1. What is an 11 GPM Electric Tankless Water Heater?

Definition: This calculator helps size an electric tankless water heater for large commercial or multi-unit applications requiring approximately 11 gallons per minute (GPM) flow rate.

Purpose: It helps determine if an 11 GPM commercial unit is appropriate for your application based on fixture count and flow requirements.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Total flow rate required (GPM)
• \( Q_i \) — Flow rate per fixture (GPM)
• Safety Factor — Accounts for simultaneous use (typically 1.2)

Explanation: The calculator sums the flow rates of all fixtures (adjusted by a safety factor) to determine if an 11 GPM unit is sufficient.

3. Importance of Proper Sizing

Details: Proper sizing ensures adequate hot water supply, energy efficiency, and prevents overloading electrical systems.

4. Using the Calculator

Tips: Enter the number of fixtures, average GPM per fixture (default 1.5 GPM), and safety factor (default 1.2). The calculator will determine if an 11 GPM unit is appropriate.

5. Frequently Asked Questions (FAQ)

Q1: What's typical flow rate for fixtures?
A: Standard fixtures: 0.5-1.5 GPM (sinks), 1.5-2.5 GPM (showers), 2.0-3.0 GPM (tubs).

Q2: When is an 11 GPM unit needed?
A: For commercial applications, multi-unit dwellings, or homes with 4+ bathrooms.

Q3: What electrical requirements are needed?
A: 11 GPM units typically require 3x 60A circuits at 240V (consult an electrician).

Q4: Can I use multiple smaller units?
A: Yes, parallel installation of smaller units is sometimes preferred for redundancy.

Q5: What if my calculation exceeds 11 GPM?
A: Consider multiple units or a commercial-grade system with higher capacity.