Studies say carbon dioxide concentrations affect sleep: window ventilation can help improve sleep quality.

Foreign media say a small new study suggests that opening a bedroom window or door at night may make it enough to get a better quality of sleep.
dutch researchers used high-tech methods to track the night activities of 17 healthy volunteers for five nights, the Website of the United Press International reported on November 27. Some participants opened the bedroom door or window while they slept, making the room more ventilated, while others did not.
A team led by Asit Kumar Misra, an environmental researcher at Eindhoven Polytechnic University, said the results showed lower concentrations of carbon dioxide in the air in better-ventilated rooms, which the body naturally exhales, which appears to be associated with better sleep quality.
The team reported in the November 22 issue of Indoor Air: "Lower levels of carbon dioxide in the bedroom mean increased sleep depth, increased sleep efficiency, and fewer wake-up times." According
american sleep expert, nighttime environments are important for sleep quality.
. Steven Van Silver said: "This study does remind us that all bedrooms are different and that the quality of our sleep must be affected by the physical properties of our surroundings at night. Van Silver is the director of the Sleep Medicine Center at Lynox Hill Hospital in New York City.
he said that while it has long been known that sleep quality is higher in cooler environments, "indoor air quality problems may be related to sleep quality and this has not received much attention."
Van Silver added that further detailed research could provide more insight.