How should changes in elevation impact sprinkler pipe sizing according to NFPA 13?

Changes in elevation must be factored into hydraulic calculations because they significantly influence the water pressure and flow characteristics within the sprinkler system. When a sprinkler system has pipes that travel up or down elevations, the pressure will change due to gravitational effects. Specifically, an increase in elevation typically requires additional pressure to maintain the desired flow rate, while a decrease in elevation can increase pressure.

By including these factors in the hydraulic calculations, designers ensure that the system can deliver the required amount of water at the necessary pressure to effectively protect the area in question. This consideration helps avoid under- or over-sizing pipes, which can lead to inefficient system performance and potentially compromise fire protection capabilities. Proper sizing and pressure requirements must be confirmed through these calculations to comply with NFPA 13 standards.