Thread: Dust extractor and ventilation.

The answers to your question re reducing a HVLP hose to 1 1/2” is yes, it’s really bad.
I use a 2200W K-mart cyclone vacuum cleaner with a 32mm hose on my hand help tools and it works fine. I have a modified 2hp HVLP unit with 6” pipe and hose to my table saw and a 5” hose from the 6” pipe to my router table. A separate VC with 2” hose is used for my router fence and above table saw hood.

Originally Posted by Tigglez

Like a lot of people I was looking at those 2HP HVLP units however my table saw, belt sander, band saw well now that I think of it everything has a 1.5ish inch extraction port. Is the performance of dropping the 4" on these HVLP down to 1.5" really that bad? Would I be better off the a LVHP vac unit instead?

Vacuum cleaners are better at collecting chips and some fine dust from power tools, but less so from machines.
However, vacs can also make more fine dust than they pick up.
HVLP are less effective at picking up chips but do a better job than vacs at collecting fine dust at source.
Remember you can easily wear a face mask while sweeping up chips with a broom and running some extractor fans but it's much harder to clean up the fine dust once it escapes from the source.

The extent of extraction required depends on your exposure. eg how long you spend in your shed and the nature of your dust making activities, techniques/machines/tools/wood/sharpness of blades etc OTOH it is possible to become allergic to wood dust with only a small exposure - the risk is yours to take,

If you are spending only a couple of hours a week in a shed using mainly hand tools then decent ventilation, a vac and a broom and a face mask may be enough.

If you spend much more time in your shed and use mainly machinery/power tools and wish to minimise fine dust risks then you need more extraction than even a stock 2HP can provide. The generic 2HP needs to be modified along the lines of the sticky at the top of this forum to be able to make use of 6" ducting and machinery dust ports have to be opened up to to utilise larger ducting.

If you make a list of your gear that has 1.5" ports we can make suggestions as to how to deal with these.

While it's not as convenient as a vac, it is possible to use HVLP extraction on power tools provided they have a built in fan because the fan determines most of the air flow from the tool. I usually only use a vac when I am away from the shed (eg in the house or off site) and even then it is a wet and dry vac which has an exhaust port that enables a long hose to be added so I can vent the vac outside a nearby door or window

For ventilation I was thinking a few 150 or 200mm wall fans along the back, do I need intake fans opposite them or will they perform fine with just the double doors open?

I would recommend 300 mm fans if you can if not 250 mm.
Fans will be OK if they are located opposite the double doors as long as they suck out and not blow in.
If you have no other fine dust collection at all and you spend a many hours in your shed each week the you will need about 20 room air changes per hour of ventilation to stay relatively fine dust free.

And with adequate ventilation would there be much benefit in a room air filter?

Filters are useful if you want to reduce your shed air of all dust such as when you want to a apply a dust free finish. Don't forget that outside air dragged in by wall fans and DC will contain some dust. You can either close all doors and turn off fans and wait over night for the dust in the shed air to settle or use a room air filter for about a hour or so.

Nothing wrong with VAc cleaners as long as they are maintained.
My large wet and dry had its exhaust port connected to an exhaust hose that goes outside the shed. The cyclone unit has a HEPA filter directly on the exhaust port.
All My units are regularly checked for leaks

Regular checking for is good for leaks but unfortunately with vacs it's not just leaks. Unless the vac has a filtered air cooling circuit for the motor then that seems to be the main culprit at mincing fine dust suspended in the air into even finer dust. Of course it can only mince fine dust if it has access to it. This usually comes from dust not captured by a vac or DC or vented from a shed in the first place so if your systems are on top of it this is much less of a problem. If a vac with an unfiltered motor cooling loop is used in a dusty shed the motor cooling loop can become contaminated so when its taken into a clean shed it can add to the fine dust load there. This can be attended to by taking it outside the shed and giving the motor cooling loop a blast with a compressed air.

All exit air, including motor cooling, goes out via the Hepa exhaust filter.

