Suction Isn’t the Only Thing That Matters When Choosing a Robot Vacuum Cleaner
Right before the Consumer Electronics Show (CES) in January, I noticed a trend in robot vacuum cleaners. The suction power these robots reported was astronomical. While the Pa (suction power measured in pascals) in 2024 was considered “high” at 8,000 or 10,000, the Ecovacs x8 is 18,000, the Dreame x50 is 20,000, and the Roborock Saros 10 is 22,000. In conversations with the marketing representatives and engineers of these machines, I usually asked: “Is there a limit?” how beneficial is suction really? And more than once, engineers have discovered that the reason Pa levels skyrocketed in the first place was because internal research showed that suction power was the main factor why consumers choose robot vacuum cleaners. While I don’t agree that suction power equals a good vacuum, I understand why consumers use this criterion to make a choice: what other criteria would be important?
Suction is just one factor in removing debris from the floor.
To understand why suction power is not a good determining criterion, you first need to understand how robot vacuum cleaners work. Regardless of the brand, almost all robots work like a regular vacuum cleaner. At the bottom of the robot there is a roller or a series of rollers, like a conventional vacuum cleaner. As the rollers pass through the debris, the robot sucks the debris off the rollers and sucks the debris into a bagless inner chamber. To move debris toward these rollers, most robots have brushes that sweep away debris. Ideally, all debris is picked up by the rollers, sucked off them into the chamber, and the floor remains clean.
The reality is that some types of debris, such as hair, clog the rollers that wrap around the roller and can cut the silicone on it. Larger debris, such as a receipt or even a small piece of mulch, may become stuck in the roller and require a person to remove it. Debris can also be sucked up, but it will clog the pipe because it gets stuck on its way into the inner chamber. In some of these cases, increasing the suction can help, but it also matters how straight the suction tube is designed, or even how large the flap in the inner chamber is. In truth, the entire design of the system and all the parts working together is what makes a robot vacuum successful (or not).
For example, during a recent test of the Eureka J15, which has pressures greater than 16,000 Pa, I noticed that although the sweepers were moving debris directly toward the rollers, the debris was not getting into the roller, so the robot was leaving the debris behind. The Dyson 360 Vis Nav , which has a pressure of more than 20,000 Pa, descends so low to the ground that some debris cannot reach the rollers and is not affected by suction, but instead is simply pushed along the floor by the robot. Meanwhile, the original Switchbot K10+ only had 3000Pa of pressure and did a great job of picking up debris from the floor because it rises a little higher, allowing the rollers to access more debris, and the rollers are designed so that debris doesn’t get stuck as often. My favorite robot vacuum and mop of all time, the Roborock MaxV Ultra Vacuum, only has 10,000 Pa of power, but it doesn’t mind any debris and gets floors cleaner than any other vacuum I’ve tried. Roborocks has a very efficient roller design that doesn’t seem to suffer from debris getting in, and their sweepers are constantly being improved to be more efficient at sweeping debris toward the rollers.
Navigation, artificial intelligence and the size of robots matter too
It’s not just the rollers, sweeper, and suction that determine how well it will suck up debris from the floor—the robot must also have access to the space where the debris is. Robots are getting thinner now so they can slide under more furniture, but they are typically still 12- to 13-inch objects trying to squeeze into a space, and if you have a lot of floor furniture, the robot will have a hard time moving between those objects to clean effectively. Robots work best in large open spaces with walls that don’t have fingers. The artificial intelligence on board most robots can sometimes recognize debris as an obstacle and tell the robot to avoid the debris altogether. (This is the fallout from several robot vacuum cleaners accidentally turning over pet waste and smearing it all over the room a few years ago; robots are now overly wary of anything that could be remotely interpreted as such by AI).
Garbage must also be moved through the dock.
There’s one more place where suction matters, although most product lists don’t discuss it: the robot dock. This is where, in most cases nowadays, the robot automatically empties into a real vacuum bag, which needs to be changed every few months. The value of autoempty is infinite; this is what makes robot vacuum cleaners autonomous. If the dock gets clogged, it will take a lot more work than if a robot did it. I’ve recently seen mentions of docks like the Narwal Freo Z that have been retrofitted to have fewer turns in the suction pipe that takes debris into the dock as this will result in fewer clogs.
Ultimately, there likely isn’t one “best” robot vacuum, but rather a best robot vacuum for your home, since every home is different. For example, if you have a lot of large debris in your home, you’ll probably want the Roborock as they handle this type of debris better than most others. If your home has a lot of obstacles, you may want to consider the Switchbot K10+ Pro , which is much smaller than most robots and can navigate smaller spaces. If you have high thresholds in your home, a robot that can negotiate these thresholds is important, such as the Dreame x50 or the Roborock Saros line. While suction is a factor in the success of a robot, it should not be the only or determining factor in your purchasing decision.