1. What is an Electric Tankless Water Heater Calculator?

Definition: This calculator estimates the total flow rate (GPM) needed for an electric tankless water heater based on your fixture requirements.

Purpose: It helps homeowners and plumbers determine the appropriate size for an electric tankless water heater system.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Total flow rate required (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 total demand on the water heater.

3. Importance of Proper Sizing

Details: Correctly sizing your tankless water heater ensures adequate hot water supply while avoiding oversized units that waste energy.

4. Using the Calculator

Tips: Enter the flow rates for each fixture in your home. Default values are provided for typical fixtures. All values must be ≥ 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical flow rate for a shower?
A: Standard showerheads use about 2.5 GPM, while low-flow models may use 1.5-2.0 GPM.

Q2: How do I find my fixture's flow rate?
A: Check manufacturer specifications or measure by timing how long it takes to fill a one-gallon container.

Q3: Should I include all fixtures in my home?
A: Only include fixtures that might run simultaneously. For example, you might shower while the dishwasher runs.

Q4: What if my total GPM exceeds available models?
A: Consider installing multiple units or staggering hot water use during peak times.

Q5: Does this account for temperature rise?
A: No, this calculates flow rate only. You'll also need to consider the temperature increase required for your climate.