Thread: Alternative Dust Extraction Solution

Originally Posted by mick59wests

I still have not ruled out getting a ClearVue but I would prefer to have the main DC outside of my shed as I have an attached woodshed that I can insulate and the CleaVue will be too high to do this

Mick,

Don't know your shed layout, but one reason I went for a ClearVue is its very small footprint. I too was thinking about putting my DC outside when I was looking at options, but in my case I would have needed to build a shed, making that option with a 3 HP dusty more expensive than a CV dropped into the shop. You have an existing shed into which you can drop the dusty. However, the footprint of a CV is essentially the same size as the rubbish bin you choose, which generally makes it easy to install it in the shop. This sometimes shortens ducting and may make it easier to hook up to power.

So far as noise goes my CV measured 97dB without ducting. They are noisy. However, by my reckoning once you get the noise of the dusty below your main machines (table saw, thicknesser etc), there is little point trying to reduce it further. Some have used nothing more than a couple of layers of HVAC ducting; some have built a muffler, but we all seem to have got the noise down to 70dB or lower.

I think it was BobL who once posted that there has never been a fire or other nasty incident caused by static in PVC ducting in a workshop, but would be interested to hear his comments on this subject.

Originally Posted by John Samuel

Mick,

Don't know your shed layout, but one reason I went for a ClearVue is its very small footprint. I too was thinking about putting my DC outside when I was looking at options, but in my case I would have needed to build a shed, making that option with a 3 HP dusty more expensive than a CV dropped into the shop. You have an existing shed into which you can drop the dusty. However, the footprint of a CV is essentially the same size as the rubbish bin you choose, which generally makes it easy to install it in the shop. This sometimes shortens ducting and may make it easier to hook up to power.

So far as noise goes my CV measured 97dB without ducting. They are noisy. However, by my reckoning once you get the noise of the dusty below your main machines (table saw, thicknesser etc), there is little point trying to reduce it further. Some have used nothing more than a couple of layers of HVAC ducting; some have built a muffler, but we all seem to have got the noise down to 70dB or lower.

I think it was BobL who once posted that there has never been a fire or other nasty incident caused by static in PVC ducting in a workshop, but would be interested to hear his comments on this subject.

John,
I very much appreciate your input and a few things I had thought of and not some others:
- it would be easier to hook up to power in my real shed and I know I have glossed over this in my own mind. I am going up to look at the new place this weekend so will add that to my list.
- the main thing I use is a lathe and mine is much quieter than my other powered machines so I will try to get the dusty as quiet as possible. I don't use ear-muffs for the lathe and have music going as well.
- I have found a few posts from the US where there were no known fires caused by static in PVC ducting

cheers

Mick

Originally Posted by mick59wests

Bob,
as always thanks for your input. The woodfast comes with a 200mm inlet so I rang them today and the very helpful chap (I should have got his name) told me that it would be fine to run this with 200mm ducting all the way. He also said that the impeller design with straight blades made it noisy (90db at source) but this increased the cfm. If they had used curved blades (which they do sometimes) it makes it quieter but at the expense of air-flow.

I don't agree with the last statement. Straight blades would definitely explain the increased noise, BUT, now that I know it is a straight bladed fan I would steer right away from it. Do a search for impeller efficiency and you will see that straight bladed fans backwards curved fans are LESS efficient than backwards curved fans - this means expending more electrical power to move the same amount of air. Straight bladed fans are used mainly to move air containing sticky or abrasive dust, which does not really apply to woodworking and especially not when used in a cyclone. Straight bladed fans can be made very strongly and are cheap to make (and this will in part explain the lower cost) but are an outdated technology for wood working. Even the backwards curved fans are relatively old technology and have been replaced by 3D curved blades in higher end engineering applications.

Based on this I would hope to get better than 1250cfm (excludiong the cyclone) especially if I use 200mm ducting (at least for my lathe)

.
I would still like to see current draw values for 4, 6 and 8" ducting before buying

He also mentioned static electricity when using PVC so this is another thing for me to investigate.

This has been discussed ad nauseum on these forums and is a non-issue in causing fires. The fact that this is even mentioned tells me that the wood fast people do not know that much about dust extractors.
Despite extensive searching on the web no one can point to a single incident of PVC ducting causing fires - the laws of physics says there cannot be static charge build up inside a PVC duct as any charge that is generated immediately moves to the outside of the PVC well before it builds up to sparking in air levels.
Some people do not like the tingle they get when they touch the outside of charged PVC dusting so they do run conductors to ground on the outside but this is not always effective.
There have been a number of fire in DCs but fire investigators have show that either something hot or flammable (like oily rags) have been sucked up by the dust extractor.

Mick,

As has been observed here so often, no two sheds are alike. What works in mine might be unsuitable for yours. I am very content with a noise level about 65 dB, but if you spend a lot of time at a quiet lathe, it is easy to see why you might want it even quieter.

