The Climate Council recently released The Angriest Summer, a report that named the summer of 2018/19 as “the hottest summer on record”, characterised by “prolonged, continental-wide heaves and record hot days, bushfires throughout Australia and heavy rainfall and flooding in northern Queensland”.   

According to the report, in just 90 days, more than 206 records were broken around Australia, reaching the record-highest summer temperature in 87 locations, topping out at Port Augusta in South Australia with a sweltering 49.5°C on 24 January.

With Australia set to have a warmer than average Autumn this year, it is widely accepted that changes in climate patterns are set to continue. These statistics raise questions as to whether current design guidelines will need to be reviewed to capture the change in climate. According to the Bureau of Meteorology, the mean surface air temperature in Australia has increased by around 1°C since 1910 with most of this increase occurring since 1950. 

Overheating in schools

Incidentally, some schools have become prone to overheating and a recent review of the NSW Department of Education Air Cooling Policy conducted by Steensen Varming for School Infrastructure NSW indicated excessive temperatures have a detrimental impact on cognitive function and student performance in learning environments. 

Working closely with the University of Sydney’s Professor Richard de Dear, who holds a PhD in Climatology, the review led to the development of the new Thermal Comfort and Indoor Air Quality Policy, underpinning the Cooler Classrooms Programme which is already underway, and pointing toward a holistic approach to healthy environmental conditions, for now and in the future.

“The change in focus from just air conditioning in classrooms to improved thermal comfort and indoor air quality is an important step forward in government policy,” says Chris Arkins, director at Steensen Varming.

“To deliver sustainable schools which provide better learning environments is a great platform for students to embrace and learn sustainable habits.”

The effect of learning environments on cognitive performance is best measured by Cognitive Load Theory, comprising both ‘long term memory’ and ‘working memory’ (which is limited in capacity).

When dealing with novel information, limited working memory resources often fail to meet the demands of complex tasks, but once the new information has been assimilated in the long-term memory, the constraints of the working memory are eliminated. 

Previous studies have found the learning environment, including thermal comfort and indoor air quality, is one of several challenges to working memory availability.

The effect of heat on learning

The influence of moderately elevated temperatures on student performance was investigated in a series of field experiments conducted in Danish classrooms (Wargocki and Wyon 2006, Wargocki and Wyon 2007). The results indicated that the average speed of performance decreased by around 2 percent for every 1°C increase in temperature.

Lower ventilation rates are consistently linked to absenteeism, fatigue, loss of concentration, and impaired cognitive function. Multiple studies have shown that when steps are taken to mitigate poor indoor environmental quality, there is a positive effect on cognitive function, and students’ academic performance improves.

The same Danish study also addressed air quality through monitoring the effects on the performance of students of adjusting the outdoor air supply rate from 3 to 9.5 l/s/person.

It found that an increase in ventilation has a positive effect on student performance, with a doubling in outdoor air supply rate improving performance of schoolwork in terms of speed by about 8 percent overall and by 14 percent for certain tasks that were affected significantly.

A study of school-leaving exam results in New York City (Park 2016) investigated the effects of more extreme temperatures and found that taking an exam on a 32°C day relative to a 22°C day increased the risk of failing to pass by 12.3 percent. 

There was also an adverse effect on learning, as an increased number of hot days (above 27°C) during the school year prior to taking the school-leaving exam reduced performance by 2.2 percent.

While the review conducted was focused on thermal comfort and indoor air quality, there is clear evidence that good design, including acoustics and visual comfort can boost academic results. This aligns with the New South Wales government’s newly launched Environmental Design in Schools Guide, which urges a greener approach to classroom infrastructure and design.

Image credit: NCEE