A Preliminary Study on the Association Between Ventilation Rates in Classrooms and Student Performance

This pilot study explores whether ventilation deficits in elementary classrooms are linked to lower standardized test scores. Researchers measured 4–5-hour carbon-dioxide (CO₂) profiles in one fifth-grade classroom at each of 54 U.S. elementary schools, then calculated per-person outdoor-air delivery. After removing two outliers, 50 classrooms had a mean ventilation rate of 3.9 L s⁻¹ person⁻¹ (range 0.9–11.7)—roughly half the ASHRAE 62.1 minimum of 8 L s⁻¹ person⁻¹. Ventilation data were paired with class-level results on state math and reading exams and with socioeconomic covariates such as free-lunch eligibility, student mobility and limited-English proficiency. Linear and generalized-additive models revealed a modest but significant positive association between higher ventilation and math performance (P < 0.10) after adjusting for confounders; reading showed a similar trend but did not reach significance, possibly because of greater score dispersion. Curve-fitting suggested the relationship may be non-linear, with benefits tapering above ~6 L s⁻¹ person⁻¹. The authors note that low ventilation was common and likely underestimated because many rooms never reached CO₂ steady state. They recommend larger studies and inclusion of additional IAQ indicators (e.g., pollutants, moisture) to confirm how adequate outdoor-air supply supports sustained academic achievement.