Gas Fire Suppression

Gas fire suppression systems work by starving a fire of oxygen or heat and therefore eliminating the fire.

To ensure the gas suppression system doesn’t release gas for a false alarm such as in response to dust in the air, we provide a series of detector activations known as “first and second” stage alarms. This is where two different detectors on two different zones have to be triggered in the event of a fire.

How a Gas Suppression System Extinguishes a Fire

Initially one detector will be triggered on zone one (first stage), if a second detector (second stage) is triggered then a countdown timer is started and once this time has elapsed, the gas will be released.

During the above process a series of alarms will be triggered. During the first stage a sounder will be triggered, then during the second stage a different tone sounder will be activated. After the countdown timer has elapsed a bell and flashing strobe will trigger when the gas is released.

The main control panel provides details and control of the current status of the system. In an emergency the gas can be released immediately by hitting a break glass call point or if you want to “hold off” the release process we can provide “hold off” buttons.

Additional Benefits of Gas Fire Suppression

Other benefits of gas suppression systems include:

Safe and environmentally friendly gas.

No cleanup operation is required as no residue is left by the gas ensuring your critical systems keep operating.

The systems can be applied to a variety of different areas including server rooms, switch rooms, battery rooms and transformer rooms.

Synthetic Gases

FM200 (HFC227ea), FE13

These gases are stored as a liquid, with nitrogen used to pressurise it. When released the FM200 has a chemical reaction with the fire and extinguishes it.

Advantages

• Cost effective as the footprint of the cylinder is small – this is an advantage for data centres that charge out their rack space, and so are looking for minimal space requirements of their data room. This enables them to gain more revenue by having more floor space for servers. IG 55, 01 etc. do take up more floor space but the cylinders can be put remotely from the room.
• Stored as a liquid so takes up less space.
• Well known brand – FM200 is a brand name, the agent is a chemical called HFC227ea.
• Easy to install because the cylinder is usually in the same room. Sometimes just a standpipe on top of the cylinder is required.
• No reduction of oxygen so it’s safe for humans on discharge.

Disadvantages

• FM200 does not travel well (because of the pressure) or is rarely cost effective over inert gases if it’s a large room or the gas requires diverting to different areas/rooms. Cylinders must be stored as close to the application as possible.
• Some companies are saying it’s a potential future banned gas as it’s a hydro fluoride chloride (HFC) – we have had clients who insist on an inert gas because of this. In fact Dupont, who manufacture FM200, are actively giving guarantees to replace the gas (less installation) if it gets banned in the next 20 years.
• Pipe work design has to be accurate. A slight change of pipe run in distance or length can mean the design calculations have to be changed and a potential major costs change. Because of this, don’t use FM200 if you cannot guarantee the pipe run design and installation will remain the same.

Applications

• Electrical Data Processing (EDP Areas)
• Data rooms/halls
• Switch rooms
• UPS rooms
• Communications rooms
• Substations
• Archive rooms/stores
• Some small cabinet protection applications (with no leakage)

Inert Gases

IG01,IG-55, Inergen, Argonite, Pro-inert, CO2

Stored as a pressurised gas, inert gases are usually a mix of nitrogen, argon and sometimes added Co2.

Advantages

• Travels long distances because of the high pressure.
• Easily diverted to separate rooms using diverter valves and pilot cylinders. Large cost saving as you only need enough gas to protect the largest room. If you are considering this make sure you consider a quote for a replacement cylinder bank. You have to be aware of the downtime in replacing the gas cylinders after a discharge which is usually 5 -15 working days at Assured. Also check that it’s acceptable that only one room can be covered at any one time with this type of solution.
• More cost effective with larger systems.
• Environmentally friendly. Argon and Nitrogen are a natural gases so it just gets released back into the atmosphere.

Disadvantages

• Larger pipe sizes required along with more pipe work and associated fabrication.
• More cylinder space required, although this can be placed a distance away from the risk or even outdoors if protected.
• Damper relief required, because more gas is going into the room and over pressurisation occurs.
• Media such as photos and video tape when burning can create an oxidising effect where more oxygen is given off from a fire. This means inert gases which reduce the oxygen volume cannot be used as the original calculation would be incorrect. It is not possible to calculate how much reduction would be required, so in these circumstances synthetic gases should be considered first. However other solutions are possible.

Applications

• Electrical Data Processing (EDP areas)
• Switch/Communication Rooms
• Archives/Stores
• Cabinet/Enclosure Protection

Carbon Dioxide System

Mainly used for local application or cabinet protection where room integrity cannot be guaranteed or is uneconomical. This is a heavier than air gas so ensure if there are any off shoot low level ducts or voids where the gas may leak to, these areas are covered for warning of discharge. It’s not uncommon for these areas to be separate or a distance away from the risk.

Mechanical and electrical heavy duty locks are required to ensure any person going into the risk area has to put the system in manual only mode or isolate the system. This is to avoid discharge whilst a person is in the room or area, which could be fatal.

Ideal for local application as the gas discharge can be over a 3-4 minute period and have additional discharges afterwards. This avoids an initial high pressure and short blast (synthetic gases – 10 seconds, inert gases – 60 seconds to propel the whole amount) which could potentially blow the enclosure apart and enables a longer discharge to avoid issues with gas leaking from holes/gaps in the cabinet.

Advantages

• Ideal for open areas with no or low room integrity. Heavy gas permeates lots of areas so ideal for printing machines and other machinery.
• Economical and can be used in large areas.
• No major effect on pipe work design or size.

Disadvantages

• Can quickly cause asphyxiation.
• Locking devices may be required on all entry and exit doors to protect staff.
• Bad press – some systems have caused death so are being replaced by inert gases. Some people are nervous about the health and safety aspects of using this gas, but when designed properly it presents minimal risk.
• Though CO2 is a non-toxic gas, it does have an occupational exposure limit assigned to it under the Control of Substances Hazardous to Health Regulations (COSHH).

Applications

• Machine Spaces
• Switch Rooms
• Transportation
• Cabinets
• Generators (local application)
• Fryers and Ovens (local application)

Our Clients

Some of the clients we have the pleasure of working with

“Our existing intruder system and devices had become obsolete and did not meet with current installation standards. SS Systems provided a modern hybrid system that provided a logistical solution without disruption to the fabric of the property. SS Systems now provide us with the necessary support and ongoing preventative maintenance service.” – Phil Blunt, Owner, Adby Farm