Today, I’ll compare the iRobot Roomba I3 vs S9: One has an auto-emptying base, one doesn’t, and that’s just the beginning of the story. I compared them on every single aspect before deciding to give the winning ticket to the Roomba S9+.
The Roomba S9+ spares you from the dirty job of emptying its bin since it ships with a self-emptying base and has excellent cleaning performance on all types of surfaces thanks to its incredibly high airflow. It also offers more smart features via the iRobot app compared to the Roomba I3, which comes at a more budget-friendly price tag.
iRobot Roomba I3 Vs S9+: Comparison Chart
iRobot Roomba I3 Vs S9+: Differences
The S9+ wins strongly against the I3 with a score of 4-1. We have an overall winner, but what differentiates these two bots, exactly?
Cleaning Performance
Winner: Roomba S9+
Suction Power
| Roomba I3 | Roomba S9+ | |
|---|---|---|
| Max Suction (Pa) | N/A | N/A |
| Max Airflow (CFM) | ≈ 7.4 CFM | ≈ 24.6 CFM |
iRobot obviously didn’t reveal the suction power figures of their robots. So I took matters into my own hands, measuring airflow going through their rollers using an anemometer and obtaining the above results. While the I3 robot has a below-average airflow of 7.4 CFM, the S9+ reached nearly 25 CFM, making it among the robots with the highest airflow output. This difference certainly leads to a significant difference in their cleaning performance.
Hard Floor
| Roomba I3 | Roomba S9+ |
|---|---|
| ≈ 96% | ≈ 99% |
Combining wide extractors and super high airflow, the S9+ easily wins this round, picking up 99% of the total debris and leaving almost nothing on the floor. The I3 also achieved a score of 96%, which is not bad considering its subpar airflow.
Carpet
| Roomba I3 | Roomba S9+ | |
|---|---|---|
| Low-pile Carpet | ≈ 96% | ≈ 99% |
| High-pile Carpet | ≈ 87% | ≈ 99% |
The Roomba S9 also picked up the highest percentages of 99% on both the low- and high-pile carpets. The Roomba I3 did a great job on my low-pile carpet and was decent on the high-pile one (96% and 87%, respectively) – there’s life in the old dog yet!
Hair
| Roomba I3 | Roomba S9+ | |
|---|---|---|
| 5-inch Strands | ≈ 85% | ≈ 89% |
| 10-inch Strands | ≈ 72% | ≈ 76% |
Both are among the best options for cleaning hair, and the S9+ was still the best choice, collecting more hair of both lengths. The absence of bristles on their rollers made it easier to remove hair wraps, while all the strands on the axles also easily came off.
Design & Usability
Winner: Roomba S9+
First Look & Dimensions
| Roomba I3 | Roomba S9+ | |
|---|---|---|
| Dimensions (W x H) | 13.3 x 3.6 inches | 12.25 x 3.5 inches |
| Weight | 7.44 lbs | 8.15 lbs |
Unlike previous Roombas and later ones, including the I3, the S9+ features a D-shaped frame and is more square on the front, like the Neato D10 and its siblings. This groundbreaking design allows the S9+ to clean corners and edges better but also poses a challenge when navigating around chair legs or narrow areas. As for the I3, it has the same round shape as other Roombas.
The higher price tag of the S9+ can be justified by many bells and whistles, not least of which is its self-emptying home base. This bulky tower will suck out all the contents from the robot’s dustbin after every cleaning cycle as soon as the bin reaches its capacity.
Extractor & Side Brush
Both the I3 and S9+ use a pair of rubber brush rollers. The S9+ uses wider extractors, spanning across the square end rather than locating in between the wheels as the I3’s rollers. These broader extractors indeed improved the S9+’s cleaning performance.
The change in the frame also necessitated a change with the S9+’s side brush, which has a smaller diameter and five arms. The I3 has a three-prong side brush with longer prongs. Their corner brushes don’t spin at a rapid velocity, so they are effective at dragging dust and dirt toward the main brush instead of scattering them.
