Illustration of a person sleeping in a dark bedroom with a microphone

We often talk about the importance of bedding when it comes to sleep health and wellbeing. But there’s something else, something invisible, that matters just as much: - and that’s the air quality in your bedroom.

At Devon Duvets, we know that true rest comes from a combination of factors, and what you breathe during the night can be just as important as what you sleep on or under. One of the most overlooked elements that may be affecting your sleep is the level of carbon dioxide (CO2) in your bedroom.

What is CO2 and why does it matter during sleep?

CO2 (carbon dioxide) is a natural gas that we exhale when we breathe. In small amounts, it’s harmless. But when you sleep in a closed room, especially during cooler months, CO₂ levels can rise quickly. This happens because doors and windows are often shut, and there is limited airflow to bring in fresh oxygen.

As the night goes on, the concentration of CO2 increases - particularly between 3am and 4am - and your body starts to react. You may find yourself waking up during these early hours, even if everything else in your routine remains unchanged.

How does CO2 affect my breathing and heart rate?

As CO2 builds up in your bedroom, your body responds by increasing your breathing rate to expel the excess gas and take in more oxygen. This is a natural defence mechanism, but it also means you’re no longer in a deep, restful sleep.

Your heart rate may rise as a result. During restorative sleep stages, your heart rate should ideally drop below 60 beats per minute. However, when CO2 levels are high, your heart may continue to beat faster, signalling that your body is working rather than resting. This can prevent you from reaching the deeper stages of sleep, which are crucial for mental and physical recovery.

Can high CO2levels disrupt my sleep cycle?

Elevated CO2 levels often trigger micro-awakenings – those brief periods where your body transitions from deep sleep to lighter stages - or can even wake you up completely. These interruptions, even if not fully remembered, can significantly affect how refreshed you feel in the morning.

One study published in Indoor Air found that improving bedroom ventilation lowered CO2 levels and led to better sleep, as well as improved performance the following day. So, the effects are not just noticeable in your sleep, but you are likely to notice an increase in your alertness and wellbeing the next day.

Can high CO2 levels disrupt my sleep cycle?

Elevated CO2 levels often trigger micro-awakenings – those brief periods where your body transitions from deep sleep to lighter stages - or can even wake you up completely. These interruptions, even if not fully remembered, can significantly affect how refreshed you feel in the morning.

One study published in Indoor Air found that improving bedroom ventilation lowered CO2 levels and led to better sleep, as well as improved performance the following day. So, the effects are not just noticeable in your sleep, but you are likely to notice an increase in your alertness and wellbeing the next day.

What can I do to improve air quality in my bedroom?

There are several easy and effective ways to reduce CO2 in your bedroom:

Open up: Open a window slightly before bed to allow fresh air in.

Monitor: Use a CO2 monitor to track air quality levels.

Purify: Consider an air purifier with a circulation mode to keep air moving.

Let it flow: Keep interior doors ajar to promote airflow.

Keep it natural: Choose natural, breathable bedding to prevent overheating and promote airflow around your body.

At Devon Duvets, we individually handcraft our duvets using 100% natural fillings, such as wool and alpaca and we also offer a 100% natural plant-based range, Botanic – all with 100% cotton casings. All these naturally breathable options support better air circulation and body temperature regulation.

Frequently Asked Questions

Can CO2 make me wake up in the early hours of the morning?

Waking up at the same time every night, particularly around 3am, can often be linked to elevated CO2 levels in the bedroom. As CO2 builds up through the night in a poorly ventilated room, your body may respond with increased heart rate and breathing, prompting you to wake up.

Can CO2 really impact my heart rate while sleeping?

During deep sleep, a healthy resting heart rate typically drops below 60 bpm. However, elevated CO2 can cause your cardiovascular system to work harder, which may result in a raised heart rate and disrupt your sleep cycle.

What’s a safe level of CO2 for a bedroom?

A well-ventilated room should ideally have CO2 levels below 1,000 ppm (parts per million). Levels above this threshold can lead to poor sleep quality, headaches, and grogginess upon waking.

How can natural bedding help improve sleep quality?

Natural fibres like wool, alpaca and cotton allow air to circulate more effectively around the body, helping to regulate body temperature and reduce the feeling of stuffiness during sleep. At Devon Duvets, our handcrafted bedding is chemical-free, breathable, and made from 100% natural and sustainable materials.

If you have any questions about our individually handcrafted range of duvets, mattress toppers and pillows, then please get in touch with the team, who will be happy to discuss your requirements.