Smoke detectors or smoke alarms are devices that can detect smoke in the air and therefore alert against any potential fire. In a larger fire alarm system, smoke detectors are just a component of the system, but in most homes, smoke detectors are the main anti fire appliances popular with many home owners because of their size and ease of use. In most ordinary homes, smoke detectors function as standalone fire prevention devices.
The difference between smoke detectors in large buildings versus home versions is the complexity. Smoke detectors inbuilt into large automated fire prevention systems are all interlinked to the main central fire alarm control panel, which in turn is powered by the main building power source, in many cases hooked up with backup power generators.
Smoke detectors designed for homes are often just powered by a simple battery or group of batteries attached to the back. These batteries would need to be checked yearly to ensure the smoke detector can work properly when called upon.
There are three types of smoke detectors, the optical or photoelectric smoke detectors, the ionization smoke detectors and the hybrid smoke detectors, which are a combination of both ionization and photoelectric technology. We will look into all three types here on this site.
But first of all, why are smoke detectors useful?
Every year, millions of fires occur worldwide and a large proportion of these happen in homes. Many injuries and fatalities are also caused by these home fires, which could have been minimized had many of these homes installed smoke detectors. The difference between life and death can often be just a few minutes, which is what smoke detectors are designed for. It is estimated that smoke detectors reduce the fatality risk by 50%.
You might think this is trivial, but think of the consequences. Once a fire has spread it can and will be deadly. Most fatalities occur not because of the flames, but because of smoke inhalation. Smoke from fire is dangerous because it contains a lot of carbon monoxide which can kill a human being very fast.
Smoke also contains hydrogen cyanide, a deadly poison that was even used in wartime. It stings the eyes and burns your lungs and windpipe. In an enclosed area, smoke from a small fire can be enough to obscure all visibility. A few minutes of exposure to smoke is enough to be fatal. Therefore, early warning of a fire is essential, and that is why smoke detectors are that important as the first line of defense against fire.