Using Video Cameras to Monitor Fire Activity

Video Image Detection systems can play an important dual role providing both fire protection and facility security.

Advances in video analytics, imaging, processing speed, and chip miniaturization now allow for surveillance systems and software technology that reliably and cost-effectively detect smoke and flame faster than conventional, commonly used methods in high-rise facilities.

By combining the enhanced resolution and picture clarity of a standard network camera with built-in flame, smoke, and motion detector capabilities, video analytics fire detection can be used in high-rise facility applications such as machinery spaces, generator rooms, electrical equipment/switchgear rooms, and any areas with large-volume space and/or high ceilings with stable lighting. VCA detection is commonly used in rooms with ceiling obstructions or other obstacles that pose problems for ceiling-mounted smoke detectors. Additionally, VCA can be utilized in rooms with beam pockets (of which NFPA 72 may require a smoke detector in each pocket).

Video surveillance and analytics technology is also being used in firefighters’ elevator lobbies for detection and visual confirmation of smoke and fire on floors being serviced during an active fire or emergency scenario.

Video analytics or “video content analysis” (VCA) offers facilities professionals a solution that automatically analyzes surveillance video to detect and determine temporal and spatial events. The technology can be applied with firmware in specially made cameras, or by analyzing video from installed security cameras via software in a server.

For decades, VCA technology has taken the use of surveillance cameras beyond traditional monitoring capabilities. VCA has been used in manufacturing facilities to ensure quality control and process monitoring, in security systems for facial/license plate number recognition, and in many other applications. Video content analysis for fire and smoke detection uses the same proven technology and principles. The software is written by fire protection engineers and biophysics PhDs who keep the fire detection application of the VCA technology in mind.

An example of flames detected by video content analytics. Credit: Fike

Why VCA?
Implementing VCA for fire and smoke detection offers several benefits, including the ability to detect smoke as it rises. This eliminates the potential for stratification detection issues found in ceiling-mounted detectors (where smoke doesn’t rise high enough or quickly enough to reach), while also detecting flame and the reflection of flame. With reflected flame detection, the camera doesn’t need to “see” the flame directly – it can detect flickering light that is being reflected off of walls, machinery, and electrical cabinets.

Another benefit of implementing VCA into your fire protection plan is the help live video provides to first responders. Video content that displays the live fire can help determine if it is safe to send personnel into a room, and also helps plan a method of response and fire investigation. VCA is acknowledged by the 20th edition of the Fire Protection Handbook to “provide very useful input to emergency management decisions” of events due to remote video capabilities.

The Way it Works
In simple terms, VCA smoke detection is initially performed with the software “learning” the environment in the camera’s field of view and refreshing at 15 frames per second. For smoke detection, the analytics are normally monitoring a sharp video image in pixels; when smoke develops, effected pixels become opaque or fuzzy.

Benefits of Using Video Content Analytics for Smoke/Fire Detection

• Constantly record video streams on to internal hard disk
• Customizable storage space to meet application needs
• Monitoring of live videos and fire events
• Maintain an event log for all alarm conditions
• Dispatch alarms and videos to remote locations
• Network management interface for configuration and maintenance

The analytics monitor the effected pixels to determine whether or not the smoke is moving in an organized pattern consistent with known smoke signatures. For flame detection, the analytics are looking for pixels affected by slow-changing brightness, as well as tracking dynamic flicker for known signatures of flame.

The cameras’ floor-to-ceiling, wall-to-wall field of view allows very early detection and the ability to detect low-lying smoke in the room, unlike conventional detection methods that require additional time for smoke to physically interact with the detector or detection beam.

Working with digital images and software, detection can be digitally targeted to specific equipment or to areas with the potential for false alarms or low hazard. These areas can easily be blocked or ignored by detection algorithms. Listed cameras include relays to be monitored by fire alarm systems for alarm and trouble, and can send unique signals of either smoke or flame.

The diagram on this page displays a typical system architecture of a UL Listed IP-based VCA system. The cameras have onboard analytics, are powered either over Ethernet (PoE) or 24VDC from the fire alarm system and networked to the network video recorder (server).

CODE
Video analytics fire detection equipment has listing/approval by Underwriters Laboratories (UL), Factory Mutual (FM), and local jurisdictions. The technology is also included for use by National Fire Protection Association Standard NFPA 72, Fire Alarm and Signaling Code. FM datasheet 5-48 for Automatic Fire Detection specifically recommends video fire detection in commercial and industrial applications.

Maintaining a VCA System
NFPA-required maintenance is accomplished by performing a “verify” routine at the computer. The software compares the commissioning report settings with the current camera conditions, and compares a sketch of the objects in the field of view at commissioning with current conditions to assure it has not been moved. This is all done at the computer terminal; it can also be performed remotely over the internet. The camera also continuously checks for obstructions, network and lighting conditions, and dirty lenses.

Video content analytics offer an approved fire detection solution for various high-rise facility applications. By combining video cameras and VCA, smoke and flame can be detected in their earliest stages.

The availability of this technology, along with the reliable performance of video detection, can help you achieve a cost-effective, early warning detection solution for your facility.