Clothes Washers Key Product Criteria
The ENERGY STAR criteria for clothes washers was changed on April 22, 2021 and is as follows:
Clothes Washer Efficiency Requirements
| Product Type | Current Criteria Levels (as of April 22, 2021) |
|---|---|
| ENERGY STAR Residential Clothes Washers, Front-loading (> 2.5 cu-ft) | IMEF ≥ 2.76 IWF ≤ 3.2 |
| ENERGY STAR Residential Clothes Washers, Top-loading (> 2.5 cu-ft) | IMEF ≥ 2.06 IWF ≤ 4.3 |
| ENERGY STAR Residential Clothes Washers (≤ 2.5 cu-ft) | IMEF ≥ 2.07 IWF ≤ 4.2 |
| ENERGY STAR Commercial Clothes Washers | MEFJ2 ≥ 2.20 IWF ≤ 4.0 |
| ENERGY STAR Combination All-in-One Washer-Dryer | Meets IMEF, IWF and the current ENERGY STAR requirements for clothes dryers (except the time requirements) for the closest product type |
ENERGY STAR Qualified Clothes Washer Eligibility
Only front and top-loading clothes washers with capacities greater than 1.6 ft3 and less than 8.0 ft3; and are not defined as Residential Clothes Washers with Heated Drying Functionality, or top-loading commercial clothes washers are eligible for ENERGY STAR Certification.
Energy Performance Metrics
Modified Energy Factor, MEFJ2, is the energy performance metric for ENERGY STAR certified commercial clothes washers as of February 5, 2018.
MEFJ2 is the quotient of the capacity of the clothes container, C, divided by the total clothes washer energy consumption per cycle, with such energy consumption expressed as the sum of the machine electrical energy consumption, M, the hot water energy consumption, E, and the energy required for removal of the remaining moisture in the wash load, D. The higher the value, the more efficient the clothes washer is. The equation is shown below and the metric units are ft3/kWh/cycle:
| MEFJ2 = | C |
| M + E + D |
Integrated Modified Energy Factor, IMEF, is the energy performance metric for ENERGY STAR certified residential clothes washers as of March 7, 2015.
IMEF is the quotient of the capacity of the clothes container, C, divided by the total clothes washer energy consumption per cycle, with such energy consumption expressed as the sum of the machine electrical energy consumption, M, the hot water energy consumption, E, the energy required for removal of the remaining moisture in the wash load, D and the combined low-power mode energy consumption, L. The higher the value, the more efficient the clothes washer is. The equation is shown below and the metric units are ft3/kWh/cycle:
| IMEF = | C |
| M + E + D + L |
Integrated Water Factor, IWF, is the water performance metric for ENERGY STAR certified residential clothes washers as of March 7, 2015 and ENERGY STAR certified commercial clothes washers as of February 5, 2018. It allows the comparison of clothes washer water consumption independent of clothes washer capacity. Manufacturers must submit their water consumption factors with their ENERGY STAR certified residential clothes washers.
IWF is the quotient of the total weighted per-cycle water consumption for all wash cycles, QA, divided by the capacity of the clothes washer, C. The lower the value, the more water efficient the clothes washer is. The equation is shown below:
| IWF = | QA |
| C |
The federal EnergyGuide label on residential clothes washers shows annual energy consumption and cost. These figures use the IMEF/MEFJ2, average cycles per year, and the average cost of energy to make the energy and cost estimates. The Integrated Modified Energy Factor, or Integrated Water Factor may not appear on the EnergyGuide label.