Smoke and CO Detectors

Smoke and carbon monoxide detectors from First Alert and BRK: ionization, photoelectric and dual electrochemical/photoelectric, in battery-powered, hard-wired and hard-wired with battery backup, including 10-year sealed battery models. Sensor type matters more than the price. Ionization responds faster to fast flaming fires, photoelectric responds faster to smoldering fires, and a dual-sensor or one of each is what covers a house properly. Combination smoke and CO units save a box but have two different service lives — smoke sensors are generally good for ten years from manufacture and CO sensors less, so the unit expires on whichever comes first. Hard-wired detectors are meant to be interconnected so one alarm sounds all of them, and mixing brands on an interconnect line often does not work.