Frequently asked questions

• Does the SAWF-08P also measure PM2.5/PM10 dust?

  No. The SAWF-08P measures CO2, temperature and humidity. Fine particles are covered by a separate model in the series, the AirGuard PM2.5/PM10 (SAWF-07P).
• Do I need a hub for Apple Home, Google Home or Alexa?

  Yes — third-party Matter ecosystems require a Matter hub: a HomePod mini or Apple TV for Apple Home, a Nest Hub for Google, an Echo for Alexa. In eWeLink it works directly over Wi-Fi. Viewing CO2 in Apple Home needs iOS 26 or later.
• Can the monitor be wall-mounted?

  The manufacturer advises against it: the back of the case has air vents for gas sampling, and flush against a wall the accuracy drops. It is designed to sit on a desk, shelf or nightstand.
• Can I manually calibrate the CO2 reading?

  No — the service menu only calibrates temperature and humidity. The NDIR cell is factory-calibrated; to keep readings honest, place the unit away from windows, cooker hoods and AC airflow.
• Why does the buzzer come back some time after I switch it off?

  Manually silencing the alarm starts a 30-minute quiet window; if CO2 stays high, the alert resumes afterwards. To disable sound entirely, press the button again and check that the buzzer icon on the screen is off.
• What CO2 level counts as normal?

  The device uses these bands: up to 1000 ppm — good (green), 1001–1500 ppm — fair (yellow), above 1500 ppm — poor (red). Outdoor air sits around 400–420 ppm; an unventilated bedroom often passes 2000 ppm overnight.
• Does it have a battery?

  No — it runs solely on continuous USB Type-C power at 5V⎓1A. The NDIR sensor needs constant power for its 5-second refresh, so plan a socket or USB port nearby.
• Does the sensor work without internet?

  The display, LED and buzzer work standalone — Wi-Fi is only needed for the app and ecosystems. Through a Matter hub, Apple Home or Home Assistant automations run locally; history and air advice require an eWeLink account.