Dyson V12 Slim Review

I loved this Dyson's accessories, including the hard surface-specific head that's great for hardwood and a mini motorized attachment perfect for upholstery.

Carpet Performance

Carpet performance is one of the most important features of a vacuum. We test it rigorously, with 1.5 cups of sand, rice, and cheerios spread over 27 square feet of carpet. The different debris sizes give us a realistic grasp of a vacuum's performance with a variety of household messes, and the large area lets us evaluate cleaning forward, backward, and lateral overlap.

The V12 comes with Dyson's Motorbar head, rather than the Digital Motorbar that's stocked on higher-end models. The distinction may seem minor, but there's a difference in real-world performance. With more clearance between the head and floor and lower suction, the V12 Detect doesn't achieve the perfect clean of some of Dyson's top-tier products. What's more, its small dustbin fills quickly, causing the vacuum to detect a clog and shut itself off.

Low Pile

Over the three trials I conducted, the V12 picked up an average of 78% of the debris I laid out for it, and with a few more passes, I could have eliminated my mess completely. The problem is that I would have had to empty the dustbin to make those extra passes. By the end of the first 24-second trial, the vacuum had detected a clog and shut itself off. In fact, it wasn't exactly clogged, but chock full to the point that the debris had nowhere else to go.

Still, I'd gathered 88% of my mess and wanted to see if the vacuum could do better. So, after emptying the dustbin, I put down another batch of debris and tried again. It wasn't an improvement. During the second round, the V12 clogged mid-trial, successfully gathering just 70% of all debris. I conducted a third trial, as is our policy when there's a significant discrepancy between first and second-round results, and split the difference at 74% pickup. It was abundantly clear that the dustbin, at just 0.34 liters, was not intended to capture a cup and a half of debris in one go.

Admittedly, this testing is rigorous. It also bears mentioning that the Dyson performed well during each trial prior to clogging. But the fact is that large, tough-to-tackle messes are common in many people's lives, and the speed with which the vacuum filled up and shut itself off felt like a real flaw.

High Pile

High pile carpet, or shag, is tough terrain for cordless vacuums, and few really shine there. To put things in perspective, our best-performing cordless test subjects captured just over half of the debris we laid out for them in trials conducted identically to the low pile trial I described above.

Knowing this, the V12's 44% average sounds respectable, and it is. It felt less effective than the more premium Dysons, which have more power and a different head design that helps them create a good seal and maximize suction in deep carpets. But the capture rate of the Dyson Gen5detect, some $300 more expensive, was only six percent higher.

I found that the head articulation sometimes felt stiff, causing the brush roller to tilt up and away from the carpet surface when I wanted it to lie as flat as possible to maximize suction. It drove some Cheerios and rice deep into the weave, making it harder to clean out on a second pass. Still, regarding cordless vacuums, the V12 performed fairly well on high pile carpet.

Overall Carpet Cleaning Performance

All things considered, the V12 Detect Slim might be a great vacuum for small areas and minimal messes on carpet. But it will certainly struggle with high volumes of debris.

If you live in a large space with a lot of carpet, or if your household tends toward bigger messes, this probably isn't the one for you.

Hardwood Performance

Vacuums often excel at one particular floor surface. In the case of the V12, that surface is hardwood, in large part because of the Fluffy Optic cleaner head, a feature that we've loved in other Dysons and were excited to see in this more affordable model. The laser-like beam of green LED light throws grit and detritus into sharp relief on hard surfaces.

Cleaning Performance

When I set out a half cup of sand, rice, and Cheerios again, this time on hardwood, the specialized hard surface head made the cleanup process feel like an arcade game. It's incredibly satisfying, especially when the numbers back it up. I averaged 95% debris capture with the V12 between my two timed trials.

At the end of each trial, the dustbin was yet again full to bursting, and the vacuum had started to feel weaker. Still, Dyson's laser detection system works so well that I'd feel confident recommending this vacuum for a hardwood-floored house, though perhaps not a particularly large one.

Crevice

To test crevice performance, I dropped sand between the slats of a bamboo mat and gave the vacuum 4 passes (forward and back) to pick it up. The bamboo mat is a good proxy for floorboard gaps, transition stripping between flooring types, or grouted tile.

The V12 excelled in this test, picking up 100% of my sand in just two passes. I am confident this vacuum could tackle any uneven surfaces with this vacuum, and I even think it would do a great job dusting my bookshelves in handheld mode.

