Review: Coral One

To keep dog hair and toddler mess at bay, I use three separate vacuums: a heavy corded one for deep cleaning; a robot vac that I run daily for light maintenance cleaning; and a cordless handheld for quickly picking up small messes.

However, it is possible to go overboard. You don't want your descendants to find you buried, a skeletal arm sticking out from under piles of dusty, decaying vacuuming devices. That's where the Coral One comes in. The new vacuum ingeniously combines a portable handheld vac inside the automated robot vacuum. After you’ve done your daily maintenance clean, you can pop out the handheld unit, click on the dustbin and cleaning attachment, and clean out the cupholders in your car.

Coral Robots

The Coral One combines an astonishing array of features in a good-looking package. It’s easy to use, and decently priced: It retails for $545, but right now, it’s marked down to $495. That's about half as much as a premium botvac from Neato or iRobot.

But it's just too big. At five inches, it’s too tall to chase dust bunnies out from under my stove, or my children's cribs. And its utility is severely diminished without an app. It’s annoying to start a cycle, leave the house, and not realize until the next day that you can’t use the handheld because it got stuck behind a lamp and ran out of battery. Depending on your needs, I’d suggest economizing on the handheld and getting a Wi-Fi-enabled robot vacuum instead.

The Coral One arrived in an astonishingly large box—35 inches wide, 35 inches long, and 10 inches tall—which contained the robot, a remote, a home base, and the handheld accessories.

The robot’s height posed the first problem. Normally, I set up robot vacuums under my couch. It's the only free wall in my house that has two feet of clear wall space on either side; I also like freeing up floor space. But because the Coral One is 5.3 inches tall and 12.5 inches across, it didn’t fit. My couch only has five inches of clearance underneath.

Once you plug in the charging stand and click the side brush on the bottom of the vacuum, you also have the option of setting a daily cleaning schedule manually, via buttons on the base. Unlike pretty much any other robot vacuum that has an app, you can’t schedule cleanings for only Tuesdays and Thursdays, or cancel and reschedule them easily. Since I never know what’s going on in my house on any given day, I opted to not set a schedule at all.

In my testing, it took four hours for it to charge completely, with a very long runtime of two hours on regular mode and 45 minutes on turbo. Coral states it can guarantee up to 90 minutes of runtime, depending on the surface. You can bump up the vacuum to turbo mode by pushing what looks like a volume button on the botvac, or by clicking the same on the remote. The remote has three other buttons--an off button, a button to tell it to return home, and a button to switch languages. There’s no directional button to direct the Coral One to or from specific areas.

As a robot vacuum, the Coral One has a powerful motor that Coral claims can produce up to 2.7 kilopascals of air pressure to suction (they claim that a typical premium botvac produces about 1.7kPa). It also sits only 2 millimeters above the floor surface, in order to utilize that full power. In normal mode, it was 75 decibels loud, and in turbo, 80 decibels--or about as loud as a running garbage disposal.

The Coral One works on a variety of surfaces, including hardwood, high-pile rugs, carpet, and tile. It left our hardwood entryway free of leaves and grit; it cleaned under the kitchen table on laminate, and our tile bathroom floor. Many robot vacuums are too small and light to be very effective on carpet, but at 8.9 pounds, the Coral One’s heft let it dig into our low-pile rugs just a little more. After I ran it, I was unable to scrape further grit and dog hair out of the piling.

Both the handheld and the robot vacuum also have HEPA filters to pick up particulates that are 0.3 microns in diameter, small enough to capture dust, pollen, and animal dander.

The Coral One has gyroscopic mapping technology to let it clean your house more efficiently. Unfortunately, it's impossible for me to verify the accuracy of the map, since the robot doesn't upload it to the cloud. Each time I ran it, it took about two hours to clean 500 square feet of my house. That cleaning time didn’t get shorter over two weeks.

It navigates via infrared sensors, wall-following sensors, and drop sensors, all of which were remarkably sensitive. (They're also necessary, since the Coral One doesn’t come with any navigational aids.) I didn't notice any bumps or dings. In particular, the drop sensors were very sensitive. Sometimes the Coral One rolled over the wooden floor molding that divides our kitchen and living room, paused, and tipped one end into the air. When that happened, it breathlessly beseeched me to return it to solid ground.

The handheld unit is easy to use. Just unclick the handheld unit from the middle of the robot vacuum, snap on the clear plastic dustbin, and stick on the carpet or crevice cleaning attachment. When you need to empty the dustbin, just click it off and pull out the filter to release the trapped dirt.

Finally, I appreciated a number of small, thoughtful design details. For example, when the vacuum is in the charging base, the glowing handle shows you how much battery is left. The dustbin has a small carrying handle and easily clicks open with your thumb. It’s also gorgeous. The exterior is hand-polished and the tones with which it signals that it’s powering on are so musical! There’s also something vaguely droid-like about the white-and-black colorway that I very much liked.

Whenever I’ve converted someone to using a robot vacuum, they always mention how it vacuums places that they’d never think to clean on their own. I’ve noticed that, too—and my allergies have markedly improved since robot vacuums have started regularly chasing down dog hair dust balls out from under my couch.

But the Coral is too tall to fit in many of these places. It can’t fit under my children’s cribs or under the stove. It doesn’t fit in the space underneath my cabinets to edge clean in my kitchen.

For some people, the Coral One’s simplicity might be a big bonus. You don’t need to follow instructions to connect yet another Wi-Fi-enabled device to your home network; you don’t need to clutter up your phone with yet another proprietary app. But I missed having an app. I like the flexibility of being able to cancel or reschedule cleanings on a whim. I like knowing if the robot got stuck, even if I’m out. It didn’t happen often, but when the Coral One did get stuck, it was hard to find. It’s annoying to not be able to ring a bell or look at a map to find it. (It had wedged itself under the couch. Coral, you know better than to go under there!)

Finally, the dust bin for both the robot vacuum and the handheld unit are very small. The robot vacuum's dust bin is 0.45 liters; I can usually count on most vacuums having a capacity of around 0.7 liters. This is far too small for my dog-filled house, and when the dust bin gets too empty, the suction tube gets clogged. The handheld unit has a capacity of 0.5 liters, which is just enough to clean the sand and dog hair out of my car.

The Coral One got several important points right. It’s a powerful robot vacuum that is also beautiful and easy to operate. Including a handheld unit saves storage space in a small house or apartment, and the company kept the product at a very reasonable price point (for robot vacuums, anyway).

Still, I found that having to re-vacuum the edges under the cabinet and get on my hands and knees to peer under the stove to be more of a hassle than it was worth. Turns out that more vacuums are still better... for now, at least.