Study: Classroom ventilation affects student performance

Wednesday, December 08, 2010

Test scores improved when fresh air was properly circulated

Students in well-ventilated classrooms perform significantly better on standardized tests than their peers who receive inadequate fresh air, according to newly published research conducted by The University of Tulsa’s Indoor Air Program.

“Far too many schools fall short of providing a healthy learning environment for children. By doing something as simple as introducing more fresh air into the classroom, schools potentially could help every student perform at a higher level,” said Richard Shaughnessy, program director of Indoor Air Quality Research at TU and a research associate in the Department of Chemical Engineering.

The study suggests that increasing classroom ventilation rates toward recommended guidelines translates into improved academic achievement. Reaching the recommended guidelines and pursuing better understanding of the underlying relationships would support sustainable and productive school environments for students and personnel.

Circulating adequate outdoor air through classrooms dilutes the amount of pollution and contaminants. Other researchers have found that improved air quality at schools leads to healthier students, and Shaughnessy’s team is conducting similar studies.

“With poor ventilation, all contaminants that may be present in a classroom – including particles, molds, viruses and odors from products such as cleaning supplies, art supplies, adhesives, paints, textiles and chemicals – are more concentrated, which may result in more sick days and higher absenteeism. This is especially important as financially challenged public school districts attempt to improve test scores and learning ability in elementary schools,” he said. “This information has national and even international implications.”

The latest TU-based research examined the ventilation rates in 100 fifth-grade classrooms, each from a different elementary school in two southwest U.S. school districts. Carbon dioxide concentrations were measured along with students’ standardized test scores, and 87 of the 100 classrooms evaluated had ventilation rates below the guidelines recommended by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE).

The research suggests a correlation between stagnant air and students’ academic achievement within the range of 0.9 to 7.1 l/s per person. The study showed that for every unit (1 l/s per person) increase in the ventilation rate, the proportion of students passing standardized math test (i.e., scoring satisfactory or above) is expected to increase by 2.9 percent, and the proportion of students passing the standardized reading test is expected to increase by 2.7 percent.

The linear relationship observed may level off or change direction with ventilation rates higher than 7.1 l/s per person, but researchers were unable to test this hypothesis given the limited number of observations.

“We have done parallel studies in Scandinavia, Spain and the Netherlands and found similar inadequacies in ventilation being provided to classrooms. This is a global school-related problem,” Shaughnessy said.

The study has been published online and will appear in the February issue of the Indoor Air Journal.


Mona Chamberlin