Edges

Edge performance is surprisingly important in terms of the overall experience of vacuuming. If you clean your whole floor, but the inch closest to each wall remains dirty, it's not going to feel very clean. Some vacuums do well with head-on vacuuming against walls and stairs, others can be run parallel. To test this metric, I sprinkled ⅛ cup of coffee grounds along a wall in our testing lab in two separate strips. I vacuumed one head-on, and the other parallel.

Before Testing After Testing

On both test strips of coffee grounds, this product left no crumbs behind. This bolstered my overall impression that this vacuum would be great for small spaces like a dorm room or studio apartment, where tight spaces, a high edge-to-floor space ratio, and potentially different flooring types, but not for a large house with wide open rooms.

Overall Hardwood Cleaning Performance

The V12 did quite well on hardwood, and unless you're dealing with high-volume messes frequently, it would probably be a great choice for a smaller house. Seeing as it ranked highly, I think few users would feel a meaningful difference between the V12 and some of the much more expensive Dysons on hardwood.

Because of the dustbin size, I'd still hesitate to recommend it for bigger houses, even if they are all hardwood. However, if you don't mind taking a few breaks to empty the dustbin, it could be a high-performing, lightweight, and relatively affordable option, even for larger spaces.

Pet Hair

Pet hair is one of the most difficult messes to clean up, and cordless vacuums, with their power limited by battery life and size, especially tend to struggle. However, just like the rest of us, many pet owners are attracted to the ease and maneuverability of going cordless. To test this product's ability to deal with pet hair, I gathered 4 grams of fur from real pets (no animals were harmed in the testing of this vacuum) and worked it into the weave of both low and high pile carpets. Then, because humans lose hair, too, I did the same with 1 gram of long hair extensions. Finally, I set a timer for twelve seconds and vacuumed.

The V12 did pretty well with pet hair cleanup. On low pile carpet, I was able to gather 75% of the hair I'd put down, and on high pile, I got 57%, an above-average performance.

Before Testing After Testing

On both carpet types, there were clumps of pet hair left behind when my time was up and long hairs wrapped around the brush roll. This is a very common problem; despite various brush roll head technologies that promise to eliminate hair wrap, almost all vacuums struggle with it.

Filtration & Suction

Suction is one of our most straightforward metrics. There's generally a direct relationship between a vacuum's suction power and its ability to clean, particularly on high-pile carpet. Filtration, while less tangible, is equally important.

Once air enters the head of a vacuum, it has to go somewhere, and if the vacuum isn't equipped with a good filter, it can return to your house, still bearing dust, pollen, pet dander, and a wide array of other airborne particles. If you're sensitive to allergens, this can have real impacts on your health, and even if you aren't, it can be unpleasant and cause coughing, sneezing, or eye irritation.

Filtration

To test the V12's filtration capabilities, I first turned on three air purifiers overnight in an enclosed room at our testing lab. After letting the purifiers do their thing, I took a day's worth of data on thirty minute intervals from two Dylos Laser Particle Counters, to get a good sense of the room's baseline. Then I poured ⅓ cup of flour on the floor. Flour is a great substrate for this test because it's composed of particles of many different sizes, from less than 1 micron to over 100 microns. Pet dander, household dust, pollen, and mold also fall within this range, so we can see how well a vacuum can filter them.

I vacuumed the flour for 30 seconds and recorded the Dylos's peak counts of both small (0.5 to 2.5 microns) and large (>2.5 microns) particles. This product's HEPA filter performed excellently, and there was no significant increase in airborne particulates from the room's baseline. Dylos designates that any reading below 75 particles is excellent air quality for small particle filtration. Small particles are more hazardous than larger particles because they can enter your bloodstream, causing chronic problems. This makes the V12 Detect Slim a great option for anyone sensitive to allergens.

Suction

Suction is often tested at the end of the stick vacuum's handheld itself. But this doesn't necessarily translate into real-world performance: after all, when we vacuum, we generally use a wand and cleaning head, which can impact suction. To get a true read on usable suction, we used a manometer (which measures pressure differential) to monitor the air pressure inside a shallow box as we vacuumed over a hole in the top of it. This gives us an accurate understanding of the amount of suction the vacuum actually exerts on the floor.

