20% of dishwashers go unused, but experts say the appliance is good for the planet

Nearly 20% of all dishwashing machines nationwide go unused, data from the Energy Information Administration shows. If your dishwasher is one of them, experts say you could save time, energy and water by putting down the sponges and letting your appliance do the work.

“(Dishwashers) definitely save compared to handwashing. It does seem to be kind of counterintuitive to people,” said Joe Vukovich, staff attorney at the Natural Resources Defense Council. “It feels rare to have something that's saving you time and effort that's actually also the better thing for the environment.”

The most recent standards for dishwashers were set by the federal Department of Energy in 2012, requiring that the appliances use no more than five gallons of water per cycle. Meanwhile, running your tap can consume as much as 2.2 gallons per minute.

“You'd have to do an entire load of dishes in less than 2.5 minutes of running your faucet for the water use to be comparable to the least efficient product you can buy today,” Vukovich said.

Dishwashers certified by Energy Star, an energy efficiency program run by the Department of Energy and the Environmental Protection Agency, use even less water at a current maximum of 3.2 gallons per cycle. ​​Energy Star-certified dishwashers cost about $35 a year to run and can save an average of 3,870 gallons of water over their lifetime, according to the program.

From an environmental standpoint, using your dishwasher also conserves the energy needed to filter, heat and pump water to your home, which in turn reduces your carbon footprint.

Using less water also keeps more of it in our ecosystems, the health of which is more and more threatened by climate change. Global warming is expected to shrink freshwater supplies and bring water shortages to one-third of all counties in the lower 48 states, according to the Natural Resources Defense Council.

“There's a huge, huge infrastructure that goes into making sure the water that comes to your home is safe and drinkable,” Vukovich said. “In a warming climate, reservoirs are going to be harder and harder to maintain because the air is going to be hotter more of the time, and that problem isn't going away.”

Shirley Hood, the appliance expert at Abt Electronics in Glenview, said she's heard a number of misconceptions about dishwashers that prompt people to rely on handwashing instead, a common one being that the machine isn't going to clean dishes as well as the hands-on method.

Hood said she often points out to customers that dishwashers sanitize at unreplicable temperatures — going up to 170 degrees. She added that people typically hand-wash dishes by reusing sponges and towels, which isn't as sanitary as using the machine.

“The bottom line is it gets your dishes cleaner because of the length of time that they are in the water as well as the temperature of the water,” she said.

For those who do use the dishwasher, Hood said there are three ways to increase the appliance's energy and water use efficiency: Always run full loads, avoid pre-rinsing and let your dishes air dry.

Typical dishwashers use the same amount of energy and water each cycle regardless of the number of dishes. Prioritizing full loads is one of the most effective ways to maximize the machine's use, Hood said.

Avoiding rinsing dishes before they make it into the dishwasher can save up to 20 gallons of water, according to Energy Star.

Hood said people should instead scrape off as much food residue as possible, and avoid overloading the appliance to make sure dishes are cleaned completely. Most dishwashers will catch excess food scraps in a filter, which should be cleaned periodically.

Opting for a no-heat drying option can also save energy, Hood said.

Though it can be difficult for people to visualize the amount of water they can save by practicing efficiency — or the positive impact individual actions can have on the environment — Vukovich said these choices can go beyond just one person.

“Twenty percent of dishwashers go unused — imagine if all those people went from doing dishes by hand to using the dishwasher,” Vukovich said. “For all of those people, possibly doing dishes more than once a week, that's an enormous amount of water over the course of one week, let alone an entire year.”

• Jenny Whidden is a Report For America corps member covering climate change and the environment for the Daily Herald. To help support her work, click here to make a tax-deductible donation.