Thread: New Dust Extractor

The unit in Pic. 1 is a Low Pressure High Volume Dyst extractor which are the type to attach to wood working machinery for workshop dust extraction. A lot of the specifications supplied re airflow regarding are usually overstated for a unit in actual use and are usually quoted with the impeller unit itself not connected to inlet piping or filters.

The unit in Pic. 2 is a High Pressure Low Volume unit which is in essence a household vacuum cleaner.

LPHV units suffer greatly if you reduce their inlet pipe. They have normally a 4” or 100mm inlet although there maybe a 5” (150mm) inlet with two 4” inlets in a Y connection. Larger units maybe 6” or even 8”

HPLV units can be used to connect to power tools like sanders, hand held routers etc. but are not ideal at picking up fine dust. Their inlets are 35 to 50mm (1 1/2” to 2”).

There is some great info in the three Stickies at the top of the Dust Extraction threads

More specific advice could be provided if you were to let us know
(a) what power tools you use
(b) What machinery you use
(c) the size of your workshop (length width and height)
(d) the cross sectional area of ventilation you can can keep open while working
(e) Usage patterns (hours per week).

BobL , the space is an extension I had built a while ago . It is 21ft long x 8ft wide x 8ft high . There is 2 windows in it so plenty of light , There is a garage at the other end with probably the same measurements ( only the one window in the garage though ) . There is an 8ft x 4ft workbench i'm on building , just finished putting a new coat of emulsion on the walls and ceiling yesterday . There is lots of old timber a few floorboards old doors etc , that's in the kitchen at the moment I'm working on that .I'm thinking of doing my own kitchen units there are double French doors to go in also. My tools are a 10in blade sliding mitre saw , a planer , an old Elu router and a new Bosch GTS 10 XC Professional table saw ( which hasn't been used yet ).I don't know if it will get much use or not .

Originally Posted by nettlewarbler

BobL , the space is an extension I had built a while ago . It is 21ft long x 8ft wide x 8ft high . There is 2 windows in it so plenty of light , There is a garage at the other end with probably the same measurements ( only the one window in the garage though ) . There is an 8ft x 4ft workbench i'm on building , just finished putting a new coat of emulsion on the walls and ceiling yesterday . There is lots of old timber a few floorboards old doors etc , that's in the kitchen at the moment I'm working on that .I'm thinking of doing my own kitchen units there are double French doors to go in also. My tools are a 10in blade sliding mitre saw , a planer , an old Elu router and a new Bosch GTS 10 XC Professional table saw ( which hasn't been used yet ).I don't know if it will get much use or not .

Thanks for the info, what is your average estimated hours per week of use. of power tools or machinery?

I was in a bit of a hurry this morning , there is also an 8ft x 2ft workbench down one side of the room . I decided to build the 8ft x 4ft bench to give me extra workspace , I can remove the smaller bench if need be . There is also a wood frame on castors to put my tablesaw on , it fits about the same size as the table top when the saw is mounted . There is also 20 + 18ins x 18ins paving slabs about 6 and a half cement bags and a barrow under there somewhere ,I decided to give it a fresh coat of emulsion , I don't know when it will be next done . I don't use my work tools too much , I used to build a couple of cd stackers with glass doors nothing major but who knows . I do enjoy making things from wood , I'm no expert but it keeps me busy and occupied .

The main reason for asking all these questions (especially the usage patterns) is because safe dust collection from machinery and tools requires moving massive amounts of air. This is simply not possible in workshop situations without; a) using 150mm diameter ducting , b) 3HP+ dust extraction and c) modifying machinery so that enough air can get into machines to carry the dust out. The latter is not possible without modifying most machine dust ports.

However, occasional (a few hours per week actually making dust) DIY users can usually get away with wood chip collection systems you describe above and adequate ventilation. Unless you live in a windy area then forced ventilation is required to remove fine dust and normally targets around 20 room changes per hour. The shape of your work area long and thin is ideal for forced ventilation and you should be able to work out what size fan(s) you need to get 20 room changes per hour. Even using bathroom ventilation fans is usually good enough provided enough of them are used.

Back to your original question - you will need both the Jet style extractor to collect the chips from the sliding mitre saw, planer and table saw, and the vacuum cleaner style for the router.
If you had to restrict yourself to one I would go for the Jet Style unit.

Mornin all , I picked a dust extractor out its

a

Charnwood Dust Extractor – W691

, but everyone in the country must have at least 2 of them . Every supplier I contact is out of stock ( exept the really dear ones ), most say it will be the end of april before they get more stock . So I will have to hang on for my new Dust Extractor .Charnwood Dust Extractor – W691.JPG

You should look for a machine that has a finer filter. That one is a 5 micron and would at times let the smaller particles through. They cause you the most harm. See if you can find a 1 micron or finer filtering machine. If you do decide to use a 2hp machine like you show, read the sticky at the top of the title page. There is information of modifying them to get better performance.

Pete

Even though I realise the OP and QC are located in cold climates, if the DC is located outside a workshop or in an enclosure that vents outside the workshop then the 5 micron rating is not a problem.
The 5 micron rating is nominal because once the bag is conditioned it's the wood dust layer on the inside of the filters that provides the majority of the filtering.
My measurements of conditioned DC filters show similar filtration efficiencies of >95% for 1 micron Pleated filters and 5 micron Needlefelt bags at 0.3 microns.
Whether this is sufficient filtration depends on sensitivity to wood dust and the amount of fine dust made per unit time.
If you are not sensitised to wood dust and using your DC for a couple of hours a week then your overall exposure may not be significant, but it could be for an every day user and even more so for a sensitised user.
For frequent users of those with existing health issues then a Real HEPA or Nano type filter with >99% at >0.3 microns would be needed if venting inside a workshop.

The time taken to condition Needlefelt bags and Pleated filter is when they are the leakiest. This can be overcome by taking the DC outside and sucking up a couple of buckets of sawdust into the DC and running it outside for a few hours.

The more significant long term issues with conventional DCs venting inside a shed are not usually filter efficiency related but that,
- they eventually all leak, much more than the fine dust that gets through filters
- if only 4" ducting is used, and the filters are not cleaned regularly then they never even collect enough of the fine dust to begin with

BobL , I don't have any

sensitivity to wood dust

. Could someone recommend a suitable Dust extractor , it will be the end of April before they get the

Charnwood Dust Extractor – W691

back in stock anyway . All advice is very welcome . Thanks very much .

Evnin all , are any of these any good .Fox Dust extractor.JPGScheppach.JPGScheppach 1.JPG

Evnin all , are any of these any good . Fox Dust extractor.JPGScheppach.JPGScheppach 1.JPG I looked at some Axminster ones but they were far too expensive for me .

I'm going to buy the Scheppach Woova 3.0 Dust Extractor .Scheppach Woova 3.0 Dust Extractor.JPGScheppach Woova 3.0 Dust Extractor 1.JPG

I wouldn't if I were you. My reasons are that the motor (gleaned from other sellers) is only 0.8hp which is about 40% of what you should have as a minimum. The filter surface area claim is 2 to 3 times what most come with so I don't understand how they could cram that much more filter media in it. The 4" hose it comes with can't move enough air to be useful except on the smallest dust makers yet the spec claims the dusty moves 50% more than is possible through the 4" hose.

I wish manufacturers and sellers wouldn't lie about the performance of their machines but they do because they are only interested in their profits. If they were truthful they loose sales.

You should be looking for a 2hp machine(1500 watts) with a 6" inlet (150mm).

Pete