Originally Posted by BobL

If you make a list of your gear that has 1.5" ports we can make suggestions as to how to deal with these.

Metabo TS 254 Table Saw, Ozito CMS-1621 Mitre Saw, Baumr-AG BS30 Band Saw, Baumr-AG 400W Bench Sander, Baumr-AG DP12 Drill Press, AEG EX125ES Random Orbital Sander, Makita RTO7000CX Router.

Originally Posted by BobL

Unless the vac has a filtered air cooling circuit for the motor

How do you find out if they do or not? I havn't seen anything about the cooling in the specs or manuals for the units i've looked at even in the L/M Class units from Festool, Makita or Milwakee.

Originally Posted by Lappa

All exit air, including motor cooling, goes out via the Hepa exhaust filter.

What model do you have?

Most of your machines are relatively small, budget/entry level type machines which fortunately have the benefit of making relatively small amounts of dust. I assume if you are not spending up big on machinery you are unlikely to want to spend up big on dust extraction?

In that case the simplest/cheapest most effective way I would handle these machines is using a ducted vacuum system
Start with at least a 2 or 3 HP vacuum cleaner with as much dust capacity as possible (30L+) and locate it outside your shed, or enclosed it in a air tight box inside the shed and vent the box outside the shed. This also gets the Vac noise out of the way.
If you locate or vent it outside there's no need to get a HEPA filtered version as these reduce air flow especially when they get clogged.
You can add a small Suit deputy style cyclone chip collector if you wish to reducing vac filter clogging.
Then run 50 mm PVC ducting from the vac around the walls and or across the ceiling across to each machine and/or to a selection of ports to which you can connect hoses/machines.
Then install enough ventilation as possible to get as close as you can to 20 room air changes per hour.

The machines which will struggle most with a ducted vac system are the TS and sander - you might want to use these outside for any lengthy sessions until you can purchase a 2HP HVLP 2HP DC which you will also need if you decide to get larger machines. Then you will need to run a larger diameter set of ducting around your shed but the 50 mm ducted vac system will always be extremely useful for the smaller machines even if you decide to go with a 150 mm ducted system later for larger machines.

John Samuel and FenceFurniture have posted a particularly detailed and useful threads about their fully ducted vac systems.

Originally Posted by BobL

I assume if you are not spending up big on machinery you are unlikely to want to spend up big on dust extraction?

Well I only got most of those because they were on sale and I needed something small as I didn't have much space out side to store them and if I was able to make space I couldn't see myself moving out bigger heavy machines into the yard every time I wanted to use one.

Looking at putting in a shed between 4.6m x 2.3m 23m3 and 6.1m x 3.1m 40m3 depending on available space after I dig out some trees and how much i'm *ahem* allowed to use . I figure around $1k would get me adequate dust extraction and ventilation for it to be safe to use.

If I don't have adequate dust extraction for relatively safe use i'd never use the equipment so there wouldn't really be a point even getting the shed so I can be flexible with the amount just not overly so.

Originally Posted by BobL

Then install enough ventilation as possible to get as close as you can to 20 room air changes per hour.

That's why I was looking at the 2 or 3 150mm fans as they'll easily pull out the sheds volume more than 20x per hour unless their specs are largely exaggerated. Just wasn't sure if they'd need opposing intake fans in order to do that or just the doors open would be enough.

Originally Posted by BobL

The machines which will struggle most with a ducted vac system are the TS and sander - you might want to use these outside for any lengthy sessions until you can purchase a 2HP HVLP 2HP DC which you will also need if you decide to get larger machines.

Will that work with this TS and sander, I can't see how you'd modify the ports of either to a larger diameter so it would just be the larger hose stepping down to 1.5" and the associated performance loss.

John Samuel and FenceFurniture have posted a particularly detailed and useful threads about their fully ducted vac systems.

Will have a look.

Originally Posted by Tigglez

Well I only got most of those because they were on sale and I needed something small as I didn't have much space out side to store them and if I was able to make space I couldn't see myself moving out bigger heavy machines into the yard every time I wanted to use one..

Sure, I have seen this situation many times.

Looking at putting in a shed between 4.6m x 2.3m 23m3 and 6.1m x 3.1m 40m3 depending on available space after I dig out some trees and how much i'm *ahem* allowed to use . I figure around $1k would get me adequate dust extraction and ventilation for it to be safe to use.
If I don't have adequate dust extraction for relatively safe use i'd never use the equipment so there wouldn't really be a point even getting the shed so I can be flexible with the amount just not overly so.

Assuming you do all the installation, $1k should be able to get you;
1) A complete 50mm ducted vac system - This the best single way to deal with your mostly smaller size machines in your proposed size shed
2) Ventilation fans - bathroom type fans are cheap but a tad noisy and not very efficient - you can effectively halve their quoted specs. see comment below
3) You should even have enough left over to purchase a 2HP DC but unfortunately that is far from the end of the story - its just the beginning.

The 2HP needs to be modified along the lines of the sticky thread at the top of this forum.
Then you will need a vented soundproof enclosure for the 2HP
And purchase the components for and install an independent 6" ducting system to suit the modified 2HP DC.

Only then will you safely be able to do all your work with the TS, MS and Sander inside your shed.

That's why I was looking at the 2 or 3 150mm fans as they'll easily pull out the sheds volume more than 20x per hour unless their specs are largely exaggerated. Just wasn't sure if they'd need opposing intake fans in order to do that or just the doors open would be enough.

If you post links to the fans you have in mind I should be able to comment on the validity of their specs. You won't need opposing fans. Unless the fan is HUGE like an Evap AC fan, fans that push air into shed are not very efficient at removing dust - all they do is "stir it up"

Will that work with this TS and sander, I can't see how you'd modify the ports of either to a larger diameter so it would just be the larger hose stepping down to 1.5" and the associated performance loss.

With a ducted Vac system you don't want to use ducting any bigger than 50 mm in diameter or the sawdust will settle out of suspension inside the ducting.
- Machines like the mitre saw can benefit from using a vented vac on the blade port port and then building a surrounding enclosure that is captures fine dust by the modified 2HP DC.
- Same with the table saw. Completely remove the lower guard and dust port and build a special bench so you can suck the dust away from the cabinet from underneath with the 2HP DC and 6" ducting, and attache the vented vac to the top blade guard. This is basically what I did to my contractor saw. But I use 4" extraction on the name guard.
- With the sander I would completely remove the 1.5" port and make new 6" dust collection port that uses a bell mouth hood sucked on by the 2HP DC.
Like this
IMG_2089.jpg

It sounds like you are on a slippery slope and will probably end up purchasing better machines with bigger dust ports

It sounds like you need to do some cruising through the dust forum to get some ideas and then float them here for comment.

There is no magic bullet or one size fits all situations. Like life, its complicated an there are infinitely man ways to skin teh dust cat.

Originally Posted by BobL

The 2HP needs to be modified along the lines of the sticky thread at the top of this forum.
Then you will need a vented soundproof enclosure for the 2HP
And purchase the components for and install an independent 6" ducting system to suit the modified 2HP DC.

What about the 3HP units that already have a 6" inlet like this do they need further modification?

Originally Posted by BobL

If you post links to the fans you have in mind I should be able to comment on the validity of their specs.

Was looking at 3 of these across the back, depending on shed 38 - 22 room changes if they live up to their spec.

Originally Posted by BobL

Completely remove the lower guard and dust port and build a special bench so you can suck the dust away from the cabinet from underneath with the 2HP DC and 6" ducting, and attache the vented vac to the top blade guard. This is basically what I did to my contractor saw. But I use 4" extraction on the name guard.

So replacing the top guard with a sharkguard with 4" and connecting it to the DC as well would be better than using the stock guard with a vac?

Originally Posted by BobL

With the sander I would completely remove the 1.5" port and make new 6" dust collection port that uses a bell mouth hood sucked on by the 2HP DC.

