Dust collection in a small shop. How to suck?

[BigShot]

Hi Folks,

I'm finally getting around to clearing out the garage and now have a bit more money available so should be able to make a half decent (for a beginner) bench without resorting to too many bodges; this has got me thinking again about how best to set it all up.

On the dust front I'm probably going to go with something like Mike Garnham has shown on here (it was mentioned in the drift on this thread with more pictures on page 3 of the same) built to fit into a convenient spot somewhere... I'm not sure what to use to give suction though.

I like the idea of using a vacuum cleaner as Mike did - but I don't really want something too loud if I can help it. Are the Henry type vacs reasonably quiet? If not, can you suggest something quiet I can get fairly cheaply? (I'll buy used rather than new for the sake of a few bob I'd be better spending on wood for my bench and storage)

Are there any affordable (considerably sub-£100 - sub £50 would be far better) alternatives to Henry (or domestic vacs) I could use?

 

[wizer]

My Henry is my quietest extractor and in it's current position it's even quieter. I have fixed it permanently in a cupboard under my workbench with the hose fed through a hole in the side up to the top. You could do something similar boxing in the cyclone\collector thingy with the Henry on top.

 

[GraemeD]

If I was starting from scratch, I'd definitely consider doing what you suggest. You can pick up a secondhand Henry quite easily on Ebay....or even for nothing on Freecycle. Remember that the motor in a Henry is the same as those used in almost all the popular vacuum-type extractors (eg. Record, Axminster, Camvac, etc.), so you're not actually compromising a great deal! Used alongside a dust separator....either something simple like the one you linked to, or more sophisticated like a Thien cyclone (http://www.cgallery.com/jpthien/cy.htm).....you're not going to go far wrong. It can always be upgraded in the future!

Noise wise, I'm with Tom here.....my Henry is quieter than my Axminster Woodvac!

Hope that helps!
Graeme

 

[BigShot]

Fan-chuffin tastic!
I'm sure you'll all know that warm feeling you get when something you thought was a compromise turns out to be about the best solution of all.

I'll be off down to a car boot if I can find one this weekend, keeping a close eye on realcycle* and on ebay. I've seen a few go for peanuts in the "completed items" part so will keep looking for a cheap live auction.



Tom - I was thinking about boxing the whole thing in. I can probably guess the answer here, but have you had any issues with it over heating when it's fully enclosed like that?
Also, how do you have the compartment vented so the air the vac blows out can escape? Anything more complicated than a few slits or a hole?


Graeme - I thought about making a cyclone a while back, but when I saw Mike's setup on that thread and realised the vac could be fitted with HEPA filters for about £10 and needed emptying so infrequently I decided to save myself a load of effort. If it works half as well as Mike's it'll be all I need.


Would it be possible to run something like this as a more general workshop air filter? I'm aware that jobs like sanding a workpiece as it's being spun in a lathe throw up a lot of fine dust, so could this thing be set up to clean the air itself to a reasonable degree like it does with tools like routers and the likes or is that going to take something completely different?


*freecycle is rubbish in Manchester - they've split the city up in an utterly thick way which means I can't use the same list as someone a 5 minute walk away from my house, but instead have to use the list extending as far as a 15 minute drive away with me at the very bottom end of it... realcycle just have a single list for Greater Manchester - much smarter.

 

[GraemeD]

Glad you're happy!! My Henry is actually a metal bodied one (same machine but slightly more industrial....and without the smiling face!) and has a hose outlet vent, where the warm filtered air comes out, and can be attached to a hose as a blower. This would make boxing it in quite easy, though my bet is that a lot of the noise comes out of the outlet. A plastic bodies Henry (as I recall) has some slats for the venting, so making a port in an enclosure would be harder. the air is warm too, so it is important to exhaust it efficiently. Remember you may have this switched on for long durations after all! I'd be tempted to leave it unenclosed, and just tuck it away somewhere....then see how it goes. You may not be so worried once you get your router screaming!

