How do you find the energy factor?

Energy Factor (EF) is a measurement that’s used to describe theenergy-efficiency of a water heater. To calculate a water heater’s energy factor, you take the amount of energy the water heater puts to use and divide it by the total amount of energy that goes into powering the unit.

What is the EF rating on 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. This includes the following: Recovery efficiency – how efficiently the heat from the energy source is transferred to the water.

What is a good energy factor?

If you’re going to buy an electric water heater, we suggest you look for one with an Energy Factor equal to . 93 or greater. This represents a 5 to 10 percent savings compared to a standard efficiency electric water heater.

What is EF in temperature?

Generally, the EF number represents the thermal efficiency of the water heater as a percentage, since it is an average of the ratio of the theoretical heat required to raise the temperature of water drawn to the amount of energy actually consumed by the water heater.

How is UEF calculated?

The UEF calculation is based off of how much energy the water heater uses and how much energy is used to power the water heater itself. Think of UEF like an exchange rate: Water heaters with high UEF ratings will yield a higher return on every dollar of energy you put in.

What is the uniform energy factor?

Uniform Energy Factor (UEF) is a new metric for determining the energy efficiency of a water heater. UEF’s are determined by the estimated usage of a water heater: It’s important to remember – the higher the UEF, the higher the efficiency and the lower the energy bill.

Is a higher UEF better?

Uniform Energy Factor (UEF): The newest measure of water heater overall efficiency. The higher the UEF value is, the more efficient the water heater.

What is a uniform energy factor?

Uniform Energy Factor (UEF) rating A water heater’s UEF rating is a measure of its energy efficiency, with higher numbers denoting more efficient units. The UEF calculation is based off of how much energy the water heater uses and how much energy is used to power the water heater itself.

Is thermal efficiency the same as energy factor?

Uniform Energy Factor (UEF) calculates a water heater’s overall energy efficiency with other heaters with similar hot water output 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.

What is the difference between EF and UEF?

Previously, you may have seen efficiency measured by Energy Factor (EF). UEF replaces this metric. A higher UEF means a water heater is more energy efficient and will cost less to operate compared to other water heaters in the same bin. A water heater’s UEF can only be compared with water heaters within the same bin.

Is higher or lower UEF better?

What do you need to calculate power factor?

To calculate power factor, you need a power quality analyzer or power analyzer that measures both working power (kW) and apparent power (kVA), and to calculate the ratio of kW/kVA. The power factor formula can be expressed in other ways:

How is power factor used in energy management?

Simply put, this technology offsets the inductive reactive currents by introducing equal and opposite capacitive reactive currents. Typically this can reduce electricity bills by 5-8%, with a payback period of 12 to 18 months. In addition, the consumer shall gain from improved supply availability, improve voltage and reduced power losses.

How are reactive and apparent power factors calculated?

You will also need to know what units each type of power is in. Apparent power is measured in Volt-Amps. True power is measured in Watts and your Reactive power is measured in the units called Volt-Amp-Reactive (VAR’s). There are several equations to calculate these and all will be covered in the article.

What is the ratio of watts to power factor?

What is Power Factor Power Factor is the cosine of the phase angle between current and voltage. Power Factor is the ratio of true power to apparent power. Power is measured in Watts. Watts only equals Volts X Amps when the Power Factor is 1 or unity.

How is the energy factor of a water heater determined?

The energy factor for residential water heaters is determined using the results from the 24-hour simulated use test. During the test 64.3±1.0 gallons of water are drawn from the water heater in six equally spaced draws that begin one hour apart.

How is the energy factor used in the US?

The energy factor is currently used for rating the efficiency of water heaters, dishwashers, clothes washers, and clothes dryers. The term is used by the United States Department of Energy to develop and enforce minimum energy conservation standards under the Energy Conservation Program.

How is the Green Power equivalency equation determined?

The factors for this equation were determined in consultation with experts at the National Renewable Energy Laboratory (NREL) based upon conservative best estimates and utilization of NREL’s Annual Technology Baseline (ATB) tool and PVWatts Calculator. Based on these resources, NREL recommends these factors: