Yep, another call for help with an extraction system design

[FletcherP]

Hi all,

I’ll preface this post by saying I’ve spent many hours trawling through the valuable information that has previously been provided by the multitude of generous contributors. Although the answers and advice I am looking for may have been (and probably has been), supplied in the many pages of information here, please don’t assume that I am being lazy; more over I am looking for confirmation of my understanding, and suggestions pertinent to my specific requirements / constraints. Apologies in advance if you feel I’ve not done enough research.

I am planning to install an effective dust collection for my modestly sized workshop, which is located underneath the house, and is overhung by a veranda / deck. The house is cut into a slope, so the main brick wall running along the long side of the workshop is not a practical location option as this is constrained for both access and working height. Additionally, the working height available under the veranda and workshop ceiling is limited to 2100mm, and even less in my preferred location for the collection unit. For reference, rough layout below (although I reserve the right to shoehorn additional toys into this space in future).

Workshop.jpg

To establish a couple of points; I am committed to using 6” (150 or 160mm) ducting throughout, and a collection unit that can effectively handle this sized system – to meet the rate and speed objectives. So the questions I would appreciate your thoughts on are;

1. I started this project somewhat seduced by the thought of a installing a cyclone system, although I now suspect, after much reading, that short of a BP style unit (which I would struggle to fit in unless I used a 400mm high collection bin), this would be a false economy. I am hell bent on locating the collection unit outside of the workshop space, both because of valuable real estate, and for the practical benefits of allowing fine particles the opportunity to escape to the wide blue yonder. Is a single phase 3 or 4 hp dusty my best option, or am I unfairly dismissing non BP cyclones?
2. Given the height constraints, are there any suggestions how I might ‘squeeze’ a unit in, particularly as my preference is to locate the unit outside the workshop at the left had end (under the veranda), where the space drops to about 1900mm (after I do some excavation)? I couple of thoughts I’ve had include using a unit with pleated cartridges, that are lower height than normal needle felt bags, and / or stealing some height from the collection bags by allowing them to bunch up a couple of hundred mm’s on the bottom.
3. For twin bag DC’s, are there any particular advantages / disadvantages between the horizontal fan designs (like the Carbatec CT-003VB) and the vertical fan designs (like the Powermatic PM1900TX)? I have a sneaking suspicion that having a reasonable length of straight section duct directly before the fan could be beneficial, and if this is true, a horizontal design may suit my installation better. Happy at this point for any suggestions for any specific units people might like to recommend – I’m currently interested in a Felder AF22W – appreciate thoughts on this unit as well.
4. Steel ducting or PVC? Appreciate there is a significant cost difference, just interested if this difference is any way justifiable. There appears to be a bit of division around the risk of static with PVC.
5. I am very mindful of minimising run lengths to improve efficiency, regardless of duct material. Every layout I consider seems to have pros and cons in terms of overall length. Also interested in thoughts of 30 degree versus 45 degree branches, and location of blast gates. Are there some types of machines that should be prioritised in terms of run length? Also interested in opinions of running duct at ceiling height versus ground level, or somewhere in between.
6. For handheld tools, I am intending to use a HPLV system in addition to the DC. My intention is to locate the vacuum unit in a sealed enclosure with venting to outside, and to use a mini cyclone to reduce dust load. Is this suitable, and with this approach is a common garden variety shop vac unit OK, or should I be considering a Festool or similar?

Appreciate your thoughts, comments, observations etc in advance.

Fletch

[QC Inspector]

"Given the height constraints, are there any suggestions how I might ‘squeeze’ a unit in, particularly as my preference is to locate the unit outside the workshop at the left had end (under the veranda), where the space drops to about 1900mm (after I do some excavation)?"

If you have no width restriction beyond the 1900mm height one a BP style Cyclone can be mounted on an angle along the wall to drop the chips in a taller container. They don't need to be vertical to function properly. If it were my shop I would mount the motor and fan unit outside at the top left corner of the long wall. The 6" duct exiting the shop at a 45 degree angle ducted around the corner into the cyclone with the motor separately mounted to the bottom of the veranda above.

Pete

[BobL]

[QUOTE=FletcherP;1766345]

Workshop.jpg

Given the height constraints, are there any suggestions how I might ‘squeeze’ a unit in, particularly as my preference is to locate the unit outside the workshop at the left had end (under the veranda), where the space drops to about 1900mm (after I do some excavation)?

