With a range of options for Energy Star–rated appliances, recycled content, and low-VOC finishes, the kitchen is one of the easiest places to go green. And you can bet it’s the most noticeable. One place to start is with one of the most visible energy hogs in the room: Cycle by cycle, the dishwasher motors away to heat, spray, and drain the water necessary to remove those baked-on, caked-on, stuck-on foods.

To its credit, the average dishwasher is much more water friendly than traditional hand washing. Using any Energy Star–qualified dishwasher instead of hand washing saves 5,000 gallons of water, $40 in utility costs, and 230 hours of labor annually. Still, manufacturers report that even the greenest dishwashers on the market must continue to find a balance of energy efficiency, water conservation, sound emission, and basic performance.

“That is exactly the difficult trade-off that we have to strike on all of our projects,” says Paolo Falcioni, international technical affairs manager for Indesit, an Italian company launching its line of Hotpoint Ariston dishwashers in the U.S. this year. “It is easy to use less water and less energy, but without having clean dishes at the end; the task at hand is to clean dishes, and that needs to be done perfectly. That’s why someone is ready to buy a dishwasher to begin with.”

Pure Energy

In Europe, Falcioni and his peers rely on the EN50242 standard, which measures washing and drying efficiencies but also sets base standards for energy and water conservation and noise emissions reduction. The stateside equivalent is Energy Star; qualifying dishwashers consume 40% less than the federal standard. Although the Energy Star program does not include a metric for water consumption, qualified dishwashers typically use one-third less water than nonqualified models.

A metric called the Energy Factor—the reciprocal of the sum of a machine’s electrical energy per cycle plus the water heater energy consumption per cycle expressed in cycles per kWh—determines energy consumption. As of Jan. 1, 2007, the federal minimum Energy Factor for dishwashers is 0.46, thus a machine must achieve an Energy Factor of 0.65 to qualify for the Energy Star label.

Ever since Energy Star began certifying dishwashers in October 1996, manufacturers have been quick to adjust performance metrics to meet program standards. The amount of hot water a dishwasher uses largely establishes its energy efficiency. Older dishwashers sprayed large amounts of hot water on dishes in a short period of time, while contemporary models use finer, more targeted streams.

Currently, 695 dishwasher models across 52 brands qualify for the Energy Star label. In fact, dishwasher manufacturers are getting so efficient that the government is raising the thresholds for both the minimum federal standard and the Energy Star program. As part of that process, a metric for water consumption likely will factor into qualification requirements for the first time.

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.”

Energy usage: 330 to 357 annual kWh or an energy factor between 0.65 and 0.70 and a corresponding percentage improvement on the minimum federal energy standard between 41% and 46%
Sound transmission: 53 dBA or less
Water usage: 4 gallons or less per cycle

Energy usage: 280 to 325 annual kWh or an energy factor between 0.71 and 0.89 and a corresponding percentage improvement on the minimum federal energy standard between 48% and 74%
Sound transmission: 48 dBA or less
Water usage: 3 gallons or less per cycle

Energy usage: 190 to 249 annual kWh or an energy factor between 0.92 and 1.14 and a corresponding improvement on the minimum federal energy standard between 100% and 147%
Sound transmission: 43 dBA or less
Water usage: 2 gallons or less per cycle

Waterless Washing

The Airwash prototype uses ionization to clean clothes, a technology that could eventually lead to waterless dishwashers.
The Airwash prototype uses ionization to clean clothes, a technology that could eventually lead to waterless dishwashers.

Clean dishes without getting them wet? It’s a possibility. In much the same way clothes can be dry-cleaned, technologies to get dishes dirt-free without turning on the faucet may soon be science fact rather than science fiction. More specifically, the application of ultraviolet and ionic technologies to loosen and remove soil holds promise for eventually going water-free. During the 2005 Electrolux Design Lab Awards, for example, a team of students from Singapore developed a prototype for the Airwash, a waterless washing machine that uses atmospheric air and negative ions to clean clothes, a technology that could easily apply to waterless dishwashers, according to Bob Martin, Electrolux director of industrial design.

“The technologies that the teams are espousing are very cool and very theoretical,” Martin says. “But that is how companies and industries innovate. The designers in my position are thus forced to question why we cannot develop what seems, at first, so far-fetched.”

Paolo Falcioni, international technical affairs manager for Indesit, says he’s seen several designs and prototypes for waterless washing machines at European appliance shows, but is also quick to characterize those efforts as an exercise in brainstorming.

“Still, I side with James Bond,” Falcioni says. “From steam to ultrasonic to microwave and UV, it is technology that we are all looking into from an R&D perspective, so never say never.”

Energy Star: www.energystar.gov
American Council for an Energy- Efficient Economy: www.aceee.org
Association of Home Appliance Manufacturers: www.aham.org
National Kitchen & Bath Association: www.nkba.com

Chris Wood is a senior editor for Multifamily Executive and Developer, sister publications of EcoHome.

