The key to selecting the right one is to look beyond the initial costs when evaluating the lifetime value of the system. There are many associated factors with each type of system that may make one a better choice than the other. A closer look at some of the key differences between conventional and addressable systems can be summarised as below:
- False Alarms: False alarms are always an important consideration as they are expensive for fire departments majorly in terms wastes cost, time & efforts. False alarms are far more common with conventional systems. In contrast, addressable devices are always getting monitored by alarm panel for their sensitivity preventing the occurrence of false alarms. The sensitivity of the sensors in addressable devices can also be adjusted. Also, addressable devices provide “drift compensation” – the ability to distinguish between subtle changes in the level of smoke detection that occur over time due to contamination, like dust, and rapid changes resulting from a real fire.
- Safety Considerations: Without a doubt, addressable systems provide a greater level of fire safety because they allow fire-fighters to respond more quickly and effectively by pinpointing the exact location of a fire in a building.
- Reliability: An addressable system is generally more reliable than a conventional system mainly due to how the different systems are wired. With a conventional system, if a device’s wire is damaged or severed, its signal and the signal of other devices down the line cannot be transmitted to the control panel. With an addressable system, both ends of the wire connect to the control panel. Therefore, if one end becomes damaged or severed, signals can still reach the control panel through the other end of the loop. In addressable systems, a device can be removed or disabled and it will not affect the other devices in the loop.
- Scalability: Addressable systems provide a great deal of flexibility in comparison to conventional systems. While the number of devices either system can accommodate is determinant on the manufacturer of the alarm panels, every type of device added to a conventional system requires a new circuit. Because they require less wire, an addressable alarm control panel can accommodate far more devices than a conventional system. They can have anywhere from one to 30 loops, commonly referred to as a Signalling Line Circuit (SLC), each of which can monitor and control several hundred devices.
- Life Cycle Cost: The equipment required for conventional systems usually comes with a much lower price tag than addressable systems, which is why conventional systems are still a popular choice for small businesses. However, it is wise to look beyond the initial costs. Even for small buildings, the lower initial costs to purchase the equipment needed for a conventional system are often offset by higher installation costs. Remember that conventional systems require a single circuit for each zone, one which can lead to much more complex wiring than an addressable system in which all the devices are wired into a single loop. This increase in complexity not only drives up the cost of installation but also introduces a greater risk of human error. While both types of systems require regular inspections and testing, troubleshooting and maintenance are easier and less expensive with addressable systems. With independently wired zones in a conventional system, each device must be checked separately to find the problematic device. Addressable devices can send maintenance alerts and trouble signals to the control panel to make finding problematic devices and getting them repaired or replaced much faster.
Conventional Fire Alarm System
- Suitable for Smaller Applications
- Not Suitable for Large and Complex Buildings
- No special or complex peripherals are needed as compared to its intelligent counterpart
- Simple Panel requiring no special skill sets are needed
to operate - The location of fire need to be estimated
- More judgement time for identification.
- It is not a self-diagnostic system needing more frequent routine maintenance to ensure its functionality
- Integration with is BMS not possible.
Intelligent Fire Alarm System
- Cost Effective for Larger Applications
- The Location of a Fire Condition is Detected and Recorded at Each Individual Device, Identifying Exactly Where the Fire Is Occurring improving Response Time for Emergency Responders
- Lower On-going Service Cost, Because When a Device Goes into Trouble (i.e., Needs Cleaning, Repair or Replacement), the Panel Will Tell You the Exact Location of the Device Needing Service
- Faster Identification of Fire Location
- Online Capabilities: New Intelligent Panels Have The Capability to Provide Detailed Online Notification of Alarm/ Trouble/ Supervisory Events
- Self-diagnostic system reducing the routine check-up and maintenance cost
- Integration with BMS is an added advantage.
Integration of Fire Alarm System with Building Automation System
Fire safety is extremely important in all buildings making it most critical for the facility managers in order to focus on their fire protection strategies, maintenance of existing technologies, and identify where system upgrades are needed. A reliable fire alarm system should quickly detect a fire and provide clear messages within the facility with least disruption to the operations of buildings.
The conventional fire alarm systems provide an adequate and cost effective fire alarm system for many small buildings, however with rise of more complex buildings more sophisticated ‘intelligent’ fire alarm systems were needed-systems which can offer benefits in speed of detection, identification of the location of a fire and easier maintenance. These Intelligent systems also offer tolerance to faults in the system wiring, which allows a single pair of wires to be used to connect up to 198 devices to the system, allowing cost savings in the wiring of large systems. In larger installations, the benefits of improved maintenance and reduced cabling cost are overwhelming.
Despite significant advancement in building designing, construction and its other integrated systems as a whole including Building Automation System, unfortunately fire alarm & fire fighting systems have not been given similar importance. This is because of a mind-set assuming a low probability of fire incident happening yet forgetting another critical associated risk factor that is severity while taking a call on it. Most of this assumption stems from the fear of the unknown and the desire to mitigate risk along with the old adage of “This is the way we’ve always done in” or “That fire has never happened in my deign” In reality, the integration of building automation and fire alarm systems can result in overall reduction in equipment, installation, and maintenance costs while still maintaining the level of safety required for these systems to operate.
With the advent of smart building technology, heating, cooling, electrical, and lighting, security, and other systems need monitoring and intercommunication for optimized efficiency and operation. With sophistication comes the need for a Building Automation System (BAS) to allow for nearly seamless operation of these various interrelated equipment.
