Throughout history, the fire has systematically wreaked havoc on the industry. Today’s data centers and network rooms are under enormous pressure to maintain seamless operations. Some companies risk losing millions of dollars with one data center catastrophe. In fact, industry studies tell us that 43% of businesses that closed due to fire never reopen and 29% of those that do reopen fail within 3 years. With these statistics in mind, it is imperative that all businesses prepare themselves for unseen disasters. Let us see some of the real world incidents too,

In 2008, a small data center operated by Camera Corner Connecting Point in Green Bay, Wisconsin, was wiped out. The fire destroyed 75 servers, routers, and switches, and it took the company 10 days to get customer websites back online, according to Data Center Knowledge. This is obviously a nightmare situation that data center providers don’t want to face.

For instance, a June fire at one of the Belfast data centers run by U.K. based communications company BT Group disrupted service, according to The Register. A BT spokesman mentioned that though a number of customers were affected by the event, no customer equipment was damaged.

“Today’s incident disrupted the power supply to the data center only,” the spokesman said.

Though the fire was described by the company as “small,” one customer, Internet service provider Tibus, experienced downtime and had two of its power distribution units damaged during the return of power to servers. This fire, which was suppressed by several fire crews on the morning of June 24, will no doubt continue to cause BT issues as questions arise as to why it occurred in the first place.

Before discussing fire protection, it’s important that you must understand the basic theory behind the fire. There are mainly four things that each individual should be aware of when discussing the fire protection systems,

• The Fire Triangle
• Fire load
• The classes of Fire
• Fire’s Stages of Combustion

By studying about these factors it is easy to determine what type of fire protection system will best suit the needs of a data center.

THE FIRE TRIANGLE 

The “fire triangle” represents the three elements that must interact in order for fire to exist. These elements are heat, oxygen and fuel.

Fuel is defined as a material used to produce heat or power by burning. When considering fire in a data center, fuel is anything that has the capability to catch fire, such as servers, cables, cardboard boxes or flooring.

A heat source is necessary for ignition to occur and different materials have different ‘flashpoints’ or the lowest temperatures at which they can ignite. Combustion reactions, however, also produce heat as they burn, which further increases the fuels’ temperature. The heat may be cooled by applying water, but this is only possible for some types of fire.

Oxygen is needed to sustain the combustion reaction since it reacts with the burning fuel to release carbon dioxide and heat. The atmosphere of the earth consists of 21 percent oxygen, which means that there’s enough to trigger a fire as long as the other two components are present. Some fire extinguishers and fire blankets remove the oxygen ‘side’ of the triangle by displacing or removing it thus causing suffocation and ceasing the combustion reaction.

The Triangle of Combustion symbolized the concept of fire for a long time and represented heat, fuel, and oxygen. Further research into fire led to the conclusion that a fourth element was a necessary component of fire, which is a chemical chain reaction. The fire triangle was subsequently changed to a fire tetrahedron (also referred to as fire diamond, pyramid, or combustion triangle) to reflect the fourth element.

Once a fire has started, the resulting exothermic chain reaction sustains the fire and allows it to continue until or unless at least one of the elements of the fire is blocked. As you can see, when one of these factors is taken away, the fire can no longer exist. This is the basic theory behind fire suppression. Foam can be used to deny the fire the oxygen it needs. Water can be used to lower the temperature of the fuel below the ignition point or to remove or disperse the fuel. Halon can be used to remove free radicals and create a barrier of inert gas in a direct attack on the chemical reaction responsible for the fire.

FIRE LOAD

In simple terms, fire loading is a measurement used by fire-fighters and other fire safety professionals to determine the potential severity of a fire in a given space. It describes the amount of combustible material in a building or confined space and the amount of heat this can generate. The more flammable materials there are present in a space, the higher the fire load and therefore the faster a fire will spread, increasing the potential impact of the fire.

A bare room with no furnishings or items present and concrete walls will have a fire loading of nearly zero. The problem occurs when people bring combustible materials into space, as this increases the fire loading. However these materials are often essential for the useful functioning of the building, so you can’t completely eliminate fire loading in a building, although you can take steps to reduce it.

CLASSES OF FIRE

Fire can be categorized into five classes such as A, B, C, D, K. Class A fires involve ordinary combustible materials, such as cloth, wood, paper, rubber, and many plastics. Class B fires involve flammable and combustible liquids such as gasoline, petroleum, alcohol, oil-based paints, lacquers. Class C fires involve energized electrical equipment, i.e., Class C fires are usually Class A or Class B fires that have electricity present. Class D fires involve combustible metals, such as magnesium, titanium, potassium, and sodium. The last class is Class K fires. These fires involve cooking appliances that use cooking agents such as vegetable or animal oils and fats. Generally, Class A, B and C fires are the most common classes of fire that one may encounter in a data center. This chart represents all of the different classes of fire that are able to be extinguished successfully with a basic fire extinguisher.

STAGES OF COMBUSTION

In simple terms, combustion is the burning of something. So how does the combustion is related to fire? Answer is pretty simple that the fire is the visible effect of the process of combustion – a special type of chemical reaction. It occurs between oxygen in the air and some sort of fuel(fuel is anything that has the capability to catch fire, such as servers, cables, cardboard boxes or flooring) which usually accompanied by the generation of heat and light in the form of flame. A familiar example is a lighted match. When a match is struck, friction heats the head to a temperature at which the chemicals react and generate more heat than can escape into the air, and they burn with a flame. The reaction will keep going as long as there is enough heat, fuel, and oxygen. If a wind blows away the heat or the chemicals are moist and friction does not raise the temperature sufficiently, the match goes out. Combustion can be slow or fast depending on the amount of oxygen available. Combustion that results in a flame is very fast and is called burning.

