1. What is a Heat Pump Flow Rate Calculator?

Definition: This calculator determines the total flow rate (GPM) needed for a heat pump water system by summing the flow rates of individual fixtures.

Purpose: It helps HVAC professionals and engineers properly size heat pump systems to ensure adequate water flow.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Total flow rate (gallons per minute)
• \( Q_i \) — Flow rate of each individual fixture (GPM)

Explanation: The total system flow rate is simply the sum of all fixture flow rates that will be operating simultaneously.

3. Importance of Flow Rate Calculation

Details: Proper flow rate estimation ensures efficient heat transfer, prevents pump overload, and maintains system performance.

4. Using the Calculator

Tips: Enter the flow rate for each fixture in GPM. Leave blank for fixtures not in use. The calculator sums all entered values.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical flow rate for residential fixtures?
A: Common flow rates: shower (2.5 GPM), sink (1.5 GPM), bathtub (4 GPM), dishwasher (1.5 GPM).

Q2: Should I consider simultaneous use?
A: Yes, the calculator sums all entered fixtures assuming they might operate together during peak demand.

Q3: How does flow rate affect heat pump performance?
A: Insufficient flow can cause poor heat transfer, while excessive flow may reduce efficiency.

Q4: What if I have more than 4 fixtures?
A: You can add multiple fixture values in a single field (e.g., enter "2.5+1.5" in one field).

Q5: Does this include system losses?
A: No, consider adding 10-15% to the calculated flow rate for pipe friction losses.