Ubiquiti's $99 Vape [Air Quality] Detector is pretty good

Ubiquiti’s $99 UP-AirQuality is a vape detector and air-quality monitor that Geerling tested against established devices, including AirGradient, Aranet4, and Air Lab. Its low price initially raised doubts because inexpensive monitors often estimate CO2 indirectly and can be inaccurate. In testing, however, the Ubiquiti unit tracked the comparison devices closely. A breath test provided a clear check: CO2 readings rose rapidly from about 600 ppm to nearly 4,000 ppm, while the device’s status light changed from green to red. That response indicates it measures actual CO2 rather than relying on a synthetic estimate.

A teardown revealed the reason for its performance: a Sensirion SEN66-SIN-T, a compact integrated sensor that measures particulate matter, humidity, temperature, VOCs, NOx, and CO2. The sensor sits apart from the networking and power components, separated by a molded plastic barrier; the network hardware is coupled to a heat spreader, and a light pipe carries status illumination to the enclosure. The SEN66 costs roughly $50-62 on its own, making its inclusion notable at this device’s price. Geerling considers it an unusually good-value CO2 monitor, but its main limitation is ecosystem dependence: it requires a Ubiquiti network controller running UniFi Protect. It cannot simply connect to an arbitrary PoE switch or operate with Home Assistant on its own, although UniFi provides API access to the readings.