Advances in commercial smoke detection technologies and application techniques have produced tangible and intangible benefits for everyone: building owners, management, and occupants; the installation, maintenance, and service contractor; the manufacturer; and the industry.
In general, the tangible benefits represent savings in time and costs, and the intangible benefits relate to greater confidence in the systems.
The installation and maintenance of automatic fire detection and alarm systems in public and commercial buildings is generally required by local building codes. The commercial automatic fire alarm market is estimated at $2 billion annually in the United States.
To be successful in this market over the long term, it is not enough to provide systems utilizing a code-driven cookbook approach. You must understand the purpose of the system, its detection devices, and how they relate to the entire fire protection scheme of the building. Then, you can select and apply the technologies that meet and exceed the needs of the building, its owner, and the authority having jurisdiction.
Smoke detectors are the most common electronic devices used to indicate a fire condition; yet, they have been the most misunderstood and misapplied commercial fire detection devices.
Thus, the false alarming of smoke detectors has been an industry-wide concern. Frequent false alarms have resulted in lost confidence in the systems, thus damaging the reputations of the installer, manufacturer, and industry.
When unwanted alarms have been reported by smoke detectors, investigations have frequently shown the problem to be attributed to improper maintenance and service, the age of the detectors, or misapplication of the detector. Manufacturers of commercial fire detectors have built-in new technologies to combat those errors.
Commercial smoke detectors now make decisions with respect to the conditions of the detectors and their environment. New technologies include: self-adjusting sensitivity, cleaning alert, sensitivity programming, multi-sensor technology, and more. The devices are available at competitive prices, and their long-term benefits can reflect significant savings.
Self-Adjusting Sensitivity Increases Alarm Integrity
Self-adjusting sensitivity improves the integrity of alarm condition signals generated by the detector.
Several of these types of smoke detectors monitor for changes in the operating characteristics of their circuitry and the environmental conditions within their smoke sensing chamber. Then, the detectors make adjustments to compensate for these changes and assure maintenance of their alarm sensitivity levels.
Usage of detectors with these features provides two benefits to customers: reduction in unwanted alarms which means improved confidence in the system, and elimination of physical sensitivity testing which means a reduction in maintenance costs.
Sensitivity testing is normally required of smoke detectors. With some exceptions, they need to be tested within a year after their installation and every other year thereafter. A specifically designed electronic monitoring approach relying upon communication between the detectors and the fire alarm control unit to provide trouble signals is an acceptable alternative to manually performing calibration testing.
Self-adjusting sensitivity testing has reduced the usefulness of alarm verification as an approach to assure that an alarm signal is valid. The purpose of alarm verification is to minimize spurious alarm signals.
Under the alarm verification approach, the control panel turns off a detector when it indicates an alarm condition and holds the detector in the off state for 60 seconds. The control panel then turns the detector back on and, if the alarm condition remains or if another detector signals an alarm condition at any time during the off period, the control panel initiates its alarm sequence functions.
Detectors ‘Beep’ to Indicate Contamination
The newer technology smoke detectors self-monitor their smoke chambers for cleanliness. When the environmental conditions of the smoke chamber become contaminated beyond desired levels, the detector produces an indication that it needs to be cleaned. Most detectors provide a second level of cleaning notification when the condition worsens.
The control panels react to these signals and provide specific messages describing these conditions. This feature identifies potential problems before unwanted alarms occur, allowing an orderly cleaning process vs. a reactionary process when an alarm condition occurs. This means that the user can provide advance notification to occupants of an interruption and, if you are providing the cleaning service, you can schedule technicians to perform the work. To reduce the cleaning efforts, one manufacturer’s photoelectric smoke detectors utilize disposable smoke chambers that can be easily removed and replaced.