I woke up at 3:00 am this morning and was vaguely aware that something wasn’t right. It wasn’t an emergency, but something was off. I was warm, but it felt stuffy and I suspected my lack of ventilation was causing me problems again.
Breathing without Ventilation
At 3:00, in a drowsy stupor, I was aware that there appeared to be at least one extra rhythm of breathing present. I knew one of my children was sleeping in the room, as sometimes happens when Natalie is away. But last night our youngest son also decided to join the sleepover.
I was also quite warm so I got up, nearly tripped over Xavier, who was sleeping on the floor, and turned off the ceramic wall panel heater. I also closed the bedroom door to keep the dog out.
Now, nearly 4 hours later as I write this, I still have a mild headache, and here’s a likely explanation – carbon dioxide.
Feeling Low with High CO₂
With three of us inhaling oxygen and exhaling carbon dioxide, it got very stuffy. The ensuite window was slightly open, but the other windows were closed. Output from my uHoo air monitor shows that CO₂ peaked at 1,828 parts per million (ppm) at 5:00 am and stayed there at least until 6:00 am when I got up.
How much CO₂ is too much?
Ambient CO₂ of fresh air is around 350 ppm. We can handle up to 700 – 800 ppm without too much trouble. Some even say 1,000 ppm for a few hours is fine. When CO₂ stays above 1,000 ppm or even 1,500 ppm it starts to induce headaches. Elevated CO₂ also causes drowsiness, loss of attention and can increase your heart rate. This is why fresh air is important in offices, classrooms and in homes.
Staying Warm with Fresh Air
The real issue in my bedroom is that I closed the windows and the door. I did this to stay warm. At 6:00 am is was 12 degrees outside here in Auckland, not too cold but still lower than optimum. Bedrooms should be at a minimum of 16 – 18 degrees celsius.
My bedroom was 16.8 degrees at 6:00 am (down from 18 degrees at 3:00 when I turned the heater off).
Warm or Fresh
Like most old New Zealand homes, I’ve made a choice to keep my children warm but at the expense of having fresh air. Without good ventilation, this will remain a choice. One or the other. We can have fresh air, but be cold. Or we can be warm, but stuffy.
Warm and Fresh
The solution to this problem is to install a balanced ventilation system with heat recovery. This is a topic that I’ve covered in the past, and will cover more in future posts and podcasts.
Know Your Air
Knowing what’s going on in your own home is the first step to diagnosing then fixing indoor air quality. I’ve found my uHoo air monitor to be excellent for this and I’d like others to benefit from the insights of easy-to-use monitoring technology. A limited number of uHoo air monitors will be available soon here in New Zealand. If you’d like one, please get in touch.
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