Conventional Fire Alarm Systems
A conventional fire alarm system requires a building to be divided into a number of areas called zones. The detectors and manual call points within each zone are wired on dedicated circuits. When a detector or manual call point is triggered, the panel identifies which circuit contains the triggered device and which zone the fire alarm has come from. It is then necessary to manually search the indicated zone to find the exact cause of the fire alarm.
A conventional fire alarm system needs separate alarm circuits to signal a fire to the building users.
When designing a conventional system it is important to ensure that the panel has enough zone capacity for the size and complexity of the building and that the panel can support the intended sounder circuit wiring and loading.
Analogue Addressable Fire Alarm Systems
With an addressable fire alarm system, each smoke or heat sensor and manual call point is coded with a unique address. The control panel is able to communicate with any of the addressable devices by using the address number to define which device it wishes to communicate with. When a detector or manual call point is triggered, the panel will indicate the specific device address that has been activated.
Addressable fire alarm systems are wired on loops rather than radial circuits which allow for audio visual warning devices such as sounders and beacons to be connected onto the same circuits as detectors and call points, which reduces installation costs. Most addressable systems now provide combined detectors, sounders and beacons in a single unit.
Aspirating Smoke Detector (ASD)
An aspirating smoke detector consists of a central detection unit which draws air through a network of pipes to detect smoke. The sampling chamber is based on a nephelometer that is capable of detecting the presence of smoke particles suspended in air by detecting the light scattered by them in the chamber.
ASD design corrects shortcomings of conventional smoke detectors by using sampling pipes with multiple holes. The air samples are captured and filtered, removing any contaminants or dust to avoid false alarms and then processed by a centralized, highly sensitive laser detection unit. If smoke is detected, the systems alarm is triggered, and signals then are processed through centralized monitoring stations within a few seconds.
Aspirating smoke detectors are highly sensitive, and can detect smoke before it is even visible to the human eye.Radio linked wireless fire alarm systems offer several key advantages over traditional conventional or addressable fire alarm systems. All the components are linked together by means of a radio signal, meaning that there is no need for them to be wiring them directly together. Radio linked wireless fire alarm systems provide an ideal solution where quick installation is required, or where particular care is need in preserving the decor and structure of a property.
Radio Linked Wireless Fire Alarm Systems
Radio linked components are fully addressable and offer complete customisation for the user, meaning the fire alarm system can be perfectly tailored to the premises required.