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Clothes Washers: Buyer’s Guide

Buyer’s Guide

Today’s washers are built with many options for saving water and energy. When comparing models, there are three  standard metrics to pay particular attention to: the EnergyGuide label, Modified Energy Factor (MEF) and Water Factor (WF).

Look for the Label: EnergyGuide

Most major appliances, electronics, and lighting must meet specific energy standards outlined by the U.S. Department of Energy. Energy use and efficiency are displayed on the yellow EnergyGuide label, which compares the estimated annual operating cost with similar models and states how much energy the appliance is expected to use annually. The EnergyGuide label will also display the ENERGY STAR® logo, if the particular model qualifies.

EnergyGuide label compares the estimated annual operating cost with similar models


This example of an EnergyGuide label shows the annual cost of running the appliance compared to other similar models. The amount is based on the national average rate for electricity. Look for models with the lowest operating costs.

Look for the Logo: ENERGY STAR®

ENERGY STAR® is a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy. The program sets minimum efficiency standards for appliances and building products and recognizes and labels the top performing models on the market. ENERGY STAR standards are more rigorous than federal standards, and vary by product category. A list of qualified clothes washers can be found online at energystar.gov.

ENERGY STAR® Washer Standards:

  • Minimum Modified Energy Factor (MEF) of 2.0 or higher
  • Maximum Water Factor (WF) of 6.0 or lower
  • Check a machine’s efficiency before you buy as there are models that are 2 to 4 times as efficient as those that meet the minimum ENERGY STAR® standards1

Modified Energy Factor (MEF):

A washer’s Modified Energy Factor is way to measure efficiency based on how much energy a machine uses along with its tub size and how much water it leaves in clothes after a wash. A more efficient machine will have a higher MEF. The highest MEF of ENERGY STAR®-rated products is 3.4. You can find the complete Qualified Product List at energystar.gov.

Low Water Factor (WF):

A washer’s WF is the number of gallons used per each cubic foot of laundry. The lowest WF of ENERGY STAR®-rated products is 2.5.

Other Efficiency Features:

Front-Loading Washers: 

These machines are generally much more efficient than top-loading washers—they use 30% to 60% less water and 50% to 70% less energy.2 Thanks to gravity, front-loading machines can fill partially and have the clothes pass through the water as the drum spins while top-loading machines must be completely filled with water in order to operate properly.

Advanced Controls: 

New machines have controls that either sense load size and adjust water levels, or have various wash and rinse cycles.

Faster Spin Cycle:

Spinning moisture out of your clothes is significantly more energy efficient than heating air to dry your clothes in the dryer. As such, improved spin speeds on new machines allow you to either air-dry your clothes or use the dryer less, which not only save energy but will also serve to promote the longevity of your clothes.

Use & Care

Proper maintenance and installation of your home’s washer will maximize efficiency measures. Learn more about Clothes Washers Use , where to start, and how to use and care for washing machines for the most savings.


If you’re thinking about making efficiency improvements, the Clothes Washer Overview is a great place to get acquainted with the basics and your options, before you buy or install a new washing machine in your home.

1Goorskey, Sarah, Wang, K., Smith, A. (2004).  Rocky Mountain Institute’s Home Energy Briefs #6 Cleaning Appliances. Snowmass, CO: Rocky Mountain Institute. Retrieved October 2, 2012, from http://www.rmi.org/rmi/pid217. (p. 1).
2Goorskey, Sarah, Wang, K., Smith, A. (2004).  Rocky Mountain Institute’s Home Energy Briefs #6 Cleaning Appliances. Snowmass, CO: Rocky Mountain Institute. Retrieved October 2, 2012 from http://www.rmi.org/rmi/pid217. (p. 2).

This program is funded by California utility customers and administered by Southern California Edison under the auspices of the California Public Utilities Commission.

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