My CamVac dust collector is a noisy sucker, but I am extremely happy with it. And one of its features is very useful for noise reduction. Let’s make a couple of hush-up’ers! In addition, let’s look at my dust collection system.
I found this thread when researching dust collectors, and that post tipped the scale for me and made the decision easy – a CamVac unit was the weapon of choice to battle the dust clouds. Since I have a rather small shop, I want to reduce the noise as much as possible. While I primarily use hand tools, I do use machines too. The band saw sees a lot of use, and it needs dust collection (DC for short). When I use my jointer/thicknesser, DC noise isn’t really a concern as that thing howls and screams like Kerberos getting its family jewels caught in the gates of Hades – but the overall racket could benefit from some noise abatement procedures.
My green Kerberos aside, I would like to be able to use more quiet tools while also enjoying dust control. A pillar drill is on the shopping list, and I have both a belt/disc sander and a spindle sander that I would like to use without cropdusting the shop in the process. I also bought a hand sanding kit from Mirka for their Abranet sand paper, which has built-in dust extraction – basically a sanding block with dust extraction. I’ll post a review of it once I have some mileage on it. It would be nice if I could use that without needing my ear protectors. Low noise also means that I can enjoy music from my rather excellent shop sound system, even if the DC is running.
So a CamVac unit was purchased. And I could not be happier with it. My old dust collector was the common “bag filter, huge impeller” dust distributor (as that “filter bag” does next to nothing for fine dust control and the huge volume of air is a sure way to saturate the shop air with very fine dust) high volume low pressure, or HVLP type. It too was a good howler – starting it up made me feel like I was experiencing the London blitz in ’41. aaaaAAAAwwwWWRRRRoooOOOOO… Horrible!
The CamVac is a totally different beast – it is a low volume high pressure (LVHP) type. Basically, it is two vacuum cleaner motors in a drum. That “low volume” is kind of a misleading description though, as it moves 108 litres per second. That’s 388 m3 per hour. If we compare that to the Powermatic PM1300TX “the gold standard….. since 1921* “, “low volume” makes sense.
*tribute to the early Marc videos
At 1300 CFM, which is about 2200 m3/hour, the PM1300 moves about 1800 m3/h (1060 CFM) more air – but at a much lower pressure. And, I might add, spewing anything smaller than 30 microns out into the shop air. Adding a canister filter improves this to some degree – rated at 2 microns (finer filters might be available). The CamVac is rated at 0.5 microns, which means it will even filter out most bacteria (they are between 0.2 and 3 microns). The size of pollen is from 1 micron and up. And I don’t have to buy anything extra; it comes built into the machine.
Caveat: I use the manufacturer provided numbers. I’ve seen the exact same machine (as the one I had, not the Powermatic one) – with different color and label stickers – listed with wildly different specs. If you measure the volume of air on a dust sucker without any bags, filters, hoses – “ya gon’git good numbers, kiddo”. Not useable for any real application, but nice numbers still…
Think about this for a second: at 388 m3 per hour, all the air in my 30 m2 shop passes through the dust collector over 6 times per hour. The PM1300 would circulate the air ten times that. It might sound like a good thing at first glance, but in reality it is bad news. If the filter does not stop all the fine dust - the type of dust that goes deep into your lungs - you will work in an environment filled with (potentially) hazardous dust, and you would need to use a dust mask all the time. In a sunny day, you'll soon discover that dust "hangs" in the air for a very long time. Don't remove that mask too soon! Another aspect of this is that your shop will be a filthy place in no time, with layers of fine dust everywhere. Not good news for that pristine finish you want.. The moral here is that you ought to take clean air seriously. It might be okay for a good while, but eventually you'll run into problems. HSE is important - or as the instructor at the boom lift safety course put it: are you paid well enough to fall down and die?
The motors on the CamVac units has an exhaust port per motor, which we then can hook up to a noise baffle. In the image above, the two black pipes next to the red switches are the exhaust ports. These are 2 1/2” (63.5mm) in diameter.
We can even make a big filter box with even better filtration if we are so inclined. I haven’t seen any other dust collectors where this can be done as easy as on the CamVac units. Of course you could just vent it outside, but the shop might be a bit nippy in the winter… Gotta replace the air somehow.
So with all this background information (yes, I tend to ramble on at times) – let us make a noise baffle already! Turn page…