Consider a robot vacuum.

post by BrandonReinhart · 2012-06-05T08:08:45.546Z · LW · GW · Legacy · 21 comments

My wife and I recently acquired a robot vacuum. It has turned out to be a really great time-saving and life-improving investment. Some simple math suggests it may be worth you also considering buying one.

Let's say you spend 20 minutes a week vacuuming. That's about 17 hours of vacuuming per year. The Neato XV-11 costs about $350 bucks with basic shipping. For the purposes of our Fermi calculation we will say that your time spent vacuuming with the robot is zero. This is close to true. See below for exceptions.

At $350, if you value an hour of your time at more than about $20 you would be better off buying the robot than doing the vacuuming yourself in the first year. (17*$20=$340 - close enough for our fermi estimate)

Consider also that if you spend at least 20 minutes or less a week vacuuming, you can also instruct the robot to vacuum 20 minutes a week or more and raise the quality of your life by living in a better cared-for environment by some amount. For example, you could increase the pay-out of the robot by having it vacuum every other day.

If you have the robot do 60 minutes of work a week, then you'd only have to value your time at about $7 for the robot to be worthwhile in the first year. (52*$7=$364)

Do the calculation to see if it makes sense for you:

b = value of your time in dollars/hour

y = hours/year you spend vacuuming

350 = estimated price of a robot

x = b*y - 350

If x > 0, then the robot would save you money in time, according to how you value your time. If x < 0, then you either don't clean often enough or value your time so low that doing the work yourself makes sense. (So this is a simple model, feel free to make it more complex but the purpose of this post is to illustrate a fermi calc that seems to yield an easy choice.)

Given the cost of many upright vacuums, if you can avoid buying an upright and only buy the robot the calculation shifts drastically in favor of only getting the robot (and perhaps borrowing an upright if you really need one).

If vacuuming causes you particular disutility, you could put a dollar premium on that disutility and add it to b. On the flip side, if you really like to vacuum you'd want to discount b to reflect the extra utility you get from spending your time doing something you enjoy.

Considerations:

- The robots are claimed to be pretty good at navigating complex room layouts. Our robot rarely (but sometimes) gets stuck behind places where it has little clearance to enter. You can adjust furniture layout to compensate or lay down (ugly) magnetic strips that stop the robot. You might want to try out the robot to make sure it can navigate your layout before you commit.

- Once our robot failed to back itself fully into its charging dock and it ran out of juice and missed a scheduled vacuum session.

- The robot won't drive itself off cliffs (down stairs to its doom). On the down side, it won't vacuum stairs. You may still need an upright to handle stairs.

- You can make the robot do a lot more vacuuming than you would normally do yourself.

- They are really quiet on carpet. Somewhat noisier on hard wood. Depending on your sensitivity, you may be able to run it while you sleep.

- If you shed hair, you'll need to regularly clip the hair from the brush (like a normal upright). This takes almost no time. Do it as a part of the bin-emptying ritual.

- It isn't clear to me how long the robot will last, so I don't know what the replacement period or cost is.

- This is the robot we use, but there are many types. It isn't clear to me if the upgraded types are worth the extra money: http://www.amazon.com/Neato-XV-11-Robotic-Vacuum-System/dp/B003UBPB6E/ref=sr_1_1?ie=UTF8&qid=1338882167&sr=8-1

- I haven't investigated central vac, so I don't know what the trade-offs are. It seems like central vac still requires time to use and our goal was reducing time spent doing an automatable home maintenance task.

Maybe this is a trivial post, but I hadn't realized how much cleaner our environment could be or how much happier we could be for such a small relative investment. Much of the benefit comes from the robot being able to vacuum far more often than we'd ever have a desire to do ourselves.

