Water Heater Energy Factor Vs Efficiency

The fuel used by a water heating system will not only affect annual operation costs but also the water heater s size and energy efficiency.
Water heater energy factor vs efficiency. Expressed as a decimal the uniform energy factor is determined by running a department of energy specified simulated use test sut. Just 15 of the nation s 4 7 million gas water heater shipments were high efficiency gas storage water heaters with an energy factor of 0 62 instead of conventional models with an energy factor at the federal standard the aggregate energy savings would amount to 13 4 million therms per year. 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 uniform energy factor.
Most new water heaters have an efficiency factor ef of 58 60. An older measure of water heater overall efficiency that is being phased out due to new test methods for water heaters. Use the energy factor to determine the energy efficiency of a storage tankless or demand type water heater or heat pump water heater. Exploring water heater options by fuel type.
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. The two figures are related but different. That means that 58 60 of the energy that is being used to heat your water is effectively converted into heat. 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.
An energy factor is a metric used in the united states to compare the energy conversion efficiency of residential appliances and equipment. The following is a list of water heater options by fuel or energy source. The term is used by the united states department of energy to develop and enforce minimum energy conservation standards under. The greater the energy factor the more efficient the appliance is.
On the contrary thermal efficiency is the amount of energy delivered as heated water compared to the energy consumption of the water heater. The higher the ef value is the more efficient the water heater. The energy factor is currently used for rating the efficiency of water heaters dishwashers clothes washers and clothes dryers. That means that 58 60 of the energy that is being used to heat your water is effectively converted into heat.
Energy factor is a measure of efficiency for a variety of appliances including water heaters. The new uef rating method improves the industry s ability to. 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. Define consistent standards for measuring energy efficiency performance.
Simplify the water heater selection.