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's the sum of static head, friction head, and pressure head.

2. How Does the Calculator Work?

The calculator uses the TDH formula:

Where:

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

Explanation: The equation accounts for all components of resistance that the pump must overcome to move fluid through the system.

3. Importance of TDH Calculation

Details: Accurate TDH calculation is crucial for proper pump selection and ensuring the pump can provide enough pressure to overcome system resistance and deliver the required flow.

4. Using the Calculator

Tips: Enter all values in feet. Static head is the vertical distance, friction loss can be calculated separately or estimated, and pressure head is only needed if there's specific pressure requirement at discharge.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between static head and dynamic head?
A: Static head is the vertical distance only, while dynamic head includes all resistances (friction, velocity head, pressure requirements).

Q2: How do I determine friction loss?
A: Friction loss depends on pipe size, length, material, flow rate, and number of fittings. Use hydraulic tables or calculators.

Q3: When is pressure head needed?
A: When the discharge point requires specific pressure (e.g., sprinkler systems, pressure tanks). Convert psi to feet (1 psi = 2.31 ft).

Q4: What are typical TDH values?
A: Residential systems often range 20-60 ft, commercial systems can be 100+ ft depending on design.

Q5: How does TDH affect pump selection?
A: The pump curve must show adequate flow rate at your calculated TDH. Select a pump where your operating point is near its best efficiency point.