What CO₂ reveals about your ventilation - and your team's focus
Carbon dioxide is the cheapest honest signal of how well a room is ventilated. It also tracks how well people think in it.
Outdoor air sits around 420 ppm of CO₂. Indoors, the people in a room exhale it continuously, so the concentration climbs until ventilation carries it back out. That makes CO₂ a convenient proxy for fresh-air supply: a room holding steady near outdoor levels is well-ventilated; a room drifting past ~1,000 ppm isn’t moving enough air for the people in it.
It isn’t just stuffiness
A controlled Harvard study - the COGfx study - put office workers through cognitive tests under different air conditions and found scores markedly higher on well-ventilated, low-VOC days than on conventional ones, with CO₂ and VOCs each independently associated with worse performance across domains like strategy and crisis response. [10] The air that merely feels stuffy is measurably denting decision-making.
Why you can’t just trust your nose
People acclimatise to a slowly rising CO₂ level and stop noticing it within minutes, which is exactly why a number beats a nose. By the time a meeting room feels obviously close, it has usually been under-ventilated for a while.
What we do about it
A one-off survey tells you where each space stands today. Live monitoring puts the number on a dashboard and alerts you the moment a room tips over a threshold, so you can act - open a damper, boost the air handling unit, or add capacity - before the afternoon slump sets in.