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 total energy required to move fluid through a piping 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 (ft)
• Friction Loss — Head loss due to friction in pipes and fittings (ft)
• Pressure Head — Additional pressure required at discharge (converted to feet of head) (ft)

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 and system design. 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 lift, friction loss includes pipe and fitting losses, and pressure head is any additional pressure requirement at discharge (set to 0 if not applicable).

5. Frequently Asked Questions (FAQ)

Q1: How do I determine friction loss?
A: Friction loss can be calculated using the Hazen-Williams equation or Darcy-Weisbach equation, or obtained from pipe friction charts based on flow rate, pipe size, and material.

Q2: What's the difference between static head and dynamic head?
A: Static head is the vertical height difference only, while dynamic head includes all resistances (static head + friction losses + pressure requirements).

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

Q4: How does TDH affect pump selection?
A: Pumps are selected based on their performance curves at the required flow rate and TDH. The operating point should be near the pump's best efficiency point.

Q5: What units should I use?
A: This calculator uses feet. For metric units (meters), convert all values accordingly (1 ft = 0.3048 m).