Smoke Detectors

One of the most overlooked safety devices in your home is the smoke detector. There are two types of smoke detector systems available today:

• The type that has smoke detector wiring that issues a signal to a monitored fire alarm system
• The smoke alarm that generally issues a local audible and/or visual alarm from the detector itself

Most smoke detectors work either by optical detection or by physical process, while others use both detection methods to increase sensitivity to smoke. Smoke detector wiring can be powered by a central fire alarm system, which uses a battery backup, or, as is the case in many single family detached and multi-family homes, a smoke alarm is powered only by a single disposable battery.

Installation and placement
Smoke detectors are generally placed where they will do the most good. In the United States, most state and local laws regarding the required number and placement of smoke detectors are based upon standards established in the National Fire Prevention Association (NFPA 72) fire code. Laws governing the installation of smoke detectors vary from jurisdiction to jurisdiction. The United States requires smoke detectors on every inhabitable level, in attics that are accessible and within the vicinity of all bedrooms.

Battery Backup
Most residential smoke detectors run on 9-volt alkaline or carbon-zinc batteries. When these batteries run down, the smoke detector becomes inactive. When the battery is low most smoke detectors will signal with a chirping sound at regular intervals.

Some detectors are also being sold with a lithium battery that can run for about 7 to 10 years, though this might actually make it less likely for people to change batteries, since their replacement is needed so infrequently. By that time, the whole detector may need to be replaced. Though relatively expensive, user-replaceable 9-volt lithium batteries are also available.

Protecting Your Safety
If you have questions or concerns regarding smoke detector installation or repair in your home, contact the Mister Sparky team for assistance. Smoke detectors save lives, and at Mister Sparky we want to help ensure your safety.