Mapping & Navigation
The S9+ is a vSLAM-based robot vacuum, meaning it uses a top-mounted camera to recognize landmarks inside your living space for mapping and navigation. Just like we need adequate light to see everything, this one needs light to do its job. It doesn’t need a very bright source to function, but it requires a decent amount of light to work efficiently.
On the flip side, the I3 relies on a set of floor sensors to draw a map and move around during cleaning. This bot can learn your house and draw the map, but it can’t save multiple maps like the S9+. It will have to draw a new map every time it runs on a new floor or area. This limitation earns it the title of the “dumbest Roomba” and makes it a less-than-ideal option for those residing in multi-story apartments, where cleaning spans across more than one level.
Both are smart navigating robots or at least that’s what iRobot calls them, since they smartly traverse in straight lines. This is obviously better than low-level bots moving in random patterns, such as the Roomba 690. It’s worth pointing out that they have no obstacle avoidance algorithm. Their built-in bumpers will protect themselves and objects from damage, but it’s advisable to take a pre-clean step, particularly for those with pets.
Battery Life
| Roomba I3 | Roomba S9+ | |
|---|---|---|
| Battery Life | ≈ 61 mins | ≈ 64–81 mins |
| Charging Time | ≈ 112 mins | ≈ 124 mins |
The S9 has a larger capacity battery because it uses a 3300 mAh battery, while the I3 features an 1800 mAh battery. Their real-world run time figures aren’t impressive, considering most other brands, such as Roborok, equip their robots with 5200 mAh batteries with a working time of up to three hours. But it shouldn’t be a deal-breaker since they both have a recharge and resume feature: they can return to their charging stations when their battery is low and then resume cleaning once they are charged up again.
Control
Winner: Roomba S9+
Manual Control
The I3 and S9+ share a three-button system: one to start/stop a full cleaning cycle, one to prop up the bot to come home, and one to clean a small zone. These physical buttons are a boon for those days when you prefer to jump straight into your daily cleaning chores without the need to use your phone.
App Connectivity
The I3 and S9+ are compatible with the iRobot app, where you can unlock all the smart features of these bots. You can schedule multiple cleaning cycles per day, customize the number of cleaning passes, and review past cleaning cycles. You can have both of them clean specific rooms and use your voice to communicate with them by using your Alexa device. You can also set the robot to automatically start cleaning when you leave home.
If you opt for the S9+, you will get more smart features. You can add keep-out zones by drawing rectangular or square blocks on the map to stop the bot from going into areas it shouldn’t (as for the I3, you need to use the virtual wall barriers sold separately by iRobot). You also have the option to add rectangular or square “cleaning zones” for spot cleaning.
You can also adjust the power of the S9 Plus and link it to the Braava Jet M6 mop robot so they can team up effectively without your intervention.
Cleaning & Maintenance
Winner: Roomba S9+
To ensure these robots perform at their best for years to come, regular maintenance is key. This includes routinely cleaning their dual rollers, inspecting the side brush, tapping the HEPA filter on a solid surface to remove trapped dirt, cleaning the wheels, and emptying the dustbin. The app will alert you when there is a consumable that needs to be replaced.
They both use a 500-ml dust container. The S9+ stands out with its clean tower feature that automatically empties the dustbin into a 2.5-liter bag, sparing you from the hassle. This bag does need replacement, but it only requires attention every week or month, depending on usage. You have a lot of options for where you can purchase dust bags: you can purchase these dust bags from iRobot or save money by opting for third-party brands available on Amazon.
Other Features
Winner: Roomba I3
Noise
| Roomba I3 | Roomba S9+ | |
|---|---|---|
| Working | ≈ 63 dB | ≈ 62-72 dB |
| Self-Emptying | None | ≈ 75 dB |
The S9 is the noisier option, reaching up to 72 dB in its maximum setting, while the I3 is quieter at approximately 63 dB. The self-emptying process at the home base makes the S9+ even noisier at close to 75 dB.
