Hydraulic calculation is used to determine what aspect of a new sprinkler system, and which factors influence it?

• A. It determines required water flow and pressure; factors include design density, area of coverage, pipe friction losses, elevation changes, and residual pressures.
• B. It determines the color of piping; factors include building color and material.
• C. It assesses only the maximum pipe size; factors include ceiling height.
• D. It estimates energy usage for pumps; factors include motor efficiency and voltage.

Answer: (A)

Hydraulic calculation in a new sprinkler system is used to determine the required water flow and pressure to reliably operate all sprinklers in the protected area. This calculation is driven by the design density (the rate of water per unit area) and the area of coverage, which together specify the total demand. It also accounts for pipe friction losses along the network and any elevation changes between the water supply and the heads, which reduce available pressure as flow increases. Finally, it enforces residual pressures, ensuring the minimum pressure at the most remote or highest point remains above the required threshold. These factors together define what the water supply must deliver; options like piping color, merely the maximum pipe size, or pump energy usage are not determined by hydraulic calculation in this sense.