Viomi Alpha UV (S9): robot vacuum with self-cleaning, LIDAR, UV-lamp and wet cleaning

Viomi Alpha UV (S9) Xiaomi

Hey guys, welcome to RobotObzor! Today I’ll show you a new robot vacuum from Viomi, a sub brand of Xiaomi. This is the Viomi S9 UV, also known as Viomi Alpha UV. The main additions to this model that set it apart from the other Xiaomi vacuums are: a new auto-empty base, a more powerful battery and an ultraviolet light that disinfects the surface. It’s hard to know if it actually works, but the battery and base are definitely a benefit to the robot. Later, I’ll thoroughly describe and test Viomi Alpha UV, after which I’ll give you my personal opinion on whether or not this is the right robot for you. By the way, this robot costs around $650. Now, let’s get rolling.

Amazon: https://amzn.to/47XJE0I

What’s inside?

First, let’s look at what came in our box. Aside from the robot and the base, I got:

  1. A container for mopping with a microfiber cloth.
  2. A kit of 10 single use wipes for mopping.
  3. An extra side brush.
  4. Two extra dust bags for the base.
  5. And a manual written in several languages.
Viomi S9 package
Viomi S9 package

The box has a lot of spares, but the cherry on top would be an extra HEPA-Filter, so that way we don’t have to buy anything extra at all.

Design

Now let’s look at Viomi Alpha UV’s outside view. Our vacuum came in white with blue pieces. It looks very modern and stylish. It also comes in black with purple, which is also a cool design.

Design
Design

The LIDAR system is the prime navigator, but it also has a bumper with two sensors on the sides for detecting walls and one on the front for detecting obstacles. The LIDAR is presented with a button, which protects the system from low furniture. On the top you can find two buttons: return to base for charging, and start/pause.

Control panel
Control panel

We also see info about the robot having a UV lamp.

Disinfect
Disinfect

The conjoined water and dust container can be removed from the back. The container fits 250 ml (8 Oz.) of water, and the dust container fits 300 ml (10 Oz.) of dirt. The container has little door that stops from coming out when the container is removed. The filter is MESH and HEPA-Filter.

Container
Container
Filtration system
Filtration system

On the back are clips for attaching the base, and a door, through which the self-cleaning takes place. We also see a pump in the container for electronic water regulation.

Rear view
Rear view

Now let’s look at Viomi Alpha UV from below. Here we can see four anti-fall sensors. In the center is the UV light, thanks to which the robot can sanitize your floor.

Viomi Alpha UV from below
Viomi Alpha UV from below
UV light
UV light

The central brush is very bristly. The bristles aren’t very dense, but instead are elastic. On one side the cap can be taken off for cleaning the brush off hair and fur. On the other side only the duster is released.

Central brush
Central brush

The cloth gets water through the three openings in the container. The cloth is pretty dense, but is smaller than the previous Viomi V3 and Viomi SE.

Cloth
Cloth
Viomi Alpha UV from below with cloth
Viomi Alpha UV from below with cloth

And here are our disposable wipes. They are also dense, but the quality is obviously worse, so just as the name implies, it’s better to dispose of it after one use.

Disposable wipes
Disposable wipes

Now let’s check out our base.

Auto-empty base
Auto-empty base

First of all, the suction channels are not on the bottom, like in most robots, but is on the end. Thanks to this the quality is better and the auto-cleaning process is much faster. Secondly, on the base is a display screen that shows how the base is doing, and tells you when you need to change the bag, and the battery percentage. I think the most useful is that the base tells you when you need to change the dust bag.

Display on the base
Display on the base

Inside we see a tool for cleaning the base and the central brush in the robot, and the dust bag itself. Removing the bag closes the holes so dust doesn’t fall out. Under the bag we see the fan that actually takes the dirt into the base from the robot.

Base design
Base design

The quality itself is pretty good. It’s pretty heavy, which could imply a nice surprise with the internals. The assembly is also impressive, so the Viomi engineers really tried their hardest on this robot.

Technical features

Viomi Alpha UV’s main characteristics:

  • Battery Li-Ion 5200 mAh.
  • Suction power up to 2700 Pa.
  • Battery life up to 220 mins.
  • Charging time 220 mins.
  • Cleaning space 250 Sq.M.
  • Dust collector size 300 ml (10 Oz).
  • Water container size 250 ml (8 Oz).
  • Obstacle size up to 20 mm (.78 inches).
  • Size: 350*98 mm.

Functions

Now let’s look at Viomi Alpha UV functions. The vacuum is controlled through the Mi Home app. Setting up and connecting your robot is really easy, just follow the instructions and you shouldn’t have any problems.

App control
App control

In the app the robot draws a map and zones it into separate rooms. In the settings you can find:

  1. Additional sweeping after vacuuming
  2. Going through a room two times.
  3. Mopping mode: the standard S-shaped or the more detailed Y-shaped, like in robot-polishers.
  4. The cleaning log, where you can view past cleanings.
  5. Cleaning schedule. Here you can chose the time, date, and cleaning mode (including the suction power and amount of water), as well as individual rooms for cleaning.
  6. Do not disturb.
  7. The right map. Yeah, this robot can save multiple maps.
  8. The language and sound level.
  9. Water level
  10. “Find my robot”
  11. And manual control.
Mi Home
Mi Home

Plus, you can calibrate the sensors, manually use the robot, share the controls with others, check for updates, and get help.

On the main screen you can chose one of three cleaning modes: sweep only, simultaneous vacuuming and mopping, and only mopping. You can also chose how much water your cloth gets.

Cleaning modes
Cleaning modes

In the map settings, you can combine or separate rooms, and name your rooms. Here you can also set up virtual walls and no-go zones, and no-go zones only for mopping. The functions don’t have the best translation, but you’ll figure it out. If you have any questions, ask them in the comments below. You can also chose a specific point, or a rectangle area that you want to be cleaned.

Map settings
Map settings

These are the app’s main functions. Note that Viomi Alpha UV automatically increases power on carpets and can be controlled through virtual assistants.

Testing

Finally, let’s get to the tests. Let’s first check Viomi Alpha UV’s navigation in a room with obstacles First the robot goes around the perimeter, and then goes through all of the available space in a snake-like pattern. It didn’t get stuck on the drying rack, it cleaned round each individual chair leg and box, and returned to the base for charging. The robot definitely passed this test.

Navigation in a room with obstacles
Navigation in a room with obstacles

Well and as for the rest of the house, after it got used to the house and zoned all of the rooms, it went room after room, first around the perimeter, then in a snake-like pattern. On 32 Sq.m (104 Sq.F) it spent 26 minutes. It’s fast, and the navigation is excellent. Let’s move on.

Navigation within the house
Navigation within the house

Suction power

As for the suction power, I got a little problem. On one hand, the volume and sensation is above the other models, but it could only suck dirt out from 2 mm (.07 inches). Basically it acts like other vacuums with a PA of 2700. So the suction is above average, but isn’t that different from Viomi V3 and SE.

Suction power
Suction power

Hard floor vacuuming

The hard floor vacuuming is exceptional. I added cat food and litter to the test, as asked by our loyal subscribers. And so the robot was good with vacuuming the floor, and could get the corner dirt better than most vacuums. Take a look for yourself. The vacuum passed with flying colors.

Hard floor vacuuming
Hard floor vacuuming

Carpet cleaning

To my surprise the robot cleaned the carpet very well, which isn’t common in Xiaomi vacuums. Usually they specialize in mopping, but are very bad on carpets. And so Viomi Alpha UV showed good results, and cleaned the carpet from various dirt, as well as fur. As I already mentioned, this robot automatically increases power on carpets, so it’s great for cleaning most surfaces.

Carpet cleaning
Carpet cleaning

Mopping

Like always, I have no complaints about the mopping. The vacuum could get dried dirt without leaving marks. Only a small line along the baseboard remains, but that’s common among Xiaomi vacuums.

Mopping
Mopping

In general, Viomi Alpha UV did a great job with the details while mopping, from stone to wood. The mop is never too wet, and the floor doesn’t get flooded, even on max. So don’t worry about your floors.

Obstacles

The vacuum was able to get over 2 cm (.78 inch) obstacles with ease, so the robot is great with obstacles.

Passage of obstacles
Passage of obstacles

Dark spaces

Viomi Alpha UV, like most others, is afraid of dark spaces, and this is my first complaint to the robot.

Passage of dark surfaces
Passage of dark surfaces

Noise level

Lastly let’s check Viomi Alpha UV’s sound level. In scrubbing mode it goes from 58-61 Db. On minimum it goes to 65 Db. In standard mode it reaches 69 Db. In the middle mode it goes it 72.5 Db. And On pressure cleaning it reaches 74 Db. Yeah, its loud, so I don’t recommend being in the same room with it.

Noise level
Noise level

In conclusion

Viomi Alpha UV was thoroughly tested and described. Our algorithm gave it 78/100.

The overall rating of models that passed the Robotobzor test https://robotobzor.com/ratings/general-rating-of-robot-vacuum-cleaners.html.

So what can I say about this model? Here are the benefits:

  1. An auto-empty base with a control panel and a better located suction opening.
  2. Great LIDAR navigation.
  3. Good vacuuming and mopping, especially on carpets, where it automatically increases power.
  4. Viomi S9 UV does better with corners, than other robots.
  5. All of the functions are in the app.
  6. The suction power is above average.
  7. Good with obstacles.
  8. And is just great with collecting the dirt itself.

Amazon: https://amzn.to/47XJE0I

I can’t put the UV lamp there, as I have no way of actually testing it. But don’t forget about it, as it is possible that the robot can actually disinfect the floor while cleaning.

The only downsides are the noise level and the fact that the robot is scared of dark spaces. Other than that the robot is great, especially if you’re looking for a robot that can mop with a self-cleaning base. Viomi Alpha UV is honestly one of the best robots I’ve ever reviewed, and so I extremely recommend it.

On this note I’d like to end this review. If you still have questions, make sure to ask them in the comments below. Have fun shopping, bye!

Alexander Miasoedov

The founder and chief editor of the project, an expert on the choice of robot vacuum cleaners.

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Add a comment

  1. Leonid

    Great review! Thank you.
    I bought this robot on Ali Express, but it speaks Chinise, and I don’t know how I can switch the languige. Can you advice on it?

    Reply