What is the relationship between ceiling height and sprinkler spacing according to NFPA 13?

The relationship between ceiling height and sprinkler spacing is outlined in NFPA 13 and indicates that higher ceilings do indeed require greater spacing between sprinklers. This is due to the physics of how water is distributed during a fire event and the need for effective coverage.

When ceilings are higher, the water droplets from a sprinkler discharge have a longer distance to travel to effectively suppress a fire. To ensure that each part of the intended sprinkler coverage area receives adequate water before it falls to the ground, sprinklers must be spaced further apart. This adjustment compensates for the increased distance that water must travel to reach the floor, ensuring that there is enough density of water at the surface to effectively extinguish or control a fire.

In contrast, for lower ceilings, the spacing can be closer together because the water has less distance to cover, allowing for more efficient coverage without the need to account for vertical drop. Thus, understanding this relationship is critical for the proper design and installation of a sprinkler system in accordance with NFPA 13, ensuring that all areas are adequately protected based on ceiling height.