Dusting up a storm

Some further thoughts and developments on the dust extraction system.

I’ve been giving some thought to what happens next – as in how does the dust run get to the dust extractor, and just how far that is – how much more length, how many more bends are required.  The simple answer is “too far and too many”.

Hmm. So the question arose in my mind again – just why did I think the original idea of having the dust extractor on the mezzanine floor was a bad one?  Back in mid Feb, I had thought about it, and opted to bring the dust extractor back down from the mezzanine where it had just been put (and what a pain that was!)  However, now that the machine positions have settled, it is really looking like the mezzanine was a good idea after all.

Looking back at my earlier musing on the subject, I highlighted good points to be
a. free up workshop floorspace
b. for it to be inside the main shed, as it draws a lot of air, and if outside the main shed, that is a lot of hot (or cold) air that would be drawn into the workshop, and
c. as that would make it generally central to the machines it is drawing from.

On the other hand, I had thought having it in the timber store next door gives better access, better noise separation, better workshop air quality (particularly on the mezzanine).

Now that I have been working in the shed for over 1/2 a year, more informed decisions can be made.

These lead to the following justifications for relocating the dust extractor back to the mezzanine:

1. Significantly shorten the length of ducting, and minimises the number of bends required.
2. Noise isolation would be the same as having the dust extractor in the area I currently have placed it.
3. Dust isolation from the main shed is maintained, although the mezzanine will not be as clean, it is not used as I was anticipating. If I ever do start to make use of it for something other than storage, I can look at physically isolating the extractor at that point. It still has a pleated filter, and I can still run an air filtration system up there if I choose.
4. It does not draw air from the outside (hot or cold), so running the dust extractor will not significantly impact on the shed environment
5. Changing bags is as easy (if not a little easier), and I do have the hoist to remove full bags from the mezzanine.

To compare the two locations, let’s take the biggest producer of sawdust in the workshop (which also produces the heaviest particles), being the thicknesser.

With the dust extractor outside in the side shed, it would involve approx 12m of ducting (up, across and down), and a total of 6x 90 degree bends (each elbow is estimated to be the equivalent of 2m of straight pipe), so a total of 24m equivalent length.

With the dust extractor on the mezzanine, it would involve approx 4m of ducting and a total of 4x 90 degree bends (at worst), giving a total of 12m.  That is one significant saving to be had, for the machine that needs the most drawing capacity.  All other machines benefit to lesser degrees, but each ends up saving about 10m in equivalent straight pipe length, if not more.

So I guess that makes the decision an easy one.  The ducting is a lot less complicated, and shorter.  There is power already available (I originally placed a GPO up there to be dedicated to the dust extractor).

The future plan will be to look at continuing to improve and upgrade the dusting system – moving as much up to 6″ ducts as possible, rather than the current 4″.  But let’s see how the system works once I get it up and running, to see just how much that will be a priority.

Onwards and upwards (quite literally!)

3 Responses

  1. Cyclone ? 3HP should pull at least two machines the distance you are planning. Not scientific, just from my observation in use in my shop. http://mysaw.com/shop/shop-projects/2008-cyclone-dust-collection-duct-work/

    • Don’t have a cyclone collection at this stage (future?).
      Have a 2HP dusty with pleated filter.

  2. I have a dust collector and learned a few lessons from a friend that has a large shop with piping all over the place that would make a plumber proud. Here’s what he told me. No sharp corners, no 90 degree elbows, and no “T” connections. The idea is to smooth out the flow. Replace one 90 with 2 – 45s and a short straight pipe between. Replace T’s with Y connections. Make any flexible connections to the trunk line as short as possible. And he put his collector in a closet with walls 2 feet from each side. The front door had a furnace filter on the top and bottom. Not sure any of this would work for you but its food for thought 🙂 I spend a lot of my time controlling dust at the source and started buying tools that can hook up to my Festool CT36 or my dust collector.

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