That looks about all you can do.

couple of thoughts I’ve had include using a unit with pleated cartridges, that are lower height than normal needle felt bags, and / or stealing some height from the collection bags by allowing them to bunch up a couple of hundred mm’s on the bottom.

Either would be fine but I would go for the PFs as they can more easily be cleaned in situ - seeing as they're outside I would use the cheapest PFs you can find.

For twin bag DC’s, are there any particular advantages / disadvantages between the horizontal fan designs (like the Carbatec CT-003VB) and the vertical fan designs (like the Powermatic PM1900TX)? I have a sneaking suspicion that having a reasonable length of straight section duct directly before the fan could be beneficial, and if this is true, a horizontal design may suit my installation better. Happy at this point for any suggestions for any specific units people might like to recommend – I’m currently interested in a Felder AF22W – appreciate thoughts on this unit as well.

The Powermatic PM1900TX style DC is an older design and a bit less efficient than the horizontal fan designs.efficient.
With the horizontal fan design you can also let the plastic collection bags bunch up a little at the bottom to help with your height problem

Steel ducting or PVC? Appreciate there is a significant cost difference, just interested if this difference is any way justifiable. There appears to be a bit of division around the risk of static with PVC.

The risk of static with PVC is WAY lower than still gets thrown around often using un-sound science. Some folks still earth it because they don't like getting zapped but otherwise there is no significant risk with it.

I am very mindful of minimising run lengths to improve efficiency, regardless of duct material. Every layout I consider seems to have pros and cons in terms of overall length.

Swings and roundabouts.

. . . 30 degree versus 45 degree branches, and location of blast gates.

The gain is small but worth having. I you can find PVC junctions that do this I'd like to hear about them.

Are there some types of machines that should be prioritised in terms of run length?

Some of the following depends on how you use tools but machines that make a lot fine dust like belt sanders, routers and lathes work better with shorter ducting lengths

Also interested in opinions of running duct at ceiling height versus ground level, or somewhere in between

Ground level ducting is a PITA and a serious trip hazard.

For handheld tools, I am intending to use a HPLV system in addition to the DC. My intention is to locate the vacuum unit in a sealed enclosure with venting to outside, and to use a mini cyclone to reduce dust load. Is this suitable, and with this approach is a common garden variety shop vac unit OK, or should I be considering a Festool or similar?

Yes this is definitely feasible - if you vent outside there is no need to get a VC that filters superfine duct, just get the most powerful unit you can afford.


Have you also looked at your machinery. It's very like that they are the choke point for any DC system so be prepared to get out the angle grinder if you really want a clean shed.

[John Samuel]

DC UNIT. You can still use a BP cyclone. It can be placed at a 45 degree angle, and that is what I would do. The Clear Vue is a superior unit, but I am a very happy Clear Vue owner, so my comments are likely biased. If I had my time again, I'd get a CV Max rather than a CV 1800.

LOCATION. The unit can be placed inside, because it is small and has negative pressure to everything except the exhaust, which is easy to seal, so no dust leaks. By my reckoning the main reason for parking it outside is noise suppression.

DUCTWORK. Last time I looked 6" PVC was cheaper. It also gives the lowest resistance to flow (see BP's site). Given that it is cheaper, more effective and easier to install, I struggle to understand why some folk prefer steel ... but some do. That's OK. We all get to do what we want in our own shops. BobL is right. Ducts at ground level are a trip hazard ... and a PITA. Don't sweat the static issue. My research indicates it is a non-issue, especially given that the static reports to the outside of PVC pipe.

MORE DUCTWORK. ronboult was kind enough to come to my shop with his clever instruments and measure my airflow. The data are clear. The biggest restrictions are the machines themselves and the hoods/shrouds ... and by a country mile. Don't fuss too much with duct length ... do fuss with machine ports/hoods/shrouds ... where it counts. A metre or two more straight pipe here and there will make bugger all difference IF you have a good impeller and motor. I could not find 30 degree bends. Only had one 90 degree bend in the main line, so I made up that bend with 15 degree fittings. See pic. ronboult's data say any loss in this bend is indiscernible.

IMAG0021.jpg

SHOP VAC. As BobL keeps reminding us, these things are wicked fine dust producers. Rather than spend a fortune on a top-shelf vac I bought a Hoover wall mounted Garage Vac (on special for about $170, I think), parked it outside under a hood, removed the filters and ducted it into my shop with 50 mm PVC. It works like a charm and was an economical solution. It does not need a mini cyclone because it has no filters to clog. The wall under it gets grubby, so I hose it down about once a month. Some vacs don't like to have their filters removed, so check with BobL before doing that. As BobL said, get a powerful unit. The Garage Vac is 2 HP. Another reason to park it outside is noise suppression.

