When smoke detectors are interconnected, they are able to communicate with one another so that when one alarm detects smoke, all the alarms go off. This helps residents escape a house fire more quickly. Smoke detectors can be hard-wired to one another or connected wirelessly using radio frequency signals.
When interconnected smoke detectors sound an alarm, lights on the individual alarms indicate which specific detector triggered the alarm. Running a test on the smoke detectors reveals whether a system is interconnected; if it is, the test should cause all the alarms to go off, and if not, only the detector tested goes off.
Interconnected smoke detectors that use RF signals instead of being hard-wired are cheaper and faster to install. Their installation also provides greater flexibility, making it possible to install more smoke detectors in more locations. They are also easy to change; additional smoke detectors can be programmed into the system quickly, sometimes within a few minutes. Renters can use them to have interconnected smoke detectors without asking a landlord to perform costly construction.
The Consumer Product Safety Commission has approved the use of RF signals for interconnected smoke detectors and considers them a promising technology for the purpose. RF signals are already used for communication between cellphones, garage door openers and walkie talkies.