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Kyvol Cybovac S31 Review

Budget, Self-Emptying Robot Vacuum

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Kyvol S31

The Kyvol S31 is a budget-friendly robot vacuum (that also mops) and has a self-emptying dust bin on the docking station. It has good navigation, although not the most efficient, and good performance—93% overall in our cleaning tests. It struggled the most with low pile carpet, but seemed to switch into the Auto Carpet Boost for cleaning high pile carpet. Not a bad vacuum overall.Check Price

Pros

  • Self-emptying dust bin; holds up to 60 days of debris
  • Long 240-minute run time
  • Zoned cleaning and digital mapping

Cons

  • Struggled with low pile carpet (especially the finer debris)
  • Average mopping performance
  • Build quality not as good as some other models we’ve tested

Scoring

Self-Empty Bin on a Budget
  • Design - 92%
    92%
  • Performance - 93%
    93%
  • Quality - 90%
    90%
  • Usability - 94%
    94%
  • Value - 92%
    92%
92%

Summary

The Kyvol S31 is a 2-in-1 mopping robot vacuum that has the capability to vacuum or mop and includes a self-emptying dust bin integrated into the docking station. It uses LIDAR navigation to map the space, which allows you to set up zones, or targeted cleaning cycles. The S31 also has a long run time, up to 240 minutes with 3,000 Pa suction power. When cleaning carpets, it will switch to Auto Carpet Boost which can help improve performance. All-in-all, I was pleased with the overall performance of this vacuum. It was not flawless and lacked some points in build quality, but it is a nice budget option if you want all the bells and whistles.

Cleaning Performance

Overall, the Kyvol S31 robot vacuum did a good job cleaning debris. It mainly struggled with ultra-fine debris (like our sugar test) and when interacting with low pile carpet.

Kyvol S31 brushroll
Kyvol S31 brushroll

It navigated smoothly and had plenty of run time to complete the job, up to 240 minutes. The S31 offers 3000Pa of suction power and a 5200 mAh battery for longer run times.

Here are the exact debris removal scores for cleaning with the Kyvol S31 robot vacuum:

Overall

93%

Hardwood

99%

Low Carpet

88%

High Carpet

93%

Hardwood Floor Cleaning

On hardwood floors, the S31 did a solid job, cleaning 99% of the debris we tested. Not sure what else to say here besides that it got the job done—solid performance.

Kyvol robot vacuum cleaning tests - hardwood flooring
Kyvol robot vacuum cleaning tests – hardwood flooring

Low-Pile Carpet Cleaning

On low pile carpet, the performance was not quite as impressive, only capturing 88% of debris. Most of the debris missed was the sugar, which is not uncommon for robot vacuums.

Kyvol robot vacuum cleaning tests - low pile carpet
Kyvol robot vacuum cleaning tests – low pile carpet

But that being said, the S31 boasts a 3,000Pa suction power so that really should be sufficient for low pile carpet.

High-Pile Carpet Cleaning

A little surprising, the performance was actually a bit better on high pile carpet compared to low pile carpet—93% of debris captured. Again, sugar was most of the debris that was left.

It’s a bit unclear why the performance was better on the high pile carpet compared to low pile carpet.

Kyvol robot vacuum cleaning tests - high pile carpet
Kyvol robot vacuum cleaning tests – high pile carpet

There is an Auto Carpet Boost feature on this vacuum so it is possible that it switched into boost mode for high pile carpet, but stayed in standard mode for the low pile carpet.

Mopping Test

For our mopping test, I would say that the S31 was okay. It was a little hard to tell how effective it actually was because the cleaning pad is gray so debris tends to blend in.

Kyvol 3S1 robot mopping attachment - after a cleaning cycle
Kyvol 3S1 robot mopping attachment – after a cleaning cycle

In addition, the mopping tank felt a little small. According to the manufacturer, the water tank has a capacity of 0.46 cups, which is slightly smaller than other competitive 2-in-1s that we’ve tested.

For example, the Roborock E35 has a tank capacity of 0.63 cups.

How we test?

To be able to make a fair assessment on cleaning performance, we do testing in our lab testing lane and our larger Modern Castle office and studio space.

We use three types of floors:

  • Hardwood floors
  • Low-pile carpet
  • High-pile carpet

We spread the following items along each type of flooring to test the vacuum cleaner:

  • Rice – 0.5 ounces
  • Dry Cereal – 0.5 ounce
  • Kitty Litter – 0.5 ounces
  • Sugar – 0.5 ounces
Cleaning performance test - dry debris
Cleaning performance test – dry debris

We use an engineered hardwood floor as our base test.  Low-pile and high-pile carpet inserts are laid over the hardwood floor to do the carpet testing. Debris is scattered over each type of floor covering one at a time.

We use the same vacuum cleaning process to test all our vacuum cleaners. This creates a true to life real world, consistent and fair atmosphere to provide the performance assessment.