Good luck with your installation. For what its worth I found creating a hierarchy of wants helped make my decision easy in the end. I wanted, in priority order:

1. To achieve the magic numbers of 1000 and 4000 so I had a shot at capturing the very fine material and at avoiding clogged lines ... or put another way, LOTS of airflow (hence the VFD running at 60 Hz).
2. A ducted system so I was not dragging machines around the workshop.
3. To vent outside (no filters ... out of laziness as well as effectiveness).
4. A small footprint (so I could keep the system in the shop and did not need to build a shed outside for a dusty).

Noise was not considered at the outset. When I first started the CV the noise nearly blew me out of the shed, but thankfully I got it down to a satisfactory level.

Originally Posted by John Samuel

Mick,

As has been observed here so often, no two sheds are alike. What works in mine might be unsuitable for yours. I am very content with a noise level about 65 dB, but if you spend a lot of time at a quiet lathe, it is easy to see why you might want it even quieter.

Neighbours aside I agree about the peace obtained when working quiet which is one reason I often drag out the hand tools.
BTW, an open 6" intake port at a lathe will be struggling to reach 70 dB let alone 65 db. An 8" port might reach 70 db

Originally Posted by BobL

I don't agree with the last statement. Straight blades would definitely explain the increased noise, BUT, now that I know it is a straight bladed fan I would steer right away from it. Do a search for impeller efficiency and you will see that straight bladed fans backwards curved fans are LESS efficient than backwards curved fans - this means expending more electrical power to move the same amount of air. Straight bladed fans are used mainly to move air containing sticky or abrasive dust, which does not really apply to woodworking and especially not when used in a cyclone. Straight bladed fans can be made very strongly and are cheap to make (and this will in part explain the lower cost) but are an outdated technology for wood working. Even the backwards curved fans are relatively old technology and have been replaced by 3D curved blades in higher end engineering applications.

.
I would still like to see current draw values for 4, 6 and 8" ducting before buying


This has been discussed ad nauseum on these forums and is a non-issue in causing fires. The fact that this is even mentioned tells me that the wood fast people do not know that much about dust extractors.
Despite extensive searching on the web no one can point to a single incident of PVC ducting causing fires - the laws of physics says there cannot be static charge build up inside a PVC duct as any charge that is generated immediately moves to the outside of the PVC well before it builds up to sparking in air levels.
Some people do not like the tingle they get when they touch the outside of charged PVC dusting so they do run conductors to ground on the outside but this is not always effective.
There have been a number of fire in DCs but fire investigators have show that either something hot or flammable (like oily rags) have been sucked up by the dust extractor.

Bob,

thanks once again. Another thing to add to my list for research - blade technoclogy for wood dust extractors. For now I will just believe you but will add it to my list . It is not a real simple topic!!!

I also did some checking on PVC after my post so am happy about that as well.

cheers

Mick

Originally Posted by John Samuel

Mick,

As has been observed here so often, no two sheds are alike. What works in mine might be unsuitable for yours. I am very content with a noise level about 65 dB, but if you spend a lot of time at a quiet lathe, it is easy to see why you might want it even quieter.

Good luck with your installation. For what its worth I found creating a hierarchy of wants helped make my decision easy in the end. I wanted, in priority order:

1. To achieve the magic numbers of 1000 and 4000 so I had a shot at capturing the very fine material and at avoiding clogged lines ... or put another way, LOTS of airflow (hence the VFD running at 60 Hz).
2. A ducted system so I was not dragging machines around the workshop.
3. To vent outside (no filters ... out of laziness as well as effectiveness).
4. A small footprint (so I could keep the system in the shop and did not need to build a shed outside for a dusty).

Noise was not considered at the outset. When I first started the CV the noise nearly blew me out of the shed, but thankfully I got it down to a satisfactory level.

John,

a good idea. At this point in time, I'd say my priorities are:
1. the magic numbers
2. Vent outside
3. Noise
4. Ducting to fixed place machines
5. Something do-able to setup in a reasonable time period

thanks

Mick

Originally Posted by mick59wests

John,

a good idea. At this point in time, I'd say my priorities are:
1. the magic numbers
2. Vent outside
3. Noise
4. Ducting to fixed place machines
5. Something do-able to setup in a reasonable time period

thanks

Mick

Mick,

So far as time is concerned, my experience was that the big job remained the big job regardless of the DC chosen, and that was making/converting hoods and ports for machines (although that depends to some extent on the number and nature of the machines). The ductwork is likely pretty much the same whatever system you choose. If you opt for a CV, it will be installed in a day or less, especially if you have another set of hands. I did it by myself (except for when my son helped be lift the impeller and motor into place), and it was not really a big job.

I researched DC systems until my head was swimming. In the end the CV won because it was the best, and for my shop, the cheapest. No contest!

