1. What is the Pump Horsepower Equation?

The pump horsepower equation calculates the power required to move fluid through a system. It considers flow rate, total head, fluid density, and pump efficiency to determine the mechanical power needed.

2. How Does the Calculator Work?

The calculator uses the horsepower equation:

Where:

• \( Q \) — Flow rate in gallons per minute (GPM)
• \( H \) — Total head in feet
• \( SG \) — Specific gravity of fluid (1.0 for water)
• \( \eta \) — Pump efficiency (decimal, typically 0.7-0.9)
• 3960 — Conversion factor (foot-pounds per minute per horsepower)

Explanation: The equation calculates the power required to move a given flow rate against a specific head, adjusted for fluid density and pump efficiency.

3. Importance of Proper Pump Sizing

Details: Correct pump sizing is crucial for energy efficiency, system performance, and equipment longevity. Oversized pumps waste energy while undersized pumps can't meet system demands.

4. Using the Calculator

Tips: Enter flow rate in GPM, total head in feet, specific gravity (1.0 for water), and pump efficiency (typically 0.7-0.9). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is total head?
A: Total head is the sum of static head (vertical distance) and friction head (pressure loss due to pipe friction and fittings).

Q2: How do I determine pump efficiency?
A: Efficiency is typically provided by the manufacturer. For estimation, use 0.7-0.9 (70-90%) for most pool pumps.

Q3: What's a typical flow rate for residential pools?
A: Typically 40-60 GPM for residential pools, but depends on pool size and turnover requirements.

Q4: Should I round up the calculated horsepower?
A: It's common to select the next standard pump size, but avoid excessive oversizing which reduces efficiency.

Q5: Does this work for saltwater pools?
A: Yes, saltwater has nearly the same specific gravity (SG ≈ 1.02) as freshwater, so the difference is negligible.