Have fun!

John

[shedman]

Hi all,

I’ll preface this post by saying I’ve spent many hours trawling through the valuable information that has previously been provided by the multitude of generous contributors. Although the answers and advice I am looking for may have been (and probably has been), supplied in the many pages of information here, please don’t assume that I am being lazy; more over I am looking for confirmation of my understanding, and suggestions pertinent to my specific requirements / constraints. Apologies in advance if you feel I’ve not done enough research.

I am planning to install an effective dust collection for my modestly sized workshop, which is located underneath the house, and is overhung by a veranda / deck. The house is cut into a slope, so the main brick wall running along the long side of the workshop is not a practical location option as this is constrained for both access and working height. Additionally, the working height available under the veranda and workshop ceiling is limited to 2100mm, and even less in my preferred location for the collection unit. For reference, rough layout below (although I reserve the right to shoehorn additional toys into this space in future).

Workshop.jpg

To establish a couple of points; I am committed to using 6” (150 or 160mm) ducting throughout, and a collection unit that can effectively handle this sized system – to meet the rate and speed objectives. So the questions I would appreciate your thoughts on are;

1. I started this project somewhat seduced by the thought of a installing a cyclone system, although I now suspect, after much reading, that short of a BP style unit (which I would struggle to fit in unless I used a 400mm high collection bin), this would be a false economy. I am hell bent on locating the collection unit outside of the workshop space, both because of valuable real estate, and for the practical benefits of allowing fine particles the opportunity to escape to the wide blue yonder. Is a single phase 3 or 4 hp dusty my best option, or am I unfairly dismissing non BP cyclones?
2. Given the height constraints, are there any suggestions how I might ‘squeeze’ a unit in, particularly as my preference is to locate the unit outside the workshop at the left had end (under the veranda), where the space drops to about 1900mm (after I do some excavation)? I couple of thoughts I’ve had include using a unit with pleated cartridges, that are lower height than normal needle felt bags, and / or stealing some height from the collection bags by allowing them to bunch up a couple of hundred mm’s on the bottom.
3. For twin bag DC’s, are there any particular advantages / disadvantages between the horizontal fan designs (like the Carbatec CT-003VB) and the vertical fan designs (like the Powermatic PM1900TX)? I have a sneaking suspicion that having a reasonable length of straight section duct directly before the fan could be beneficial, and if this is true, a horizontal design may suit my installation better. Happy at this point for any suggestions for any specific units people might like to recommend – I’m currently interested in a Felder AF22W – appreciate thoughts on this unit as well.
4. Steel ducting or PVC? Appreciate there is a significant cost difference, just interested if this difference is any way justifiable. There appears to be a bit of division around the risk of static with PVC.
5. I am very mindful of minimising run lengths to improve efficiency, regardless of duct material. Every layout I consider seems to have pros and cons in terms of overall length. Also interested in thoughts of 30 degree versus 45 degree branches, and location of blast gates. Are there some types of machines that should be prioritised in terms of run length? Also interested in opinions of running duct at ceiling height versus ground level, or somewhere in between.
6. For handheld tools, I am intending to use a HPLV system in addition to the DC. My intention is to locate the vacuum unit in a sealed enclosure with venting to outside, and to use a mini cyclone to reduce dust load. Is this suitable, and with this approach is a common garden variety shop vac unit OK, or should I be considering a Festool or similar?

Appreciate your thoughts, comments, observations etc in advance.

Fletch

If you want to use a BP design such as the ClearVue it is quite ok to mount the impeller and motor beside the cyclone to allow for a bigger bin. You do need to construct your own housing but I can send you a plan if you want.

[John Samuel]

If you want to use a BP design such as the ClearVue it is quite ok to mount the impeller and motor beside the cyclone to allow for a bigger bin. You do need to construct your own housing but I can send you a plan if you want.

Just for the sake of interest, can you please send me a copy of that plan?

Thanks,

John

[safari]

I would also appreciate a copy of the plan too Shedman if you would,t mind.

Thanks for your trouble.

[mick59wests]

as I have separated my impeller and motor from the cyclone (although have jot got it up and running - waiting for my brother the electrician) I'd also be very interested in any plans.

cheers

Mick