IKEA VINDSTYRKA (E2112) VOC sensor device_class in Home Assistant

[tomaszn]

IKEA VINDSTYRKA reports volatile organic compounds (VOC) values correctly in Zigbee2MQTT (Z2M). However, these measurements lack a device class in Home Assistant, preventing their inclusion in an area badge.

Issue #17208 was previously closed because the VOC sensor did not use the µg/m³ unit, which was required for setting the device class at that time.

However, Home Assistant now supports two device classes for VOC:

volatile_organic_compounds: Concentration in µg/m
volatile_organic_compounds_parts: Ratio in ppm or ppb

What changes are necessary to classify the VINDSTYRKA VOC measurements as volatile_organic_compounds_parts in Home Assistant?

[Koenkk]

What is the unit of pm25? Currently it is µg/m³ and for _parts it needs to be ppm or ppb (CC: @sjorge)

[tomaszn]

If I correctly assume that the sensor inside is SEN54 (source), then the units for tVOC (total VOC) are (should be) ppm (source).

[sjorge]

voc_index is sadly not tVOC and not ppb|ppm|µg/m³, It's a relative offset to the previous 24h, ikea uses it to map to the red/yellow/green an the Up or Down arrow depending on the trend. IIRC 150 is the base line so >150 is worse air quality <150 is better air quality compared to the last 24h average. The further from 150 the better/worse it is.

[tomaszn]

Oh, you are right. Details are described here. The key sentence is:

The VOC Index mimics the human nose’s perception of odors
with a relative intensity compared to recent history. The VOC
Index is also sensitive to odorless VOCs, but it cannot
discriminate between them.

[sjorge]

A possible improvement would be to map the voc_index value to the color codes perhaps and expose it as an event to home assistant.

[tomaszn]

Or even display the trend value as arrows, the same way as visible on the built-in VINDSTYRKA display: 🡲 🡵 🡶.