How about the hand sander, would that work better on the vac or on the DC with a reducer?

Originally Posted by BobL

It sounds like you are on a slippery slope and will probably end up purchasing better machines with bigger dust ports

Not anytime soon though, the current equipment does the job so it will be a hard sell to convince someone I need better ones

Long as i'm not too extravagant, better dust equipment is easy enough since it's for health.

After my first thread on P2/P3 filters I purchased a Moldex 9000 which works good however on really hot and humid days I do sweat a bit in it, do you know if the Trend Airshield is as effective at keeping fine dust out?

Originally Posted by Tigglez

What about the 3HP units that already have a 6" inlet like this do they need further modification?

They will be OK especially for your size shed. Will you be able to vent or locate it outside your shed?
If you go for a 3HP ducted system and a ducted vac system you won't need any ventilation fans because you can run your DC instead - however the fans use a lot less power and will be quieter even if the DC is outside the shed so they are really nice to have. If you have 3-4 fans you can turn each one on as needed.

Was looking at 3 of these across the back, depending on shed 38 - 22 room changes if they live up to their spec.

Assuming their spec is right and your shed is 4.6 x 6.1 x 3 = 88 m^3
81 L/s x 3 fans = 243 L/s = 875 m^3
I could be wrong, but make that about 10 room changes per hour?
Anyway i seriously doubt they even move this much air, Axial fans are notoriously inefficient so are unlikely to be very effective - maybe they will move around half or 2/3rds of their claimed spec
The flow rates are also worked out using a dodgy method, the grille (especially that fine mesh across the front) is way too restrictive and it will easily clog up although these could be removed.

I have never used one myself but thanks to the hydroponics industry I reckon something like these would be much better.
https://www.ebay.com.au/sch/i.html?_...OWER+&_sacat=0
The use a centrifugal action which is more efficient and they have no grille although I would suggest something like a cake rack or coarse chicken wire mesh be used to protect users and the fans.
A single 10" fan is supposed to move 1080 m^3/hr so that makes it about 12 room changes per hour.
2 x 6" of these fans will move about 1500 m^3/hr so that makes it 17 room changes per hour.
Their claimed spec are not likely to absolutely correct either but they are likely to be closer than the bathroom type fans and won't clog.
As you can see there's a bit of price difference between the cheap bathroom fans and the better centrifugal.

If you want to go lower budget I would suggest 4 or 5 of these but the last one of these I bought only lasted 5 years.
https://www.bunnings.com.au/arlec-25...t-fan_p4440572
Replace the grille with much coarser one.
Interestingly the combined noise of 4 of these fans is 54dB which is about the same as for two x of the 6" centrifugal fans (52 dB each)

So replacing the top guard with a sharkguard with 4" and connecting it to the DC as well would be better than using the stock guard with a vac?

Yep - much better - see this Shark Guard table saw blade guards, splitters, riving knives and anti-kickback pawls. Safety Guards
I reckon the design can be further improved, but let's crawl before we try walk ing.

How about the hand sander, would that work better on the vac or on the DC with a reducer?

Assuming
1) both the Vac and DC are outside the shed
2) the Sander has an internal fan
3) Sander connected to vac with 35 or 32 mm hose
4) Sander connected to DC with 50 mm hose
- then there's not that much difference.
I measure slightly more air and dust being sucked up by the the DC than a vac BUT because the DC hose is larger its more awkward to work with - depends on your priorities.

Not anytime soon though, the current equipment does the job so it will be a hard sell to convince someone I need better ones
Long as i'm not too extravagant, better dust equipment is easy enough since it's for health.

Good point.

Originally Posted by BobL

They will be OK especially for your size shed. Will you be able to vent or locate it outside your shed?
If you go for a 3HP ducted system and a ducted vac system you won't need any ventilation fans because you can run your DC instead - however the fans use a lot less power and will be quieter even if the DC is outside the shed so they are really nice to have. If you have 3-4 fans you can turn each one on as needed.

