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How keeping CO2 low with a bathroom fan gave me 100% sleep score

5 May, 2026

🌡️ Update: 100% sleep score with bathroom fan on to keep CO2 low

It sucks CO2 out of the room and creates a low pressure field that brings in new fresh air from outside the room

Last time 100% sleep was in an Airbnb in Brazil we stayed which was a house built in 1970s mostly wood and very breathable, but our house is modern and very insulated

So it seems it worked to improve our sleep

Science supports this: high CO2 levels above 1500 cause fragmented sleep, more brief awakenings, less deep sleep and worse REM

Also CO2 levels are a proxy for other air contaminants which build up in a closed bedroom so keeping it low is good

We can go lower to 400-500 ppm with a real bedroom fan/vent but again this is a good start

So if you're having sleep problems, check your CO2 levels

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