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 both the static head (vertical distance) and friction losses in the system. It's a crucial parameter for selecting and sizing submersible pumps.

2. How Does the Calculator Work?

The calculator uses the TDH formula:

Where:

• \( Static\ Head \) — Vertical distance from water surface to discharge point (feet)
• \( Friction\ Loss \) — Pressure loss due to pipe friction (feet)

Explanation: TDH represents the total resistance the pump must overcome, including both the physical height and the resistance caused by pipe friction.

3. Importance of TDH Calculation

Details: Accurate TDH calculation is essential for selecting the right pump. A pump with insufficient TDH capacity won't deliver water effectively, while an oversized pump wastes energy and may cause system damage.

4. Using the Calculator

Tips:

• Measure static head as the vertical distance from the water surface to the discharge point
• Calculate friction loss based on pipe diameter, length, material, and flow rate (use separate friction loss calculators if needed)
• Add safety margins (typically 10-20%) to account for unexpected losses

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between static head and TDH?
A: Static head is just the vertical distance, while TDH includes both static head and all friction losses in the system.

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

Q3: What's a typical TDH range for residential submersible pumps?
A: Typically 100-300 feet, but depends on well depth and system design. Deep wells may require higher TDH pumps.

Q4: Why is my pump not delivering expected flow rate?
A: Likely causes include underestimated TDH, pipe restrictions, or pump wear. Recheck your TDH calculations and system components.

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