The study provides a nuanced understanding of how bedroom ventilation affects sleep health

The study provides a nuanced understanding of how bedroom ventilation affects sleep health

Good sleep is the key to good health, general well-being and optimal cognitive function. Sleep disorders or lack of sleep can lead to various health problems such as cardiovascular disease, cancer and other morbidities such as Alzheimer's and obesity. Therefore, it is important to ensure that environmental factors that affect sleep quality, including temperature, noise, light and air quality, are optimally maintained in the bedroom. Recent studies have repeatedly shown that inadequate ventilation in the bedroom can affect sleep quality. With the help of these studies, it is possible to more comprehensively rethink existing ventilation recommendations in bedrooms.

Building on these foundations, a research team led by Ms. Mizuho Akimoto, a research fellow at the Advanced Collaborative Research Organization for Smart Society (ACROSS), Waseda University, Japan, in an innovative study together with Professor Shin-ichi Tanabe from the Faculty of Architecture, Waseda University; Prof. Pawel Wargocki from the Department of Environmental and Resource Engineering at the Technical University of Denmark; and Prof. Li Lan of Shanghai Jiao Tong University recently conducted a novel analysis under the ASHRAE-funded project (1837-RP); Prof. Wargocki and Prof. Lan were the principal investigators of the project. The overall aim was to contribute to bedroom ventilation standards to ensure sleep quality is not affected by poor bedroom air quality. Their novel findings were made available online on July 21, 2025 and published in Volume 31, Issue 8 of the journalScience and Technology for the Built Environmenton September 1st, 2025.

Ms. Akimoto highlights the motivation behind her work."The present study not only encompasses a more representative body of evidence, but also introduces several new perspectives. It provides a multidimensional assessment of how ventilation affects various sleep parameters, distinguishes between interventional and cross-sectional studies, and considers population-specific carbon dioxide (CO).₂)Emission rates during sleep.”

The team reviewed 17 studies, including 22 experimental data sets, to find that the slightest ventilation with outside air causes sleep disturbances when (absolute) CO₂ concentration reaches 1,000 ppm. They found that the highest CO2 concentration that had no effect on sleep was 850 ppm at the lowest ventilation rate. However, due to sensor accuracy and safety margins, this cannot be considered a limit without observed harmful effects. Therefore, the researchers suggested the lowest level of ventilation with outside air in bedrooms to keep CO2 levels at or below 800 ppm; This is the goal that bedroom ventilation should be based on. In all of these recommendations, CO2 acts as a proxy indicator for ventilation rate rather than as a pollutant. To meet recommended CO2 targets, bedroom ventilation rates would need to be around 8L/s per person, which is at least double the amount required by many current housing standards.

“Our results suggest that the current minimum ventilation rates required for homes could make this possibleinsufficientaffects the ventilation of the bedroom and can therefore lead to sleep disorders. By identifying a CO2 target of 800-1,000 ppm to determine ventilation, the review provides evidence that can support reconsideration of ventilation requirements in building regulations. This has implications for the housing industry and ventilation system manufacturers, who face the challenge of balancing energy efficiency with human health. We also suggest methods to achieve these levelsalthoughFurther developmentis necessary"says Ms. Akimoto.

Therefore, the present findings have potential implications for revising residential building standards regarding ventilation in bedrooms. However, proper ventilation of bedrooms with sufficient outside air should minimize energy consumption. It is assumed that this recommendation leads to improved sleep quality and a holistic increase in quality of life.

Taken together, the present contributions provide a more informed and nuanced understanding of how bedroom ventilation affects sleep health and provide information relevant to future ventilation policies.

Sources: