Water Heater Energy Factor Vs Efficiency

An energy factor is a metric used in the united states to compare the energy conversion efficiency of residential appliances and equipment.

Water heater energy factor vs efficiency.

The new uef rating method improves the industry s ability to. Energy factor is a measure of efficiency for a variety of appliances including water heaters. 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 two figures are related but different.

Use the energy factor to determine the energy efficiency of a storage tankless or demand type water heater or heat pump water heater. Simplify the water heater selection. 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.

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. The uniform energy factor. Exploring water heater options by fuel type. Fuel type and its availability in your area may narrow your water heater choices.

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. That means that 58 60 of the energy that is being used to heat your water is effectively converted into heat. The following is a list of water heater options by fuel or energy source. Define consistent standards for measuring energy efficiency performance.

Energy factor calculates the amount of energy delivered as hot water compared to the energy consumption of a residential water heater over a 24 hour period. On the contrary thermal efficiency is the amount of energy delivered as heated water compared to the energy consumption of the water heater. That means that 58 60 of the energy that is being used to heat your water is effectively converted into heat. 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.

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. 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. Most new water heaters have an efficiency factor ef of 58 60. The energy factor is currently used for rating the efficiency of water heaters dishwashers clothes washers and clothes dryers.

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.