NFPA Today - September 11, 2020

Can Sprinkler Protection Be Omitted If Another Extinguishing Agent Is Used?

While water is often the ideal medium for fire suppression based on availability, price, and effectiveness, there are certain buildings, contents, and equipment that building owners want to protect from exposure to water. This is a common topic of discussion for historical buildings, irreplaceable artifacts such as those that can be found in museums, sensitive electrical equipment areas including data servers, and power plant control rooms. It has also been asked about hospital operating rooms and MRI rooms. Building owners and designers will often question if there are options to omit sprinklers and piping from these spaces or from the building entirely, citing concern over water damage either from accidental sprinkler discharge or from leaks in the piping.  


The alternative proposed by those questioning the need for sprinklers in these instances is typically another extinguishing system that will have much lower impact to the contents of the protected space. These systems can include carbon dioxide, water mist, or clean agent extinguishing systems. While these are effective systems that, when designed and installed properly, should activate and extinguish a fire in a space before a sprinkler is likely to even operate, their installation does not necessarily allow for the omission of sprinkler protection in that space. Here, we'll look at some considerations when asking this question, why sprinklers are not normally allowed to be omitted, and some other steps that can be taken to reduce the perceived risks of water damage. 


Are Sprinklers Required for the Building? 

Determining if sprinklers are required is the best place to start and will depend on the locally adopted building code.  The mandate for sprinklers will be based on the occupancy, construction type, stories in height, and floor area among other factors.  Life safety codes, fire codes, and any specialty codes or standards related to the building, equipment, or contents that have been adopted can also impact this determination (more on those below). Generally, a person arrives at the question of omitting sprinklers after having, determined that they are required for the building.  


Can other suppression systems replace sprinkler protection? 

If the building is required to be protected with a sprinkler system, it is unlikely though we won't rule it out just yet, that sprinkler protection can be omitted from certain spaces or areas even if an alternative extinguishing system is provided. There are several reasons for this but the primary one is that fire and life safety is complex and is part of an overall system where many different components work together in order to provide a safe environment for occupants, property protection, and safer conditions for first responders. Many allowances in building codes and life safety codes are based on the condition that a building is “protected throughout” by an automatic sprinkler system. For example, providing sprinkler protection can allow for less fire resistive construction type than would otherwise be allowed for the building's size, reduced fire protection ratings for occupancy separations, increased travel distances, allowances for special door locking arrangements, and numerous other allowances that are not permitted for buildings without sprinkler protection throughout. 

Now, the fact that the building would require sprinkler protection based on occupancy, construction type, size, and any other factors makes the argument to omit sprinklers in certain areas more difficult, but it does not completely end the discussion. 


Does This Imply that Other Suppression Systems are Inferior to Sprinkler Systems? 

A logical follow up to these points is questioning if the codes and standards are therefore implying that other suppression systems are inferior to or not as effective as sprinkler systems. This is not the case. Specialized suppression systems can certainly be effective against fire, and are typically designed to activate at stages of a fire well before a sprinkler would activate. This provides increased property protection for the material in these spaces especially when the extinguishing media won't harm the structure, equipment, or contents of the space.  

The operational characteristics of these systems are where the real differences come in. These alternative systems are commonly designed for local application or total flooding of a space and have a finite volume available. If a fire is not controlled in that time before the volume of agent is completely used, there's nothing else that can be done. Sprinklers on the other hand, even if they fail to extinguish a fire are designed to be able to flow water for several hours or indefinitely based on the water supply.  


What Occupancy or Hazard Specific Code and Standards Should be Referenced? 

Outside of the broadly applicable building, life safety, and fire codes there are numerous codes and standards that apply specifically to special building types, types of equipment, and materials. These include but are certainly not limited to: 



It should be identified if these codes or standards are adopted in the jurisdiction either directly or through reference. The scope and purpose of these documents are also important to understand. Some, such as NFPA 75, will require sprinkler protection if the building is sprinklered, others such as NFPA 909 will allow sprinkler protection or alternative suppression systems.  


If sprinklers must be provided, how can the potential for water damage be minimized? 

If sprinklers are still required to be provided, there are several approaches that can help limit concerns of water damage in the space. Pre-action sprinkler systems, either single- or double-interlock can be used to limit that potential for water damage due to accidental discharge resulting from a sprinkler being physically damaged. Piping can have increased pitch, additional auxiliary drains can be provided, and thorough inspection, testing, and maintenance programs can be implemented to limit the potential for corrosion issues. Of course, the installation of another extinguishing system (while maybe not eliminating the need for sprinklers) can also greatly limit the potential for water discharge in the actual event of a fire if it is able to effectively suppress or extinguish a fire in its incipient stage before sprinkler activation. 



The potential for water to discharge in certain buildings, on certain spaces with special contents, or equipment within a building can certainly be a concern to building owners whether in a fire situation, an accidental discharge, or leaking. Often looking to still protect the building, the contents, and/or the equipment, the removal of sprinklers in favor of an alternative suppression system is often proposed. While these alternative systems can be very effective for protecting the property in question it is not always as simple as a straight replacement. There needs to be awareness of the overall fire and life safety approach for the building and an understanding of the building, life safety, and fire codes as well as the specialized codes and standards that may modify those requirements. Even where sprinklers need to remain, there are approaches that can be taken to limit the potential for water discharging in these spaces. 

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Jonathan Hart
Technical Lead, Principal Engineer at NFPA

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