What determines the pressure required to achieve a specific flow rate?

The pressure required to achieve a specific flow rate is fundamentally influenced by the design of the piping system. This encompasses several design considerations, including the layout of the piping, the length and configuration of the pipes, the presence of bends and fittings, and the overall resistance to flow.

A well-designed piping system can minimize friction losses, which allows for efficient fluid movement at a lower pressure, while a poorly designed system could lead to increased turbulence and friction, requiring higher pressure to achieve the same flow rate. Additionally, the design can incorporate valves and throttling devices that can further affect the flow characteristics and pressure requirements in specific scenarios. Hence, understanding the design elements is critical for predicting and managing flow rates effectively in HVAC/R systems.