Using a dishwasher saves money over hand washing as long as certain conditions apply.
According to Energy Star using an Energy Star qualified dishwasher rather than washing dishes by hand will save you $40 a year in utility bills, saves half as much energy, and saves nearly 5,000 gallons of water per year.
The statistics provided by the US government have been attained through numerous studies and are based on averages and particular criteria. But ultimately, the consumer’s habits will dictate what savings are realized if any at all.
You the Consumer Control How Much Money You Save
The way in which you the consumer chooses to use your dishwasher will ultimately dictate how much money is saved . . . if any. When considering apples for apples, for example, the same number of dishes are washed, the dishes have the same soil level, etc. then in most cases the dishwasher will save you money. But there are habits that will quickly negate any savings.
Washing Dishes before Washing Dishes
Many people swear by the rule that dishes need to be rinsed before they go into the dishwasher. In a fascinating study conducted by researchers at Virginia Polytechnic Institute to assess dishwashing and water conservation, researchers found that 93% of those surveyed pre rinsed their dishes prior to loading them in the dishwasher, even though manufacturers suggest scraping only.
Most dishwashers have a pre-rinse cycle that lasts only a few minutes and uses only a few gallons of water. Studies have revealed that rinsing every dish under running water results in a water usage of 25 gallons. [Journal of Extension]
Cost of Habit: 25 gallons of water
Running Old Dishwasher Models
You can’t seem to fit that new Energy Star qualified dishwasher into the budget, but when considering how much water and energy your old one is using, can you afford not to? Energy Star models manufactured after August 2009 are required to run on 5.9 gallons of water or less. That’s at least 10 fewer gallons than used in previous models. This equates to a 1,300 gallon savings of water over the lifetime of the dishwasher. [Energy Star]
Cost of Habit: 1,300 gallons of water
Ignoring Optional Features
If you haven’t learned what all those buttons and cycles are on your new dishwasher, now is the time. They aren’t just bells and whistles added to sell an appliance. Newer models are equipped with many energy savings features, which will save you money.
New features include soil sensors, improved water filtration, more efficient jets, and dish rack designs that maximize cleaning.
Most models are now equipped with water efficient cycles that include load size, pre-rinse, and rinse only cycles.
In the above mentioned study by researchers at Virginia Polytechnic Institute, the researchers found that only 25% of the study’s participants took advantage of the water efficient cycles on their dishwashers.
If Time Is Money Then Dishwashers Are a HUGE Savings
Few consider just how much time that using a dishwasher actually saves. In a 2010 UK study published in the International Journal of Consumer Studies, researchers studied the dish washing habits of 150 participants comparing both their habits while hand washing dishes followed by their habits loading a dishwasher. Surprisingly, among supporting evidence that hand washing used three times more water than the dishwasher, they also found that hand washing dishes took an average of 60 minutes to complete compared to 9 minutes to load and unload the same dishes from a dishwasher.
If time is money, these findings are astounding. Take for example a busy family that dines together and creates a load of dishes daily. The savings in time for the dish washer in this home would add up to 310 hours per year. If those extra hours equated to time off from work, this dish washer would be happily accepting nearly 8-40 hour weeks of vacation time.
Cost of Habit: 310 personal hours
“Dishwashers Push the Right Buttons and Save.” Iowa Energy Center. N.p., n.d. Web. 25 Mar. 2011. http://www.iowaenergycenter.org/wp-content/uploads/2012/03/HomeSeries4.pdf
Berkholz, Petra, Rainer Stamminger, Gabi Wnuk, and et. al. “Manual dishwashing habits: an empirical analysis of UK consumers.” International Journal of Consumer Studies 34.2 (2010): 235-242. Print.
Emmel, Joanne, Kathleen Parrott, and Julia Beamish. “Dishwashing and Water Conservation: An Opportunity for Environmental Education.” Journal of Extension 41.1 (2003): n. pag. Joe.org. Web. 13 Mar. 2014.
“Dishwashers.” ENERGY STAR. N.p., n.d. Web. 13 Mar. 2014. <http://www.energystar.gov/certified-products/detail/dishwashers>.