Back to school - Research-driven insights about indoor climate and student learning

Students may spend 10-20 years in classroom-based education.

We spend a seventh or a quarter of our lives in school buildings. Decades of research have already showcased evidence that a good indoor climate provided by ventilation affects children's learning in schools.

The school buildings promote a healthy learning environment, ensuring fresh air, ample daylight, and excellent acoustic conditions for children. With that in mind, it becomes evident that indoor environmental quality must be ensured so that they can learn and perform at their best.

Ensuring indoor environmental quality in schools for optimal performance and learning.

The indoor environment has these major components: thermal environment (optimized indoor temperature and humidity), indoor air quality (IAQ) and ventilation (carbon dioxide concentration and other VOCs parameters), sound (acoustics and noise issues) and light (including daylight and connection to the outdoors) environments.

Thermal environment – The classroom air temperature has a significant impact on children's schoolwork.

• Meta-analysis of all available data shows that children’s performance of tasks typical of schoolwork is reduced by 20% as the classroom air temperature is increased by 10°K (Wargocki et al., 2019).
• Raised temperatures have twice the negative effect on schoolwork as on office work (Wargocki and Wyon, 2013; 2017).
• The optimum temperature for schoolwork is 2-3K lower than it is for office work, and children in school subjectively prefer lower temperatures than are preferred in offices (Wargocki and Wyon, 2017).

Indoor air quality - The air in classrooms affects the actual schoolwork, including test results, as it impacts students' concentration.

• Children perform schoolwork 12% faster and 2% more accurately when the outdoor air supply rate is such that the resulting CO₂ concentration in a typical classroom is 900 ppm instead of 2,100 ppm (Wargocki et al., 2020).
• School test and examination results are 5% better when the outdoor air supply rate is such that the resulting CO₂ concentration in a typical classroom is 900 ppm instead of 2,400 ppm (Haverinnen-Shaughnessy et al., 2011; Wargocki et al., 2020).
• National test results are 5% better with a 7.5 L/s/p than with a 2 L/s/p outdoor air supply rate in classrooms (Haverinnen-Shaughnessy et al., 2011, Mendell et al., 2016; Wargocki et al., 2020).

Noise and sound conditions – Noise has a distracting effect on children's attention and it disturbs classroom discussions.

• Classroom noise negatively affects speech intelligibility, comprehension, and memory, but there is little evidence that it affects non-verbal tasks such as reading, writing, or mathematics (Astolfi et al., 2012).
• Longer reverberation times exacerbate the negative effects of classroom noise (Klatte et al., 2010; Ljung et al., 2009).

Daylight, lighting and viewing out – Research highlights the importance of a good lit environment for anyone's performance in classrooms.

• Daylight in itself has beneficial effects on children in classrooms (Gentile et al., 2017; Studer et al., 2019).
• A green view-out has measurably beneficial effects on the performance of schoolwork (Matsuoka, 2010).

Conclusion

The optimal environmental conditions in school classrooms provide spaces for children's effective learning and schoolwork. The research provides crucial information on understanding the effects of classroom environments on students' learning performance.

Children are more sensitive than adults to thermal stress. However, there is also a difference between learning new things and performing already-learned tasks. Learning is new to children; however, skilled office people perform well-practised and already-learned tasks.

Controlling the air supply can potentially impact cross-infections, such as viral infections affecting students' absenteeism and the impact of future pandemics on school learning.

The negative effects of noise and acoustic environments in schools are "more hearable/more disturbing" than the harmful effects of "invisible air quality".

The human need for daylight and light is well-known due to our physiology and body mechanisms, and there is substantial and measured evidence on the effects of light, daylight, lighting and view-out.

These research-driven insights showcase the effects of thermal environment, poor air quality, noise, and inadequate light conditions on children attending schools. Students thrive in healthy environments, and smart school buildings with excellent indoor air quality can optimize learning and safeguard students' well-being.

References

This text is based on the report edited by Pawel Wargocki and David. P. Wyon. The full report has an extensive reference documenting all evidence from a variety of authors. Pawel Wargocki is the Professor at the International Centre for Indoor Environment and Energy, at the Technical University of Denmark (DTU). And David P. Wyon works as a consultant at the International Centre for Indoor Environment and Energy, Technical University of Denmark (DTU).

Wargocki P., Wyon D. P. (2021) Research-based recommendations for achieving high indoor environmental quality in classrooms to promote learning. The full report. Technical University of Denmark. 

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Download the research paper 'Education and ventilation in schools' to learn more about indoor climate quality in schools.