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AIR-1 LED Indicator

The AIR-1's three onboard RGB LEDs can double as an air quality gauge. Pick what they track and they shift from green to red as that reading climbs, so you can read the room from across it.

Requires firmware 26.6.25.1 or newer

The Air Quality LED Source control ships in AIR-1 firmware 26.6.25.1 and later. If you don't see it, update your firmware first.

Turn it on

The indicator is off by default. Open the AIR-1 device in Home Assistant, find the Air Quality LED Source dropdown, and pick what you want the LEDs to track.

Option LEDs show
Off LEDs stay dark (default)
NowCast AQI US EPA Air Quality Index
CO2 Carbon dioxide, in ppm
VOC Index Sensirion VOC Index

Switch back to Off any time to turn the indicator off and leave the LEDs free for your own automations.

Set the brightness

Drag the Air Quality LED Brightness slider to dim the LEDs, handy if the AIR-1 sits in a bedroom. It runs from 5% to 100% (default 100%) and applies the moment you change it.

Color scale

Every source uses the same six colors, green for good through deep red for hazardous. The numbers behind each color differ because each reading has its own range.

Color NowCast AQI CO₂ (ppm) VOC Index Meaning
🟢 Green 0 to 50 up to 800 0 to 79 Good
🟡 Yellow 51 to 100 801 to 1000 80 to 149 Moderate
🟠 Orange 101 to 150 1001 to 1500 150 to 249 Unhealthy for sensitive groups
🔴 Red 151 to 200 1501 to 2000 250 to 399 Unhealthy
🟣 Purple 201 to 300 2001 to 2500 400+ Very unhealthy
🟤 Maroon 301+ 2501+ Hazardous

The VOC bands line up with the VOC Quality sensor (Improved, Normal, Abnormal, Very abnormal, Extremely abnormal).

Tips and quirks

  • The color updates whenever the selected sensor reports a fresh reading, so NowCast AQI and VOC refresh every few seconds while CO₂ updates about once a minute.
  • With CO2 selected, the first color appears once the SCD40 has a reading, up to a minute after boot. That wait is deliberate: the sensor needs a moment to settle, and an early reading would not be trustworthy.
  • A sensor that's still warming up reads as unknown. The LEDs stay off until there's a real value rather than flashing a false color.

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