Like BAS, over the time now fire protection and alarm systems have also evolved into sophisticated computer-based systems, which integrate fire detection and emergency communication systems as part of overall building operations during an emergency event.
Often fire protection and alarm systems must interact with other building systems to provide a proper level of protection. While the fire alarm system is fully capable of performing and initiating the necessary actions to accomplish the fire alarm and building systems’ responses, efficiencies can be obtained by integrating with the BAS. These efficiencies include minimizing additional equipment, expediting system acceptance testing, reducing installation costs, and sharing and consolidating information at a central location where all of the building systems can be precisely monitored during emergency incidents.
Therefore, in order to integrate system alarm and control functions with the BAS in a manner other than relay logic, fire alarm system manufacturers had to also design and support the open communication protocols used for building automation, in a manner that would not compromise the integrity or the operation of the fire alarm system. This process of sharing information between both fire alarm and BAS came to be known as bridging, or open gateway processing. Because of the strict code and listing requirements of fire alarm systems, much of this communication has been primarily limited to one-way communication. However, some manufacturers of both fire alarm and BAS do produce equipment such as gateways that are listed for bi-directional communication with their equipment.
The use of these open gateway processors has the potential to eliminate the need for costly interface equipment and enclosures. A single gateway can replace hundreds of conventional or electronic relays and input sensors for control and monitoring while also eliminating the need for multiple wire terminations that can decrease the potential for system
failure points.
Advantages of Intelligent Fire Systems in Complex and Large Buildings
- Addressable fire alarm systems give information about individual detectors, whereas conventional systems only give information about specific circuits (zones).
- Addressable systems allow a courtesy text label to allow easy identification of any event. For instance detector 1 may be given the label “Bedroom 1”.
- Most addressable systems allow an early “pre alarm” warning, which allows the responsible person to investigate potential alarms before the system activates its sirens.
- Many addressable systems can alter the alarm threshold of the detectors, in order to meet the needs of different environments in different areas of the system.
- Addressable systems are usually wired in a loop.
- Conventional systems are usually wired as radial circuits.
- Addressable systems usually have a real time clock & event log to record system events.
- Larger addressable systems usually have the ability to use sophisticated programming options to operate certain outputs only with specific events.
Why to Integrate Fire Alarm System with BAS
There are many reasons for integrating fire alarm systems with other building automation and control systems e.g., for smoke control, building access information, easier maintenance, sharing sensor data, obtaining information about the location of people during an emergency, and providing infrastructure for new technology to improve performance and safety.
Fire detection systems have been integrated with door locks and with HVAC fan and damper controls for smoke management for several years, but these systems have relied on relays controlled by the fire alarm system to override the normal controls. This kind of integration has primarily been limited to only on/off control of fans and dampers. Many modern HVAC systems are far more complex. Smoke management is much more complicated with these systems and outside of the capability of most fire alarm systems. What is needed is a way for the fire alarm system to command the HVAC control system to enter a smoke control mode and let the HVAC controllers manage the equipment. New sensors are being developed that can recognize various contaminants in the air that can represent a fire signature or a hazardous contaminant that poses a life safety threat. In an integrated system, these sensors could be used by the HVAC control system to control ventilation rates with no adverse impact on their life safety functions. Multiple uses for the same information will make it more cost-effective to implement new sensor technology. In some buildings, access control systems monitor the location of building occupants. Providing access to this information to the life safety systems could be very helpful in an emergency. Emergency response personnel would know where to look for occupants who need to be evacuated. They could also reduce the risk to themselves by avoiding dangerous areas where no people are present.
Challenges in Integration of Fire System with BAS
Maintaining the integrity of fire alarm systems in any building, while integrating them Building Automation Systems (BAS) requires more than just communication standards. The technology of building automation and control systems has advanced at much faster pace and more rapidly over the past many years. Today’s technology provides building owners and designers with a rich assortment of options and flexibility with intelligent distributed controllers that process complex set of building information at lightning speed to efficiently characterize state-of-the-art building automation and control systems. These advances have taken place across a variety of building services including Heating, Ventilating, and Air Conditioning (HVAC) control systems, lighting control systems, access control systems, and fire alarm systems. In spite of these advances in BAS, due to non-availability of any standard interfacing protocol, fire alarm systems have been finding it difficult to get integrated with BAS. However, to overcome this difficulty, in 1987, BACnet communication protocol was developed by the American Society of Heating Refrigerating, and Air-Conditioning Engineers (ASHRAE). It has been adopted as standard in many countries and has also been proposed as an ISO standard (ISO 16484:2017). BACnet product offerings range from gateways that connect proprietary systems to complete product lines that use BACnet as the primary or sole means of communication. The adoption of BACnet1 as the standard communication protocol for integrating building control products has changed the industry and opened the door to new innovation in building control technology and true integration of previously isolated building systems. Though BACNet provides the necessary isolation to Fire Alarm System, it also limits the integration possibilities. An alternative approach is to develop best design practices for constructing networks of integrated systems. By appropriate selection of network technology and appropriate use of routers and bridges to filter traffic, interference problems and concerns about guaranteed access to network bandwidth in an emergency can be effectively eliminated.
Prabhat Khare possesses a BE (Electrical) degree from IIT Roorkee (Gold Medalist). Now, he is the Director of KK Consultants.
