“The measurements of CO2 concentration in the rooms showed a marked difference between the two conditions – a night-time average of 2395 ppm in the condition without ventilation and 835 ppm with ventilation, with no difference for the measured indoor air temperature, so the objective of the intervention was achieved.
Supplying air using a CO2 controlled fan had a significant positive effect on the assessed freshness of air. The lower relative humidity in the ventilation condition resulted in more mouth and skin dryness.
The subjectively assessed mental state and the subjects’ feeling of being rested were significantly greater in the condition with ventilation. The Groningen Sleep Quality Scale showed a tendency for the subjects to sleep better with ventilation, a result supported by the actigraphy data. The subjects also reported feeling less sleepy the day after sleeping with the ventilation running, and their objectively measured performance of a logical reasoning task improved.”
Findings from the conference paper “The Effect of CO2 Controlled Bedroom Ventilation on Sleep and Next-day Performance” (link to download the paper here) by Peter Strøm-Tejsen, Pawel Wargocki, David P. Wyon, and Daria Zukowska. International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark.