Viomi Alpha UV (S9): self-cleans, effectively cleans and disinfects surfaces

Hello readers! This article will review the latest product from Viomi, a sub-brand of Xiaomi. It's the flagship Viomi S9-UV, also known as the Viomi Alpha UV. The key innovations in this model, compared to its predecessors in the line, include a self-cleaning base, a more powerful motor, and a UV lamp for surface disinfection. While it's difficult to assess the effectiveness of the latter upgrade, the other features undoubtedly improve cleaning performance and the longevity of the robot vacuum cleaner. Below, I'll review and test the Viomi S9-UV in detail, after which I'll share my opinion. It's worth noting that at the time of writing, its price ranges between $450-$500. So, let's get started!

Equipment

First, let's look at the Viomi S9 UV package. In addition to the robot itself and the self-cleaning base, the package includes:

1. Wet cleaning nozzle with a microfiber cloth installed.
2. Set of 10 disposable wipes for wet cleaning.
3. Spare side brush.
4. Two spare bags for the base.
5. And the operating instructions are in several languages, including Russian.

The package isn't exactly sparse, but to be on the safe side, I'd like to see a spare HEPA filter included, so that there's a full set of consumables for the first few months of using the robot.

Appearance

Let's take a look at the Viomi S9 UV's appearance. Mine is white with blue accents. It looks very stylish and modern. There's also a black and purple colorway, which is equally striking.

Navigation is handled by a lidar, as well as a mechanical bumper, which has two wall sensors on the sides and an obstacle detection sensor in the center.

The lidar is equipped with a mechanical button to prevent it from getting stuck under furniture. The body also features two mechanical buttons: a forced return to the charging base and a start/pause button.

In addition, we see information that the robot is equipped with a UV lamp.

The combined water and dirt container is removable from the rear. The tank holds up to 250 ml of water, and the dust container holds 300 ml of dry dirt.

The container has a shutter to prevent accidental spillage when removing debris from the robot. The filtration system uses a mesh, foam, and HEPA filter.

At the back, we see the terminals for connecting to the base, as well as a shutter through which the container is emptied. We also see a pump installed in the tank for electronically regulating the water supply.

Let's take a look at the Viomi S9 UV's underside. It's equipped with four drop protection sensors.

In the center we see a UV lamp installed, which is used to disinfect the surface.

The central brush is made of bristles and petals. The bristles are not very dense, but are quite springy. The cap on one side is removable for cleaning the brush of tangled hair and fur. On the other side, only the dust cover is removable.

Water flows through three holes in the nozzle to the cloth. The cloth is quite thick, but smaller in size than its predecessors. Viomi V3 And Viomi SE, reviews of which are available on our website.

Here's what disposable wipes look like. They're also thick, but the quality is obviously inferior, so they're only effective for single use.

Let's see how the self-cleaning base is designed.

Firstly, the suction channel opening is located at the end rather than at the bottom, as was previously the case with most similar robots. This design solution improves self-cleaning efficiency and speeds up the process. Secondly, the base itself features a display that displays the base's status, promptly alerting you when it's time to replace the bag or monitoring the self-cleaning process. The display also displays the battery charge and the charging process. Perhaps most usefully, this display shows the status of the bag.

Inside the base, you'll find a conveniently located tool for cleaning the dust bin and central brush, as well as the dust bag itself. When you remove it, the opening closes, preventing dust and debris from falling out. Under the dust bag is a mesh-protected vent for the motor, which actually sucks debris out of the dust bin.

Overall, there are no complaints about the robot's performance. It's quite heavy, which indirectly speaks to the high quality of its components. It's also well-designed, so it's clear Viomi engineers put a lot of effort into developing this flagship product.

Technical specifications

The main characteristics of the Viomi S9 UV, as stated by the manufacturer, are listed below:

• Li-Ion battery 5200 mAh.
• Suction power up to 2700 Pa.
• Operating time up to 220 min.
• Charging time up to 220 min.
• Cleaning area up to 250 sq.m.
• Dust collector capacity is 300 ml.
• The water tank capacity is 250 ml.
• Obstacle clearance up to 20 mm.
• Dimensions: 350*98 mm.

Functional capabilities

Let's move on to an overview of the Viomi S9 UV's features. The robot vacuum is controlled via the Mi Home app. Pairing is straightforward; follow the manufacturer's instructions, which are in Russian.

In the app, the robot creates a precise map of the room and automatically divides it into rooms. In the settings section, it's important to highlight the following features:

1. Additional sweeping around the perimeter after covering the entire accessible area.
2. Double passage of the room.
3. Select a floor cleaning mode: standard S-shaped or more thorough Y-shaped, like robotic floor cleaners.
4. Cleaning log, where you can view information about the cleanings performed by the robot.
5. Set up a scheduled cleaning. Here you can select the time, days of the week, cleaning mode (including suction power and water flow level), and the rooms you want to clean.
6. Do not disturb mode at a specified time.
7. Selecting the right cleaning maps. Yes, this robot stores several unique maps in its memory.
8. Setting up the language pack and voice alert volume. In my case, there's no Russian language pack, only English.
9. Monitoring the status of consumables.
10. Search for a robot by sound signal.
11. And manual joystick control.

You can also calibrate sensors, manually control the robot vacuum cleaner, share control with other users, check for updates, and explore the help section.

