SONOFF AirGuard CO2 (SAWF-08P)
CO2 and air quality monitor (Matter)
Tells you when the room is stuffy and needs airing. Measures CO2, temperature and humidity and goes straight into Apple Home or Google Home via Matter.
Compatibility
Matter ✓HomeKit ✓Google Home ✓
An accurate NDIR sensor at a fair price, with Matter. Great for bedrooms and home offices. How we rate
About the product
The SONOFF AirGuard CO2 (SAWF-08P) is an air quality monitor for the home or office. It measures CO2, temperature and humidity and shows you when the room is stuffy and needs airing.
Why CO2 matters
When CO2 rises above roughly 1000 ppm, tiredness, headaches and poor sleep usually follow. Without a monitor you only notice when you feel it.
What it does
- A real NDIR sensor: it measures CO2 optically instead of estimating it from other gases like cheap monitors. Range 400–5000 ppm, accuracy ±(50 ppm + 5%), new readings every 5 seconds.
- Matter over Wi-Fi: add it straight to Apple Home or Google Home, so a fan or ventilation system can switch on when CO2 climbs.
- Alerts by sound, light and app, plus measurement history.
Watch out for
It runs on mains power, so it needs a socket or USB charger nearby. It does not measure dust (PM2.5) or smells.
Who it is for
Bedrooms, kids’ rooms and home offices, especially well-insulated flats with airtight windows where the air does not refresh by itself.
Photos: seller on AliExpress.
Where to buy
-
AliExpress
usually the lowest price, from China, in stock
Go to shop€40.47
price as of 14/11/2026
Links to shops are affiliate links: if you buy through them, we earn a small commission. Your price stays the same.
Price history
Price tracked since 14 November 2026. The chart appears once we have a few weeks of data.
Pros
- +Real NDIR CO2 sensor, not an estimate
- +Matter: Apple Home and Google Home without a hub
- +Alerts by sound, light and app
Cons
- −Mains powered, no battery
- −Does not measure dust (PM2.5)
Specifications
| CO2 sensor | NDIR |
|---|---|
| Range | 400–5000 ppm |
| Accuracy | ±(50 ppm + 5%) |
| Also measures | temperature, humidity |
| Connection | Wi-Fi, Matter |