Claim · according to Coridum · status published
Claim C-0018
In classrooms, mechanical ventilation may lower indoor carbon dioxide: two independent measurement campaigns found lower concentrations where central mechanical ventilation was present than where it was not.
Structure
- Factor
- Carbon dioxide (CO₂)
- Intervention
- HVAC systems
- Population
- schoolchildren
- Relation
- decreases · mean 1 087 ppm against 1 510 ppm in the European campaign
- Evidence grade
- C · consistent
- Caveat
- both supports are measurement campaigns, not intervention studies: the classrooms were not randomised to ventilation, so buildings with mechanical ventilation may differ in other ways
Based on
- Finding F-0040: “About 11% of the SINPHONIE classrooms featured mechanical ventilation. In these classrooms the concentration of CO2 was significantly lower than in classrooms without mechanical ventilation (mean values 1,087 ppm and 1,510 ppm, respectively).” (CKB 0012, p. 52)
- Finding F-0043: “Elevated levels occurred in all buildings, although schools with central mechanical ventilation had lower concentrations and variability than schools without.” (CKB 1363, p. 1)
Counter-evidence
None found after an active search.
A Claim is Coridum’s synthesis of Findings and Observations; the evidence grade follows the study designs behind it.