As for ambient air filters, although it seems like a lot of airflow, a Henry can't handle the volume of air required to clean the while room. I did a maths myself a while back, and it isn't really enough. Add to that the fact that a proper air cleaner only uses maybe 100watts (Henry = 1kW), then you'll see why this isn't a good idea. You can either buy a proper unit for the job....which isn't cheap....or make your own. There are threads in these forums about exactly this. Best bet however is to collect as much dust as possible at source, and then use a mask if you think there's still the fine stuff getting out. The air cleaners are not an instant solution!

Cheers
Graeme

 

[wizer]

I've no special venting in my current arrangement. The cabinet is only shallow and has a 2-3mm gap between the double doors and the hole for the pipe is over size leaving about a 5mm gap all around. I regularly use it for sanding with all my power sanders. Here's an example of typical usage. A couple of says ago I sanded 2 shelves that are 50mm thick, 1200mm long, 280mm deep with a 1/4 sheet sander using 120g, 180g and 240g. The Henry must have been on for 20mins? No problems with overheating. If I was designing a dedicated enclosure, I'd be tempted to rout some vents in it and then back it with some sort of filter material. Hence letting the air out but any dust that might be about should get caught. If you really want to reduce noise, then line your enclosure with insulation. This is what I'm going to do with my camvac clone when I plumb it in.

 

[Niki]

I use the Electrolux home vac....1800W and strong enough to use with a table saw and /or the router table...

Some modification of course like, changing the hose to 2".

I wanted one unit to carry around the garage...

The best thing that I love about it is the "Power control" - not all the time I need the "full vacuum" (or, the full noise) (like when I work with the sanders)...in general it's not so noisy.

I made a special "hammer" to bang the pre-filter from time to time leaving it almost clean so, no decrease in the efficiency...

niki

 

[BigShot]

Thanks again, all.

Niki, that looks like a pretty tidy setup. Though I won't need the portability (I'll be better off with a stationary box and a longer hose for if I need to reach further than the bench top) I like the look of that.


Tom, I think I'll go with the vents idea - probably with a HEPA filter clamped over it somehow (probably just a wooden frame screwed into place with the filter between it and the enclosure wall). The noise issue has become slightly smaller considering Graeme's comment "You may not be so worried once you get your router screaming!"; in that case the vac's hardly going to be the loudest thing in the shop! I'll see how it goes when I've got it set up and add in some noise reduction if I feel the need later.


Graeme, I'll have to come up with something else on the ambient air front then. I've seen DaveL's filter which looks a likely design.
Are there any other threads you had in mind when saying there were such things on here?
I see the air cleaner more as something to keep the shop dust down and make the air safer for people nipping in for a sec (the freezer, washer and drier will be in here - all enclosed along with some storage I'm building in too) - I figure that less dust in the air means less to settle on things so easier to stay on top of cleaning. For my own health it's all about extraction and masks.


So what sort of airflow should I be looking for in an ambient filter in a 14m³ (495ft³) workshop (I said it was small! )?

 

[wizer]

I've been scanning ebay for a bargain fan on and off for weeks. It's a hard thing to search for because there are so many type of fan. Not all give the appropriate specs. You have to do a bit of educated guessing. As yet I've not found anything that is cheap enough. At the moment the Jet filter is on sale at just over £150. You'd have to at least half that to make it worth building your own filter. So my budget for the fan alone is about £30-40 you then have to add a speed controller, wiring, filters, ply, etc. Google is helpful at working out the maths. I'm lazily just shooting for the same output as Axminster's MTM unit which circulates at 600m³/hr which I think is about 350cfm. This is over specced for my workshop but I'd rather it was over than under and allows for expansion.

 

[frugal]

I just had a look. The £150 Jet at Axminster says in the specs that it is suitable for a room up to 120m3. My oversided single garage at 6m x 3m x 3m is only 54m3 (less if you take in account the fact that the top meter is the pitched roof).

