1. What is Water Pump Horsepower?

Definition: This calculator determines the required horsepower for a water pump based on flow rate, total head, and pump efficiency.

Purpose: It helps engineers, plumbers, and irrigation specialists properly size pumps for various applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( HP \) — Horsepower required
• \( Q \) — Flow rate (gallons per minute)
• \( H \) — Total head (feet)
• \( \eta \) — Pump efficiency (0-1)
• 8.34 — Weight of water (lbs/gallon)
• 3960 — Conversion factor (ft-lb/min to HP)

Explanation: The formula calculates the power needed to move water against gravity and system resistance.

3. Importance of Proper Pump Sizing

Details: Correct horsepower calculation ensures efficient operation, prevents motor overload, and reduces energy costs.

4. Using the Calculator

Tips: Enter flow rate in GPM, total head in feet, and pump efficiency (default 0.85 for 85%). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is total head in pumping systems?
A: Total head is the sum of static head (vertical distance) and friction head (pipe resistance).

Q2: What's a typical pump efficiency value?
A: Most pumps operate between 50-85% efficiency, with centrifugal pumps typically around 70-85%.

Q3: Why is 8.34 used in the formula?
A: This represents the weight of one gallon of water in pounds at standard conditions.

Q4: How do I find my system's total head?
A: Measure vertical distance plus calculate friction loss using pipe size, length, and flow rate.

Q5: Should I round up the calculated horsepower?
A: Yes, always select the next available pump size to ensure adequate capacity.