1. What is an Electric GPM Tankless Water Heater Calculator?

Definition: This calculator determines the required flow rate (in gallons per minute) for an electric tankless water heater based on your fixture usage.

Purpose: Helps homeowners and plumbers properly size an electric tankless water heater for adequate hot water supply.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The calculator sums the flow rates of all fixtures that might run simultaneously to determine the total GPM requirement.

3. Importance of Proper GPM Calculation

Details: Correct sizing ensures your tankless water heater can meet simultaneous hot water demands without temperature fluctuations.

4. Using the Calculator

Tips: Enter the flow rates for each fixture in your home. Default values are provided based on typical fixture flow rates.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical GPM range for tankless water heaters?
A: Electric models typically provide 3-8 GPM, with most households needing 5-7 GPM.

Q2: Should I add all fixtures or just those that might run together?
A: Only include fixtures that might run simultaneously during peak usage.

Q3: What if my actual fixture flow rates are different?
A: Measure your actual fixture flow rates or check manufacturer specs for more accurate calculations.

Q4: Does this account for temperature rise?
A: No, this calculates flow rate only. Temperature rise depends on incoming water temperature and heater capacity.

Q5: How much GPM can electric tankless heaters provide?
A: Typically 3-5 GPM for whole-house units, with point-of-use units providing 1-2 GPM.