1. What is the Pump Power Equation?

The pump power equation calculates the power required to move fluid through a system, accounting for flow rate, head pressure, fluid density, and pump efficiency. It's essential for designing and optimizing HVAC systems.

2. How Does the Calculator Work?

The calculator uses the pump power equation:

Where:

• \( P \) — Power (kW)
• \( \rho \) — Fluid density (kg/m³, 1000 for water)
• \( g \) — Gravity (9.81 m/s²)
• \( Q \) — Flow rate (m³/s)
• \( H \) — Head (meters)
• \( \eta \) — Pump efficiency (0-1)

Explanation: The equation calculates the theoretical power needed to move fluid against gravity and system resistance, adjusted for pump efficiency.

3. Importance of Pump Power Calculation

Details: Accurate power calculation helps in selecting properly sized pumps, estimating energy costs, and optimizing system performance in HVAC applications.

4. Using the Calculator

Tips: Enter flow rate in m³/s, head in meters, pump efficiency (typically 0.7-0.9 for centrifugal pumps), and fluid density (1000 kg/m³ for water). All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical flow rate for AC systems?
A: For chilled water systems, typical flow rates range from 0.001 to 0.01 m³/s per ton of cooling.

Q2: How do I determine pump head?
A: Head includes static lift plus friction losses in pipes, valves, and fittings. Consult system design specifications.

Q3: What's a good pump efficiency value?
A: Centrifugal pumps typically have 70-90% efficiency. Higher for larger pumps, lower for small circulators.

Q4: Why does density matter?
A: Power requirement increases with fluid density. Water at 1000 kg/m³ is standard, but glycol mixtures are denser.

Q5: How can I reduce pump power?
A: Optimize pipe sizing to reduce head, select high-efficiency pumps, and right-size the pump for the load.