Thread: Shed Feedback Appreciated!

Originally Posted by Dan87

My aim - build a workshop on a residential block (6500m2) to operate one-man workshop fulltime whilst keeping noise to a minimum so I don't bother my neighbours.

Humm . . . . Not sure I would call 6500m2 residential?

I have budgeted $3000 for mainly 150mm metal ducting including blast gates, connections and brackets... Does this sound possible if I install??

Depending on how many machines you have your will probably need about doubt that. A mate of mine has a 100m^2 shed and it cost him $10K ($6.5k for ducting, the rest to have it installed) to do his shed in metal ducting. We did a similar size area at the mens shed in PVC for about $2.5K in PVC and Junctions. A 75m^2 mens shed machinery shop I got a quote for was for $13k (installed). I've installed both and I definitely prefer working with PVC.

I would go with PVC ducting and invest the difference in these https://autoblastgates.com.au

Thanks BobL, definitely food for thought.
I will sketch out my shed layout and dust ducting to get a better idea of lengths and see if I can get a quote for metal ducting before ruling it out. It may be silly but I would much prefer metal ducting but the price may decide if have to go Pvc.
Those auto blast gates look great, I'm so used to manually opening and closing them that I would probably keep pulling at them out of habit 😂.

I dont think $3k can go very far with metal ducting (quick release type, not spiral), my workshop is only 54m2, and it costed me $10k and I have to install them, 5-6 machines connection, mains 300mm.

your relationship with your neighbour can only go one way when the noise from the shed starts full time. I only do mine part time and I am sure my neighbour is not happy, I have silenced compressor and spiral cutter on my AD951 but its not enough. if you want to do it full time, you will only have more noise.

You may need to allow at least $10k to have the 3 phase electrical done properly inside the shed. thats how much I spent on mine and I am sure your shed will cost more as its almost double the size of my workshop, and you are doing it full time.

Originally Posted by Albert

I dont think $3k can go very far with metal ducting (quick release type, not spiral), my workshop is only 54m2, and it costed me $10k and I have to install them, 5-6 machines connection, mains 300mm.

your relationship with your neighbour can only go one way when the noise from the shed starts full time. I only do mine part time and I am sure my neighbour is not happy, I have silenced compressor and spiral cutter on my AD951 but its not enough. if you want to do it full time, you will only have more noise.

You may need to allow at least $10k to have the 3 phase electrical done properly inside the shed. thats how much I spent on mine and I am sure your shed will cost more as its almost double the size of my workshop, and you are doing it full time.

I have been thinking a lot about this and think the only way I can make it work is to keep windows and doors closed whilst using machines, keep machine use to during the day on weekdays and to build to minimise noise transfer towards the neighbours... Like position my water tank in-between shed and line of site of neighbours house and sound dampening construction throughout. Also the position of the dust extraction is probably significant. I also will not be advertising what I am up to in the shed, the block is bushy and no neighbour can see the shed unless they are standing at the back of there properties. For sound and privacy, no windows will face the neighbours either.

Yeah by the sounds of it I have to find more money or go down the PVC rout.
I need to connect 6 machines with 150mm mains.

Yes, great advice. I have budgeted 12k but my experience from previous house builds and renovations is to expect electrical, plumbing and sometimes excavations to blow the budget a bit.

I have been quoted 38k for 8x14m shed with 3m eaves, 100mm slab and a few extras, including planning, DA etc, excavation, slab and install of Fair Dinkum shed, I'm awaiting two more quotes from other companies. Does this price sound about right to others??

150mm mains for a 100m2 shed maybe a bit small?
You may also want to install the compressed air line which includes the drier, filter and so on, the blue pvc compressed air line is not expensive but when you add them up it is a small fortune.

Have you checked the capacity of your 3phase? This will limit what machines you can turn on at any given time. To give you an example, for me the worst case is compressor + sander + extractor. That’s roughly 30kw when all of them are fully loaded.

Not familiar with shed built by these companies but you should be alright, don’t go with the cheapest.

Originally Posted by Dan87

I have been quoted 38k for 8x14m shed with 3m eaves, 100mm slab and a few extras, including planning, DA etc, excavation, slab and install of Fair Dinkum shed, I'm awaiting two more quotes from other companies. Does this price sound about right to others??

