Bedroom environment
A HEPA air purifier added 12 minutes of sleep per night
At a glance
| Study type | Randomized controlled trial |
|---|---|
| Year | 2023 |
| Journal | Journal of Sleep Research |
| Effect size | +12 min total sleep, +19 min total bed time |
| Population | General adult |
Background
A double-blind, randomized, placebo-controlled crossover trial in 30 healthy adults compared a real HEPA air purifier to a placebo filter. The active filter added ~12 minutes of total sleep time and ~19 minutes of total time in bed per night.
Why might cleaner air mean more sleep?
Particulate exposure (PM2.5, allergens) drives airway inflammation, nasal congestion, and micro-arousals that don't always reach conscious awareness but cost time-in-stage. Removing those particulates reduces respiratory work overnight.
How was the trial designed to rule out placebo effect?
Crossover, double-blind, with a sham filter that looked and sounded identical. Participants did not know which two-week arm they were on, and the physical setup was indistinguishable. Sleep was measured by both actigraphy watches and sleep diaries; air quality was independently verified to differ between arms.
Was every outcome better?
No — and this is important. Time awake after sleep onset was actually slightly higher on the active filter, and several other outcomes showed no change. The robust signal was on total sleep time and time in bed, not every sleep architecture metric.
Does this matter more for some people than others?
Yes. The signal should be larger if you have allergies, live in a high-pollution area, share a bedroom with pets, or sleep with windows open near traffic. Pregnancy compounds the gain because nasal congestion is already elevated by hormonal changes.
How does Solas apply this?
If you log allergies, pets in the bedroom, or live in a city we know has elevated PM2.5, Solas may recommend a HEPA purifier and cite this trial. It also surfaces the trial's caveats so the recommendation is honest about which outcomes did and did not move.
Source
Lamport DJ, et al.
(2023).
Can air purification improve sleep quality? A 2-week randomised-controlled crossover pilot study in healthy adults Journal of Sleep Research.
DOI: 10.1111/jsr.13782
Read the original paper →
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