For the last decade, the efficiency story for appliances has been all about energy. But in recent years, the industry has realized that water savings is just as important to sustainability efforts, not to mention the overall efficiency of water-using appliances.

In fact, the two go hand in hand: The less water an appliance uses, the less there is to heat, and, therefore, the less overall energy used.

The government has caught on, too, adding water standards to its dishwasher requirements in 2010 and to clothes washer requirements in January. Energy Star has included water consumption as part of its efficiency equation for the last two years.

The efforts are paying off, as today’s dishwashers and washing machines use 60% less water than they did 10 to 15 years ago. In fact, if a homeowner replaced an eight-year-old clothes washer with a new Energy Star model, he or she would save about 5,000 gallons of water per year. And that’s just one appliance.

Super Savers

The good news is that the list of water-efficient clothes washers and dishwashers is vast. Thanks to technology advancements such as front-loading washing machines and soil sensors in dishwashers, most well surpass the current federal standard, and the majority meet or exceed Energy Star requirements. There is also a subset of extremely efficient appliances that qualify for the Consortium of Energy Efficiency’s (CEE) Super-Efficient Home Appliance (SEHA) program. The initiative calls out products that go above and beyond Energy Star requirements for both water and energy, categorizing them within two or three tiers, depending on the appliance.

Still, while this growing number of water-efficient appliances is certainly beneficial, it can be overwhelming for specifiers. For washing machines, a good place to start is looking for models that carry the Energy Star label. As of January, Energy Star washing machines must have a Water Factor (WF) of 6.0, which indicates the number of gallons of water needed for each cubic foot of laundry (the lower the WF, the lower the water consumption; the federal minimum requirement is 9.5).

Contractors looking to offer homeowners the most water-efficient clothes washers can turn to the CEE tier system, which also was updated in January. Tier 1 clothes washers currently fall in line with Energy Star requirements (6.0 WF); however, Tier 2 products have a WF of 4.5, and Tier 3 products have a WF of 4.0 or less. Homeowners with a Tier 3 washer can potentially save more than 6,000 gallons of water per year compared to models that meet minimum federal requirements.

On the dishwasher side, standard-sized units (eight or more place settings) can use no more than 5.8 gallons of water per cycle to qualify for Energy Star, and compact models (less than eight place settings) use a maximum of 4.0 gallons per cycle. (Federal standards require 6.5 gallons or less per cycle.)

Hefty changes are in the works, however. In 2012, Energy Star is expected to raise energy and water usage requirements for dishwashers significantly—so much so that the percentage of qualifying dishwashers will likely drop from 80% of available units to 25%. Both of CEE’s dishwasher tiers exceed current Energy Star requirements, making it a safe bet for builders who don’t want to re-specify once the new Energy Star standards are put in place. Currently, Tier 1 dishwashers only use 5.0 gallons of water per cycle, and Tier 2 models use 4.25 or less gallons per cycle.