Simplify the water heater selection.
Water heater energy factor list.
365 days year x 12 03 kwh day ef x fuel cost kwh annual cost of operation.
Expressed as a decimal the uniform energy factor is determined by running a department of energy specified simulated use test sut.
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.
An older measure of water heater overall efficiency that is being phased out due to new test methods for water heaters.
The higher the ef value is the more efficient the water heater.
365 x 12 03 2 0 x 0 0842 185.
It s important to note that energy factors can vary significantly depending on their fuel source.
Define consistent standards for measuring energy efficiency performance.
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.
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.
Electric water heaters typically have energy factors between 0 75 and 0 95.
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.
The new uef rating method improves the industry s ability to.
The uniform energy factor.
The typical energy factor for a gas water heater is between 0 5 and 0 7.