Researchers observed a 5% decrease in “power of attention” in poorly ventilated classrooms, roughly equivalent to the impact that a student might feel from skipping breakfast (Coley et al., 2007). With similarly poor CO2 levels and ventilation rates in school buildings, students have been observed to experience greater fatigue, impaired attention span, and loss of concentration (Chatzidiakou et al., 2012); poorer performance on tests of concentration (Dorizas et al., 2015a); and lower levels of focus among university students during lectures (Uzelac et al., 2015).