We "inherited" one of these (7m x 10m) when we bought our place outside the "big smoke".

We've been slowly working on turning it into a home office at one end, and workshop at the other, though we paused over summer for heat etc. We're about to get back into it, and are documenting our fitout here: Midnight's Shed

I can't comment on your price, but I had a feeling I'd seen some guidance previously, so I found that again: Shed Cost Per Square Metre - Central Steel Build Essentially, $106-$176 per square metre is their guidance (though I am assuming this includes a slab, it may not). Go for middle of the range of prices and you work on $141 per square metre. In your case, that works out to high $13,000 mark (backing up that it won't include the slab).

Also - make sure the slab you get includes a moisture barrier - you don't want damp seeping up through the concrete!

EDIT: Also found this link as I was about to close out of Google: Buy Industrial Sheds - View Sizes & Prices | Best Sheds

Please note, none of the links I give here are endorsements for those suppliers, I am simply using them to highlight price - and as someone before me has already mentioned, the cheapest deal is rarely the best one.

In general I would also say that a 150mm main will be too small for a 100m^2 shed.

The factors to consider include
1) How many users/operators are likely to operate machines at the same time. If it's more than one operator at any time, then a bigger main will be needed
2) Type of machines. eg If you have a big drum sander these require at least 2 x 150 extraction ports. Even TS can benefit with a 150 mm on the cabinet and a 100 on the OH guard.
3) How far your machines are spread out inside the shed. If they were contained in say the 50m^2 near the DC then after considering 1&2 above you might get away with 150mm ducting.
4) Given you wish to keep doors and windows closed unless you add addition ventilation fans then having a large main and opening up more than one 150 mm port is a good way to vent the shed.
A 7 x 14 x 4 m shed has a volume of ~14000 cubic ft. A 150 mm main can at most carry about 1250 CFM so that means a theoretical shed vent time (TSVT) of 11.2 minutes but in practice it takes ~4 TSVT to reach >90% shed air turnover, so more like 40 minutes. Provided the DC can deliver, a 200mm main will have at least double the flow rate of a 150mm so it will halve the TSVT. At our mens shed the wood shop floor is about the same size and we have 3250 CFM Evap AC on the roof and that seems to clear escaped fine dust in under 10 minutes. We are able to open a 3.3 m high roller door and some other doors and windows which also helps a lot. If you intend keeping all doors and windows shut you will need a decent baffled air input as well as output.

Originally Posted by Albert

150mm mains for a 100m2 shed maybe a bit small?
You may also want to install the compressed air line which includes the drier, filter and so on, the blue pvc compressed air line is not expensive but when you add them up it is a small fortune.

Have you checked the capacity of your 3phase? This will limit what machines you can turn on at any given time. To give you an example, for me the worst case is compressor + sander + extractor. That’s roughly 30kw when all of them are fully loaded.

Not familiar with shed built by these companies but you should be alright, don’t go with the cheapest.

Thanks Albert,
Point noted about the 150mm ducting maybe not being up to the job.

Great point about the three phase capacity! I hadn't considered this. I'll look into it asap.

Thanks for the input 👍

Originally Posted by Midnight Man

We "inherited" one of these (7m x 10m) when we bought our place outside the "big smoke".

We've been slowly working on turning it into a home office at one end, and workshop at the other, though we paused over summer for heat etc. We're about to get back into it, and are documenting our fitout here: Midnight's Shed

I can't comment on your price, but I had a feeling I'd seen some guidance previously, so I found that again: Shed Cost Per Square Metre - Central Steel Build Essentially, $106-$176 per square metre is their guidance (though I am assuming this includes a slab, it may not). Go for middle of the range of prices and you work on $141 per square metre. In your case, that works out to high $13,000 mark (backing up that it won't include the slab).

Also - make sure the slab you get includes a moisture barrier - you don't want damp seeping up through the concrete!

EDIT: Also found this link as I was about to close out of Google: Buy Industrial Sheds - View Sizes & Prices | Best Sheds

Please note, none of the links I give here are endorsements for those suppliers, I am simply using them to highlight price - and as someone before me has already mentioned, the cheapest deal is rarely the best one.

