What is the maximum horizontal spacing for in-rack sprinklers?

The maximum horizontal spacing for in-rack sprinklers is 12 feet, making this option the correct answer. This specification is based on standards set forth in fire protection codes, which are designed to ensure effective coverage and control of fire within racks. Proper spacing is critical in optimizing the performance of the sprinkler system, as it helps to achieve the necessary density and distribution of water to suppress or extinguish a fire.

Spacing beyond this maximum could lead to insufficient coverage, potentially allowing a fire to spread more rapidly through the rack storage area. By adhering to the 12-foot maximum, installations are more likely to meet the safety requirements and provide adequate fire protection in a variety of storage configurations. Understanding these specifications is essential for ensuring compliance with local and national fire codes as well as for the overall safety of the facility.