For Barry Schwaiger, the Director of the Powermatic Division of the WMH Tool Group, the issue of sawdust is all about health, and he’s concerned that not all of us go far enough in dealing with the problem.
“I think of dust collection in three lines of defense,” Barry explained. ” The first line is at the machine or sanding table in the form of a bag, cyclone, cylinder or shop vac dust collector. Next, for most people, comes personal dust collection, usually a dust mask. The third, and the one most often overlooked, is an air filtration system (AFS). Most people use at least one of these methods, and some folks use two. That’s good and necessary, but it really isn’t enough. Sadly, not enough people use all three, which to me is the ideal.”
I asked him to explain why, since I am sure to some this seems like overkill. “There are particles that make it through the filter media of most dust collectors,” Barry pointed out. “A bag type dust collector can leak particles as large as 30 microns. Canister type dust collectors, which use a pleated filter inside a cylinder, grab down to two microns. That’s better, but not good enough. Sadly, the particles that are most dangerous to our lungs are the ones we can’t see, typically between five microns and 0.3 microns, and these are precisely the ones that can slip past even a canister filter.
“Particles from four to five microns are usually filtered out either by a canister filter or, if they get past that, by our body’s own filtration systems, like nose hairs. Those smaller than that, all the way down to 0.3 micron, pose the biggest health risk. They can get past our natural defenses and get past our typical shop filters as well. Clearly, we need another line of defense.
“Personal dust collection in the form of a dust mask can do it, but that has a filter area only about the size of your mouth. That does little for the rest of the shop, or for you when you are not wearing the mask in that room. Dust settles elsewhere and gets stirred up again later, perhaps when you are doing something that is a non-dust generating task. In such a case, you might not be wearing a dust mask, but the problem dust will still be there. The solution, then, is to rid the shop of this dust once and for all.
“The best way to do that is with an air filtration system (AFS). Although this is usually the last thing a woodworker adds to his dust collection arsenal, in my opinion, it should probably be the second, right after tool-mounted dust collectors. An AFS can filter the air and rid it of harmful airborne products vastly faster than your lungs can do the job working through the small surface area of a dust mask.
“In a nutshell, an AFS consists of a fan, typically a squirrel cage fan, pulling air through at least two filters and dumping the now scrubbed air back into the shop. Do that enough and all the air in your shop will be clean.” With that in mind, Powermatic last month introduced the PM 1200 Air Filtration System, boasting a triple dose of sleek good looks, powerful efficiency and a wealth of convenience features.
“First and foremost,” Barry told me, “the PM 1200 AFS was designed with convenience in mind. A radio frequency remote, which does not require a line of sight sensor to work, turns on the unit from anywhere in the room or even outside the room. The remote itself has a liquid crystal display (LCD) showing things like fan speed, timer settings, battery levels: pretty much everything you need to know. A built-in panel on the box itself sports all the same controls, allowing you to also operate the unit without the remote, in the event you misplace it.
“There are three blower speeds, allowing you to get the power you need, but also to save energy when lower speeds will do. A re-settable, pop-out fuse protects the unit in the event of an overload or power surge. Both the onboard and remote controls operate a timer with nine settings, allowing continuous operation for up to nine hours and automatic shutoff even while you’re away. That’s important, since most experts suggest you run your AFS at least two more hours after you leave the shop.
“Inside are three separate filter banks, all covered by a pair of protective end caps reminiscent of stylish pickup truck grills. The caps and the filters behind them come off and go back on quickly with no tools required. There’s even a ‘change filter’ reminder light that comes on after 200 hours of use. The outer filter is a standard size 12 by 24 HVAC filter available at any home store, making it easy and inexpensive to change filters when needed. If you prefer, you can clean the filter many times before you need to replace it. I clean mine by sliding the filter into a garbage bag and tapping it to release the dust into the bag.
“Behind the first filter is a high efficiency inner bag filter with a huge surface area that traps 85 percent of 1 micron particles on each pass of air. It slides out as easily as the first filter, and can also be cleaned numerous times. Drawing the air through both these filters is a squirrel cage fan designed to work with the high efficiency induction motor to generate the greatest amount of airflow possible. In order to avoid stirring up more dust by dumping high speed air back into the shop, the exhaust air passes through a mesh screen filter that acts as a diffuser to gently reintroduce the clean air.
“You should be cleaning the air at the rate of about once every 10 minutes if possible,” Barry explained, “and that’s a breeze for the PM1200 in most small shops. If your shop is the size of a typical two-car garage, it contains about 4,600 cubic feet. With the ability to move 1,200 cubic feet per minute, the PM1200 will clean the air in a shop that size in about four minutes, and will work well in a shop more than twice that size. Any bigger than that ,and you may need to start thinking about two units.
“When it comes to your health,” Barry insists, “you shouldn’t take chances. You need a system that performs well and is convenient enough to make you likely to use it. The Powermatic PM1200 AFS was created to do just that.”