1. What is a Water Heater Size Calculator?

Definition: This calculator estimates the required water heater size based on peak water usage and the heater's recovery rate.

Purpose: It helps homeowners and plumbers determine the appropriate water heater capacity for a building's hot water needs.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( S \) — Water heater size (hours of operation)
• \( P \) — Peak water usage (gallons)
• \( R \) — Recovery rate (gallons/hour)

Explanation: The peak water usage is divided by the recovery rate to determine how many hours the heater needs to run to meet demand.

3. Importance of Water Heater Sizing

Details: Proper sizing ensures adequate hot water supply, energy efficiency, and prevents unnecessary strain on the heating system.

4. Using the Calculator

Tips: Enter your peak water usage in gallons and the heater's recovery rate (default 20 gal/h). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine peak water usage?
A: Estimate based on the number of occupants and their water usage habits, or measure actual usage during peak times.

Q2: What's a typical recovery rate?
A: Standard residential water heaters typically have recovery rates between 20-40 gallons per hour.

Q3: Should I round up the calculated size?
A: Yes, it's recommended to round up to the nearest standard water heater size for safety margins.

Q4: Does this account for simultaneous use?
A: The peak usage should already include your maximum simultaneous demand (shower + dishwasher + etc.).

Q5: How does tank size relate to this calculation?
A: The result indicates how many hours your heater needs to run to meet peak demand. Choose a tank size that can store enough hot water for your needs.