By John Allan
From the August 2019 Issue
How can an up-to-date “smart” fire detection system help facility management professionals outfit their buildings to provide safety and comfort to occupants and the organization overall? Following are five aspects to consider when evaluating fire detection equipment.
Early detection keeps fire damage small. Today’s fire detection technology can detect a fire in what fire safety science calls the “incipient” stage, when it is still small and controllable, and damage is minimal.
This is particularly important given the fact that many commercial buildings stand empty more than half of each workday, as well as during most weekends and holidays. When there is no one present to pull a fire alarm, the fire may grow to an uncontrollable size before it is even noticed. This may increase the scope of loss of business momentum as well as physical assets.
Pinpoint location selection. Previous fire detection systems were on a single circuit. From the control panel, it was difficult to tell which part of the building might have a problem. As a result, fire crews would have to search throughout the building, wasting precious time, and the fire had time to build. In addition, sprinkler systems might be activated for a larger area of the building than needed, causing unnecessary water damage.
Current systems can tell exactly where the fire was detected, allowing for prompt and efficient response while the threat is still small. With less need for firefighters to check the whole building, evacuated staff are able to return to work more quickly, restoring productivity sooner rather than later.
Customized to meet facility needs. The heat plume from a fire lofts into the air the by-products of combustion, which then pass through the detection chamber of the alarm unit and trigger the sensor. Picking the right kind of detector—one that is matched to the type of combustible materials on the premises—will help ensure a timely response to a fire, while also helping avoid false alarms.
Today’s alarms can be programmed to change their sensitivity according to factors such as the time of day. This works particularly well with businesses that have repair shops and manufacturing areas which produce a dirty atmosphere during the workday, but as the air clears at night, the sensitivity of a detector can be increased.
Modern detection systems can also be interfaced with building control systems to perform critical functions. This includes shutting down ventilation blowers, closing fire doors, and opening smoke exhaust systems. (See sidebar for an overview of common detection technology.)
Risk and cost management. Having a good fire detection system may help reduce insurance costs. And, remember that many insurance policies cover just the basics of a fire loss, but there are other costs that will not be covered unless specific riders (likely adding to premiums) are added. Of course, the larger goal is to stop a fire before it has a chance to do much damage. This means that fire detection technology is a big part of smart risk management for buildings.
Attract and retain employees and tenants. In the quest to attract and retain top talent, being able to demonstrate caring for employees—by showing how they’re being protected from danger due to fire—can help with staffing goals. In buildings that include tenants, having a good fire detection system can help with tenant relations and improve the building’s competitiveness.
Choosing A Fire Detection System
According to the National Fire Protection Association (NFPA), “the goals for fire detection in any scenario require the use of a detector that will provide the optimum performance in terms of early detection and freedom from false alarms, and remain operationally reliable during its life cycle.”
Some of the factors to consider in selecting a system meeting those criteria are:
- Cost. What best suits the application? (Note: Be wary of what might be called “dollar store” systems that meet basic needs but lack reliability as well as the capacity for expansion)
- Serviceability. Are there service companies available locally to maintain, test, and repair systems?
- Flexibility. Can the system be upgraded? If the business expands, can the system expand with it?
- Longevity. In 15 or 20 years, can parts and components be replaced, and will there be technicians still available who are trained to service that system?
Many states and local authorities require that fire alarm systems comply with NFPA 72, National Fire Alarm Code. This code does not specify where systems must be installed, but it does define how the equipment must be installed to ensure optimum performance. Factors for decision-makers to consider include:
Common Types Of Fire Detection
- Ionization-type alarms have radioactive material between two electrically charged plates which ionize the air and cause current to flow between the plates. Smoke entering the chamber disrupts the flow of ions, reducing the current and triggering the alarm.
- Photoelectric alarms aim a light source into a sensing chamber; smoke reflects light onto a light sensor to trigger the alarm.
- Heat detectors come in various types, including fixed temperature and rate-of-compensation. These are best used in dirty environments or in those with high hazard flammable liquid processes.
- Air aspirating detectors use laser sensors in a detection housing. Air is drawn into the detector head through a pump connected to tubing routed throughout the room. These are used in areas where very early detection is required, such as clean rooms, computer rooms or high dollar risk areas.
- Linear beam detectors are used in large spaces and use ceiling-mounted detectors at opposites sides of a room. These look for smoke obscuration by measuring reflectivity.
- Ultraviolet and infrared detection systems provide high-speed detection around large industrial and flammable liquids facilities.
A qualified engineer can help to choose the right technology, or combination of technologies, to meet a facility’s specific needs.
- Requirements for the designer and the installer to follow for code-compliant installations, including drawing requirements, documentation, testing criteria, and reports
- Detector spacing (the distance between the detectors based on the height and slope of the ceiling)
- Location of detectors relevant to projected air movement in the building
- Placement of visual and audible alarms based on sound projection of the horn and visual acuity of the strobe light
- Protection of alarm signal wiring so it survives under fire conditions.
- Reporting of alarm systems to monitoring locations such as the fire department or an alarm services company
For new or renovated facilities, while many builders will offer to install a fire detection system, it’s too important a task and demands too specialized knowledge for a general contractor to provide this service. Some points to look for:
- Engineers licensed in your jurisdiction as Professional Engineers (P.E.)
- Qualified to analyze the hazards your building faces
- Membership in a professional organization such as the NFPA
- Qualified fire protection system designers with at least five years’ experience
An intelligent fire detection and alarm system can be an added safety feature to a building that will provide many years of reliable service. It is a 24/7 guardian of an organization’s premises and occupants. Properly installed and maintained, these life safety systems will provide long-term protection with relatively low annual maintenance costs.
Allan is a fire protection engineer with the Buffalo, NY area multidisciplinary firm Encorus Group, which is a service-disabled veteran-owned small business (SDVOSB).
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