Water Heater Energy Factor List

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 list.

A heat pump water heater with an ef of 2 0 and an electricity cost of 0 0842 kwh. You need to know or convert the unit cost of electricity by kilowatt hour kwh. An older measure of water heater overall efficiency that is being phased out due to new test methods for water heaters. It s important to note that energy factors can vary significantly depending on their fuel source.

365 days year x 12 03 kwh day ef x fuel cost kwh annual cost of operation. This means that between 75 and 95 percent of the energy used to heat the water ends up being delivered to your taps as usable hot water. The typical energy factor for a gas water heater is between 0 5 and 0 7. The higher the ef value is the more efficient the water heater.

Expressed as a decimal the uniform energy factor is determined by running a department of energy specified simulated use test sut. Define consistent standards for measuring energy efficiency performance. Simplify the water heater selection. 365 x 12 03 2 0 x 0 0842 185.

The new uef rating method improves the industry s ability to. Ef is determined by the department of energy s test method outlined in the 10 cfr parts 200 to 499 edition revised as of january 1 2014. Electric water heaters typically have energy factors between 0 75 and 0 95. Beginning june 12 2017 ef ratings will be replaced with the new industry standard for measuring energy efficiency in water heaters called uniform energy factor uef.