21 comments

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comment by fubarobfusco · 2012-06-05T16:48:30.617Z · LW(p) · GW(p)

Some other things to think about:

  • The Neato and the Roomba run very different algorithms. The Roomba is a bucket of random numbers with some constraints. The Neato actually makes a plan. The Neato is better at not getting trapped under dining room chairs; the Roomba is better at not getting tangled in electrical cords.
  • They are also very different hardware. The Roomba is mostly a sweeper (it took me forever to realize that "Roomba" is "broom" inside out) whereas the Neato is mostly a vacuum cleaner. The Roomba is better at hair (although you have to clear its brushes pretty often). The Neato is vastly better at dust. Both are good at dry dirt; neither one can handle anything wet.
  • The Roomba's "virtual walls" are light beams; as such, they reflect off of mirrors — and glass surfaces such as sliding glass doors, depending on incident angle. Also, the virtual wall generators take batteries. The Neato's magnetic strips don't look that bad along existing borders (e.g. carpet to tile).
  • The Neato knows what a doorway is without being told, and can complete one room then migrate to the next. The Roomba requires doorways to be marked with special virtual wall generators if you want it to do that.
  • An upright vacuum cleaner usually has attachments. While this keeps it from achieving Buddhist enlightenment, it also means you can use it to dust the furniture or remove cobwebs from the ceiling corners. You can do a lot of this with a cheaper handheld, of course; but you can't do it with a robot.
Replies from: None, Richard_Kennaway, Alicorn, moreati
comment by [deleted] · 2012-06-05T17:34:23.184Z · LW(p) · GW(p)

While this keeps it from achieving Buddhist enlightenment,

This is the humorous cherry on top of a solid post filled with details. Well done!

comment by Richard_Kennaway · 2012-06-05T21:18:37.357Z · LW(p) · GW(p)

Do you have any information about comparative reliability? For me, reliability is a virtue second only to "does it work at all?"

I had a Roomba some years ago, the second-series "Discovery" model. I had less than two years use out of it before the cliff sensors started behaving like it was always looking over a cliff. Taking it apart (a very long and fiddly task which left me distinctly unimpressed by its design) and cleaning everything I could get at helped for a while, but not enough and I eventually relinquished attachment to the sunk cost (i.e. I threw it out). iRobot after-sales service outside the US was nonexistent then, and spares were unobtainable.

Replies from: fubarobfusco
comment by fubarobfusco · 2012-06-05T21:32:02.716Z · LW(p) · GW(p)

Do you have any information about comparative reliability?

Not really; I've only had the Neato for a couple of weeks. My Roomba experience was similar to yours — I'm pretty sure the fatal problem was sensory rather than cognitive or motor.

comment by Alicorn · 2012-06-05T17:39:25.449Z · LW(p) · GW(p)

An upright vacuum cleaner usually has attachments. While this keeps it from achieving Buddhist enlightenment

Bahahahaha :D

Roomba is better at hair (although you have to clear its brushes pretty often). The Neato is vastly better at dust.

"Better at hair" as in "better able to pick hair up at all", or as in "better able to avoid being crippled by a long hair"? I have really, really long hair and if I were to get a cute pet robot it would do well to be able to handle that, but dust is important too.

comment by moreati · 2012-06-05T22:35:42.477Z · LW(p) · GW(p)

They are also very different hardware. The Roomba is mostly a sweeper (it took me forever to realize that "Roomba" is "broom" inside out) whereas the Neato is mostly a vacuum cleaner.

Does this have any bearing on the hard floor vs carpet suitability of each? I have both, but I'd like to optimise for carpet

Replies from: fubarobfusco
comment by fubarobfusco · 2012-06-05T23:07:36.944Z · LW(p) · GW(p)

I haven't run either on hard floors much.

comment by Oligopsony · 2012-06-05T15:16:30.239Z · LW(p) · GW(p)

I've gotten so used to wacky speculation on this site that I thought this thread would be about, like, what if the quantum vacuum... was actually a robot???

