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 equation:

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 of head)

Explanation: The equation accounts for all resistance 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. An undersized pump won't deliver required flow, while an oversized pump wastes energy and may cause operational issues.

4. Using the Calculator

Tips: Enter static head and friction loss in feet. Include pressure head if the system requires pressure at discharge (e.g., for sprinkler systems). All values must be positive numbers.

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 friction losses and pressure requirements.

Q2: How do I calculate friction loss?
A: Friction loss depends on pipe size, length, material, flow rate, and number of fittings. Use the Hazen-Williams equation or consult friction loss charts.

Q3: When is pressure head needed?
A: Pressure head is required when the discharge point needs pressure (e.g., sprinkler systems, pressure tanks). Convert psi to feet by multiplying by 2.31.

Q4: What units should I use?
A: Consistent units are critical. This calculator uses feet for all components. Convert all measurements to feet before entering.

Q5: Does TDH change with flow rate?
A: Yes, friction loss increases with flow rate, so TDH is typically calculated for the design flow rate.