Thread: Extraction System Men Shed

Originally Posted by Brian45

Hi
I think what BobL was meaning was how I would need to run it, in PVC pipe, not what is in your system.

Will need to check the static electricity thing out I've now heard it two different ways, YES and NO lol. If I don't have to run it ill be very happy as you are correct Bobl, a lot of work and cost.

Two physics BBQ stoppers.
1) as soon as the tiniest of charges are formed inside a duct, well before the charge has time to build up to form a spark, that charge moves (slowly) through to the outside of the duct so little or no charge builds up inside a duct so no sparks can form.

2) PVC is an insulator which means the charge moves slowly across it's surface. To cause a spark a certain amount of charge is needed but if the outside of the PVC is grounded the only charge on the duct that can contribute to the spark is the few mm^2 of contact area and that will not contain enough charge to cause a spark. You can definitely feel it but a human body can feel a very small charge. This is why if a PVC duct has built up a charge on the outside you can get a zap from one spot and and another from an adjacent spot etc.

This is one fo the best explanations out there by a qualified person - this is the same link that Bill Pentz uses to pour cold water on this myth.
WoodCentral Articles & Reviews

BTW copper wire inside flex will do nothing - the charge will still sit on the outside of the ducting.

The most likely cause of a fire in a DC system is a hot piece of material ending up in the sawdust bin. This has been reported several times. I have my DC collecting dust coming off a belt sander but in between I have an al metal chip catcher so if a piece of hot metal ends up inside the ducting the chip catcher will prevent it going any further.

!00% agree with BobL.

Works for me .

Anyone have any knowledge of air filtration units.

I recently visited a number of Men's sheds in Brisbane to look at their extraction systems. All bar one had air filtration units in place in conjunction with their extraction system.

During the dry season (Darwin) we can open our place up where we get very good ventilation. I wondering as part of our extraction system we may need to consider installing some air filtration units.

At the moment I'm looking at a woodmen. Spec are:

Inner filter : 1 micron
Outer filter : 5 micron
1/3 HP motor
Suction 1400 CFM
Sound 60 DB at full power
timer 2-4-6-8 Hours.

Looking at our air volume 12m x 9m x 4m high = 432 CM looking at Rockler site, it indicated if the ceiling is higher than 3.6m use 3.6 m if that's the case, air volume 12m x 9m x 3.6m = 388.8 CM
Converting to Cubic feet 432 = 15255.93 CF and 388.8 = 13730.34 CF so if I want to cycle 8 time a minute I need to move a volume of 2034 CF. So if that is correct I would need two units mentioned above, which would move 2800 CFM. this is using the 388.8 figure.

Firstly am I reading this correctly or have I missed something and way of the beaten track.

388.8 = 13730.34 CF so if I want to cycle 8 time a minute I need to move a volume of 2034 CF. So if that is correct I would need two units mentioned above, which would move 2800 CFM. this is using the 388.8 figure.

Not sure what you mean by "8 time a minute"

FWIW Manufacturers specifications for Room air filters (RAFs) don't assume a shed full of blokes all making some dust

14000 CF at 1400 CFM (and take the 1400 CFM with a grain of salt) means 10 minutes in theory to cycle one shed air volume.
In practice it takes twice as long as theory so that means 20 minutes for one complete shed air change, or 3 per hour
The targets for RAF or ventilation use should be between 10 and 20 shed air changes per hour so you would mean between 3 and 6 RAFs

Your shed is similar in size to our mens shed.

In that case I reckon you would be better off installing a large evap AC unit like we have in our shed.
Then, when you can use the evap AC, and when its too humid you can just run the fan - that way you get fresh air all the same time.

In our shed the evap AC makes more difference in fine dust control than the Clearvue DC does. When you have ~20 blokes simultaneously using machines, power and hand tools the Clearvue simply cannot keep up, but turning on the AC fan even on low speed drops the dust levels within a couple of minutes. Just gotta remember to turn it on.

RAFs are more appropriate in brass monkey territory where you don't want to continually blast the punters with cold outside air but I would not not put Darwin in that territory.

