15 Mar ESFR as Solution to Warehouse Storage Fire Safety
When analyzing fire suppression systems serving warehouse storage and their applicability to adequately protect the storage items for temporary certificate of occupancy (TCO), there are many factors to consider. Any analysis is strictly limited to the applicability of the sprinkler system for the specific commodity to be stored. Other mitigating factors related to life safety, i.e., egress routing, are not vetted as part of this analysis.
Existing Sprinkler Design Criteria
If an overhead fire sprinkler system is currently serving the area in question, an ESFR (Early Suppression Fast Response) system is preferred. You will need to determine exactly what is being stored in the location, and then check the commodity in NFPA 13, chapter 16. In NFPA 13 Table 18.104.22.168 you will see the classifications of commodities and their corresponding maximum heights permitted. You will also need to note the warehouse’s maximum ceiling/roof height.
Commodity to be Stored
To show how ESFR systems would work in high pile storage situations, we have constructed an example storage facility for fire protection. In this example, the stored equipment primarily consists of apparent non-combustible construction, primarily decommissioned lab equipment encapsulated with shrink-wrap plastic with miscellaneous foam and cardboard utilization to protect storage contents sitting on wooden pallets. The commodity classification most likely contributed to this arrangement is Class I in accordance with NFPA 13, chapter 5. The total area anticipated to be utilized for this storage is 1,800 ft2.
Items requested are to be stored throughout the tenant improvement construction process and will remain in the location indicated below, until NREL lab activities require the equipment to be relocated. Individual items will maintain a minimum clear width of 3’ around all portions of the stored item to allow for sufficient access to the equipment and/or egress around equipment, if necessary.
Conservatively, class IV commodities stored 12’ or less is considered ordinary hazard group 2 (OH2) per NFPA 13, Table 13.2.1, and since the existing sprinkler system is designed to meet chapter 16 specifications, NFPA section 22.214.171.124 states that ESFR sprinklers designed to meet any criteria in chapter 12 or chapter 14 through chapter 20 shall be permitted to protect any of the following (specifically #3):
- Light hazard occupancies
- Ordinary hazard occupancies
- Any storage arrangement in chapter 13 referencing OH1, OH2, EH1, and EH2 design criteria
ESFR as a Solution to Storage Fire Safety
Based on the example system design criteria (i.e, storage of Class IV commodity up to 25’ in height) and the likely classification of the commodities to be stored (i.e., Class I) and the corresponding storage height (i.e., Maximum of 12’), the existing sprinkler system is sufficient to protect the requested items throughout the tenant improvement construction process.
The experts at TERPconsulting recommend looking at ESFR sprinklers as a long-term solution to high piled storage situations. Utilization of ESFR sprinkler systems minimize other fire and life safety requirements because of their effectiveness. ESFR sprinklers are recommended in storage facilities, depending on the height of the commodity and the spacing of the structural members, however they do have limitations.
ESFR sprinkler heads are limited to a minimum of 65 feet and a maximum of 100 feet per head. These storage sprinklers have been tested in specific criteria and arrangements by testing laboratories. Also note that there can be varying K factors. Other considerations are the available water supply and the minimum water pressure (these automatic fire sprinklers require a significant gallons per minute minimum) based on the k factor utilized.
Rack sprinklers, which have been used for pallet racking systems, can be avoided when using an ESFR sprinkler system design. This is beneficial to owners because the conventional sprinklers used with rack storage were often times damaged by forklifts moving the racks and destroyed in the process.