Early in my career in Fire Protection I was working with a National Canadian business in the Fire Alarm, Sprinkler and Life Safety industry. I quickly gravitated towards an area of the business called “Special Hazard Systems”. These systems fascinated me because they are designed to protect a space or equipment and to extinguish a fire BEFORE traditional fire protection methods – like wet sprinklers – would normally activate. Working with these systems, we need to consider the protection of building and equipment as the primary design objective rather than the evacuation or safety of occupants (of course in most cases special hazard systems have to be in place in addition to our tradition systems required by Codes and Standards for life safety purposes)

Most of us understand the role of sprinkler and fire alarm systems in our buildings, and the extreme value they bring to the life safety of building occupants. But, sometimes the project environment will require our professionals to bring it to the next level.

We need to ask some important questions:

• Will the introduction of water cause more damage to equipment than a fire?
• Will the evacuation of a control room, triggered by a fire alarm system notification, create a dangerous situation for occupants?
• Will there be insufficient water available to provide the fire control and suppression required for the hazards?
• Will the introduction of water via traditional sprinklers be incapable of suppressing the types of fires anticipated?

These are just a few of the questions that, if the answer is yes or maybe, you need to consider the use of a special hazard system.

Keep in mind that this category of protection systems is broad and is on the leading edge of innovation in the fire protection industry, and therefore continuously evolving. In all likelihood, by the time you finish this article, a new system has gained approval or an entirely new product has been created. This characteric of special hazard systems is what makes this category so exciting. Since we can be satisfied that our buildings are safe – because of the Code requirements for traditional sprinkler protection systems – special hazard systems are the “sandbox” where new innovation and product development are free to advance.

For those new to special hazard systems, I’m going to outline some of the popular systems that are available today – they each have a unique application and benefit – consider if these would help a Client or suit a specific design project.

Pre-Action Sprinkler Systems

The most common instances that rely on pre-action systems are where the accidental release of water could significantly damage equipment or could be deemed to be catastrophic to the building. Consider, for example, a computer server room or a cold storage warehouse.  A release of water accidentally from a traditional sprinkler system could be extremely damaging to building and business integrity. 

The term “pre-action” refers to an extra step that is required to confirm a fire before releasing water into the pipes of a dry sprinkler system. This is usually done by having electronic detection devices connected to a fire alarm panel – which controls solenoids to introduce water. This means that you will only apply water for suppression when both the electronic detection takes place and a sprinkler head is activated (by temperature). This provides a level of redundancy so as to avoid a false activation and unnecessary release of water. It also provides a time delay to potentially limit the likelihood that water will be unnecessarily released for suppression. Often these systems are available in ready-to install cabinets, which include: detection, suppression, and releasing equipment. 

Typical applications include IT/ data rooms, control equipment and cold storage warehouses.

Deluge Sprinkler Systems

When we talk about a traditional automatic sprinkler system, we are referring to sprinkler heads that are normally closed and that automatically open from the heat of a fire. Water is only released from the heads that have reached the specified activation temperature.  Deluge type systems have normally open sprinkler heads and the water is only introduced by either electronic or pneumatic type detection devices. When released, the water comes out of all the open sprinkler heads at once.  Hollywood has a bad habit of showing traditional sprinkler systems that are able to activate all heads at once, but usually these are shown in installations where automatic (“normally closed”) heads would be installed; so, this wouldn’t occur. 

A typical deluge installation application is an industrial setting where the protected hazard has an extra risk of fire and to protect the equipment and occupants, you need to introduce a high volume of water (or foam) to the entire area instantaneously  

Foam Systems

There are certain types of hazards that when a fire occurs just can’t be controlled or suppressed in an effective way using water. The only way to manage a fire is to introduce something that will really starve the fire of oxygen; this is where a foam system works best. 

Foam systems can function to control a fire in many ways: the foam can blanket surface the surface of a burning fuel to smother the fire, the fuel can be cooled by the water content of the foam, and the foam blanket can also suppress the release of flammable vapors produced by a fuel that can mix with the air and burn.  

Typical applications are high-hazard situations, such as: airport hangers, fuel storage & processing rooms, and heavy industrial environments.

Inert Gas & Clean Agent Systems

In some situations, the discharge of a water sprinkler system (even with a pre-action system) will cause significant and very costly damage to the equipment or space that it is protecting.  What if you are protecting something so valuable that you want to detect and suppress a fire before it has a chance to do damage or activate the other traditional systems protecting the building? Or maybe it is important to minimize downtime from a fire event avoiding business interruption?

Some examples of these types of applications are:  data centers, electrical vaults / switchgear rooms, file storage, or art galleries. 

These conditions present the best applications for an inert gas or clean agent system. These systems extinguish fire by releasing a non-water suppression agent into the area. The agents  are electrically nonconducting and leave no residue upon evaporation.

Water Mist Systems

There are special applications where a hazard may be present, but the site may have limited water supply such as remote locations or historical buildings. Additionally, for certain industrial projects there may have equipment that cannot be fully enclosed to allow for a clean agent or inerting gas system to be suitable, such as industrial turbines or open-processing systems. While these two challenges are quite different on the surface, the solution might be a Water Mist System in each case. Water mist systems control, suppress, and can potentially extinguish fires by discharging a fine water mist at high velocity into the protected area or at the special hazard itself. The water mist is created by pushing regular water through specialized nozzles at very high pressure.  These systems come in both high and low pressures as well with either automatic or deluge type heads. 

In December 2011, the technology achieved a critical milestone when a major brand became the first water mist fire protection product to receive Underwriters Laboratory (UL) listing for Ordinary Hazard Group 1 (OH1) applications. This, together with Factory Mutual (FM) Light Hazard (LH) system approval, has paved the way for water mist to be used in commercial buildings including data centers, high-rise buildings, hospitals, cultural heritage sites and hotels in the absence of traditional wet sprinklers.

Hybrid Systems

A hybrid fire suppression system utilizes both the oxygen displacement properties of nitrogen, as well as the cooling properties of atomized water. Instead of a traditional sprinkler head, a hybrid fire suppression technology uses an emitter to mix nitrogen with water.

A benefit of the hybrid systems is that the water droplets are also much too small to conduct electricity – so these systems can be used in spaces where electricity is present.  Additionally, with such a small quantity of water being discharged, there is no requirement for floor drains or clean-up.  Another advantage of hybrid systems is that they do not require room integrity testing as the system will run for a continuous period, unlike the inert gas or clean agent style systems..

Hybrid systems are unique in that they have many of the advantages of the inert gas or clean agent systems while also using water for its cooling effects and ability to carry the displacing gas throughout the space.  Because of this, hybrid systems are used in many spaces that may also be suitable for water mist and/or inert gas or clean agent technologies.

Summary – You learned something Special!

It’s not an exhaustive list – but hopefully this article introduced you to new technology or new concepts for fire suppression and control that may exceed the minimum requirements of the Codes and may also perfectly suit a unique fire hazard that you’ve encountered.

Find this interesting?  Want to learn more? Well you are in the right place, stay tuned to the Kilo Lima Code Community and there will be some exciting opportunities to learn more in depth on this topic and others in the near future. Sign up below, or follow along on LinkedIn.