ESFR and Storage Sprinklers: What They Are

ESFR sprinklers (Early Suppression, Fast Response) are designed to stop a fire in high-piled or racked storage at an early stage, rather than only hold it in check. Storage sprinklers is the wider term for heads and systems approved for warehouses and similar occupancies, including ESFR, large-drop and other control-mode sprinklers.

If you are planning a warehouse or distribution centre, the sprinkler type you choose depends on what you store, how high you stack it and how high the ceiling is. Standard sprinklers used for offices are not designed for these conditions.

Why storage needs different sprinklers

Goods stacked on racks or in tall piles create vertical flues. A fire can climb quickly, and heat spreads across the top of the stack before ordinary sprinklers open. Plastic packaging, foam and cartons make this worse. Storage sprinklers are designed and tested to deliver enough water, fast enough, to reach the base of such a fire.

What is an ESFR sprinkler?

An ESFR sprinkler combines a fast-reacting heat-sensitive element with a high water flow. The element is small so the sprinkler opens early, and the large discharge is meant to suppress the fire before it grows. ESFR sprinklers are used with a wet pipe system in most cases, and the common temperature rating is around 155 F (68 C).

Most ESFR sprinklers are pendent, and some upright models exist. Each model is approved only for the ceiling heights, storage heights and commodities stated on its listing or approval.

Three ways to protect storage

Your designer chooses the approach from the commodity, the storage arrangement, the height and the building construction.

What the designer needs to know

The commodity. NFPA 13 groups stored goods into Class I to IV and plastics groups. More combustible goods need stronger protection.

The storage arrangement. Palletised, rack, solid-piled or shelf storage each have different rules.

Storage height and ceiling height. Every ESFR and storage sprinkler listing has limits.

The ceiling. ESFR needs a reasonably flat, unobstructed ceiling and correct clearances. Beams, ducts and lights can interfere with the spray.

The water supply. Storage and ESFR designs demand more flow and pressure than ordinary hazard systems, so check the supply before you choose the sprinkler.

Why FM Approved matters here

Warehouses are where FM approved sprinklers are most often requested. FM Approvals groups its sprinklers into storage, non-storage and special protection categories, and an insurer such as FM reviews sites against its loss prevention data sheets for storage. A head approved for light-hazard, non-storage use is not a substitute for a storage sprinkler. To understand the difference between the marks, see UL Listed and FM Approved sprinklers.

Common mistakes

Using standard spray sprinklers where storage rules apply

Changing the stored goods or raising the stack height after the system is installed, without a redesign

Mixing ESFR with other sprinkler types in the same area without engineering approval

Mixing K-factors during replacement

Treating a warehouse as ordinary hazard

Checklist before you order

Confirm the commodity, storage arrangement, storage height and ceiling height.

Ask the designer which protection method applies.

Check the approval or listing covers your exact application.

Match the model, K-factor, temperature rating and orientation to the certificate.

Keep spare heads of the same model and a sprinkler wrench on site.

For more on reading a datasheet, see our guide to choosing sprinkler heads.

Talk to NONFIR

NONFIR is the sprinkler brand made by Ca-Fire. See the FM approved sprinkler range, or send us your storage details and our team will advise which models suit your project.

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