As a supply chain real estate practitioner, I always encourage my clients to engage the services of a qualified fire sprinkler consultant or similarly qualified employee when they evaluate the suitability of a real estate option. While experts should be consulted, actors in the supply chain should take the time to understand the basics regarding today’s fire sprinkler systems and potential pitfalls that could arise from false assumptions. In this post I briefly cover the history of the fire sprinkler system and its evolution to the current ESFR system. I also explain why an ESFR fire sprinkler system may not insure the full use of high rack storage.
According to “The Station House”, a newsletter produced by Tyco (link here), the history of fire suppression sprinkler systems goes back to the 1800’s with the founding of the Providence Steam and Gas Company in 1850, which would later become the Grinnell Company. In an effort to address the mill fires in New England, Providence tested various perforated pipe installations with actuators.
Through the next 100 years, we start to see a resemblance to modern sprinkler systems beginning in 1953, when the National Fire Protection Association issued the NFPA Pamphlet 13, which is the first code to recognize today’s standard sprinkler system. From the 1950’s to the early 1970’s, Ordinary Hazard systems were in standard use under the NFPA code. In the early 1970’s, the NFPA revised their standards to permit hydraulically calculated systems, which would eventually replace Ordinary Hazard systems in most warehouses by the 1980’s. Calculated systems are commonly shown in a volume per minute over an area calculation. Common examples are .33/3000, .45/3000, and .60/2000 calculated systems where the first number is the gallons per minute and the second the square footage.
Beginning in the 1980’s, the first fire sprinkler system was developed to address high rack storage without in-rack sprinkling. The Early Suppression Fast Response sprinkler, or ESFR, was both a concept and a type of sprinkler. The concept was to have a sprinkler capable of extinguishing fires in a high rack storage scenario. This contrasts with prior sprinkler systems, which were designed mostly to control fires until help arrived. In 1988, the first Factory Mutual (insurance company) approved ESFR sprinkler was introduced by Grinnell. Since that time, the ESFR sprinkler system has become the standard in protection for high rack storage.
One key component of the ESFR sprinkler system is the ESFR sprinkler head. Recent changes to the NFPA codes and today’s high rack storage heights require certain types of ESFR sprinkler heads to be used. These sprinkler heads are usually rated by what is called a “K factor”, or the coefficient of discharge. The larger the K factor, the more water it can discharge at a given pressure. K-14, K-17, K-16.8, K-22, K-25, and K28 are some examples of ESFR sprinkler head K factors.
The type of sprinkler heads and water pressure in an ESFR system is important to understanding high pile storage capacity for a given user. I have heard of several horror stories where companies have moved into a high cube warehouse with an ESFR system, only to learn that the sprinkler heads did not allow their desired use of the cube within the warehouse. In these events, typically the tenant will have to foot the bill to change out the heads-not an inexpensive proposition. In addition, changes to the sprinkler head may impact the required pressure-possibly requiring a modification to the pipe system. Again, not inexpensive.
In conclusion, fire sprinkler systems have evolved from little more than a perforated pipe to a highly technical engineered system capable of extinguishing the most combustible materials capable of being stored. Since fire codes and fire systems require professional interpretation and expertise, it is imperative that supply chain companies work with experts to mitigate any risk to their desired storage plans.