Fifth grade classrooms, in 54 elementary schools, were
monitored for CO2 concentrations. The monitoring
was conducted using infrared-based data loggers, in
order to provide an assessment of the approximate
amount of outside air being delivered to classrooms.
Classrooms were assessed over a 4- to 5-h period
during an occupied school day, with the ventilation
system running and windows to outdoors closed.
The CO2 concentrations were translated into ventilation
rates assuming a source term for CO2 generation,
and assuming CO2 concentrations had reached
steady state (CO2ss) in the room (ASTM, 1998; Bearg,
1993):
Ventilation rate ¼
Source generation of CO2 per person
CO2ss CO2 outdoors
ð1Þ
Ventilation rates were adjusted based on the typical
occupancy in the room throughout the school year.
Out of 54 observations, two of the data points were in
error (conditions unstable in the classroom during
monitoring) and omitted from further analyses.
In addition to ventilation data being recorded,
investigators were able to work with the district to
obtain standardized test scores and background data
related to the students in the specific classroom studied
in each school. The tests are based on math skills and
reading skills, administered throughout the state. All
students in the fifth grade are required to take these
tests. The scores are then ranked as a comparison to
the performance of other students throughout the
state. Other pertinent information related to students
(in the specific classroom from each school that was
studied) included male/female ratio, attendance rate,
and % free lunch program participants (for indication
of family income), % gifted enrolment (for indication