Fire Suppression

The protection of life and property from the devastation of a fire is an essential requirement of any business. Our key objectives are to provide our clients with bespoke solutions to ensure the highest level of protection in any given environment, working with the latest standards, overcoming the toughest challenges, designing and providing the most effective solutions, working with you to keep your colleagues and assets safe.

Fire Suppression to your most valued assets can be vital and there are several different methods which are dependent on the area and asset being protected.

• Aerosol Suppression Systems
• Water Mist Systems
• Inert Gaseous Systems
• Synthetic Gaseous Systems
• Redetec - In Cabinet Systems
• Extinguishers
• Fire Sprinklers

Aerosol Suppression Systems

Aerosol suppression systems have been around for many years, but many people are not aware of their marker presence. These systems are 'Green', being non-toxic and contain no CFCs or HFCs. Two of the more well-known brands within the industry are Pyrogen and FirePro, although other brands exist.

These systems use solid compounds over gaseous or liquid agents. When activated, the solid compound is transformed into a rapidly expanding, extremely efficient fire extinguishing condensed aerosol. The aerosol produced is evenly distributed within the protected area using the forces achieved without increasing the pressure in the protected areas and as such, removes the requirement for supplying and installing additional Over Pressure Vent units. Aerosol suppression systems also do not require Room Integrity Testing of the protected areas every 12 months as, as they are not a gaseous system, they do not fall under the requirements of BS EN 15004-1.

In a typical fire, there is a fierce inter-reaction between atoms and fragments of unstable free radicals in the presence of oxygen. This continues until the burning fuel is depleted. Aerosol systems extinguish fires predominantly by inhibiting, on a molecular level, the chemical chain reactions present in combustion.

On activation, the compound within the unit is transformed into a rapidly expanding, fire extinguishing condensed aerosol consisting mainly of Potassium salt based K2CO3 (Potassium Carbonate), H2O (Water Vapour), N2 (Nitrogen) and low levels of CO²(Carbon Dioxide). The solid particles of Potassium salts, which are only a few microns in size, are suspended in an inert gas that displays an extremely high surface-to-reaction mass ratio. This increases efficiency - which results in less quantities of the fire extinguishing agent required.

Water Mist Systems

A water mist system is a fire protection system which utilises water, high pressure and specialised sprinkler spray heads to form very fine water droplets, ranging from 50 to 300µm depending on the system design.

This increases the overall surface area of the water being deployed and such, much smaller supply quantities of water are required in comparison to a standard sprinkler system.

Small, atomized water droplets allow the water mist to suppress fires by:

• Cooling both flames and gases through water evaporation
• Reducing oxygen levels through water evaporation
• Reduces radiant heat through heat absorption by the water droplets themselves

The effectiveness of a water mist system in fire suppression depends on its spray characteristics, which include the droplet size, distribution, flex density (i.e. electric or magnetic forces) and spray dynamics, in relation to the fire scenario.

Inert Gaseous Systems

With today's world constantly pushing towards 'Green', inert gases are an excellent choice for today's fire suppression systems. These agents are based on naturally occurring gases found all around us - even in the air that we breathe.

They are a class of gases which do not undergo chemical reactions under a set of given conditions, nor typically, do they react with many other substances.

The two most common inter gases used as suppression system agents, either on their own or as part of a blended mix, are Argon and Nitrogen, and the most readily available agents utilising these two gases on today's market are:

• IG-01 - Argon
• IG-55 - Argonite: A 50/50 blend of Argon and Nitrogen
• IG-541 - 52% Nitrogen, 40% Argon & 8% CO²

Although CO² (Carbon Dioxide) is also used as a suppression agent in its own right, it has become unpopular over the years due to its adverse effect on the environment, and the potentially high risk presented to those in the immediate vicinity during a discharge (CO², under the right conditions, can be lethal.)

Inert gas systems consist of a pre-defined number of cylinders (typically 80L in size, although other sizes exist) that are pressurized between 150 and 300bar, depending on the system design requirements. They can be a simple set-up, from 1 or 2 cylinders placed within a small server room, all the way up to complex multi-diverter valve systems with dozens of cylinders, and pilot cylinders, covering a large data center.

Synthetic Gas Fire Suppression

Synthetic gas fire suppression is a type of clean agent fire suppression that uses manufactured chemicals to extinguish a fire. Unlike inert systems, the gas is contained in liquid form until deployed. This means that these systems can help a fire safety system cover a much larger at-risk area than inert agents, with much lower storage and footprint.

These agents can commonly cause problems for rooms that regularly contain people however, as they extinguish the fire by lowering the oxygen level in the room. Synthetic fire suppression systems are much more highly environmentally regulated, and are often more costly than their inert counterparts.

The gases used are approved for Class A and B fires, suitable for critical risk areas and occupied areas and are installed around the world in a variety of situations from computer centres to gas turbine enclosures, power stations and data storage sites.

Novec 1230

FM-200 and Novec 1230 are both fast, clean extinguishing agents, with zero ozone depletion potential and are suitable in many situations.

Novec 1230 extinguishing agent is a clean gas widely accepted as a substitute to Halon. Novec 1230 or dodecafluoro-2-methyplentan-3-one (CF3CF2(O)CFCF3) is suitable for the protection of most hazards where Halon 1301 had to be applied in the past. FM-200 is colourless, odourless and not electrically conductive and is therefore suitable for use in the protection of electrical hazards such as computer rooms. In addition, it is suitable for Class A fires (including solid materials) and Class B fires (flammable liquids).

FM-200 extinguishes fires by physical means, weakening and extinguishing the fire by absorbing heat. Once discharged, FM-200 extinguishes the fire quickly, reducing damage to a minimum and ensuring total safety to persons. FM-200 is super-pressurised with dry nitrogen at 25 or 42 bar and stored in steel cylinders fitted with approved valves.

Novec 123- & FM200 (HFC227) is cost-effective as the footprint of the cylinder is small. This is an advantage for data centers that charge out their rack space, and are looking to make the most of space for servers.

Room Integrity Testing

When a gaseous suppression system is installed, the protected area will need pressure testing to ensure that the suppressant is retained within the protected enclosure to hold the suppressant agent for the required time to be effective.

A room integrity test should be carried out on completion of a suppression system installation. In addition, British Standards recommend testing to be carried out if changes are made to the enclosure and tested once annually as a minimum.

TFS conduct Room Integrity Tests to ensure that in the event of a fire, the discharge of the gaseous extinguishant agent holds for the required concentration level to ensure the effectiveness of an extinguishing system.

For Enclosed Cabinets or Server Cabinets please see our In Cabinet Section - Redetec.