Birdie

Birdie is a Danish maker of indoor air quality monitors built on the old canary-in-the-coalmine idea: a small bird that drops when the air turns bad and rises again once a window is opened.

The device is a Fresh Air Monitor in recycled plastic with a Swiss CO2 sensor. When carbon dioxide builds up it sinks to signal that it is time to ventilate, conveying air quality without numbers or apps. Childhood friends Andreas Kofoed Sørensen and Hans Høite Augustenborg, who grew up in Hellebæk north of Copenhagen, founded the company in 2022 and funded the first production run with a Kickstarter campaign that raised close to $500,000 in 30 days from backers in 63 countries. A second model, Birdie Pro, has since joined the range.