Electronic Sprinklers Provide Flexibility for Non-Traditional Projects
As the storage industry evolves, it often presents unique fire hazards that require customized detection and suppression solutions. For example, modern lift technology is allowing for higher storage heights, increasing the need for fire protection systems that can monitor and help protect these increasingly larger and denser areas. In addition, the storage of exposed expanded group-A plastic (EEP) materials creates a particular challenge since they produce fires that grow much faster than similar products stored in cardboard containers. EEP materials also do not absorb water as readily as cardboard, making fires difficult to contain.
Typically, fire protection schemes used to protect EEP rack storage arrangements have required the use of intermediate-level in-rack automatic fire sprinklers. The Fire Protection Research Foundation conducted testing that influenced updates to NFPA 13, Standard for the Installation of Sprinkler Systems, incorporating a ceiling-only protection scheme using Early Suppression Fast Response (ESFR) automatic fire sprinklers to protect EEP in single, double, and multi-row rack storage arrangements up to a 40-ft ceiling height and 35-ft storage height. The protection scheme requires the use of ESFR sprinklers with a nominal K-Factor of 25.2 at a minimum pressure of 60 psi flowing through 12 sprinklers. It also requires the use of solid vertical barriers for the full storage height and limits the aisle width to 8 ft.
A Non-Traditional Project
Recently, the IKEA store in Coquitlam, British Columbia, Canada, worked with Code Consultants, Inc (CCI) and Johnson Controls on a project that required innovative storage sprinkler technologies to help protect a unique arrangement of high-rack storage containing EEP materials.
The nature of an IKEA store requires non-traditional fire protection solutions. The store layout closely mimics a warehouse or storage facility. However, the use of the space is primarily retail-focused, serving as a showroom that allows customers to try products before purchasing while shopping freely through available inventory. The high percentage of Group A EEP within that inventory requires a higher-than-usual fire protection system compared to standard retail stores. As noted with the current NFPA 13 scheme using ESFR-25 sprinklers, the higher fire hazard of EEP has much greater hydraulic requirements than would be used and available in a typical retail space.
In addition to ensuring proper facility fire safety, the project goals for IKEA included maximizing storage flexibility, realizing project cost savings, minimizing retail store downtime, and utilizing the existing pipe system and fire pump.
Considerations for Upgrade
The first consideration was replacing the existing in-rack sprinklers with a scheme capable of protecting EEP. An in-rack scheme using extended-coverage upright sprinklers with a nominal K-factor of 25.2 was considered. This option would require replacing all the sprinkler piping, including the risers, as well as the addition of horizontal barriers within the racks. This was not selected due to the cost of the piping replacement and the fact that the piping would be fixed within rack structures and limit the flexibility of moving racks. There was also concern about the potential of damaging the in-rack sprinkler.
A second option was to replace the in-rack system with a ceiling-only system using the protection scheme in NFPA 13, Standard for the Installation of Sprinkler Systems, for EEP. This scheme would require installing early-suppression fast response (ESFR) sprinklers with a nominal K-factor of 25.2, the installation of vertical barriers, and a fire pump upgrade from 1,500 gpm to 2,500 gpm to provide the necessary pressure and flowrate. While the ceiling-only scheme would provide rack arrangement flexibility, this option was not selected due to the cost of the pump upgrade and reduced operational flexibility due to the installation of the barriers.
As none of these options met the needs of high operational flexibility and minimal space downtime, CCI introduced the electronically activated sprinkler concept into the list of possible fire protection options to address the key goals of the IKEA store.
An Electronic Sprinkler Solution
The electronically activated sprinkler system was selected because it offers earlier fire detection and less water and smoke damage compared to a traditional storage space fire protection plan. The technology is designed to avoid sprinkler “skipping” and to react more efficiently to a fire. It is suited for high-rack storage applications containing more complex Group A EEP, which requires more water per square foot than other commodity classes.
The sprinkler system was specified and installed as a ceiling-only protection scheme which allows more flexibility with storage racking arrangement and helps meet the height requirements for protecting Group A EEP. The system made retrofits easy as the sprinklers use the same thread size compatible with piping infrastructure found in older storage facilities.
The specific electronically activated sprinkler system used for this project can develop a system scheme using an intelligent operation of an array of sprinklers around a point of origin. This is accomplished through various system components, including a sprinkler with a metron activator, heat sensor, and a suppression-releasing panel wired to all heat sensors.
The system detects the fire location faster than traditional protection systems through the sensors that gather data on the rate of rise in the surrounding air temperature. This temperature spike allows the system to select the most accurate sprinklers to activate. Based on the grid pattern design, between six and nine sprinklers activate simultaneously to address the fire location. This design targets the fire with a “surround-and-drown” approach which activates only the required sprinklers earlier in the development of the fire. This is a critical part of combatting fires quickly in high-rack storage while ensuring other areas of the facility remain unharmed.
The electronically activated sprinkler system allowed for a significant update in fire protection without having to upgrade the fire pump and without having to install vertical or horizontal barriers. This minimized costs for the upgrade while maximizing operational flexibility.
Based on the project location, it was necessary to add ULC Listing to all system components that were previously UL Listed only. Completing this step early in the project avoided delays in the overall timeline. As the project progressed, the local fire officials assessed the fire protection plans and the distinctive ways they met all needs.
Overall, this project required the installation of 1,360 sprinkler heads throughout the 130,000-ft2 (12,077-m2) facility. The entire project was completed, with 90 percent of the installation work being done with no store downtime. With the new combination of electronically activated sprinkler technology and modern high-rack storage sprinkler protection, the IKEA store in Coquitlam is better equipped to handle fire protection needs for years to come.
ABOUT THE AUTHOR: Manny Silva, P.E., is chief engineer and Fellow for Johnson Controls Fire Suppression Products. He is a member of the NFPA 13 Sprinkler System Discharge Criteria and Sprinkler System Installation, NFPA 30B, and NFPA 1925 technical committees. He has over 30 years of engineering experience, spent over two decades developing numerous products for use in fire sprinklers systems, and is named on 33 U.S. Patents related to fire suppression devices. Silva obtained his Bachelor of Science degree in marine engineering systems from the U.S. Merchant Marine Academy and is a registered professional engineer in Rhode Island.