 

[Digit]

As you have a vacuum system that you're happy with wizer why not simply make a box with the filter in it and a suction connection to Mr Henry?

Roy.

 

[Digit]

Niki! Are there any partitions inside that box or is there just the filter material?

Roy.

 

[BigShot]

Digit
I mentioned using Henry to run an ambient air filter earlier in the thread and Graeme pointed out that they don't move enough air for that kind of work... assuming you were referring to ambient air in your comment to Wizer, that's probably your answer too.


Frugal
120m³ is about 8 times the size of my shop, think I'll probably ave the money and go for something a wee bit smaller.


Tom
I know a bathroom extractor fan that complies with minimum ventilation regs in that case moves something like 900 litres per minute, I'm pretty sure that comes to around 54m³/hour, or 3.8 changes of air per hour in my 14m³ shop.
Enough?
I'm sure I could find something that moved more, but it's a thought.

 

[MikeG.]

Plenty, IMV.

 

[GraemeD]

From what I've read, the recommendation for an ambient air filter seems to be between 6 and 10 changes of air per hour, so in your small shop you won't need anything huge.

However....and this is the big issue.....if you put a filter which is capable of working down to sub-micron levels (which is what is required to do the job properly) with a fan, it adds so much resistance to the airflow that the m³/hour quoted for the fan is massively reduced. Worse still, if you use an axial fan, these don't respond well to having their airflow restricted to this degree, and therefore their efficiency plummets. You'll notice that commercial air filters like the Jet, Axminster, Record and Microclene all use centrifugal fans which are better able to work against a significant filter resistance. You still need a much more powerful fan than in free air though!

As you can see I've been through all this myself earlier in the year, when I considered making my own ambient air filter. How hard could it be I thought?! However when you look into it, the commercial units are made the way they are for a reason. You can certainly make your own filter using any fan, and it might look like it's doing a good job (ie. the filter collects airborne dust). But it probably won't be clearing down to submicron levels, these being the most dangerous particles, and would lull you into a false sense of security....ie. you don't feel the need to use a dust mask!

In may case I bought a used Microclene on Ebay for about £70. It seems to do the job, but is admittedly relatively noisy. Quite whether my shop is clear of all those submicron particles I have no idea......but the manufacturers claim it does the job!

Just my ten pennies worth!!

Graeme

 

[studders]

I had a thought, it had to happen sometime, as I was testing my cooker hood that I've just installed. It's got one hell of a suck (450m3/h) on full blast (3 speed) so, is there any reason I couldn't use one in the workshop and duct it outside? :?

 

[GraemeD]

You know what.....my conclusion was that if I was making an ambient air filter, I'd start by using an old cooker hood! They are centrifugal fans designed for the purpose....just need to add an appropriate submicron filter and you're away.

However, venting outside....although great for getting rid of dust.....isn't a great idea, as you're essentially chucking all your heat away. Not so bad in the summer, but not a great idea in the winter!

 

[Niki]

Niki! Are there any partitions inside that box or is there just the filter material?

Roy.

Hi Roy
No partitions, just the filter...you can see here the "Inside story"...And, the "Hammer" to bang the filter from time to time to keep the airflow at maximum.
https://www.ukworkshop.co.uk/forums/view ... highlight=

There are two links in the post that will lead you to the shop-vac and if you like, the R2D2...

Regards
niki

 

[studders]

However, venting outside....although great for getting rid of dust.....isn't a great idea, as you're essentially chucking all your heat away. Not so bad in the summer, but not a great idea in the winter!

Ah, good point. How would you get acceptable filtering though if using a recirculatory(sp :? ) type? Hmmm ... thinking. :!:

 

[Digit]

Thanks Niki, I'll be following that up. My present system is outside but I want that space for my motor bike.

Roy.