Define consistent standards for measuring energy efficiency performance.
Water heater energy factor list.
365 x 12 03 2 0 x 0 0842 185.
You need to know or convert the unit cost of electricity by kilowatt hour kwh.
Simplify the water heater selection.
The higher the ef value is the more efficient the water heater.
The uniform energy factor.
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.
The typical energy factor for a gas water heater is between 0 5 and 0 7.
It s important to note that energy factors can vary significantly depending on their fuel source.
As of september 1 2010 a water heater needs to have an energy factor of 0 67 or higher in order to qualify for the energy star label.
Expressed as a decimal the uniform energy factor is determined by running a department of energy specified simulated use test sut.
The new uef rating method improves the industry s ability to.
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.
An older measure of water heater overall efficiency that is being phased out due to new test methods for water heaters.
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.
A heat pump water heater with an ef of 2 0 and an electricity cost of 0 0842 kwh.
Electric water heaters typically have energy factors between 0 75 and 0 95.