The list of historic face-offs is long and storied. Batman versus Superman. Kong versus Godzilla. Dishwashing versus hand-washing? OK, maybe the last isn't quite as action-packed as the others, but people still have strong opinions about who should win.
Many people hand-wash dishes when there's a perfectly good dishwasher available. Often, this is because the modern convenience seem optional and wasteful. After all, dishwashers require lots of water and energy to run, right? So why not just DIY and feel good about yourself in the process?
Relax. This is one time when the easier alternative is actually the better one.
"There's a common misconception that the dishwasher fills up with water, so many people choose to wash dishes by hand instead of using the dishwasher because they believe it's more efficient," says Jill Franke, a senior scientist at Cascade (the automatic dishwasher detergent) in an email. "The reality is, according to ENERGY STAR, certified dishwashers use less than 4 gallons [15 liters] of water per cycle compared to hand-washing, which can use 4 gallons of water every two minutes."
You might not be surprised to see Cascade give a thumbs-up to dishwashers. But the Natural Resources Defense Council (NRDC) agrees.
"Today's dishwashers do a great job cleaning your dishes and only use 3 to 5 gallons [11 to 19 liters] of water to clean an entire load," says Noah Horowitz, senior scientist with the NRDC in an email.
Much of this energy-saving is thanks to advances made in dishwasher technology over the last decade. A standard ENERGY STAR certified dishwasher saves an average of 3,870 gallons (14,650 liters) of water over its lifetime. Plus, it only costs an average of $35 per year to operate.
This is despite relatively new regulations on faucet efficiency. "Per federal standards, new kitchen faucets may not use more than 2.2 gallons [8.3 liters] per minute. Efficient faucets only use around 1.5 gallons [5.6 liters] per minute," says Horowitz. "Even if you are super-fast, there is no way you can wash the equivalent of a dishwasher full of dirty dishes in under three minutes. If you leave the water running while washing your dishes you could easily consume over 20 gallons [26 liters] of water to clean the day's dishes."
So, 20+ gallons while hand-washing vs. 4 (or less) using the dishwasher? That's a pretty significant difference.
But, what about the related energy costs? Turns out the dishwasher is another clear winner there, too. "The dishwasher is actually far more energy-efficient than the sink, which uses energy throughout the dishwashing process to heat water," Franke explains. "In fact, the dishwasher is so much more energy-efficient that if you switch from handwashing to running your dishwasher just four times a week, you can save up to $130 a year on your energy bill – even if you have an older dishwasher!" (She adds that this figure assumes an electricity rate of 11 cents per kilowatt-hour.)