1. What is Total Dynamic Head (TDH)?

Total Dynamic Head (TDH) is the total equivalent height that a fluid is to be pumped, taking into account friction losses in the pipe. It represents the actual workload on the pump and is crucial for proper pump selection and system design.

2. How Does the Calculator Work?

The calculator uses the TDH equation:

Where:

• Static Head — The vertical distance from the water surface to the discharge point (ft)
• Friction Loss — Loss due to friction in pipes and fittings (ft)
• Pressure Head — Additional pressure required at discharge (converted to ft of head)

Explanation: TDH accounts for all resistance the pump must overcome, including elevation changes, pipe friction, and any required discharge pressure.

3. Importance of TDH Calculation

Details: Accurate TDH calculation is essential for selecting a properly sized pump. Underestimating TDH can lead to insufficient flow, while overestimating can result in oversized, inefficient pumps.

4. Using the Calculator

Tips:

• Measure static head as the vertical distance from source to discharge
• Calculate friction loss using pipe size, length, flow rate, and material
• Include pressure head if the system requires pressure at discharge (e.g., sprinkler systems)
• All values must be in feet of head

5. Frequently Asked Questions (FAQ)

Q1: How do I calculate friction loss?
A: Friction loss can be calculated using the Hazen-Williams equation or Darcy-Weisbach equation based on pipe characteristics and flow rate.

Q2: What's the difference between static head and TDH?
A: Static head is just the vertical elevation difference, while TDH includes all resistances the pump must overcome.

Q3: When is pressure head needed?
A: Pressure head is needed when the discharge requires pressure (e.g., irrigation systems, pressure tanks, or industrial processes).

Q4: How does TDH affect pump selection?
A: The pump's performance curve must show it can deliver the required flow rate at your calculated TDH.

Q5: What units should I use?
A: This calculator uses feet. For metric units (meters), convert all values consistently.