants of the classroom can lead to fatigue, concentration loss, and poor learning performance. Elevated CO₂ concentrations can cause headache, sleepiness, and tiredness,” Dr Haddad said. “If we want to improve productivity in the classroom, we need to revise the shortcomings of the building itself to enhance health, wellbeing and comfort.

“Improving indoor thermal and environmental quality is as important as improving the teaching material in the classroom.”

Earlier research conducted by UNSW Professor Mat Santamouris found CO₂ levels of up to 4000ppm in classrooms, more than four times the recommended threshold. “Under these conditions, both the teacher and the students are sleepy and tired, and their learning capacity is reduced tremendously,” Professor Santamouris said.

While each state has guidelines for indoor air quality in schools, classroom ventilation typically relies upon natural and manual airing, which is not always possible. However, without adequate ventilation, high concentrations of pollutants build up, and microbes are likely to circulate the environment.

“Adequate ventilation and indoor air quality in classrooms cannot be achieved by split-type air conditioners without the supply of fresh air leading to an accumulation of contaminants,” Dr Haddad said.

“A good ventilation system inside classrooms, on the other hand, can ensure good air quality and thermal comfort, which can enhance learning capacity and also protect students against the transmission of airborne diseases, like COVID-19.”