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:

• \( Static\ Head \) — 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: TDH is the sum of 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. 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 all values in feet. Static head is the vertical distance. Friction loss can be calculated separately based on pipe size, length, and flow rate. Pressure head is optional (use 0 if not applicable).

5. Frequently Asked Questions (FAQ)

Q1: 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.

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

Q3: When is pressure head needed?
A: When the discharge must be under pressure (e.g., sprinkler systems or pressurized tanks). Convert psi to feet (1 psi = 2.31 ft).

Q4: What units should I use?
A: This calculator uses feet. For metric, convert meters to feet (1 m = 3.28 ft) or modify the formula.

Q5: How does TDH affect pump selection?
A: Pumps are selected based on their performance curves showing flow rate vs. TDH. Your calculated TDH determines where on the curve the pump will operate.