Here is the procedure:

  1. Measure each type of testing debris by weight.
  2. Create a debris field in the testing lane by spreading the variable debris mix.
  3. Release the robot vacuum to clean the testing lane and debris.
  4. Run a high powered vacuum over the test lane to remove any debris left behind
  5. Empty and weigh any debris that we were able to remove in step 4.
Missed debris from the low carpet cleaning tests - Kyvol S31 robot vacuum
Missed debris from the low carpet cleaning tests – Kyvol S31 robot vacuum

RELATED See our other robot vacuum reviews here.

Kyvol S31 Design

The design of the Kyvol S31 is pretty simple from the top. It has a black glossy body with three controls.

There are buttons for the following functions.

  1. Power: turns the vacuum on / off; starts or stops a cycle
  2. Dock: sends the vacuum back to the docking station
  3. Spot: moves in a radial pattern to clean a small area only; does not return to the dock when done
Top view of the Kyvol S31 robot vacuum
Top view of the Kyvol S31 robot vacuum

What’s on the bottom of the vacuum?

The underside of the Kyvol S31 is pretty basic. The parts are basically the same as what we’ve seen on other robot vacuums we’ve tested.

  • It has two 3-arm spinning side brushes that are designed to collect debris from corners and edges.
  • Contact sensors on the front and end of the vacuum help it to navigate to the charging station correctly.
  • Edge sensors around the front perimeter also help to prevent the vacuum from dropping off fall hazards like lofts or stairs.
  • The central brushroll is in the middle of the vacuum and uses a basic spiral bristle brushroll to collect debris.
  • Wheels flank the left and right side of the brushroll and allow the vacuum to traverse varying floor heights. A smaller navigational wheel in the front of the vacuum is used for direction and making tight turns.
Underside of the Kyvol S31 robot vacuum
Underside of the Kyvol S31 robot vacuum

Size & Dimensions

The size of the Kyvol S31 robot vacuum is under 14″ in diameter and is still low enough profile to squeeze under most furniture.

Profile view - size of the Kyvol S31 robot vacuum
Profile view – size of the Kyvol S31 robot vacuum

Here are the exact specifications for this 2-in-1 robot:

  • Diameter: 13.8″
  • Height: 3.8″
  • Weight: 8.4 pounds

Accessories & Parts

Wondering what all comes in the box with the Kyvol S31 mopping robot vacuum? The list is pretty exhaustive for a robot vacuum, so let’s dive in.

Parts and accessories for the Kvyol S31 robot vacuum
Parts and accessories for the Kvyol S31 robot vacuum

What’s in the box?

Here is a list of everything included in the box with the Kyvol S31:

  • Self-emptying dock: charges the vacuum in between uses and empties the on-board dust bin
  • Vacuum bags: 2 disposable bags that install into the back of the docking station
  • Mopping pads: includes 2 washable microfiber mopping pads and 10 disposable mopping pads
  • Spinning brush: snaps into the corner of the robot and allows the vacuum to pull debris from edges and corners and deposit it into the cleaning path of the main brushroll
  • Filter: traps ultra-fine particulate and debris
  • Remote: can be used to control the vacuum hands-free

RELATED – Want to see other vacuum reviews? Check out more here.

Kyvol S31 Features

The S31 comes with a well-rounded collection of features and functions. It doubles as a robot vacuum and mopping robot with great coverage.

Here’s some of my favorite specs about this particular model:

Run Time

Up to 240 mins

Cleaning Modes

Auto, Spot, & Zone

Wireless Control

Yes, smartphone app remote control

Wondering what else is included on the S31? Check out the list below.

#1. Variable Control

You can control the Kyvol using a few different methods:

  1. Buttons on the vacuum
  2. Smartphone app
  3. Voice control (via Amazon Alexa or similar)
  4. Remote control
Remote control for the Kyvol robot vacuum
Remote control for the Kyvol robot vacuum

The variable control options may make it easier to schedule a cleaning run, view the digital map, check maintenance reports, set up zones, etc.

#2. Smart Navigation & Mapping

So let’s talk through the navigation and digital mapping.

Kyvol relies on LIDAR laser navigation to “see” where it is in space and develop a digital map accordingly.

Kyvol S31 robot vacuum and self-empty dust bin
Kyvol S31 robot vacuum and self-empty dust bin

When we ran a test run, the performance was pretty solid overall. It was able to navigate the entire space, did not get stuck, and returned to the docking station.

Also going to add that it made its way back to the dock on the first run. It is hard to ask for much more than that.

But by the same token, the S31 is not the most efficient navigator. It kept going over the same spaces several times before it felt satisfied with the clean, which used up more of the battery and didn’t seem entirely necessary.