Cheers Midnight,
I had a look through your shed thread, so much useful info in there! I will definitely keep an eye on your thread for any more developments.
Thanks for the info regarding shed pricing, very useful.
And yes I'm definitely across the importance of moisture barriers! Cheers

Originally Posted by BobL

In general I would also say that a 150mm main will be too small for a 100m^2 shed.

The factors to consider include
1) How many users/operators are likely to operate machines at the same time. If it's more than one operator at any time, then a bigger main will be needed
2) Type of machines. eg If you have a big drum sander these require at least 2 x 150 extraction ports. Even TS can benefit with a 150 mm on the cabinet and a 100 on the OH guard.
3) How far your machines are spread out inside the shed. If they were contained in say the 50m^2 near the DC then after considering 1&2 above you might get away with 150mm ducting.
4) Given you wish to keep doors and windows closed unless you add addition ventilation fans then having a large main and opening up more than one 150 mm port is a good way to vent the shed.
A 7 x 14 x 4 m shed has a volume of ~14000 cubic ft. A 150 mm main can at most carry about 1250 CFM so that means a theoretical shed vent time (TSVT) of 11.2 minutes but in practice it takes ~4 TSVT to reach >90% shed air turnover, so more like 40 minutes. Provided the DC can deliver, a 200mm main will have at least double the flow rate of a 150mm so it will halve the TSVT. At our mens shed the wood shop floor is about the same size and we have 3250 CFM Evap AC on the roof and that seems to clear escaped fine dust in under 10 minutes. We are able to open a 3.3 m high roller door and some other doors and windows which also helps a lot. If you intend keeping all doors and windows shut you will need a decent baffled air input as well as output.

BobL! Great information.
Based on what your saying I think the 150mm ducting could be okay but it doesn't give me any leeway if I do have someone else in the workshop in the future to open two blast gates at a time.
Also, from what your saying, the 150mm Ducting will take a very long time to clear the air... Another reason to consider 300mm main ducting.
Great point about needing a baffles air intake and vent to have any chance of effectively using the extraction to clear the air of fine particle.

The one thing I'm unsure of is that most machine seem to have smaller dust ports than 150mm, say 80,100,120mm seem very common so would you suggest to modify these smaller dust ports?

Thanks for the detailed information BobL, I can see Dust extraction is one of your areas of expertise!

Originally Posted by Dan87

BobL! Great information.
Based on what your saying I think the 150mm ducting could be okay but it doesn't give me any leeway if I do have someone else in the workshop in the future to open two blast gates at a time.

That was my thinking as well.

Also, from what your saying, the 150mm Ducting will take a very long time to clear the air... Another reason to consider 300mm main ducting.

There's no need to go to 300mm ducting. If you do that you will need a HONKING BIG DC because of the air flow needed to hold any sawdust in suspension in a 300mm duct will be HUGE. Your Shed should be serviceable by a 4HP DC with a 15"/16" impeller. The max size ducting that should be used as a main for that is about 200mm. Unfortunately there is no such thing as 200 mm PVC so nominal 225mm is used. (which is actually 240mm ID) and is OK to sue.
Before I reinvent the wheel here suggest you read this DRAFT Ducting Recommendations

Great point about needing a baffles air intake and vent to have any chance of effectively using the extraction to clear the air of fine particle.

A Baffled intake will only be required if you are really worried about noise escaping from machinery.

The one thing I'm unsure of is that most machine seem to have smaller dust ports than 150mm, say 80,100,120mm seem very common so would you suggest to modify these smaller dust ports?

Yes, that is likely to be a significant requirement. There are plenty of posts in the dust forum forum that show how to do this.Do a search for "150mm dust ports" If you can't find them then ask.

Thanks BoBL
I have just a read through the Draft Ducting Requirements, I'm sure I'll be reading it a few times in the future too... So much useful information in there!
I love this forum but I do find it a bit confusing to navigate and find the gold nuggets of information throughout.

Would you say the Clearvue CVMAX would be the goer for 225mm mains in 100m2 workshop?

Dan87

Originally Posted by Dan87

BobL! Great information.
Based on what your saying I think the 150mm ducting could be okay but it doesn't give me any leeway if I do have someone else in the workshop in the future to open two blast gates at a time.
Also, from what your saying, the 150mm Ducting will take a very long time to clear the air... Another reason to consider 300mm main ducting.
Great point about needing a baffles air intake and vent to have any chance of effectively using the extraction to clear the air of fine particle.

