New Zealand research finds poor classroom air quality hinders learning
10 July 2025
Clean air classrooms were in the news last month, courtesy of a new PhD thesis by Massey University graduate Dr Lara Tookey whose experiments demonstrated that students performed better on cognitive tests when their classrooms maintained a comfortable temperature with fresh air and low carbon dioxide levels.
Her research focused on two aspects: temperature and carbon dioxide (CO₂) levels.
“I went to several schools in different parts of the country and at different times of the year to measure these factors. I used special equipment to track temperature and CO₂, and also watched how often windows were opened. I also asked teachers and students about how comfortable they felt in the classrooms. Finally, I tested students' concentration, reasoning and memory using online games and activities,” Dr Tookey explains.
She found that when classrooms were at comfortable temperature, had fresh air and low CO₂ levels, students performed better on cognitive tests. However, when CO₂ levels were high or the temperature was too hot or too cold, students didn't do as well.
“Basically, stuffy and uncomfortable classrooms make it harder for kids to think!”
Some ways schools can create optimal learning environments, according to Dr Tookey’s research, include improving ventilation practices by opening windows regularly, improving insulation to reduce temperature fluctuations, installing effective heating and cooling systems in classrooms and implementing continuous monitoring systems for CO₂ levels and temperature.
Understanding the effects of these simple measures can empower teachers to take immediate action to improve classroom conditions.
Dr Tookey’s research ran over ten years.
Disturbingly, she discovered primary teachers are actually opening windows less often now than they did pre-pandemic, in 2015.
A surprising finding from Dr Tookey’s research was that a 2015 survey of 40 Auckland primary schools found that only 40 per cent of teachers opened windows during winter teaching sessions. A follow-up survey in 2024 revealed a decrease in window opening, with only 30 per cent of Auckland teachers reporting opening windows during teaching sessions across all seasons.
“Another surprising finding was the significant influence of time of day on cognitive performance. Students consistently performed better on cognitive tests in the afternoon compared to earlier in the day. This suggests that scheduling more demanding cognitive tasks for later in the school day could potentially leverage these higher performance levels. However, this needs to be carefully balanced against the potential for increased fatigue later in the day. Thoughtful scheduling that considers both the potential benefits of peak cognitive performance and the risks of student fatigue is crucial for maximising learning effectiveness.”
In response, Aotearoa Covid Action group has set up an ActionStation petition campaign targeting clean air in schools. This calls on the government to prevent the spread of airborne disease in New Zealand schools by, amongst other things:
Ensuring each school and early childcare education centre can monitor air quality; and
Supplying technology to clean the air and reduce viral load.