1. What is a Heat Pump Water Heater Size Calculator?

Definition: This calculator determines the required capacity of a heat pump water heater by summing the flow rates of all simultaneous hot water fixtures.

Purpose: It helps homeowners and plumbers properly size heat pump water heaters to meet household hot water demands.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Total required heat pump capacity (gallons per minute)
• \( Q_i \) — Flow rate of each individual fixture (GPM)

Explanation: The calculator sums the flow rates of all fixtures that might run simultaneously to determine the peak demand.

3. Importance of Proper Sizing

Details: Correct sizing ensures adequate hot water supply, energy efficiency, and prevents overworking the heat pump system.

4. Using the Calculator

Tips: Enter the flow rates for each fixture in gallons per minute (GPM). Default values are provided based on typical flow rates.

5. Frequently Asked Questions (FAQ)

Q1: What if I don't know my fixture flow rates?
A: Use the default values which represent typical flow rates for standard fixtures.

Q2: Should I include all fixtures in my home?
A: Only include fixtures that might run simultaneously during peak usage times.

Q3: How do I account for low-flow fixtures?
A: Enter the actual flow rate of your low-flow fixtures (typically 1.5 GPM for showers and 0.5 GPM for faucets).

Q4: What's the typical GPM requirement for a family?
A: Most families need 5-7 GPM capacity, but this depends on the number of bathrooms and appliances.

Q5: Does this include a safety factor?
A: No, consider adding 10-20% to the calculated value for peak demand situations.