Tool-Triggered Dust Extractors
Don't be the filter that removes the dust from your shop's air." That's a tool-industry axiom that makes a lot of sense these days. The more we learn about the health risks of airborne wood dust, the greater the need for devices that work in unison with tools to keep that dust out of our lungs. And that's where the 12 machines tested for this article really shine.
Each machine considered for this review has:
■ an onboard tool power outlet;
■ at least a 2-micron-rated dust filter.
All of them represent a big step up from the typical wet/dry shop vacuum. For starters, each can automatically turn on when a power tool plugged into the vac's 110-volt outlet switches on. It makes using the vac a no-brainer. All of the test models, except for the Makita, come with a HEPA-rated filter (see note, below). The Makita instead comes with a filter capable of capturing particles down to 2 microns, though it will accept an optional HEPA filter ($130).
Because replacement HEPA filters don't come cheap ($35–$255 per machine—some require two filters), 10 of the tested vacs come with a disposable bag prefilter that captures most of the dust before it reaches the HEPA filter. When the bag fills up, simply toss it out. The two units that don't come with a prefilter, the Metabo HPT and Fein Turbo II X AC, offer prefilter bags as an option ($15 and $10 each, respectively). A side benefit of the additional filtering: These machines run much quieter than a typical shop vacuum. Only one ran loud enough to necessitate hearing protection (more on that later), although adding in the connected tool's noise might call for some protection.
We ran each of the extractors through extensive suction, airflow, and filtration testing. Here's what we learned.Attributes of a dust extractor
1. Suction/airflow. We measured each model's suction and airflow using instruments and methods similar to those used by testing labs. (The chart provides performance grades in these areas.) Suction describes the power to pick up debris, while airflow moves it through the hose and into the tub. Airflow results from suction when the hose end is open, so you can have suction without airflow, but never airflow without suction. For dry debris, such as sawdust, high airflow (measured in cubic feet per minute, or cfm) proves much more important than suction. Fine dust, such as that generated by sanders, moves easily through a hose and requires little airflow. However, chips from a router or circular saw require higher airflow to avoid hanging up in the hose.
To measure airflow in these models, we sucked up debris of varying sizes with clean and dirty filters to replicate new and used equipment, and then assigned them a composite score for airflow. The chart below shows the maximum airflow for each unit after all testing was complete and the filters were seasoned. The top performers delivered much greater airflow than the lowest airflow unit.
Each model comes equipped with either one or two ultrafine (2 microns or finer) filters, shown below. Think of these fine filters as a last line of defense against microparticles rather than serving as the only filter. That's why most models come with a prefilter/collection bag. With these, all debris enters the paper or fleece bag, while allowing the air (and some fine dust) to escape into the vac's chamber, where it gets drawn into the fine filter. We prefer the fleece bags because they trap more dust than the paper bags, and they're more resistant to accidental rips. These disposable filter bags cost $5–$15 apiece, but without one you'd quickly load up the fine filter with dust, compromising airflow and shortening the life of that more costly ultrafine filter.
To help maintain consistent airflow, many of the vacs automatically clean the fine filter, triggering 2–3 times per minute to knock or blow off dust. During testing, we found this cleaning action improved airflow each time, especially when not using a prefilter bag. The Mirka has a cleaner you must work manually—a step easily overlooked as you work; the Festool and Fein Turbo I and II vacs do not have a filter cleaner.
Because these dust extractors prove so valuable—in performance and financial investment—avoid using them for wet suction (even though they're capable). Instead, buy a less-expensive tub-style wet/dry vac for those messy jobs.
We ran each vac through a series of tests to gauge its ability to filter large and small particles. Based on the air-quality chart provided with our particulate meter, all of the vacs tested in the "good" to "excellent" ranges. Wood dust seemed easy for these machines to filter well, but when we sucked up chalk dust—a product consisting of primarily tiny particles—a few models allowed more fine dust to escape than the majority. (See the chart below.) Bottom line, though: All of these vacuums perform well at filtering dust from shop air.
Three ways to bag up debris in a dust extractor
Power up the tool
To achieve tool actuation of the vac, plug the tool into the vac's outlet, attach the hose to the tool's dust port, set the selector switch to tool activation, and power up the tool. With each extractor you can also select manual power to operate it without a connected tool.
Each extractor has a maximum-amps rating for its own motor plus the outlet for the tethered tool. Most combined ratings do not exceed 15 amps, based on the likelihood you'll be using a 15-amp circuit. If you're using a 20-amp circuit, you'll probably never trip a breaker. But when we measured amp draw in our tests—all done on 20-amp circuits—we routinely exceeded the rated amperage without tripping a breaker. And when we used a 3-hp router and plunge-cutting tracksaw with each vac, we pulled more than 20 amps without issue.
Don't overlook the hose
A good hose proves nearly as important as the vacuum itself. The ideal hose would be large enough in diameter to allow any size debris to pass through without hanging up, but not so big as to be cumbersome. It should also be flexible but still resistant to crushing or kinking. Unfortunately, none of these hoses has all these qualities. Instead, the hose that comes with a vac usually is a compromise of one or more of those qualities.
All but one of the test vacs (Mirka) comes with a hose. Mirka's Julie Schilling says this allows you to choose the Mirka hose that best fits your needs. And that's a fair point, because hoses perform better at various tasks based on their size and qualities.
(However, it does add cost to this $1,050 vac—highest in our test.) The other factory hoses measure between 1" and 11⁄2 " inside diameter, with nozzles generally slightly smaller. These work fine for attaching to portable tools, but are too small for benchtop tools and machines.
We like Festool's hose best because it's flexible and has a woven covering that prevents the hose's spiral ribs from catching on a workpiece edge. We'd prefer more crush resistance, but not at the trade-off of being less flexible.
More valuable vac facts
■ Low noise. These dust extractors run much quieter than general shop vacuums because of the extra layers of filtration. All but three models have variable-speed motors, allowing you to reduce the suction, airflow, and noise. And at their fastest (or single) speed, only one unit (the DeWalt DWV010) made noise above the 85-decibel threshold where you should wear hearing protection.
■ Cord/hose wrap. Most models have power cords longer than 13'. The DeWalt models have 7' and 8' cords, which required extension cords at times. You don't always need a lot of cord, but it's often helpful.
But, with a long cord comes a storage issue. So we appreciate dedicated cord wraps or bungee straps on each model. All but the Fein Turbo I and Turbo II and Mirka vacs provide a way to store the hose, too; these measure 10–17' feet long.
In a great field, you can't miss All of these dust extractors perform well enough to merit a spot in your shop. But if we had to pick just one, we'd take the Bosch VAC140AH, our Top Tool. Yes, it's an investment at $650, but it scored top marks in suction, airflow, and filtration, has an excellent hose with a nozzle that fits the most common port sizes, and has a best-in-test 141⁄2 -gallon capacity.
If you don't want to spend that much, opt for the $290 Fein Turbo I. It's our Top Value. You get a smaller tank and less airflow, but it's more than adequate for collecting and filtering sanding, routing, and sawing debris.
Download HEPA Vacuum Comparison Chart