The main control panel lets you select one of three cleaning modes: sweeping only, dry and wet mopping simultaneously, or mopping only. You can also adjust the suction power and water flow to the mopping pad.

When working with the map, you can combine multiple rooms into one, manually divide a room into additional zones, and name each room. You can also set virtual walls, general no-go zones, and specific no-go zones for wet cleaning mode on the map. The translation of the functions is a bit awkward, but I think you'll get the hang of it. If you have any questions, please ask in the comments. Additionally, you can select a point on the map for localized cleaning with the robot vacuum, as well as individual rectangular cleaning zones.

These are the app's main features. It's important to note that the Viomi S9 UV automatically increases suction power when it comes into contact with carpets and is controlled via the Yandex.Alice voice assistant. These are also new features that weren't previously available. Viomi robots.

Testing

A detailed video version of all tests has already been prepared and published on the channel; you can watch it:

Navigation

And finally, let's move on to the tests. First, we'll test the Viomi S9 UV's navigation in a room with obstacles. The robot vacuum first navigates the perimeter of the room, then switches to a serpentine pattern across the entire accessible area. It didn't get stuck on the dryer, and it swept around each chair leg and box individually, before successfully returning to its base and self-cleaning. The test was successful.

As for cleaning the entire house, after a test drive, the robot automatically zoned the space into rooms and cleaned room by room, first sweeping the perimeter and then snaking through each room. Cleaning 32 square meters took just 26 minutes. Cleaning speed was fast, and navigation itself left no questions. Let's move on.

Suction power

However, there were mixed opinions regarding suction power. The robot felt and sounded significantly more powerful than its predecessors, but it only managed to suck up debris from 2mm gaps on the stand.

Basically, the same as other robot vacuum cleaners with a claimed suction power of up to 2700 Pa. So, the suction power is above the market average, but not significantly different from the Viomi V3 and SE.

Dry cleaning of laminate flooring

The dry cleaning performance was impressive. The test included cat food and litter, as per repeated requests from subscribers. The robot performed well in dry cleaning and even out-cleaned corners compared to other round robots. The test was successful.

Cleaning the carpet

Surprisingly, this model's carpet cleaning performance is exceptional, which is unusual for robot vacuums in the Viomi line. These typically specialize in wet cleaning and are less effective on carpets. However, the Viomi S9 UV performed well, effectively removing various debris, including hair and pet hair, from the carpet.

Additionally, as mentioned earlier, this model features automatic power boost on carpets, making it suitable for thorough cleaning on a variety of floor surfaces.

Wet cleaning

As always, there were no significant complaints about wet cleaning. The robot was able to remove some dried dirt from the floor. It only left a small streak along the baseboard, but this is a problem area with all the robots we tested.

Overall, the Viomi S9 UV performs gentle wet cleaning well on both tile and laminate. It evenly wets the cloth and floor surface. Even at maximum water flow, it leaves no puddles and won't damage wood flooring.

Obstacle clearance

The robot vacuum cleaner can easily move over 2 cm high thresholds, so this model has good cross-country ability.

Driving on dark surfaces

But the Viomi S9 UV is afraid of dark surfaces, recognizing them by differences in height; this is the first criticism of the robot.

Noise level

Finally, let's check the Viomi S9 UV's noise levels in different modes. In floor polishing mode, the noise level ranges from 58 to 61 dB. At minimum suction power, it reaches 65 dB, in standard mode it's around 69 dB, at medium power it reaches 72.5 dB, and in "Violence" mode, the peak noise level was 74 dB.

Yes, this robot vacuum cleaner is quite noisy, so it won't be very comfortable to be in the same room with it while cleaning if you want it to vacuum your floor effectively.

Let's sum it up

Viomi S9 UV has been thoroughly reviewed and tested. our rating systemand he was able to dial 81 out of 100 points And this is the best result at the time of writing. A new benchmark has been reached! The overall rating of robot vacuum cleaners tested on robovac.washerhouse.com: https://robovac.washerhouse.com/en/rejtingi/robovac-obshhij-rejting-robotov-pylesosov-robo.html.

What can I say about this model after a thorough review and testing? Here are some positive aspects worth highlighting:

1. Self-cleaning base with a more efficient suction hole placement and indicator on the base itself.
2. Good navigation based on lidar and sensor system.
3. High-quality dry and wet cleaning, with the robot vacuuming carpets well and automatically increasing suction power.
4. The Viomi S9 UV sweeps out corners better than other round robot vacuums.
5. All advanced functionality is provided in the application.
6. Suction power is above average.
7. Good cross-country ability of the robot.
8. High quality assembly.
9. Yandex.Alice support.

I can't count the UV lamp among its advantages, as I have no way to test its effectiveness. However, it's also worth keeping in mind. Perhaps Viomi's engineers have truly achieved results, and the robot vacuum cleaner is capable of disinfecting surfaces while cleaning.

The only downsides I can think of are the increased noise level and its sensitivity to black flooring. Otherwise, for the price, it's an excellent choice, especially if you're looking for a robot vacuum cleaner with a self-emptying base. The Viomi S9 UV has received overwhelmingly positive reviews and is highly recommended.

On that note, I'd like to end this review. If you have any questions, please ask them in the comments. Happy shopping, everyone. Bye!