(Temperature 18-22 °C, Humidity 50 %, CO₂ < 800 ppm—All Hands-Free)
1. The WHO Gold Standard—Why These Numbers Matter
| Parameter | WHO Range | What Happens When You Miss It |
|---|---|---|
| Temperature | 18–22 °C (64–72 °F) | > 24 °C → 30 % drop in REM; < 16 °C → 3× more night-wakings |
| Relative Humidity | 40–60 % | < 35 % → airway irritation; > 65 % → dust-mite & mold bloom |
| CO₂ | < 800 ppm | > 1 000 ppm → 50 % increase in micro-arousals |
2. AI Device Stack—Plug-and-Play Automation
| Device | AI Feature | DIY IFTTT Rule |
|---|---|---|
| Smart AC (e.g., Midea U-Shaped) | Learns thermal preference | IF Sleep-Tracker detects “Light Sleep” → drop set-point 1 °C |
| Humidifier (Levoit OasisMist 450S) | Auto-humidity & oil diffusion | IF RH < 45 % → raise mist 20 % |
| Air Monitor (Awair Element) | Real-time CO₂, PM2.5, VOC | IF CO₂ > 800 ppm → trigger bedroom exhaust fan |
| Sleep Tracker (Oura Gen 3) | HRV, sleep-stage API | IF Deep < 60 min → push “AC + Humidifier Boost” |
3. Case Study—Real User Data
Name: Sarah, 34, software engineer
Setup: Midea AC + Levoit humidifier + Awair + Oura
Baseline (Week 0):
Setup: Midea AC + Levoit humidifier + Awair + Oura
Baseline (Week 0):
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Deep sleep: 78 min/night
-
Avg. bedroom CO₂: 1 200 ppm
-
Humidity: 28 %
Week 4 After AI Automation:
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Deep sleep: 115 min/night (+ 37 min)
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CO₂: 720 ppm
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Humidity: 51 %
-
Subjective “morning fogginess” dropped from 7/10 to 2/10.
4. 5-Minute DIY “Sleep Lab” Script
Paste into Home Assistant → Configuration → Automations:
yaml
alias: Deep-Sleep Optimizer
trigger:
- platform: numeric_state
entity_id: sensor.awair_co2
above: 800
action:
- service: climate.set_temperature
target:
entity_id: climate.midea_bedroom
data:
temperature: 20
- service: humidifier.set_mode
target:
entity_id: humidifier.levoit_bedroom
data:
mode: high5. Cost vs. Benefit Snapshot
| Item | Up-Front | Monthly Running | Year-1 Total |
|---|---|---|---|
| Smart AC | $329 | $10 extra | $449 |
| Humidifier | $90 | $5 filters + water | $150 |
| Air Monitor | $149 | $0 | $149 |
| Sleep Tracker | $299 | $0 | $299 |
| TOTAL | $867 | $15 | $1,047 |
| Cheaper than one overnight polysomnography ($2,500+). |
6. Quick-Start Checklist
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Tonight: Download Home Assistant, add Awair & AC.
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Tomorrow: Run the script; check Oura Deep-Sleep score.
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Week 1: Fine-tune humidity; aim 50 % ± 3 %.
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Week 4: Review trend; if Deep < 90 min, drop temp another 1 °C.
Follow the gold parameters and Sarah’s 37-minute Deep-Sleep gain can be yours—no lab coat required.
