Dishwashers Combine Energy Efficiency, Water Conservation, and Premium CleaningClean and Green

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The new thresholds--which should take effect in mid-2009 or early 2010--won't be the first time Energy Star has been forced to react to advancements in dishwasher design and efficiency. Standards were upped in 2002 and 2003 when a wave of manufacturers began incorporating turbidity sensors. The sensors, which measure soil levels in the rinse cycle and adjust the amount of power and water accordingly, automatically dialed down units to their most eco-friendly levels, throwing off EPA and DOE wash tests. Energy Star increased the energy factor requirement from 0.58 to 0.65, mandated the use of soiled dishes during wash tests, and passed off the administration of those tests to the manufacturers.

That task apparently has not been a burden to product makers, which continue to introduce evermore-efficient models and even whole product lines that center on the green aspects of energy savings and water conservation. Last July, Bosch introduced two dishwashers that exceed the minimum federal standard by an astounding 147%, with a yearly usage of only 190 kWh.

And even though water consumption is not yet part of federal requirements, many models include conservation features, including the turbidity sensors. Several product makers have introduced steam-cleaning cycles that trade off the energy required to superheat water to steam for the corresponding savings in total water consumption. For example, the steam option on LG's LDF9810 model reduces the water use of any cycle by a full gallon.

Totally waterless dishwashers might not be far off, either. Prototypes have surfaced at trade shows and concept conferences in Europe that explore ionization technologies that might ultimately take dishwashers off of the spigot.

Additional Considerations

Green features in dishwashers go beyond energy and water consumption. Products made from recycled or recyclable materials, such as the recyclable stainless steel and plastic used by many manufacturers for dishwasher tubs, deserve bonus points. Also look for units that can be broken down more easily into smaller components to reduce the abandoned appliance overload crisis facing landfills.

Product makers often will point to sound suppression as another green attribute. Typically, this involves incorporating a thin layer of acoustical dampering material during construction of the box. Sound reduction has reached 42 to 50 dBA in some units, well below the 65 to 70 dBA of a normal human conversation.

Most manufacturers also offer a sanitation or homogenization feature on mid-range and high-end lines. Often certified by the National Sanitation Foundation, these cycles superheat water to remove 99.99% of bacteria.

Price Premium

Depending on how many extras the machine includes, expect to pay somewhat of a premium for the greenest dishwashers. Unit costs can range from $200 at the base end to $1,500 or more for the toniest models. Still, that's something seasoned green builders say is easily recouped in energy and water savings. According to Energy Star, certified units save a minimum of $90 over the product life cycle.

"Performance does matter, convenience does matter, appearance and aesthetics matter," advises Jonathan Philips, a senior director for Raleigh, N.C.-based Cherokee Investment Partners who headed up design and construction of the Mainstream GreenHome demonstration house in Raleigh. "From there, infuse your decision with as much environmental sustainability as you can. Green or not, I don't know any builders that haven't been able to get ROI by putting a little more money into their kitchens, especially with something that the consumer sees every day."