1. What is Pump Efficiency?

Definition: Pump efficiency (η) measures how effectively a pump converts input power into fluid flow energy.

Purpose: This calculation helps engineers evaluate pump performance, optimize energy usage, and compare different pump systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \eta \) — Pump efficiency (dimensionless, typically 0-1)
• \( Q \) — Flow rate (gallons per minute, GPM)
• \( H \) — Total head (feet, ft)
• \( \rho \) — Fluid density (pounds per gallon, lb/gal)
• \( P \) — Power input (horsepower, HP)
• 3960 — Conversion constant (ft·lb/min per HP)

Explanation: The numerator represents hydraulic power output, while the denominator is mechanical power input.

3. Importance of Pump Efficiency

Details: Higher efficiency means less energy waste, lower operating costs, and reduced environmental impact. Typical centrifugal pumps have 50-85% efficiency.

4. Using the Calculator

Tips: Enter flow rate in GPM, head in feet, density (default 8.34 lb/gal for water), and power in HP. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a good efficiency value?
A: Values typically range 0.5-0.85. Above 0.75 is excellent for most applications.

Q2: Why is water's density 8.34 lb/gal?
A: This is the density of water at standard conditions (1 gallon = 8.34 lbs).

Q3: What affects pump efficiency?
A: Pump design, operating point, fluid viscosity, wear, and system design all impact efficiency.

Q4: How can I improve efficiency?
A: Proper sizing, maintenance, reducing system resistance, and using VFDs can help.

Q5: What's the 3960 constant?
A: It converts HP to ft·lb/min (1 HP = 33,000 ft·lb/min ÷ 8.33 lb/gal ≈ 3960).