The one thing I'm unsure of is that most machine seem to have smaller dust ports than 150mm, say 80,100,120mm seem very common so would you suggest to modify these smaller dust ports?

Thanks for the detailed information BobL, I can see Dust extraction is one of your areas of expertise!

The size of your ducting and the kw of your dust extractor dependson the biggest user of your dust extraction

For me the biggest user is my sander, the user manual says itneeds a whopping 6500m3/hr (or there about)

With 300mm duct, and keep fine dust afloat a 20m/s, this is onlyabout 5100m3/hr in a 300mm duct. and this is assuming it’s a laminar flow inthe duct, where everywhere in the duct it is 20m/s, in reality the flow closerto the edge is probably only 5m/s, by using smooth edge steel duct you canincrease this to maybe 10m/s (just example) but you will never get the flow atthe edge the same as the flow at the centre.

If I want to service my sander properly, I should really go for350mm. but the cost of the 350mm gets really really high.

Originally Posted by Albert

With 300mm duct, and keep fine dust afloat a 20m/s, this is onlyabout 5100m3/hr in a 300mm duct. and this is assuming it’s a laminar flow inthe duct, where everywhere in the duct it is 20m/s, in reality the flow closerto the edge is probably only 5m/s, by using smooth edge steel duct you canincrease this to maybe 10m/s (just example) but you will never get the flow atthe edge the same as the flow at the centre.

20 m/s is an industry standard air speed to keep all dust in suspension. As you say even with a 20m/s in the middle of the pipe the flow closer to the sides of is much lower and yet we rarely see much sawdust falling out of suspension.

Really fine dust will stay suspended in air for hours so even a few m/min will be enough to clear this dust. More important to clear are large chunks of sawdust and it's less about maintaining suspension than the need for re-suspension. At some point or other some dust will fall out of suspension eg opening closing the wrong gates, power failure, other blockages. For a variety of reasons (humidity of air and wood, static, resin content of wood, length of time sitting in a deposit state, type of wood) deposited sawdust tends to want to stick together and also to the inside walls of ducting. 20 m/s is considered the minimum needed to re-suspend deposited sawdust.

In practice I've found that wood dust easily says suspended down to as low as 10m/s and, depending on conditions, most will be resuspended even at this speed. Some of this is probably because Australian conditions tend to be drier so the wood dust is less susceptible to "clinging to" the sides of ducting.

A ClearVue Max will generate about 3400 m^3/hr so a nominal 225mm (240 mmID) diameter PVC pipe will generate about a 21 m/s linear air speed. When only one 150 mm duct is connected to a 225mm main the air speed in the main is determined by how much will flow through the 150 mm duct. Given ducting and restrictions of machine dust ports etc this will be about half the 3400 m^3/hr ie 1700 m^3/hr, so this makes the air speed in the 225 mm main around 10.5 m/s. It can go even lower than this when for example workpieces pass over some dust collection apertures eg throat plates, when the flow drops even further, but as soon as the workpiece clears past these apertures the air flow increases and removes any deposited sawdust from the insides of a duct.

We have been using this approach in the mens shed (and also know of dozen air so other sheds doing the same) for more than 5 years and have not seen any significant deposition of saw dust in the 225mm ducting. Even when some sawdust has a fallen out of suspension, opening up a couple of 6" best gates has easily resuspended any deposited sawdust.

Another potential problem is when say many 6" ports are open (usually incidentally left open) at the same time which leads to low air speeds in the 150 mm ducts which leads to insufficient dust being collected at the source. This also may lead to sawdust deposition in the 150 mm duct attached to the running machine but this is easily cleared one the 150mm ducts that are not in use are closed. This is where the auto blast gates will come in handy. Better still is where say 4-5 150mm ducted machines are already in use, would be a pressure sensor which prevents an additional machine from starting until one or more others are switched off.

One of the few benefits of keeping the ducting as narrow as acceptable in sawdust extraction systems is the the flow is always turbulent, even at low speeds. The effect of this a corkscrewing, swirling, swishing, sidewall scouring stream of air and dust running through ducting which helps pick up deposited saw dust.