Have fun!

Originally Posted by John Samuel

So far as time is concerned, my experience was that the big job remained the big job regardless of the DC chosen, and that was making/converting hoods and ports for machines (although that depends to some extent on the number and nature of the machines). The ductwork is likely pretty much the same whatever system you choose. If you opt for a CV, it will be installed in a day or less, especially if you have another set of hands. I did it by myself (except for when my son helped be lift the impeller and motor into place), and it was not really a big job.

In general I agree. While some construction, e.g. lathe hood/port, is relatively easy, adapting the ports on some machines can be quite tricky, especially when needing to use an angle grinder on a machine cowling.

John and Bob,

thanks once again. I understand what you are saying about the ducting and ports but maybe I have less machines than you two . Still, now that I will have a big shed this may change .

The main thing I will want to do is get the lathe sorted out as this is the main thing I have been doing over the last couple of years so this is not a port issue as such and I know I'll be back before deciding between Bob's 'flange' (I have saved the link) or a hood like used by gidgee 1 or Robo Hippy's sanding enclosure (or maybe even something original).

The bandsaw will be next. It is not a large one and has wheels (although not so easy to move) so I can probably take it outside until I am ready. It currently has a 100mm port.

The tablesaw (a Triton) has wheels and can be easily moved (as I do at the moment) until I build a proper hood

I'll have to think about the Triton router. It has a 50mm or so port so I think of just having a hood/gulp/flange as per the lathe

For the number of times I use the thicknesser this will be outside for the foreseeable future

As I have said a number of times thanks for all your time and expertise as I could not have gotten this far without it

cheers

Mick

Originally Posted by mick59wests

John and Bob,
thanks once again. I understand what you are saying about the ducting and ports but maybe I have less machines than you two . Still, now that I will have a big shed this may change .
The main thing I will want to do is get the lathe sorted out as this is the main thing I have been doing over the last couple of years so this is not a port issue as such and I know I'll be back before deciding between Bob's 'flange' (I have saved the link) or a hood like used by gidgee 1 or Robo Hippy's sanding enclosure (or maybe even something original).

For any work you want the hood as close as possible to the work so that the fine dust gets captured at source before it gets a chance to diffuse away from the reach of the moving air.
For small and spindle work only something like a bell mouth can get you close enough where as for bigger stuff like platters and bowls you might want to look at something like this.
You can also use a hybrid of a "bell mouth hood" entry inside a removable bigger shroud or hood.

[QUOTE=BobL;1711604]I don't agree with the last statement. Straight blades would definitely explain the increased noise, BUT, now that I know it is a straight bladed fan I would steer right away from it. Do a search for impeller efficiency and you will see that straight bladed fans backwards curved fans are LESS efficient than backwards curved fans - this means expending more electrical power to move the same amount of air. Straight bladed fans are used mainly to move air containing sticky or abrasive dust, which does not really apply to woodworking and especially not when used in a cyclone. Straight bladed fans can be made very strongly and are cheap to make (and this will in part explain the lower cost) but are an outdated technology for wood working. Even the backwards curved fans are relatively old technology and have been replaced by 3D curved blades in higher end engineering applications.
QUOTE]

I raised an eyebrow when I read the above, back when I was looking into building my system.....the straight blade is a material handling fan, is built more robust and can deal with impact from larger mat'ls, the backward curved blade fan is a better design for air movement than the straight blade but is not as robust in dealing with impact, a shrouded fan is better again. This is the same as I have.
Here's a pic of some fan wheel designs
pump%20systems.JPG



Pete

Lot of info here Mick.
I went through the pain of working out a DE after I got sick from the dust and ended up with a CV. see my thread here https://www.woodworkforums.com/f200/m...lation-173110/
The most time consuming part of the exercise is fitting ports to the machines see my band saw fitt here https://www.woodworkforums.com/f27/mo...-n4400-175331/
I do a lot of non turning wood work and made myself a downdraft table which I find the biggest help with dust especially the finer dust. Also good for spray finishing and degassing as the fumes are removed to outside the shed.

R

Originally Posted by rusel

Lot of info here Mick.
I went through the pain of working out a DE after I got sick from the dust and ended up with a CV. see my thread here https://www.woodworkforums.com/f200/m...lation-173110/
The most time consuming part of the exercise is fitting ports to the machines see my band saw fitt here https://www.woodworkforums.com/f27/mo...-n4400-175331/
I do a lot of non turning wood work and made myself a downdraft table which I find the biggest help with dust especially the finer dust. Also good for spray finishing and degassing as the fumes are removed to outside the shed.

R

Rusel,
I did read through your clearvue installation thread. You may be a bit handier than me . I also just read your bandsaw DE adjustments and it was very interesting. There is also another one by John Samuel which was good as well.

thanks

Mick