RAFs are also useful to set up in a dust free finishing space like a finishing booth - but you will only need a small (600 cfm) RAF for that.

Thanks for your response.

We are unable to put a evap AC unit in, hence why I was looking at air filtration. I get your point about the cold.

As we are able to open the place up and get good air movement, I guess we would be somewhat better off putting in more large fans to help more the finer dust particles.

Our sanding method needs to change, in that, the machines need to be moved outside, this can be achieved, just need some educating. All our current sanding machines are on rollers so should not be a major issue.

Originally Posted by Brian45

Thanks for your response.
We are unable to put a evap AC unit in, hence why I was looking at air filtration. I get your point about the cold.

Is that a power or structure issue?

As we are able to open the place up and get good air movement, I guess we would be somewhat better off putting in more large fans to help more the finer dust particles.

Yes some thing that creates a positive pressure in one direction is preferable.

Our sanding method needs to change, in that, the machines need to be moved outside, this can be achieved, just need some educating. All our current sanding machines are on rollers so should not be a major issue.

That's what the Vincent Mens shed in Perth does, they move outside to a sort of veranda which is open on 3 sides and it seems to be effective.

As we are only on a 1+1year type lease arrangement, it’s hard to get any sort of approvals. For a roof AC unit, we would need to approval from the owners of the building (government) get plans, engineer, certified, then someone to install it. Costs skyrocket, I feel it would be better suited when can move to our own place.

Originally Posted by Brian45

As we are only on a 1+1year type lease arrangement, it’s hard to get any sort of approvals. For a roof AC unit, we would need to approval from the owners of the building (government) get plans, engineer, certified, then someone to install it. Costs skyrocket...

seriously ??

by the sounds of things, your landlord (NT Government or Darwin City Council) don't want you in the building. The cost of running 3 phase to various machines and installing dust extraction will constitute a significant investment commensurate with installing a a "swamp chiller" in the roof.
Personally, I think you should clarify what equipment you are allowed to operate before you go much further. If the building owner has been thinking that a men's shed involves running the occasional 2 Amp sander at the end of an extension lead they had better be re-educated pretty darn quick. In reality you are converting the old fire station into an industrial workshop that complies with contemporary OH&S requirements.

Hi Ian,

Well you would think that. The men shed had moved into this building some 18mths ago from one run by life line. Basically life line wanted their building back.

As the time the Men Shed moved, they had been struggling with only 5-10 for best part of 5 years. The government, at the time would only give 1+1 and I feel it was because of the membership size and the fact the shed had been struggling so much.

I joined about 15-16 mths ago just after they had moved into this building. Suffice to say it was packed FULL of stuff, much of which was stuff people had kindly donated. The problem was a lot was rubbish and needed to be tossed. Hence a few of us got into it and started sorting everything out and finding a home for items. I set about fixing some tools etc so people could start using the machinery safely.

Fast forward to now, we have 50 members and the government is looking at extending our lease arrangement to something more solid. Not sure how long this will take. We are also mindful our location is very valuable to the government and we will have to leave at some stage. We have just received approval to put two containers on site which will allow up to move our timber stocks out of the workshop areas.

We have the funds to do the electrical and a couple of electrician have offered to fit it all off for free. We just need to run the wires as per what they want. No biggie there, just time.

As for the roof AC, at this stage I don't feel it would happen any time soon. So I'm looking at options to help us in the short term.

To be fair our local member is very supportive of the shed and helps us all the time.

As for operating equipment we have no restrictions, and we don't operate at night.

Brian

Hi,

Well our tools are about to leave Brisbane and things are really starting to ramp up at our shed. With tool placement, electrical and benches. We roughed this out yesterday and I'm sure will be amended a bit once the tools are positioned to optimise our workable space.

At this moment this gives the electrician some indication what we require and also allows us a plan to run the wires. The inlet for the DC is 4.2 m from the roller door. Looking at the plan that is from the top right towards the Bandsaw. The room size is 11.9 x 9 m by 4 m high.

