What are ESFR Sprinklers and how they can be used in warehouses?

The ESFR (Early Suppression Fast Response) sprinkler system is primarily used for protecting high-piled storage arrangements such as palletized, solid pile, shelf, bin box, or rack storage of materials. A key advantage of ESFR sprinklers is the elimination of in-rack sprinklers in rack storage configurations, reducing the risk of accidental water discharge from damaged sprinklers or pipes. This also allows for easy rearrangement of storage racks without costly reconfiguration.

The ESFR sprinkler relies on three important factors: the sprinkler response (response time index), the Actual Delivered Density (ADD), and the Required Delivered Density (RDD). ADD is defined as the water flux delivered to the top surface of a burning rack-storage array after penetrating the fire plume. RDD is defined as the water flux required to be delivered at the top of the burning storage array to achieve suppression.

The ESFR sprinkler is based on the concept of early suppression, whereby the activation of the sprinkler occurs during the early stages of a fire while the RDD is minimal. During the early stages of the fire, the ADD will exceed the RDD and thus provide an adequate density to suppress the fire.

ESFR ceiling-mounted sprinklers can be used in warehouses in place of in-rack fire sprinkler systems, providing protection that exceeds that of in-rack systems. ESFR high output, high volume systems are located in ceiling spaces like conventional fire sprinkler systems. They incorporate very large high-volume, high-pressure heads to provide the necessary protection without the need for in-rack sprinklers.

ESFR sprinkler systems can protect a variety of commodities, from non-combustible to normal combustible products to high-hazard commodities such as plastics, without the use of additional in-rack sprinkler protection in rack storage structures. ESFR sprinklers are intended to operate differently than most other types of sprinklers. While most other sprinklers are intended to control the growth of a fire, an ESFR sprinkler system is designed to suppress a fire. To suppress a fire does not necessarily mean it will extinguish the fire but rather it is meant to ‘knock’ the fire back down to its original point of origin. ESFR sprinklers accomplish this task by using large volumes of water, nearly 380 liters per minute per sprinkler. Obviously, these systems require large water supplies and often require the installation of fire pumps.

However, ESFR cannot protect all types of rack storage; they cannot be applied to open-top containers. The concern with open-top containers is that they retain the water (like a reservoir) and therefore do not allow the water to flow down into the lowest levels of the rack.

While ESFR systems may solve many of the more challenging problems in warehouse protection against fires, ensuring that the correct type of ESFR is used involves a full understanding of the commodity and methods of storage in the warehouse. Careful consideration must also be given to the long-term use and range of flexibility expected by the owner of the building. Contact Aline Pumps today for expert advice on selecting the right ESFR sprinkler system for your warehouse and ensuring optimal fire protection for your specific needs.