Want a quiet dishwasher? Some clean better than others

Even since floor plans started opening up and kitchens became extensions of the living room, homeowners have been demanding quieter dishwashers.

While Bosch isn't afraid to shout about its low-decibel dishwashers, other brands have been closing the gap, and the quietest models around today can be as silent as 38 dBA.

But even if it barely makes a sound, a dishwasher still has to actually clean dishes. So we decided to find out if a quiet dishwasher can also be a good dishwasher.

The Data

According to appliance manufacturers, the only tradeoff for a quieter dishwasher is potentially longer cycle times.

But we wanted to know for sure. At Reviewed.com, we’ve been testing dishwashers for years, making our own dirty dishes, running key cycles, and recording the number of dishes that have not been 100 percent cleaned.

So we took that dirty dish data from sixty popular dishwashers and compared it to each machine's manufacturer-reported sound rating in A-weighted decibels. Long story short? Some quiet dishwashers clean well, while others don't.

---

The Results

If dishwasher cleaning performance and noisiness were related to one another, or one was the cause of the other, then we would expect a chart of the data to have a discernible pattern of some kind, dictated by an equation that closely predicted cleaning performance based on a certain sound rating.

Another possibility is that the data could have no discernible trend or pattern; in that case, it is more likely that the two data types are unrelated to one another. Let’s see the data for each cycle.

Here's the comparison chart for the dishwasher sound level and the number of dirty dishes leftover from a normal cycle:

This is the comparison chart for the dishwasher sound level and the number of dirty dishes leftover from a quick cycle:

And here is the comparison chart for the dishwasher sound level and the number of dirty dishes leftover from a heavy cycle:

They all kind of look like blobs, don’t they? In fact, we were unable to come up with any predictive model or equation that showed a significant relationship between dishwasher sound rating and the number of leftover dirty dishes. Based on our analysis, we believe that dishwasher cleaning ability and sound rating are unrelated to one another.

In other words, you can buy a quiet dishwasher that may or may not have good cleaning performance; it is impossible to predict the cleaning power of a dishwasher based on its sound rating alone.

---

Why?

There are so many variables that go into getting a dish clean. For instance, think about hand washing dishes in the sink. Being able to get that stubborn lasagna stain out of a baking pan depends on any number of things: What was the water pressure and temperature coming out of the faucet? What kind of scrubbing implement was used? How hard can the person doing the cleaning actually scrub the dish?

Putting that same dirty dish in a dishwasher greatly increases the number of variables when it comes to dish cleaning. Is the dish in the correct position in the rack? What is the water pressure and temperature of the water coming out of the jets? Are the jets themselves optimally placed? What sequence of rinsing, cleaning, and water filtration occurs in each cycle? How long is each dishwashing cycle?

The engineering and mechanical changes made to a dishwasher that result in a quieter noise level mainly affect both the cycle time and the water filtration, but the other aforementioned variables remain, in general, unaltered. Additionally, there’s no guarantee that those changes result in a better cleaning performance, only that they result in a quieter dishwashing cycle.

So what’s a buyer to do? When buying a new dishwasher, if you want both quiet dishwashing and high cleaning performance, try doing some good old-fashioned research. Talk to family and friends, try out products in a store, and read online reviews. To get our take on the newest dishwashers, check out our ever-expanding list of dishwasher reviews.

To see how well some of the quietest dishwashers on the market score overall in our rankings, take a look at two of our dishwasher roundups: The Best Ultra-Quiet Dishwashers and The Best Bosch Dishwashers. Good luck, and may your kitchen gossip sessions never be overpowered by a loud dishwasher.

Related Video

{{ brightcove '5054093951001' }}