I figure we need to run 240mm some part of the way across the room then reduce to pick up the machines. If we can run PVC to the machine we will however I feel there maybe some flex used. I aware the best location for the blast gates (BG)will be high up but I dare say they may need to be down near the machines for ease of use by members. The BG's will be manual operation. The jointer is 152 mm outlet and I believe all the rest are 100mm.

Yes it would be good to open them up but this will not happen till at least the warranties are completed. Instead of running directly across the room is it possible to run around the walls? like above the roller doors. My reason to ask is I have a feeling the ceiling is a suspended one and maybe an issue with the weight of the ducting. This we will not know till we are able to access the man hole.

Dusty penertration.jpgIMG_4122 Men Shed workshop plan.jpg

Any thoughts on how best to run this extraction system. I'm sure there will be a host of questions before answers can be provided. Apologise for the quick post, wife wants to go out, so best action that plan.

Brian

Originally Posted by Brian45

I figure we need to run 240mm some part of the way across the room then reduce to pick up the machines. If we can run PVC to the machine we will however I feel there maybe some flex used. I aware the best location for the blast gates (BG)will be high up but I dare say they may need to be down near the machines for ease of use by members.

Look up "Rocker" style gates in the "Blast gate gallery" thread - even in manual mode these allow the operator to stand on the shed floor and operate a gate at any distance above them

The jointer is 152 mm outlet and I believe all the rest are 100mm. Yes it would be good to open them up but this will not happen till at least the warranties are completed.

That's normal but look for cases where the machine outlets may be located on panels which can be removed and replaced with 6" ports.

Instead of running directly across the room is it possible to run around the walls? like above the roller doors. My reason to ask is I have a feeling the ceiling is a suspended one and maybe an issue with the weight of the ducting. This we will not know till we are able to access the man hole.

If you only run the ducting only around the walls you may end up with long lengths of flex all over the place as well as being a safety hazard this will serious stymie the flow. I would not attached the ducting direct to the walls but at least 100 mm away from the walls using steel brackets.

Here is one possible layout that runs the trunk line around the walls. The red lines represent tensioned SS wires run across the shed at close to ceiling level. the end f the ducting is attached to the wire before the drop down. The 6" arms coming out from the trunk lines are all really short so will not need much support. You might still need a steel rod support attachment through to the roof for the lathes .

Men-Shed-workshop-plan.jpg


Here you can the length of span you can get with 6" ducting - 3m is possible
A SS wire was the strut horizontally across the shed to stop the 6" are swinging from side to side.
Pipes2.jpg


Look in this thread for more details Mens Shed Dust Collection

Hi,

Thanks Bobl for the quick reply

The main line (240mm) will be away from the wall suspended from or sitting wall brackets. Over the roller doors we are running 200 x 2.4 mm C section channel all supported, so this can hold the ducting and the electrical wires. If you look at the first photo you may see a bracket on the wall towards the roller door, the channel will sit on this.

I looked at the link you attached, was interesting reading. It was my understanding 90 degree bends were an issue, re-sticking the flow.

My intention was to run a main line, from there tee off to 150 mm lines down to the machines, these lines will be reduced near the machine, if able we will connect the PVC direct to the machine or flex as required.

Location of blast gates, if positioned high we may need to do a similar method of operation, a green and red ball. I feel, at this stage we may not have the funds to go automatic.

With the lathes we will need to do something considering there will be 4 of them, IE maybe a post next to the two outer lathes and the other two run down the wall (off the wall by brackets) to support the extraction system.

Additionally we were looking at vac points to sweep residual dust, most likely two.

Majority of the tools are not mobile and will be in a fixed location. If I can remove a panel to increase the dust ports I will put this to the committee, as I'm only a member. I do feel this will be a big NO till the tools are out of warranty, and I can understand that.

Looks like the system will be started in the next month, if not sooner.

Originally Posted by Brian45

With the lathes we will need to do something considering there will be 4 of them, IE maybe a post next to the two outer lathes and the other two run down the wall (off the wall by brackets) to support the extraction system. .

For lathes, look up Bell Mouth Hoods as they are the most efficient type of hood around.