The First Alert SC5 is a battery-powered combination smoke and carbon monoxide alarm, measuring 5.75 x 5.75 x 1.6 inches, with an electrochemical CO sensor, a photoelectric smoke sensor and Google Home connectivity. CNET named it the best overall carbon monoxide detector in its lab-tested roundup, citing accurate sensors, phone alerts through Google Home and voice alerts that state what the alarm is sensing. Bob Vila rated it 4.5/5, reporting a three-minute setup with preinstalled batteries and a large centre button that silences cooking false alarms. It suits Google Home households that want smoke and CO coverage in places without wiring; homes where codes require hardwired alarms, or buyers fitting many rooms on a tight budget, should look elsewhere.
- — Detects smoke and carbon monoxide in one unit, with voice alerts that say which hazard it senses
- — Links to the Google Home app via Nest Protect integration for phone alerts away from home
- — CNET named it best overall CO detector after lab tests of its sensors
- — Battery-only power may not satisfy building codes that require a wired alarm
- — Costs far more than standard alarms, which adds up when equipping a whole house