Mopping Ability
The I3 and S9+ just pick up dust from your floors – nothing more, nothing less. So if you’re on the hunt for something that can vacuum and mop at the same time, you might want to look elsewhere.
Quick Rundown Of Roomba S9+
- A DEEP, DETAILED CLEAN. Groundbreaking technology makes the s9+ our legacy powerhouse robot vacuum. With 40x more the suction power*, the 3-Stage Cleaning System lifts, loosens, then eliminates debris and pet hair from deep within your carpets for a clean you won’t believe — with no effort from you. Automatically increases suction to clean even deeper into carpets with power boost technology. *Compared to the Roomba i Series robots
- EMPTIES ITS VACUUM BIN, SO CLEANING IS OFF YOUR MIND - Cleans up after itself, emptying its Vacuum Bin into an enclosed bag that holds up to 60 days of debris, which means two whole months of not thinking about vacuuming.
- CLEANS WHEN AND WHERE YOU WANT - Only IRobot brings you Imprint Smart Mapping allowing you to control and schedule which rooms are cleaned and when, while storing multiple maps for easier cleaning on each level of your home. Plus, customizable Keep Out Zones and Clean Zones allow you to tell them the exact area to avoid and clean.
- A POWERFUL CLEAN - PerfectEdge Technology with advanced sensors and a specially designed Corner Brush optimize cleaning deep into corners and along edges. Ideal for homes with pets. 40% larger Multi-Surface Dual Rubber Brushes that don't get tangled with pet hair. *Compared to the Roomba i Series robots
- GUIDED BY SERIOUS SMARTS - The s9+ learns the layout of your home and builds personal Smart Maps, enabling it to expertly clean and navigate in neat, efficient rows. Careful Drive Mode detects objects in its path and cleans around them without jostling or nudging. (objects taller than 2.5 cm)
Quick Rundown Of Roomba I3
- POWERFUL CLEANING—SCHEDULED AROUND YOUR LIFE - Whether you’re relaxing at home or out enjoying life, Roomba i3 EVO takes care of dirt and messes with a Premium 3-Stage Cleaning System and 10x the Power-Lifting Suction*. *Compared to Roomba 600 series.Runtime : 75 minutes
- CLEAN BY ROOM, YOU’RE IN CONTROL - Roomba i3 EVO learns your home and creates an Imprint Smart Map so you can direct it to clean any room you want, any time you want—either on a set schedule or in the moment.
- CLEANING IN TIDY ROWS - Cleans intelligently in straight lines back and forth, to thoroughly clean your floors while navigating around furniture. When the i3 EVO needs to recharge, it will resume right where it left off ensuring a complete clean. Charger : 120V and 60 Hz
- FOCUSED CLEANING - Patented Dirt Detect Technology allows the Roomba i3 EVO to detect dirtier areas of your home and clean them more thoroughly. Integrated sensors tell the robot where it can and can’t fit, so it doesn’t get stuck under furniture.
- PERFECT FOR HOMES WITH PETS - Instead of using a single bristle brush, Roomba i3 EVO uses Dual Multi-Surface Rubber Brushes that flex to adjust to different floor types and avoid getting tangled with pet hair.
Product Videos
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References:
- Roomba S9+: https://www.irobot.com/en_US/roomba-vacuuming/robot-vacuum-irobot-roomba-s9-plus/S955020.html
- Roomba I3: https://www.irobot.com/en_US/roomba-i3-evo-robot-vacuum/I315020.html
Richard B. Schmidt is a prominent figure in the vacuum cleaner industry, boasting over 15 years of expertise. Armed with a Robotics Engineering degree from Northeastern University and a Master’s in Consumer Science from Harvard, his unique blend of technical knowledge and consumer insights positions him as a sought-after authority in vacuum cleaner evaluation. Richard’s career began at Dyson, where he contributed to the development of innovative vacuum models. Transitioning to advocacy and reviews, he co-founded the first Vacuum-focused blog in 2008, offering comprehensive analysis and user guides for various vacuum cleaners. In 2020, he founded RoboMop.net, providing ongoing insights through columns and buyer’s guides.