1. What is a Tankless Water Heaters Gas Calculator?

Definition: This calculator estimates the total flow rate (GPM) required for a gas tankless water heater based on fixture flow rates.

Purpose: It helps homeowners and plumbers determine the appropriate size for a tankless water heater by calculating simultaneous hot water demand.

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

Explanation: The calculator sums the flow rates of all potential simultaneously used fixtures to determine the required capacity of the tankless water heater.

3. Importance of Proper Sizing

Details: Correct sizing ensures adequate hot water supply while avoiding oversized units that waste energy and money.

4. Using the Calculator

Tips: Enter the flow rates for each fixture (default values provided). Consider your household's peak usage patterns when selecting which fixtures to include.

5. Frequently Asked Questions (FAQ)

Q1: What are typical flow rates for fixtures?
A: Standard flow rates: Shower (2.5 GPM), Sink (1.5 GPM), Dishwasher (1.0 GPM), Washing Machine (2.0 GPM).

Q2: Should I include all fixtures in my home?
A: Only include fixtures that might be used simultaneously during peak demand.

Q3: What about low-flow fixtures?
A: Adjust the flow rates accordingly if you have water-saving fixtures installed.

Q4: How does temperature rise affect this?
A: This calculator determines flow rate only. Temperature requirements affect the BTU capacity needed.

Q5: Should I add a safety factor?
A: It's recommended to add 10-20% to the calculated GPM for unexpected demand.