Poor Bedroom Air Quality Ruins Sleep and Performance.

In 2015, J. R. Dalenberg and a team from Denmark conducted two field experiments with 30 students in dorm rooms. They tested ventilation by opening windows (low CO2: 660 ppm) or using a fan (low CO2: 835 ppm) vs. no ventilation (high CO2: 2,585 ppm or 2,395 ppm) for 1 week each. Sleep was tracked with wrist actigraphs, and next-day alertness via questionnaires and cognitive tests.

Lower CO2 improved sleep efficiency and reduced next-day sleepiness, boosting concentration and logical thinking by 15-20%. High CO2 led to poorer sleep and worse performance, showing fresh air is key for rest and focus.

In 2020, Y. Liu and a team from China ran a 54-day experiment with 12 adults in bedroom chambers at CO2 levels of 800, 1,900, and 3,000 ppm. Sleep quality was measured via questionnaires and EEG for onset time and deep sleep stages.

High CO2 (3,000 ppm) cut overall sleep quality to 80.8% of low CO2 (800 ppm), lengthened time to fall asleep, and reduced deep slow-wave sleep by up to 25%. Men slept better than women at low CO2, but effects worsened for all at high levels.

Ventilate your bedroom or use an air purifier to keep CO2 low for better sleep and daily sharpness.