What is Condensed Aerosol Fire Suppression

April 1, 2021

Special hazard applications are those that are not appropriate for automatic sprinkler protection, either due to the fire hazard itself, or the contents that are being protected. Automatic sprinkler systems can damage sensitive information technology equipment, and even wet chemical systems, used to protect commercial cooking operations, can damage cooking equipment, and offer clean up challenges.

Unlike other special hazard systems, condensed aerosol suppression systems do not require a separate vessel for the agent itself, nor do they require an interconnected piping network to deliver agent. Condensed aerosol systems operate by smoke or heat detection, together with control panels, thermally activated, or manually operated with pull stations.


Figure 1:
Condensed Aerosol Nozzle

Condensed aerosol fire suppression can also be used for small, local protection, such as providing fire suppression for electric cabinets or vehicle engines. Finally, condensed aerosol fire suppression can be used in portable fire extinguishers or as modules to be thrown into fire areas by first responders to suppress flames before they enter the enclosure. Figure 1 below illustrates a condensed aerosol nozzle discharging its agent to suppress a fire.

How does Condensed Aerosol Fire Suppression Work?


Figure 2:
Traditional Fire Triangle

Despite the "fire triangle" discussed as early as elementary school (Figure 2), this model does not fully explain how a fire initiates and continues to burn.

The traditional fire triangle illustrates that heat, a fuel source, and oxygen are required for a fire to propagate.


Figure 3:
Fire Tetrahedron There is a fourth element, often not discussed, that is also required for a fire to propagate—an unmitigated chain reaction. This chain reaction is mostly the propagation of hydrogen ions reacting with other chemicals to produce heat. Figure 3 below illustrates the fire tetrahedron. A tetrahedron is a solid constructed of equally sized triangles and is the simplest three-dimensional object possible in geometry.

It is important to keep this tetrahedron in mind because condensed aerosol fire suppression extinguishes or suppresses fire primarily by disrupting the chemical chain reaction.

Disrupting the chemical chain reaction of a fire is considered the most effective method of fire suppression, and this is why halon systems, which suppress a fire in the same way, were considered one of the most effective fire suppression systems. Halon and other chemicals like it were banned by the Montreal Protocol in the 1990s and are only permitted for military use. Additionally, the United States Environmental Agency (EPA) has approved condensed aerosols for use in fire suppression systems.

The sequence of operation of how condensed aerosols work are as follows:

  1. The aerosol container is sealed until it is automatically or manually activated
  2. The actuator at the top of the aerosol container energizes a proprietary compound, which creates aerosol agent by liberating energy
  3. A mixture of micro-particles and nitrogen gas exits the container
  4. Small amounts of gas and particles fill the space and extinguish the fire as described above.

The condensed aerosol pellet contains a proprietary mixture of chemicals which varies between brands.

Codes and Standards

NFPA 2010: Standard for Fixed Aerosol Fire-Extinguishing Systems is the primary standard that is used to design, install, and maintain fixed aerosol systems. This standard applies to the fixed systems that are used to protect stationary hazards, such as electrical cabinets and electrical switchgear rooms. The standard that governs the requirements of the components used within condensed aerosol systems is UL 2775: Standard for Fixed Condensed Aerosol Extinguishing System Units.

By Fireaway Inc.

Contact us for more information:

info@controlfiresystems.com

Latest posts

31
Oct
2017
Developing a Fire Suppression Equipment Maintenance Schedule That Works
Outfitting your business with ​​​fire suppression equipment that keeps your operations and employees protected against a fire is critically important, but it's only one step in the process. Fire ...
01
Jan
2010
C02 Cylinders
We have a large stock of surplus 100lb C02 cylinders with Kidde or Pyrene valve heads. Cylinders are reconditioned, H-Tested and filled. Call for quantity buy.
29
Apr
2019
What Type of Fire Suppression System Will Best Suit Your Fire Safety Needs?
Fire suppression systems Canada-wide typically represent a case of “out of sight-out of mind.” When entering a building for the first time few people ask or wonder if there “is ...