Water Heater Efficiency Calculator
Compare water heater types by efficiency factor and calculate annual operating cost for heating water.
Annual Water Heating Cost
436 USD
Annual Water Heating Cost vs Daily Hot Water Usage
公式
## How to Calculate Water Heater Costs Water heating is typically the second largest energy expense in a home (14-18% of energy bills). ### Formula **Daily BTU = Gallons * Temp Rise * 8.33** **Annual Energy = Daily BTU * 365 / Energy Factor** ### Energy Factors - Standard gas: 0.60-0.70 - High-efficiency gas: 0.80-0.98 - Electric resistance: 0.90-0.95 - Heat pump water heater: 2.0-4.0
计算示例
50 gal/day hot water, 60F temp rise, 0.92 energy factor, $0.15/kWh.
- 01Daily BTU: 50 * 60 * 8.33 = 24,990 BTU
- 02Daily energy with EF: 24,990 / 0.92 = 27,163 BTU
- 03Annual energy: 27,163 * 365 = 9,914,526 BTU
- 04Annual cost: 9,914,526 / 3,412 * $0.15 = $436
常见问题
What is the most efficient water heater?
Heat pump water heaters are the most efficient, with energy factors of 2.0-4.0, meaning they use 2-4x less energy than electric resistance heaters. They cost $1,200-2,500 installed.
What temperature should my water heater be set to?
The recommended setting is 120F, balancing safety and efficiency. Every 10F reduction saves 3-5% in water heating costs.
How much of my energy bill is water heating?
Water heating accounts for about 14-18% of the average home energy bill, or $400-600 per year. This makes it the second largest energy expense after HVAC.