Emergencies can and do happen in any building, no matter how well it is constructed or maintained. To ensure the occupants’ safety in an emergency, buildings must have a well-planned and executed emergency control program. This program should include the use of properly functioning fire doors and smoke control systems.
Managing a fire emergency is more than just putting the fire out. A fire alarm control unit is used to monitor conditions throughout a building, with strategically placed sensors measuring temperature, humidity, and pressure, as well as sensors to detect the presence of smoke or dangerous gasses. This requires integration between dozens of sensors, valves, and other devices that all work together to keep the building occupants safe. System integration is a term used to describe a fire alarm control unit integrated with other life safety systems.
In this article, we will discuss how fire alarm control units manage and respond to emergencies and keep occupants safe by integrating multiple life safety systems.
The Importance of Containment
One of the primary objectives of a fire control system is to isolate the threat and prevent the fire from spreading. Modern commercial buildings are built with fire-resistant barriers in places like elevator shafts and stairwells. With fire doors equipped with automatic closers, a fire in a stairwell or elevator shaft can be contained within that area of the building to be extinguished by the building’s sprinkler systems or when firefighters arrive on the scene.
The fire alarm control unit uses a control circuit and relay to monitor building conditions and signal problems. Information regarding the location and nature of the alarm is sent to the fire alarm control unit when a smoke, temperature, or pressure sensor measures unsafe levels or if an alarm is manually activated by a building occupant. The control circuit is integrated into the fire alarm control system to provide power to the relay—which switches state from normally open to normally closed and back.
The control circuit and relay are what allow the fire alarm control unit to control applicable devices and sensors within the integrated system. Here are some of the fire safety devices that can be managed by a fire alarm control system to control fires and keep occupants safe.
Fire doors are an essential part of any fire safety plan. If a fire occurs, you want the fire to remain as small and isolated as possible. Containment of a fire within a structure is aided by physical barriers such as fire doors. They are designed to keep flames and smoke from spreading from one area of the building to another and to provide a safe escape route for occupants. If a fire door is not working properly, it can jeopardize the safety of building occupants.
As a fire deterrence, fire doors only work when they are closed. Therefore, one important part of a fire alarm control system is the ability to ensure that these barriers are closed in an emergency. Some systems are designed to automatically close doors in the event of a fire. Others are dual-purpose and can be used to hold the door open when needed to facilitate the evacuation of the building and then close the door to contain the fire.
Elevators can be a serious vulnerability when a fire occurs. This is because elevator shafts can extend from the basement to the top floor of a building, making it an easy conduit for fire and smoke to spread from its point of origin.
When a fire alarm control system is notified of a fire threat, it can send signals to elevators in the building to either recall or shut down. The seamless integration between the elevators and the fire control system means that elevators receive the information needed to protect passengers. A properly designed and installed system will help to contain smoke and heat within the shaft. The data sent to the elevator control system contains the location of the threat, which is then used to determine if certain floors should be avoided or the best place to release passengers so they can exit the building quickly and safely.
Smoke Control Systems
A smoke control system is necessary for buildings with large common areas that span more than one floor to compensate for the lack of physical fire barriers. In addition, smoke control systems are essential for keeping fires under control. They work by drawing smoke and heat away from the fire, which helps to extinguish the blaze more quickly.
When the fire alarm control unit is alerted to the presence of smoke, it delivers a signal to a smoke control panel. This smoke control panel receives information regarding the location of smoke and initiates containment measures. These measures could include the closure of fire doors and the activation of fans, dampers, or air openings to disperse and control the spread of the smoke.
Mapping the Fire Alarm Control Unit
Given these various functions, keeping track of all the sensors, switches, and devices wired to the fire alarm control unit can be complicated. However, to keep the system fully operational, you must have a way of tracking inspections for all system components. That is why the input/output matrix is so important.
The input/output matrix organizes the applicable inputs and outputs for the system into a simple table. This information is critical for testing the system and diagnosing system failures before an incident occurs.
To learn more about how to set up your system, the NFPA offers guidance in NFPA 4, Standard for Integrated Fire Protection and Life Safety System Testing. This standard prescribes the minimum requirements for both active and passive systems. In addition, this factsheet provides important information regarding the requirements for system testing and identifies roles and responsibilities for supervising and testing system components.