At 672 pascals, the V12 was far less powerful than the more expensive Dysons we tested. Models like the Dyson Gen5detect, which pulls 2388 pascals, set the bar for suction extremely high, and their pricing reflects that. However, the Samsung Bespoke Jet is priced similarly to the V12 and has twice the suction power. Despite this, this machine has enough suction to vacuum very effectively, and the size of its dustbin is much more of a performance constraint than any lack of power.

Ease of Use

Vacuuming is a chore, but it can feel a lot less like one if the vacuum is easy to use and maintain. This vacuum has certain features that I love, like the specialized hardwood floor head and the mini motorized roller attachment. But it was also difficult to disassemble, empty, and clean, and the tiny dustbin meant that this process was necessary more often than it is on other vacuums.

I also found the dustbin really difficult to detach from the vacuum's head. Multiple coworkers tried and were similarly frustrated. It's possible that this was a manufacturing defect with the specific vacuum we bought, but it certainly didn't inspire confidence.

Despite this, the V12 was light and maneuverable, and during the vacuuming process I appreciated that it was easier to move around than other Dysons I've tested. I also loved that Dyson has finally upgraded to an on/off button! The trigger activation on previous models was genuinely tiring for my hands, and the button completely solves that problem.

Maneuverability

To assess maneuverability, I set up an obstacle course where each vacuum must negotiate hardwood, carpet, bamboo mats, cone lines, and a table, chairs, and couch. This vacuum transitioned easily between the floor types, but I found that when I was swiveling the cleaning head, it didn't articulate easily. It would pick up off the floor rather than lying flat, reducing the suction power and forcing me to correct its angle manually. Zig-zagging the cleaning head through the cones required a little muscle, but all in all, the V12 was easy to steer and cornered well. Its light weight also made getting under couches and tables easier.

Maintenance

I knew this vacuum would struggle in the maintenance category as soon as I started my carpet testing. The dustbin is very small and very difficult to detach and empty. The fact that the vacuum displays a 'clogged' message and shuts itself off when it reaches capacity is a feature, not a bug; it prevents the vacuum from overheating and deteriorating. But it still feels frustrating when it happens mid-clean.

The maintenance of the filter and cleaning heads is more user-friendly. The filter twists easily off the top of the vacuum, and a pull tab releases the fluffy roller. A coin, flathead screwdriver, butter knife, or other flat implement is needed to release the brush roller, but other than the need for a tool, the cleaning process is straightforward and easy.

Uphostery & Attachments

For my upholstery test, I used the Hair Screw tool, which is a small motorized cleaning head. I sprinkled 1/16 cup of coffee grounds across a pillow and the same amount across an ironing board. The hair screw attachment excelled on both surfaces, and though the movement of the motorized roller blew a few coffee grounds around, it left the pillow and the ironing board completely clean. I think this attachment would be great for removing pet hair from furniture.

The attachments are one of the highlights of this vacuum. I heavily depended on the mini motorized brush and hard surface roller, which felt built-to-purpose and significantly increased the quality of the clean I was able to achieve on the surfaces they intended for. The V12 also came with a crevice tool and a combination tool, both relatively standard but good quality, and a wand clip to secure the attachments to the vacuum wand.

The specificity of the V12's attachments massively upgrades the vacuum. Particularly if you're going to be focusing on upholstery or hard floors, this vacuum might be a worthwhile buy just for the attachments.

Battery

Like most cordless vacuums, this vacuum's battery isn't particularly long-lived. I got 36 minutes of run time on low mode and just 7.5 minutes on high. A caveat to these numbers is that, though less powerful than other Dysons, the V12's low (or 'eco') setting still provides a lot of suction, so you shouldn't need to use the high (or 'boost') setting all that often. It also has an auto mode, which detects the level of suction necessary and adjusts the vacuum accordingly, ostensibly providing the longest possible battery life.

The V12's battery life isn't a problem in and of itself, particularly if you're willing to split your cleaning into a couple of separate blocks. But between charging breaks and emptying the dustbin, cleaning a full-sized house with this vacuum is going to entail a lot of interruptions.

Should You Buy the Dyson V8?

I won't sugarcoat it: I would only buy the Dyson V12 Detect Slim on sale or if I want it to tackle light cleaning. If I spent $650, I'd be frustrated by the low battery life, the finicky maintenance, and the tiny dustbin. But, if I spent $400, that frustration would mostly be eclipsed by my delight at the Fluffy Optic cleaner head and the motorized hair screw. If you're cleaning a small space, particularly one with a lot of hardwood, it could be a great pick.

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