There are generally four stages of combustion which are,

1. The incipient stage or pre-combustion stage
2. The visible smoke stage
3. The flaming fire stage, and lastly,
4. The intense heat stage.

When a combustible material reaches its ignition temperature, the combustion becomes self-sustaining and is called a fire. At temperatures much below the ignition temperature, chemical reactions generate airborne particles. This is typically called the incipient stage of a fire and is followed by visible smoke, flame and finally an intense heat stage. As these stages progress, the risk of property damage, and risk to life increases drastically. All of these categories play an important role in fire protection specifically, data centers. Detection during the incipient stage allows time for corrective action, possibly preventing an escalation of the fire condition, and thus minimizing fire damage. By studying the classes of fire and the stages of combustion it is easy to determine what type of fire protection system will best suit the needs of a data center.

FIRE SAFETY REGULATORY COMPLIANCE

National Fire Protection Association or the NFPA is one of the most widely accepted standards throughout the world. The NFPA is an organization that was established in 1896 to protect the public against the dangers of fire and electricity. The NFPA’s mission is to “reduce the worldwide burden of fire and other hazards on the quality of life by developing and advocating scientifically based consensus codes and standards, research, training, and education”.

The NFPA is responsible for creating fire protection standards, one of them being NFPA 75. NFPA 75 is the standard for the protection of computers or data processing equipment. One notable addition to NFPA 75 that took place in 1999, allows data centers to continue to power electronic equipment upon activation of a Gaseous Agent Total Flooding System. It’s important to note that NFPA continually updates its standards to accommodate the ever changing data center environment. Please note, that NFPA does set the worldwide standards for fire protection but in most cases, the Authority Having Jurisdiction (AHJ) has the final say in what can or cannot be used for fire protection in a facility. Now that we have identified the standards and guidelines of fire protection for a data center, let’s get started with some facts about fire protection.

US

• NFPA 75: Standard for the Protection of Information Technology Equipment
• NFPA 2001: Clean Agent Fire Extinguishing Systems
• NFPA 12a: Standard on Halon 1301 Fire Extinguishing Systems
• NFPA 72: National Fire Alarm and Signaling Code
• NFPA 25: Inspection, Testing, and Maintenance of Water Based Fire Protection Systems

UK

• The Regulatory Reform (Fire Safety) Order 2005 applies to all businesses in England and Wales
• Replaced fire certificates and a myriad of other legislation
  • The employer is required to carry out a suitable and sufficient assessment of fire risks in the workplace
  • Similar provision is made in Scotland under “The Fire Safety (Scotland) Regulations 2006”

However, the preference for fire and safety standard is highly depending on the local rules and regulations which would be geographically best fits.

FIRE PREVENTION

Fire prevention is a proactive method of reducing emergencies and the damage caused by fire. Fire prevention provides more protection than any type of fire detection device or fire suppression equipment available. The goal of fire prevention is to educate the public to take precautions to prevent potentially harmful fires and be educated about surviving any incidents. In general, if the data center is incapable of breeding fire there will be no threat of fire damage to the facility. To promote prevention within a data center environment it is important to eliminate as many fire causing factors as possible. Some of the most effective fire prevention methods are,

• When building a new data center, ensure that it is built far from any other buildings that may pose a fire threat to the data center.
• Use caution around flammable materials.
• Regularly inspect and maintain all fire-safety systems.
• Make sure to avoid cardboard boxes and wooden materials away from white space areas and allocate specific rooms to handle those.
• Enforce a strict no smoking policy in IT and control rooms
• The data center should be void of any trash receptacles
• All office furniture in the data center must be constructed of metal. (Chairs may have seat cushions.)
• The use of acoustical materials such as foam or fabric or any material used to absorb sound is not recommended in a data center

Even if a data center is considered fireproof, it is important to safeguard against downtime in the event that a fire does occur. Fire protection now becomes a priority.

FIRE PROTECTION

Fire protection for modern data centers is complex. The overall protection program needs to be based on the level of acceptable risk for the data center and meet the rigors of reliability and business continuity goals. A comprehensive protection program developed to address expected fire risks, rather than simply meeting local codes and regulations, provides a robust approach to meet these goals.

The three system objectives of a data center fire protection system are:

1. To identify the presence of a fire
2. Communicate the threat to the authorities and occupants
3. To suppress the fire and limit any damage

Designing to typical code requirements will not necessarily meet property protection and business continuity goals. Holistic designs that consider fire ignition scenarios and design for these scenarios, rather than simply meeting the code requirements, address these goals. Such designs integrate systems into comprehensive fire protection programs and incorporate requirements for building construction, fire- and smoke-rated walls and ceilings to protect the data center, interior finish limitations, egress provisions, and fire detection and suppression systems. NFPA 75, Standard for the Fire Protection of Information Technology Equipment outlines a comprehensive risk-informed approach to data center fire safety and protection. The various aspects involved in Fire Detection and Suppression Systems of a Data Center are covered in another article and I would strongly suggest you have a look at this.

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