Replies from: gwern, satt, DanielLC
comment by gwern · 2012-06-05T15:37:34.749Z · LW(p) · GW(p)

But that would explain everything - the simulators pulling our plug equates to a collapse of the vacuum, causing the Great Silence and at a stroke account for all the major mysteries of the universe! Eureka!

comment by satt · 2012-06-06T00:38:44.552Z · LW(p) · GW(p)

I was expecting a riff on Yvain's blue-minimizing robot. Apparently the post being about literal robot vacuums was too obvious an idea to occur to me — I must be running in contrarian mode right now.

comment by DanielLC · 2012-06-05T23:22:40.095Z · LW(p) · GW(p)

I was thinking it would be something along the lines of "Consider a spherical cow in a vacuum...".

comment by Jayson_Virissimo · 2012-06-05T10:45:31.217Z · LW(p) · GW(p)

I spent $250 USD on an iRobot Roomba 550 from Costco. So far, it has lasted 11 months and cleans 6 days a week (it doesn't work on the Sabbath). It doesn't clean as well per minute as a typical stand-up vacuum, but since it cleans so often the house ends up being much cleaner than it otherwise would be. I estimate that I spend about 5 minutes per week on maintenance (emptying the container and cleaning the brushes). Before getting a robot I probably spent 20 minutes per week vacuuming.

Conclusion: Even if it only lasts a year (which seems like a conservative estimate) I am basically paying 75 cents a day to have an extra 17 hours of leisure a year and a significantly cleaner house.

Replies from: DanielVarga, dbaupp
comment by DanielVarga · 2012-06-05T12:10:02.944Z · LW(p) · GW(p)

paying 75 cents a day to have an extra 17 hours of leisure a year

that is, paying 75 cents a day for 2 extra minutes of leisure. For a U.S. knowledge worker this is probably a good deal, but for example, for a Hungarian housewife this is ridiculously bad, even if you work with more realistic annualized costs.

Replies from: aelephant, Jayson_Virissimo
comment by aelephant · 2012-06-06T01:38:23.821Z · LW(p) · GW(p)

Damn, I hope I'm not the only Hungarian housewife reading LessWrong...

comment by Jayson_Virissimo · 2012-06-05T12:50:56.664Z · LW(p) · GW(p)

Yeah, that's about right. It should also be noted that my calculations were made under the assumption that the user already owns a stand-up vacuum.

comment by dbaupp · 2012-06-05T12:27:12.631Z · LW(p) · GW(p)

it doesn't work on the Sabbath

Was this an explicit choice on your part, or does it not work then by default?

Replies from: Jayson_Virissimo
comment by Jayson_Virissimo · 2012-06-05T12:34:52.664Z · LW(p) · GW(p)

Was this an explicit choice on your part, or does it not work then by default?

I didn't realize I bought the Israeli-version until after I opened the package. No refunds apparently.

Replies from: Jayson_Virissimo
comment by Jayson_Virissimo · 2012-06-05T12:36:26.861Z · LW(p) · GW(p)

Just kidding; Saturday is my catching-up-on-sleep-and-relaxing-day, so I don't like it making noise.

Replies from: Eneasz
comment by Eneasz · 2012-06-05T17:23:37.740Z · LW(p) · GW(p)

I love that I believed you

comment by beriukay · 2012-06-05T11:10:44.650Z · LW(p) · GW(p)

Other considerations: it doesn't do a great job on long hair, or lots of hair. So if you have a huge head of hair or two dogs, shop carefully. It has no mechanism (except for the Scooba) to clean up using water; so it is only mildly useful in kitchen areas. My roomba is about 2" tall, so I had to raise my couches for better effect. I like them taller, which makes that a winning proposition. Oh, and they can get high-watered by things like doorway thresholds, for instance if you have an arctic entry. It is definitely convenient to get the kinds that can find their way to the docking station.

As a cheaper alternative, shop vacs are pretty awesome. They pick up just about anything and have long hoses. I definitely prefer them over standard vacuums.

Replies from: gwern
comment by gwern · 2012-06-05T15:35:39.454Z · LW(p) · GW(p)

Yes, this is what happened with my family. We got a Roomba maybe 6 years ago to use on the ground floor; it had a terrible time with our 4 dogs & cats' hair. It could run constantly, but that didn't help much. So when it finally broke, hardly anyone noticed.