Researchers at the Eindhoven University of Technology in the Netherlands split a small group of healthy volunteers into two, with some volunteers sleeping in more ventilated spaces with open windows and doors, while the others slept in a sealed room.
The researchers measured the carbon dioxide levels, temperature, background noise, and relative humidity in each of the rooms where participants slept. They compared that data to both qualitative and quantitative measurements of the participants' sleep.
The results, published in the International Journal of Indoor Environment and Health, found a correlation that could help all of us sleep better.
Average carbon dioxide levels for the open rooms were markedly lower than the closed rooms, and it appeared that was the biggest driving factor in a good night’s sleep. The researchers noted: “Participants subjective assessment of their sleep depth correlated with carbon dioxide levels.”
“Lower carbon dioxide levels implied better sleep depth, sleep efficiency, and lesser number of awakenings,” the researchers wrote.
So next time you’re feeling restless, just crack open a window and breathe in some fresh air.