ESFR Sprinklers

Operating Principle

ESFR sprinklers have a very fast response time index and large K-factors optimised to deliver large water droplets. The goal is suppression – extinguishing the fire within a few sprinkler cycles – rather than the control-mode approach of conventional sprinkler design. This allows large storage heights to be protected without additional in-rack sprinklers between rack levels.

Requirements and Limitations

Effectiveness depends on a defined ceiling clearance and an unobstructed space beneath the ceiling; false ceilings, beams or other obstructions in the discharge pattern are not permitted. The water supply must deliver high pressure and flow during a short, intense suppression phase. Certain storage configurations, such as multiple-row racks or highly combustible packaging, are only permitted with restrictions or not at all.

Insurance Relevance

ESFR enables cost-effective protection of very high storage without in-rack sprinklers, but it is sensitive to subsequent changes in occupancy. Deviations from the listing basis – such as greater storage height or a different commodity than originally designed for – effectively negate the protection and are a key checkpoint at every risk survey.