Which Roomba to Buy in 2019? – Part 3: Maximum Area Coverage for Cleaning Large Homes

This is the 3rd part of our series of posts to help you Choose the Roomba that Best Fit Your Home in 2019. We address here the maximum area that a Roomba can cover. This characteristic is critical for large homes.

Since Roomba are cordless vacuums, they rely on battery power. However, vacuum pumps drain a lot of current. This is why, even a 2 hour lasting battery is not enough to fully clean a large home. Luckily, iRobot engineers came up with creative solutions to mitigate this power limitation.

Which Features Matter for Cleaning Large Homes?

– Random vs. Systematic Navigation

Some Roomba follow a semi-random path while cleaning your home (See right figure below). Basically, they move forward until they hit an obstacle. Then, they turn at a random angle, and move away. The problem with this navigation algorithm is that it wastes battery. The Roomba may end up cleaning some spots several times, instead of going to areas that are still dirty.

To make the best battery usage, some Roomba perform a systematic navigation (See left figure below). They make a map of your home, and clean every spot only once. They follow a natural path, like a human with a regular vacuum.

– Recharge & Resume Cleaning

Roomba that provide this feature are capable of localizing themselves on the map used for systematic navigation. So, when the battery is low, they go back to recharge their battery. Then, they resume cleaning at the exact position where they paused.

Video below shows a Roomba 980 cleaning a 1500 square feet home (~140 square meters). Its 120 min battery is not enough to cover all the area at once. So, it pauses cleaning once the battery is low. And when fully recharged, it finishes cleaning.

Roomba 980 Recharges and Resumes Cleaning

– Persistent Maps

As discussed above, Roomba that perform systematic navigation rely on a map. Some Roomba build the map upon every cleaning cycle. However, this process requires time, and wastes the battery.

More advanced Roomba persist maps on their onboard memory. So, they can start cleaning immediately. They are even capable to memorize several maps, which is useful in homes with multiple levels.

Which Roomba is Best for Large Homes?

As discussed in our post on Roomba for large homes, Roomba i7+ is best. It allows for maximum area coverage, while minimizing maintenance.

Among the 15 Roomba we have reviewed, 4 are able to map homes. Those are the high-end Roomba 960, Roomba 980, Roomba i7 and Roomba i7+. Based on this map, they all perform systematic navigation to maximize area covered on a single battery charge. Moreover, they are all capable to localize themselves, recharge battery, and resume cleaning if the one battery charge is not enough to vacuum all the floor. However, only Roomba i7 and Roomba i7+ do save maps. Actually, they can persist up to 10 maps, which speeds up cleaning even in homes with multiple levels.


Roomba i7+
Best for Large Homes
Roomba i7+Buy Roomba i7+ from Amazon

Regarding maintenance, all 4 high-end Roomba have tangle-free brushes. But, only Roomba i7 and Roomba i7+ are ready for self-cleaning. Last, only Roomba i7+ is shipped with a dock that actually allows to automatically empty the dustbin.

Bottom line, Roomba i7+ is the best overall for large homes. However, the best value for large homes is Roomba 960. Sure, you don’t have self-cleaning, but it costs half the price of a Roomba i7+. Besides, it provides all features to maximize area coverage, except saving the map.

Roomba 960
Best Value for Large Homes
Roomba 960Buy Roomba 960 from Amazon

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