Video Fire Detection: Camera-Based Smoke and Flame Detection Explained

Point-type smoke and heat detectors work well in most buildings. Some environments break their basic assumption: smoke or heat must reach a ceiling-level sensor quickly. Large factory floors, timber and textile workshops, and open-air material yards break it routinely.

VFD was developed for exactly these cases. International standards now describe it as its own detection method. This article shows where VFD fits next to conventional point detectors.

What is video fire detection (VFD/VISD)?

VFD uses cameras and image-analysis software instead of a physical sensor. It looks for the visual signs of fire: a smoke plume forming and moving, or the flicker pattern of open flame.

One camera can watch a whole aisle or yard. It can catch a fire developing well outside the plume that a ceiling-mounted detector would need. This is the gap described above for large, open or dusty spaces.

VISD (video image smoke detection) is the older term, still used in some standards and product literature. VFD is now the more common name for the same analytics-based method.

VFDS, video-based fire detection system, video flame detection — same technology, different names

Specification documents and search queries use several names for VFD:

• VFDS (Video Fire Detection System)
• Video-based fire detection system
• Video flame detection — the name used when the focus is open flame, not smoke

All of them describe the same method: cameras and image-analysis software identify the visual signature of smoke or fire in real time. They work as an alternative or supplement to point-type detectors.

Where conventional point detectors struggle

A point detector needs the smoke or heat plume to travel to the sensor. Four environments make that hard.

How video fire detection works

A VFD system does not need a purpose-built sensor grid across the space. It uses cameras. These can be existing CCTV installed for security, or dedicated units added for this purpose. They connect to a fire alarm control panel by cable or a wireless link.

The camera becomes part of the fire detection chain. It needs the same protection as an initiating device:

• A battery or priority power feed, so it keeps recording through a power interruption.
• Infrared illumination, built in or triggered by the ambient light sensor, so night-time footage stays usable.

The control panel, or a processing unit connected to it, analyses each frame continuously. It looks for motion patterns, smoke-density changes and abnormal colour signatures consistent with flame. It does not wait for smoke or a temperature rise to reach a sensor.

Image analysis vs. thermal imaging: two different signals

VFD is sometimes confused with thermal-imaging cameras. The two work on different physical signals.

In practice the two are complementary, not competing. The right choice, or combination, depends on the specific site and what is stored there.

What the standards say

VFD is not an unregulated add-on category. It has its own reference standards.

ISO 7240-29:2017 sets technical requirements and test methods for fire detection systems that use images in the visible spectrum to detect smoke and/or flame. It names three basic components: an image-capture device, an image-processing unit, and a data transmission path back to the control equipment.

The U.S. National Fire Alarm and Signaling Code, NFPA 72 (2019 edition), also covers video-based detection. Its core requirements read like good engineering practice:

• Hardware and software should be listed for fire alarm use.
• Installation should follow a complete design, not ad-hoc camera placement.
• Every device should be installed exactly per the manufacturer’s instructions.
• The system should be protected from tampering by anyone without the training to service it.

FireSmart’s video fire detection solution is built against these two references.

What happens when the system detects smoke or flame

The alert goes out through several channels at the same time. It does not rely on a single one.

• The control panel activates the site’s own bells, strobes and any relay-driven peripheral equipment named in the building’s fire response plan.
• The system pushes the flagged image to a phone app and calls every phone number the site configured in advance. Responders get a visual confirmation and a direct call, not a text alone.

Where a fire alarm transmission device (FCOM) is connected, the same event goes to the local fire authority’s monitoring software. An unattended site, such as an overnight factory floor or an outdoor yard with no night staff, still reports to people who can respond.

For how detectors, panels and notification devices combine into a complete installation, see FireSmart’s wireless fire alarm systems guide.

Where VFD fits alongside conventional detectors, not in place of them

VFD is a targeted tool for zones where point detection struggles: a high-bay warehouse aisle, a half-open workshop floor, an outdoor stockpile with no ceiling. It is not the right choice to replace point detectors across a whole building.

