Water Heater Calculation Formula

Water Heater Recovery Formula:

\[ Recovery = \frac{kW \times 3413}{\Delta T \times 8.34} \]

Recovery (gallons per hour):

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1. What is the Water Heater Recovery Formula?

The Water Heater Recovery Formula calculates the recovery rate of a water heater, which represents how many gallons of water per hour the heater can raise to a specified temperature. This is essential for determining the capacity and efficiency of water heating systems.

2. How Does the Calculator Work?

The calculator uses the water heater recovery formula:

\[ Recovery = \frac{kW \times 3413}{\Delta T \times 8.34} \]

Where:

\( Recovery \) — Recovery rate in gallons per hour
\( kW \) — Heating power in kilowatts
\( 3413 \) — Conversion factor (BTU per kWh)
\( \Delta T \) — Temperature rise in degrees Fahrenheit
\( 8.34 \) — Weight of one gallon of water in pounds

Explanation: The formula converts electrical power (kW) to thermal energy (BTU), then calculates how much water can be heated per hour based on the required temperature increase.

3. Importance of Recovery Rate Calculation

Details: Recovery rate is crucial for sizing water heaters appropriately, ensuring adequate hot water supply for residential and commercial applications, and optimizing energy efficiency.

4. Using the Calculator

Tips: Enter the heater's power rating in kilowatts and the desired temperature rise in °F. Both values must be positive numbers for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is recovery rate in water heaters?
A: Recovery rate measures how many gallons of water the heater can raise by a specified temperature (usually 100°F) in one hour.

Q2: Why is 3413 used in the formula?
A: 3413 is the conversion factor from kilowatts to BTU per hour (1 kW = 3413 BTU/hr).

Q3: What is a typical recovery rate for residential water heaters?
A: Typical electric water heaters recover 10-20 gallons per hour for a 100°F temperature rise, depending on the unit's size and power.

Q4: How does ΔT affect recovery rate?
A: Higher temperature differences require more energy, resulting in lower recovery rates for the same power input.

Q5: Can this formula be used for gas water heaters?
A: This specific formula is for electric water heaters. Gas heaters use different calculations based on BTU input rather than kW.