Google Nest Protect uses a custom, dual-wavelength Split-Spectrum smoke sensor, a redesigned smoke chamber and an exclusive smoke algorithm to cut down on nuisance alarms.
Photoelectric smoke alarms work by using light to detect tiny smoke particles given off by a fire. When smoke alarms are on alert for smoke in the air, they sometimes sound the alarm when they detect things like dust, bugs and steam. This is an industry-wide issue. The US-based National Fire Protection Association estimated that fire departments responded to 16 false alarms for every 10 fires, which is one of the issues we wanted to address with Nest Protect.
The second-generation Nest Protect was designed with nuisance alarms in mind. Nest Protect uses several tools to help cut down on false alarms, while always remaining sensitive enough to detect real fires:
1. Redesigned smoke chamber and Split-Spectrum Sensor
Nest Protect is the first residential smoke alarm to use dual-wavelength smoke sensing. To reduce false alarms, the Split-Spectrum Sensor is encased in a redesigned smoke chamber that is shielded against outside light, etched to protect it against dust and encased in a stainless-steel screen. The screen has a hexagonal pattern that is designed to keep out bugs and fibres, while still allowing smoke to flow in.
Read the Split-Spectrum Sensor white paper
2. Rigorous testing
Smoke alarms are tested to ensure they can activate when there's a fire and that they're durable enough to work in the real world. Nest Protect passed all the tests for certification in Canada, Europe and the US. We designed our own tests to check how Nest Protect performed when exposed to dust and bugs. Nest Protect showed it could work in a lab, so we tested it in real-life homes.
Learn more about how to run a Safety Checkup
3. Steam Check
Nest Protect's Steam Check feature uses a humidity sensor and custom algorithms to help tell the difference between smoke and steam. We estimate that it reduces false alarms from steam by 57%.