Yeah whatever size shed I end up being able to get i'll be able to extend the slab a bit to put the DC and vac on and should be able to draw a little bit more out for a cyclone for the DC in the future.

Originally Posted by BobL

Assuming their spec is right and your shed is 4.6 x 6.1 x 3 = 88 m^3
81 L/s x 3 fans = 243 L/s = 875 m^3
I could be wrong, but make that about 10 room changes per hour?

Sorry for the confusion, above I only listed the length, width and rough volume the smallest and largest shed I could be getting. The largest shed would be 6.1m x 3.1m x 2.4m (42m3 taking into account gable roof) so 875m3/h would be just over 20 changes on it.

Originally Posted by BobL

Anyway i seriously doubt they even move this much air, Axial fans are notoriously inefficient so are unlikely to be very effective - maybe they will move around half or 2/3rds of their claimed spec
The flow rates are also worked out using a dodgy method, the grille (especially that fine mesh across the front) is way too restrictive and it will easily clog up although these could be removed.

I have never used one myself but thanks to the hydroponics industry I reckon something like these would be much better.
https://www.ebay.com.au/sch/i.html?_...OWER+&_sacat=0
The use a centrifugal action which is more efficient and they have no grille although I would suggest something like a cake rack or coarse chicken wire mesh be used to protect users and the fans.

I was looking at some similar (well don't know if they were centrifugal, but larger single fans that moved around 1000m3/h) but thought it might be better to have the multiple weaker fans spread out across the bag pulling out air rather than just the one larger fan.

Originally Posted by BobL

If you want to go lower budget I would suggest 4 or 5 of these but the last one of these I bought only lasted 5 years.
https://www.bunnings.com.au/arlec-25...t-fan_p4440572

It's Arlec what do you expect :P

Originally Posted by BobL

Interestingly the combined noise of 4 of these fans is 54dB which is about the same as for two x of the 6" centrifugal fans (52 dB each)

Guessing that would only be 2 or 1 with the adjustment of only being around 40m3 not 80m3.

Originally Posted by BobL

I measure slightly more air and dust being sucked up by the the DC than a vac BUT because the DC hose is larger its more awkward to work with - depends on your priorities.

If that's the case I don't think it will matter too much since I have that full face respiration now and don't use it all that often.

Originally Posted by Tigglez

Yeah whatever size shed I end up being able to get i'll be able to extend the slab a bit to put the DC and vac on and should be able to draw a little bit more out for a cyclone for the DC in the future.

Sorry for the confusion, above I only listed the length, width and rough volume the smallest and largest shed I could be getting. The largest shed would be 6.1m x 3.1m x 2.4m (42m3 taking into account gable roof) so 875m3/h would be just over 20 changes on it.

OK - but I still wouldn't recommend those small axial, if you are going to use an axial fan try to use at least a 10" fan.

I was looking at some similar (well don't know if they were centrifugal, but larger single fans that moved around 1000m3/h) but thought it might be better to have the multiple weaker fans spread out across the bag pulling out air rather than just the one larger fan.

It is, especially given they can be turned on as needed since that keeps the noise down.
It would also be useful to install them as high up a wall as possible in the shed.

It's Arlec what do you expect :P

Sure and that has implications below.

Guessing that would only be 2 or 1 with the adjustment of only being around 40m3 not 80m3.

Given they cost ~$20 ea I'd consider getting more than 2.

Longer term they maybe not that good a deal since they are only a ~5 year lifetime type fan whereas the centrifugal fans should last much longer. I have a Aussie (Reece) centrifugal fan in my shed that I installed in a laboratory at work in 1983 where it got a bit corroded from exposure to low level acid vapour exposure and was thrown out in 2008 - 25 years not bad given the harsh environment and that it ran 24/7. I rescued it from the skip and took it home and cleaned it up and gave it a fresh coat of paint and it has been used in my shed since 2011.

Might be a good idea to give Timbecon a call regarding that 3hp DC and check the amperage. If its a 15amp unit it might blow the budget if you didn't plan on installing 15 amp sockets