KitchenAid. The U Series dishwasher, part of the Architect Series II, features a steam option for more powerful cleaning that uses less water, the maker says. The unit features a four-blade food disposer that eliminates the need for pre-rinsing and turbidity sensors that adjust water amounts. A sound-dampening and insulation system reduces sound emissions to 48 dBA. The dishwasher is Energy Star certified with annual energy consumption of 334 kWh*. 800.334.6889. www.kitchenaid.com

GE. Available this August, the Profile SmartDispense 2 dishwasher boasts steam-cleaning capabilities and a 47-ounce detergent reservoir. The unit will exceed 2007 Energy Star requirements (annual kWh usage not yet reported by Energy Star), and it includes an angle rack system to prevent pooling water and a top rack–only wash cycle for half loads. An optional acoustics package reduces sound emissions to 45 dBA. It is available with top controls or a front control panel. 800.626.2005. www.geappliances.com

LG Electronics. According to the maker, a steam-cleaning system increases the LDF9810’s energy efficiency versus standard dishwashers. The unit operates at 45 dBA and includes turbidity sensors to determine soil levels and set a required number of rinse cycles. Other features include a built-in food disposal system with self-cleaning filter, interior LED lighting, a third dish rack, a delicate cycle, and room for 14 place settings in a single load. It is Energy Star certified at 285 kWh* per year and is available in white, black, and stainless steel finishes. 800.243.0000. www.lgusa.com

Bosch. The Evolution and Integra dishwasher lines feature the quietest and most energy-efficient models in the country, the maker says. 300, 500, and 800 Series models in both lines are Energy Star rated, exceed the federal minimum energy standard by 147%, and have a yearly energy usage of 190 kWh*. Infrared soil-sensing equipment, available on all models, customizes the wash cycle from 48 preset cycle options that use as little as 1.8 gallons of water per cycle. 800.944.2904. www.boschappliances.com

Kenmore. Developed in partnership with the Jane Goodall Institute’s Roots and Shoots program, the Elite Dishwasher with Ultra Wash HE exceeds 2007 Energy Star standards, and uses 34% less energy and 41% less water compared to a dishwasher manufactured seven years ago, the maker says. The unit uses 305 kWh* per year and features SmartWash turbidity sensors that assess soil levels and a top rack–only option that allows for partial loads. 800.349.4358. www.sears.com

Whirlpool. Using European wash technology, the GU2800XTV and GU3600XTV dishwashers use one-third less water and energy than the company’s models from seven years ago. Increased water pressure breaks up food more efficiently, the company says. This new wash system and a soft-start motor help reduce noise, providing for the quietest operation of any of the manufacturer’s dishwashers. The appliances are Energy Star qualified and have a yearly energy usage of 299 kWh (GU2800) and 301 kWh (GU3600). Other features include a new nozzle configuration that delivers a fan of water to clean from all angles and cleaning power that adjusts to soil levels. 800.253.3977. www.whirlpool.com

Electrolux. New to the U.S., the Fully Integrated Wave-Touch dishwasher uses 4.4 gallons per cycle and meets 2007 Energy Star standards with 324 annual kWh*. According to the firm, the unit features the largest usable capacity as measured by adjusted rack space and is one of the quietest in its class at 53 dBA. It includes leak detection, a touchscreen that fades after selections are made, and nine wash cycles and five wash options that can be customized into a programmable memory. 800.243.9078. www.electroluxusa.com

Indesit. Now available in the U.S., the Hotpoint Ariston LDF1235X freestanding dishwasher features a turbidity sensor that measures soil levels and adjusts water use accordingly. An acoustical dampening system reduces sound emissions to 43 dBA. It offers a Speed 25 cycle for half-rack washing in 25 minutes, and a “baby cycle” that heats water to sanitation temperatures. The unit meets Energy Star requirements, consuming 225.75 kWh of energy annually and 3.7 gallons of water per cycle. 800.356.0766. www.aristonappliances.us

Fisher & Paykel. Two independent dish drawers integrated in one unit offer smaller, more economical, and environmentally friendly dishwashing, the maker says. The Energy Star–certified unit uses as little as 1.98 gallons of water and 157 annual kWh* per drawer on eco cycles and only 2.4 gallons during normal cycles. Product features include nine wash cycles, a flow-through detergent dispenser, and up to 12-hour delayed start. It comes in the EZKleen stainless steel finish. 888.936.7872. www.fisherpaykel.com

Thermador. The three models in the HD dishwasher series exceed Energy Star compliance standards (annual kWh usage ranges between 290 and 315*, depending on model) and feature a soil-sensor system and triple water filtration, ensuring dishes are 99.99% bacteria free, the maker says. According to the company, the HD94 and HD64 units operate so quietly at 44 dBA that they include a PowerBeam laser that reflects on the kitchen floor to show the machine is operating. All models are available in stainless steel or fully integrated for custom panel applications. 800.656.9226. www.thermador.com

Viking. The Viking DFUD Ultra Premium dishwasher incorporates two motor/pump assemblies for more efficient water circulation and drainage than single-motor systems, the maker says. Water temperature options range from 85 degrees F to 170 degrees F depending on the cycle. All cycles focus on water efficiency ranging between 4.5 gallons of water for the normal cycle and 2.5 gallons for the China/Light cycle. The unit uses 234 kWh* of energy per year and is Energy Star certified. 662.455.1200. www.vikingrange.com