Water Heater Energy Factor Calculator

The uniform energy factor for residential and certain commercial water heaters refers to its efficiency when run under standardized conditions for a 24 hour period.

Water heater energy factor calculator.

Use the energy factor to determine the energy efficiency of a storage tankless or demand type water heater or heat pump water heater. To determine btu lost can i use the water heating energy calculator only backwards. At the bottom of the calculator are more settings you can adjust for further accuracy such as the cold water intake temperature the water heater temperature and the cost of electricity. A water heater s energy factor ef is a measure of useful energy coming out of the water heater divided by the amount of energy going in.

Typical fifty gallon electric resistance storage water heaters have energy factors that range from 0 904 to 0 95. Expressed as a decimal the uniform energy factor is determined by running a department of energy specified simulated use test sut. The term is used by the united states department of energy to develop and enforce minimum energy conservation standards under. Start temp as final and end temp as start.

Using the doe test procedure for calculations a fifty gallon electric resistance storage water heater with an energy factor of 0 95 would consume 4 622 kilowatt hours per year see table 1 on page nine for figures. Energy factor 0 92 electric 0 61 gas energy cost 0 06 per kwh 60 per therm. Hi larry the energy that is used to heat water from 40 degrees to 60 is the same amount that is lost when the water cools down from 60 to 40 only changed sign. The energy factor ef indicates a water heater s overall energy efficiency based on the amount of hot water produced per unit of fuel consumed over a typical day.

The water heaters themselves haven t changed but the way we calculate the ratings and other facts and figures associated with them is different. To calculate a water heater s energy factor you take the amount of energy the water heater puts to use and divide it by the total amount of energy that goes into powering the unit. Antonio january 5 2019. An energy factor is a metric used in the united states to compare the energy conversion efficiency of residential appliances and equipment.

Quantity of water heaters to be purchased unit s 1 unit see assumptions for various daily water use totals. The energy factor is based on the amount of hot water produced per unit of fuel consumed per day. The higher the energy factor of a water heater the more efficient it is. The comparison assumes a storage tank water heater as the input type.

Electric water heaters typically have energy factors between 0 75 and 0 95.