Study reveals how poor bedroom air quality affects sleep and next-day work performance

Need for twice as much ventilation as the rules prescribe

that an open window improves air quality in the participants’ bedrooms.
that the participants sleep better if the window is open and they perform better
if they sleep with the window open.
that an open door to the rest of the home does not have a measurable effect on sleep quality.

Below 750 ppm: Adequate ventilation—no negative effect on sleep quality. This will be a typical measurement for a well-ventilated bedroom.
Between 750 ppm and 1150 ppm: Possibly insufficient ventilation—in some cases, sleep quality may be adversely affected.
Above 1150 ppm: Insufficient ventilation—sleep quality will be adversely affected. CO₂ levels that are higher than 1150 ppm will typically occur in bedrooms that are not fitted with a ventilation system and where windows and doors are closed.
Above 2600 ppm: Insufficient ventilation—both sleep quality and next-day performance are adversely affected.