Most rooms, offices, corridors and stairwells are exactly what point-type detectors were designed for. Their spacing and placement already follow a well-defined process. See our companion guide on smoke detector spacing per NFPA 72, which uses FireSmart’s own conventional line.

A practical design for a mixed facility, such as a factory with attached offices, has two parts:

• Keep FSS-001 optical smoke detectors and FSH-001 heat detectors in the office and corridor areas.
• Reserve VFD for the production floor, warehouse or yard, where those devices would be too slow or too prone to false alarms.

Everything reports back to the same FCP or FSP-8L control panel.

Video fire detection vs. point and beam detectors

Three main options detect smoke or flame in a large or difficult space: point detectors, linear beam detectors and VFD. Each suits a different layout.

Conditions and limitations to plan for

VFD performs best under three conditions:

• Lighting in the monitored area is consistent.
• The camera has a clear, unobstructed view of the zone at risk.
• The software is tuned to the specific environment. A busy loading dock behaves differently from a quiet warehouse aisle.

VFD is generally not the right primary detector for enclosed rooms with a flat ceiling. A point detector is simpler and cheaper there. It is also a poor fit for spaces with heavy steam, dust or vehicle traffic, unless the analysis is tuned for that environment.

Linear beam detectors remain a strong alternative for large open spaces with a clear, straight sightline where visual confirmation is not required.

Using existing CCTV vs. adding dedicated cameras

A site with CCTV coverage over the areas of concern does not necessarily need new cameras. The existing feed can often connect into the fire detection analysis directly. This is the main cost advantage over a dense grid of point detectors across a very large open space.

The camera must be capable of the job:

• It covers the specific area at risk, not just a general overview angle.
• Resolution and frame rate are enough for the software to pick out smoke or flame patterns reliably.
• It has a built-in low-light or infrared mode, or the location is bright enough at night.

Where existing cameras fail these conditions in a zone, add a small number of dedicated units placed for fire detection, not security framing. This is usually more cost-effective than retrofitting a whole CCTV system’s placement.

Frequently Asked Questions

1️⃣ Is a VFDS the same as a video fire detection system?

Yes. VFDS is the acronym for video fire detection system. It is the same camera-and-software method for identifying smoke or flame described in this guide. Specification documents sometimes call it a video-based fire detection system.

2️⃣ What is video flame detection, specifically?

Video flame detection is the flame-focused branch of VFD. Image-analysis software is tuned to recognise the flicker pattern and colour signature of open flame, not a smoke plume. It complements video smoke detection and often runs on the same camera and software platform.

3️⃣ Does video fire detection replace point smoke and heat detectors?

No. It is a solution for specific environments: high ceilings, heavy ventilation, dust, or open-air areas with no ceiling to mount a detector on. Point detection is slow or unreliable there. Ordinary rooms, offices and corridors are still best served by point-type smoke and heat detectors.

4️⃣ Can a site’s existing security cameras be used for fire detection?

Often, yes. The camera’s coverage, resolution, frame rate and low-light performance must be adequate for the area being monitored. Where an existing camera falls short on one of those points for a critical zone, a dedicated unit is the more reliable option.

5️⃣ What happens to the camera and the detection system if the site loses power?

Cameras used for fire detection should be on a battery backup or priority power feed, like an initiating device. Recording and analysis then continue through a power interruption, instead of going dark when they are needed most.

6️⃣ Is video fire detection covered by a specific standard?

Yes. ISO 7240-29:2017 sets requirements and test methods for image-based smoke/flame detection systems. NFPA 72 (2019 edition) addresses video-based detection as part of its broader fire alarm code. Always treat the fire code adopted in the project’s own jurisdiction as the primary reference.

7️⃣ Does the alert only go to an on-site alarm, or further than that?

Both. The local bell, strobe and any configured relay outputs activate immediately. Where a transmission device such as FCOM is connected, the same event goes further. It reaches a phone app, preset phone numbers and the local fire authority’s monitoring software.