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 used to select the appropriate pump for a system.

2. How Does the Calculator Work?

The calculator uses the TDH equation:

Where:

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

Explanation: The equation sums all resistance components 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. An undersized pump won't deliver required flow, while an oversized pump wastes energy and may cause system damage.

4. Using the Calculator

Tips:

• Static Head: Measure vertical distance from source to discharge
• Friction Loss: Calculate using pipe size, length, flow rate, and material
• Pressure Head: Include if discharge requires specific pressure (e.g., sprinkler systems)

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 and pressure components.

Q2: How do I calculate friction loss?
A: Use the Hazen-Williams or Darcy-Weisbach equation based on pipe characteristics and flow rate.

Q3: When is pressure head needed?
A: When the discharge requires specific pressure (e.g., 30 psi for sprinklers = ~69 ft head).

Q4: What units should I use?
A: Consistent units are critical - this calculator uses feet for all components.

Q5: How does TDH affect pump selection?
A: The pump curve must show adequate flow rate at your calculated TDH for proper operation.