2016 ASHRAE Annual Conference

Indoor carbon dioxide (CO₂) has long been discussed in the context of ventilation and indoor air quality (IAQ), focusing on the impacts of CO₂ on building occupants, how CO₂ concentrations relate to perception of bioeffluents, the use of indoor CO₂ to estimate ventilation rates, and demand control ventilation. While measured indoor CO₂ concentrations are rarely close to health guidelines, much confusion has resulted regarding CO₂ in ventilation and IAQ standards. This presentation addresses the relevance of CO₂ concentrations to these standards based on their relation to indoor bioeffluent levels and odors and to ventilation rates per person.

The archival literature was reviewed to examine whether exposures to carbon dioxide (CO₂) at the concentrations typically occurring indoors would create the risks for building occupants as regards their comfort, health and cognitive performance. Laboratory experiments were performed with human subjects exposed to different levels of CO₂ lower than the occupational 8-hour limit of 5,000 ppm to further examine whether CO₂ should be considered a toxic pollutant at the levels typically occurring indoors. Should  the role of CO₂ in the context of ventilation and indoor air quality change? This presentation shows the results.