#3. Zoned Cleaning

When using the app on your smartphone, you can set up zones to help break down the cleaning area. With Zoned Cleaning, rooms can be prioritized and cleaned more often or skipped over entirely, as needed.

#4. Self-Emptying Dust Bin

The S31 has a self-emptying dust bin that automatically removes debris from the onboard dust bin and deposits it into the larger dustbin at the charging dock.

The disposable bags can hold up to 60 loads of debris from the on-board bin.

How did it score?

I really do like this feature and appreciate that it was included at such a relatively low price point, but the build quality just doesn’t seem to match some of the other self-emptying bins we’ve tested thus far.

Usability & Maneuverability

So in terms of usability and maneuverability, the Kyvol checks quite a few boxes. It has a compact body style and good navigation, although it lacked a little efficiency.

Some of the other positive features it has going for it include:

  • Self-emptying dust bin
  • Remote control
  • Digital mapping
  • Smartphone app
  • 2-in-1 mop and vacuum
  • Auto carpet boost
  • Zoned cleaning
  • Long 240-minute run time

Maintenance

Maintenance tasks for the Kyvol S31 include a similar set of tasks that you’d see on any other mopping robot vacuum, with the exception of daily dust bin emptying.

Here’s a quick review of the tasks you’ll need to do:

  1. Replace HEPA filters (as needed)
  2. Replace battery (as needed): Most robot vacuum batteries last 2-3 years thought this is just an estimate as the manufacturer does not give a lifespan on the included battery.
  3. Remove obstructions from brushroll: You’ll want to periodically remove the brushroll to remove hair and any other obstructions.
  4. Wash mopping pads (as needed): There are machine washable and can just be tossed in the washer on cold or hand-washed in the sink.
  5. Refill mopping reservoir (as needed): The tank only holds 0.46 cups of water so you may need to refill the tank more often than you think if you plan on mopping large areas.
  6. Replace the dust bags from the dock (as needed): These larger capacity bags can hold up to 2 months of debris from the smaller dust bin located on the vacuum itself.
Kyvol S31 robot vacuum dust bin
Kyvol S31 robot vacuum dust bin

Is the Kyvol S31 a good value?

With all the specs, features, and technology we’ve listed here, does the Kyvol S31 provide a good bang for your buck?

Generally, I would say yes. It has a lot of really nice features that people are looking for in a modern robot vacuum, but at a more affordable price point.

Buttons on top of the Kyvol S31 robot vacuum
Buttons on top of the Kyvol S31 robot vacuum

Of course, there has to be a compromise somewhere. With the lower price tag comes some cut corners with performance, build quality, and usability.

But if you have a specific budget in mind and don’t want to break that, the S31 can be a good way to get the features you want without spending as much as comparable models.

Kyvol Specifications

SpecificationsKyvol S31
TypeRobot
ManufacturerKyvol
ModelS31
Width13.8"
Height3.8"
Weight8.4 lbs.
Floor TypeAll (indoor)
Suction Power3,000 Pa
Battery5,200 mAh
Run Time240 mins
Dust Bin Capacity500 mL
Water Tank Capacity150 mL
Zoned CleaningYes
Digital MappingYes
Hands-free ControlRemote, smartphone app, or voice control
ReturnsVaries by retailer, other retailers will vary
Warranty1-Year Limited
PriceCheck Price

Should you buy the Kyvol?

The Kyvol is a good option if you are looking for the following in a robot vacuum:

  • Self-emptying dust bin: The self-emptying dust bin is quickly becoming one of the most attractive features for robot vacuums. Similar to other models, the S31 sucks debris from the on-board dust bin after each cleaning cycle and deposits it into the larger debris bag on the dock. The whole process is handy and can help to limit daily maintenance tasks.
  • 2-in-1 robot vacuum and mop: Although the mopping tank is small and mopping performance wasn’t fantastic, the Kyvol is still a servicable 2-in-1 mopping robot vacuum. Also, I liked how they included a mix of disposable mopping pads and washable mopping pads.
  • Budget option without sacrificing features: Considering the features of the Kyvol and relatively good performance, the price is good on this vacuum. While build quality seemed to take a hit, this little vacuum still had some nice features and could be a good option for many homes.

For more information on the Kyvol robot vacuum, click here.

About Derek Hales

Derek HalesDerek Hales is the Founder and Editor-in-Chief of ModernCastle.com. He has been featured in Fast Company, Reader's Digest, Business Insider, Realtor.com, She Knows, and other major publications. Derek has a Bachelor's Degree in Business Administration from Kansas State University. Hales has been testing and reviewing products for the home since 2014.

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2 Comments on “Kyvol Cybovac S31 Review”

  1. Hi Derek, is it OK to use a solution of Bona floor cleaner wth water in
    the S31. Look forward to your response.

    Thanks….Larry

    Reply
    • No. It will definitely void your warranty and very likely lead to problems over time (clogging and/or leaking).