There are a lot of issues with warehouses and storage building that make these facilities a significant risk as a fire hazard. The very nature of how the material is stored in these buildings, including being up on racks with solid shelving, creates challenges for fire suppression systems to have the ability to slow down or even stop the spread of the fire.
Additionally, the combustible types of storage racks and solid shelves can also become fuel, and they can easily become unstable during a fire. This leads to an increased risk of not only damage to the stored materials, but also a danger to employees, firefighters, or those trying to suppress the fire in the initial stages.
In the past, and prior to the new ESFR Code Changes in the NPFA, the early suppression, fast response sprinklers or ESFR sprinklers, were not allowed by code unless there was also an in-rack sprinkler system in place. After January of 2014, these systems are now allowed with solid shelving on rack systems, although there are some limitations and requirements that must be followed if they are installed on their own without the in-rack sprinklers.
However, there are a few factors to consider. One of the most critical issues is that the early suppression, fast response sprinklers are designed to suppress fire, and they need to be installed in agreement and accordance with the NFPA guidelines which are found in section 8.12. This includes placing the sprinklers the appropriate distance apart but also avoiding any type of obstructions or objects that may distort or block some of the spray patterns from an individual ESFR sprinkler.
Bin-Box and Shelf Storage
While the code allows for the use of early suppression, fast response sprinklers for racks, it does not allow for these systems to be used if there are bin-boxes that can block the spray from the sprinklers.
With the solid shelving units, correct positioning of the sprinklers and the configuration of the shelving to avoid blockages can alleviate this issue. It is important to also consider the height of the sprinklers, as the greater the distance the early suppression, fast response sprinklers are, the less overall effective suppression they provide.
The correct choice of early suppression, fast response sprinklers, and the attention to the potential spray patterns and obstructions with the rack storage and solid shelving is important. The choice of this option over the standard in-rack sprinkler systems does have its advantages, including less piping, fewer maintenance requirements and the ability to reconfigure racks and storage areas without having to remove and re-pipe for the entire rack area.