Energy factor

A factor is used to compare the relative efficiency of water heaters, dishwashers, clothes washers, and clothes dryers. Energy Factor (EF) is the quotient of the capacity equipment divided by the sum of the equipment electrical energy for mechanical operation or standby, and the water heating energy. The units are volume (or weight) per energy per cycle. For dishwashers, the EF is the reciprocal of the sum of energy per cycle, and expressed in cycles per kWh. The higher the EF value means a more efficient equipment. It is the ENERGY STAR energy performance metric. This factor may vary based on equipment features such as water heating boosters or truncated cycles. The federal EnergyGuide label on equipment shows the annual energy consumption and cost, which use the energy factor. The EF does not appear on the EnergyGuide label. Unlike annual energy use, the EF does not take into account the estimated annual energy use in standby mode. The energy factor for a dehumidifier is calculated by dividing the water removed from the air by the energy consumed, measured in liters per kilowatt hour (L/kWh).