When using a robot vacuum for the first time, stick
around to monitor what it’s doing. There are a few
things to keep an eye on. Shoelaces, strings, carpet
fringe, and thin or lightweight clothing can all get
pulled into the brushes or rollers. The Roborock S6
MaxV uses two cameras and artificial intelligence
(AI) to identify many common “problem obstacles”
the vacuum may encounter and avoid them.
Some units have sensors that will stop them
when the brushes meet resistance, and some will
even reverse, spitting out whatever they pulled in.
But, to avoid damage to the vacuum and whatever it
might try to suck up, you should keep the area clear.Additionally, be aware of pet food/water
bowls, plant stands, or other things that might be
“tippy,” until it’s clear how a vacuum will interact
with them. Models that leverage bump-and-go
navigation, like the Eufy G30 Edge, may bump
things a little harder, so it’s a good idea to set up
boundaries around those water bowls. Lastly, if
kids have toys with small parts, like Lego, those
can be picked up by a robot vacuum just as easily
as a full-sized unit. Many models have features to
create exclusion zones, so make use of them or
employ your own strategy to avoid all these little
hazards that could jam up the vacuum.THINGS
TO WATCH
OUT FOR
MEASURING
SUCTION POWER
Water lift, a common method of quantify-
ing suction, is relatively easy to measure.
So easy, in fact, we built a simple water lift
gauge to evaluate the strength of these robot
vacs. Here’s how it works: We set up the vac-
uums so their suction could be applied,
within a sealed system, to a tube with water
in it. The stronger the suction, the higher
the water is lifted.
Vacuum manufacturers tend to list vac-
uum strength in Pascals (Pa), which can be
converted to water lift: 249.1 Pascals equals
one inch of water lift. You’ll notice our num-
bers are lower than manufacturers’ claims,
and that’s to be expected because they don’t
tell us where or how they’re measuring. They
may take measurements at the impeller, or
without going through the filter. It’s similar
to how auto manufacturers list horsepower
ratings on cars, as an engine spec. But the
transmission, differential, and other sys-
tems all leech some of that horsepower, so
what’s actually available at the rear wheels
isn’t the same number listed in the specs. To
be as close as possible to the actual amount
of suction available under the vacuums, we
removed the vacuum brushes and measured
right through the housing above them, with
the vacuum filter in place.
ROBOROCK S6 MAXV
2,500 Pa, claimed
7 in. of water lift = 1,744 Pa
IROBOT ROOMBA S9+
N/A Pa (iRobot doesn’t list)
7.3 in. of water lift = 1,806 Pa
EUFY G30 EDGE
2,000 Pa, claimed
6.25 in. of water lift = 1,557 Pa70 November/December 2021
T h e Te s t
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