The newest edition of NFPA 13 (2019 Edition) will be adopted as early as 2019. However, the vast majority of states and jurisdictions will be adopting the new standard in January of 2020. In this article we will be focusing on the reformat and new layout of the standard and discussing changes for this latest edition of NFPA 13 in the application and use of ESFR (Early Suppression, Fast Response) sprinkler systems.
Early Suppression Fast Response Sprinkler Systems
The 2019 Edition of NFPA 13 underwent a complete rewrite of the standard focusing on simplification in the standard’s use and application. While other type of sprinkler systems had new protection schemes added, ESFR protection schemes did not change when compared to the previous edition. However, where previously ESFR, CMDA, and CMSA sprinkler schemes were embedded in each of the respective storage chapters, and each chapter was dedicated to a particular type of storage configuration such as rack, palletized, or shelf storage, now a new approach was taken:
- Chapter 21: CMDA for all overhead only protection including different commodities and storage methods. See Chapter 25 for when in-racks are required in combination of overhead CMDA. The sprinkler design criteria for retail (mainly using K-25.2 Extended Coverage Sprinklers) have been consolidated into this chapter as well. This was a standalone Chapter 20 in previous editions.
- Chapter 22: CMSA for all overhead only protection including different commodities and storage methods. See Chapter 25 for when in-racks are required in combination of overhead CMSA.
- Chapter 23: ESFR for all overhead only protection including different commodities and storage methods. See Chapter 25 for when in-racks are required in combination of overhead ESFR.
- Chapter 24: Alternative overhead only designs. Unique designs with very specific applications for different commodities and storage methods. Many of these designs were located in Chapter 21 in the previous editions.
- Chapter 25: Any sprinkler option requiring in-rack sprinklers, regardless of overhead, can be found in this Chapter. This also includes ‘Alternative In-Rack Sprinkler Protection Options Independent of the Ceiling Sprinkler Design’. In the 2016 Edition of NFPA 13 these ceiling independent protection schemes were known as ‘Alternative Protection’.
Details In Chapters
- The new Chapter 23 discusses general ESFR storage requirements for palletized and solid piled storage applications, as well as specific protection schemes that do not require in-rack sprinklers for rack storage. ESFR sprinkler schemes for storage continue to include the same 2016-edition protection options for Class I to Class IV, cartoned and exposed, expanded and nonexpanded (unexpanded) Group A plastics. Of course, tables 23.4.2 (Group A Plastics) and 23.5.1 (Class I-IV) in Chapter 23 omit any schemes that require in-rack sprinklers, which in turn are listed in Chapter 25.
- New Chapter 25 discusses general application requirements for any rack protection schemes that require in-rack sprinklers – among them ESFR protections schemes. In order to simplify the application of the rather large Chapter 25, a ‘Scope’ for the chapter is preceded providing step by step instructions and guidelines that should help practitioners in specifying in-rack sprinklers.
Solid Shelf protection schemes for racks requiring installation of in-rack sprinklers are now separated out in Section 25.6 of the in-rack Chapter 25.
- ESFR installation requirements are now located in Chapter 14 (previously Chapter 8), with general storage requirements including pallet storage are now being discussed in Chapter 20 (previously Chapter 12). Hose Stream allowances and water supply durations are listed in Chapter 24 (previously Chapter 12).
- Alternative protection schemes for ESFR systems with open shelves, are now expanded to three options, and are discussed in Section 25.8. These protection schemes can be used in combination with ESFR ceiling sprinkler systems. These options include sprinkler schemes with and without horizontal barriers. Some of them offer the possibility to consider the top most in-rack protection level as the new (virtual) floor in protecting the commodities stored above them by the ceiling sprinklers and in this way reducing the required ceiling protection pressures.
- It may be noted that in-rack sprinkler design specifications such as number of in-rack sprinklers, minimum required flows and pressures are now relocated and consolidated into Tables 220.127.116.11 and 18.104.22.168. Previously these specifications were discussed in various paragraphs for ESFR and its respective storage heights and configurations (Chapters 16 and 17).
Clarification on Some Existing Language:
It seems that obstruction criteria for ESFR sprinklers in Section 14.2.4 is creating some confusion:
‘ESFR sprinklers shall be permitted for use in buildings with unobstructed or obstructed construction’.
In the release version of NFPA 13 2019 Ed. combustible obstructed roof construction is not permitted with usage of ESFR sprinklers (as demonstrated in Table 22.214.171.124.1). However, TIA Log No.: 1416 (April 10th 2019) may change this.
If approved, this update will remove this limitation from Table 126.96.36.199.1. Or in other words, NFPA 13 will permit combustible obstructed roof construction with the use of ESFR sprinklers. As a result, ESFR sprinklers may be allowed to be installed in these construction types to coincide with the listings allowances in the sprinkler datasheets and FM 2.0
Update August 6th 2019: TIA 19-4 was approved and Table 188.8.131.52.1 now lists combustible obstructed construction for ESFR sprinklers as acceptable with the same protection areas and maximum spacing dimensions as ‘combustible unobstructed’ construction type.
No doubt it will take some time to get used to the new layout and formatting of the new standard. Initially the learning curve will be (somewhat) steep in ‘searching and locating’ familiar regulations – so easily located in the decade old and familiar layout of the 2016 Edition.
A ‘roadmap’ was included in the back of the standard providing 2019 section cross references for many of the sections found in the 2016 Edition. While this ‘roadmap’ table is very useful, it is not a complete reference by any means, and users quite often are left wondering ‘where it all went’ (we will attempt to address this headscratcher in the future, so stay tuned. Update October 26th 2019: see this article).
Then perhaps, the new layout may help plan reviewers in particular, as they were the target group for the reformatting of the standard.