Over centuries of dealing with fire, humankind has developed a fair few ways of dealing with a consuming fire. Water, of course, is the element used most often, at times with foam, to extinguish a fire. However, while it can certainly get the job done, it can also cause harm to sensitive equipment in its surroundings.
Take, for instance, a room filled with electronic equipment, or a data center storing important information. Water can, in such instances, end up causing more harm than good if used as a fire extinguishing agent. Hence, it is advisable to opt for a newer, cleaner solution- Clean Agent Fire Suppression Systems!
Clean Agent FSS- An Introduction
Clean agent fire suppression systems use what is known as a ‘clean agent’ to extinguish fires. A clean agent is an electrically non-conductive, volatile, or gaseous fire extinguishing agent that leaves no residue upon evaporation. Clean agent fire suppression systems use inert gases or chemicals stored in containers, and discharged upon fire detection. These clean agents are also substantially more environment-friendly than all other options, making them a preferred choice from a sustainable perspective.
Clean agent fire suppression systems are the best choice to use in an environment with sensitive equipment and assets, making them very popular worldwide. How do they work?
Essentially, a fire requires three components: heat, oxygen, and a fuel source. If any of these is not present or gets cut off, the fire will be suppressed. Clean agents eliminate either the heat or the oxygen to put out the fire. Here’s a look at the key types of clean agent systems.
Popular Types of Clean Agent FSS
There are a number of types of Clean Agent FSS, but three main types of clean agents are usually used in these systems.
FM 200 clean agent fire suppression systems extinguish fires by absorbing heat swiftly. The agent is kept as a liquefied compressed gas in cylinders; it flows across the system and transforms into a gaseous state that reaches the fire when the system triggers. It is relatively safe for spaces occupied by humans, and is frequently found in computer rooms, electrical panels, wind turbines and manufacturing facilities.
That being said, FM 200 systems have the highest ozone depletion ratings from among the three main types of clean agent FSS. Thus, while they are free of residue and not harmful to occupants, they are not the best clean agent option from an environmental perspective.
Inert gas clean agent fire suppression systems employ a combination of inert gases to reduce oxygen in the vicinity of the fire. Unlike FM 200 systems, inert gas cylinders being highly pressurized are situated further away from the spot they shield.
However, they require more amount of the agent substance to suppress fires, and thus use up more space. These systems also traditionally take longer to activate. Inert gas clean agent systems include INERGEN as well as CO2.
CO2-based systems dispense carbon dioxide gas into a fire, reducing the oxygen and extinguishing it. CO2 poses health risks to humans at some levels, and so this system is usually used for unoccupied spaces like electrical rooms, and flammable liquid storage areas.
However, when these systems are in occupied areas, it can be very injurious to the health of the occupants. As it depletes the oxygen around the fire for extinguishing it, the occupants may experience breathing difficulties from prolonged exposure. In such a case, facilities must have safety measures in place for building occupants. As CO2 systems can prove harmful, despite their ubiquity they are sometimes excluded from consideration for occupied areas.
INERGEN clean agent systems utilize a mixture of nitrogen, argon, and carbon dioxide to suppress fires. It reduces the oxygen content in a room such that it is insufficient for combustion but still allows the occupants to breathe.
INERGEN is the only system that has no global warming potential at all, making it safe to use for the environment. It is quite often used in occupied spaces, historical archives and sites, museums, art galleries, power transmission facilities, marine vessels, hospitals and medical facilities.
Novec 1230 clean agent fire suppression systems suppress fire through the removal of heat. They are usually located in proximity to the area they protect. The agent is, in contrast to the liquefied compressed gas of FM 200, stored as a non-toxic, colorless liquid and converted into a gas when being discharged. A replacement for halon, this clean agent is a replacement for hydrofluorocarbon (HFC) extinguishing agent. It also has nearly-zero ozone depletion potential, and is thus safest for the environment.
As it is very fast-acting, has no adverse effects on occupant health, and is extremely environment-friendly, it is considered safest to use in human occupied areas, as well as in applications with sensitive electronic equipment. These factors make it ideal for use in data processing centers, industrial facilities, race cars, merchant and recreational ships, navy vessels and aircrafts!
Parameter-based Utility of Each System
Novec 1230 is the fastest deployed agent out of the above, usually able to extinguish a fire within a few seconds. FM 200 is also quite fast-acting; and these two systems are located in proximity to the area they are supposed to protect. While inert gas-based systems are slower than the others, they are still fast-acting as compared to non-clean agent systems. However, due to being very pressurized, they are located away from the target area.
The INERGEN system has no global warming potential (GWP), making it very beneficial to the environment in terms of emissions. Similarly, the Novec 1230 system has a zero ozone depletion potential (ODP), and is an excellent replacement for the old HFC systems that had high emissions. However, the FM 200 systems still have the highest ozone depletion ratings from among the three main types of clean agents, and are hence not considered the best choice from an environmental perspective.
Safety of Life and Assets
Here we find that Novec 1230 systems leave zero residue and are exceptionally non-conductive, making them ideal for sensitive, electronic-heavy facilities. At the same time, they have no effect on the occupant’s health, making them safe for occupied areas. Similarly, INERGEN systems are also very safe for use in occupied areas, and are used in areas where the assets need to be preserved. FM 200 systems also leave minimal residue for cleanup. However, since CO2-based systems pose a health risk, it would be ill-advised to use them in occupied areas.
In terms of cost, there are a great many factors involved, such as the area to be covered, the amount of agent per sq. ft., and more. However, generally speaking, CO2 systems are the least expensive, while FM 200 systems are slightly more expensive. Understandably, since Novec 1230 and INERGEN systems are the ones providing maximum benefits and features, they are more expensive than the others.
As we can see, all the types of clean agent systems have their advantages and disadvantages, and are used in different situations for different applications. It is usually best to consult experts when selecting fire suppression systems for your facilities.