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 is the sum of the 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 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 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 the discharge point (e.g., for sprinkler systems).

5. Frequently Asked Questions (FAQ)

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

Q2: What's a typical TDH range for residential systems?
A: Most residential water systems operate between 50-150 ft TDH, depending on elevation changes and piping configuration.

Q3: When is pressure head needed?
A: Pressure head is required when the discharge point needs pressure (e.g., irrigation systems, pressure tanks). 1 psi = 2.31 ft of head.

Q4: How does TDH affect pump power requirements?
A: Pump power is directly proportional to TDH. Higher TDH requires more powerful pumps to achieve the same flow rate.

Q5: Should I add a safety factor to my TDH calculation?
A: It's common to add 10-20% safety factor to account for system aging, fouling, or unanticipated flow requirements.