Choice of workshop vac?

[MikeJhn]

Siggy7?

Adjudicate please?
Sam

Siggy is too much of a gentleman to prove either of us wrong, we will just have to agree to disagree.

 

[gwreis]

Hi,

I have very good experiences with Nilfisk vaccum cleaners. I did a lot of reaserch 2 years ago and decided to buy a Nilfisk Aero 26-21 PC from Screwfix. The price was by far the best I could find anywhere. At the time I´ve paid 129 euros and I´ve bought a Hepa filter for it for an extra 130 euros at another dealer. I just checked and the price now is bit higher at 169 euros. It has 1250 watts, 1900 watt power tool socket, plenty of suction power and 3700 liter per hour air flow. At 64db I still think it´s a bit loud, but much better then other shop vacs. I´ve paired it with a Dust Deputy Cyclone and a 30l metal container to collect the dust/shavings and I coudn´t ask for more. I´ve being using it for the past 2 years and have no complaints so far.

If you willing to spend more money, I worked with a L Class Nilfisk Attix 33 extractor and is a very good machine. Quiet (60 db), speed selection, 1400 watts, 4500 liter a minute of air flow, power tool socket as well... If I had the money I would go with this machine. It´s truly a quality high end machine. It´s expensive though, costing aroung 400 to 700 euros depending on the specification. Normally the HEPA filter is no included, so you have to put around 130 euros on top of that. There is also the option for the Attix 30. It´s an older design and a bit cheaper. It´s also super quiet at 59 db at max speed, but a bit top heavy.

As you can tell, I´m a big fan of Nilfisk products and definitely would recomend them.

Cheers

 

[weekend_woodworker]

Thanks for all the discussion and advice. Having done a bit more reading up, based on HSE guidelines I think I need an M class filter as I work with both hardwoods and softwoods.

The Numatic system mentioned earlier looks good, but to get it to M class seems to be about £900. I am not sure the Fein or Nilfisk vacs off M class.

Looking at the market it seems possible to get one for about £500, but I am not sure if they are any good.

I have found this V Tuf for about £120, but don’t know if anyone has experience of it?
V-Tuf vacuum

Thanks,

Mark

 

[Eric]

The M class filter for the Fein is £22 https://www.mtmc.co.uk/Product.aspx?Pro ... rch&PPGR=0

 

[weekend_woodworker]

Thanks for the link Eric. That seems much better value as even the 35L variant with tools is £290 + £20 for the filter gets a system at £310 rather than over £500.

The other thing I noticed on the Miles website is the dust bags for the Fein which are about £5 each which seems fairly steep. Although looking at the bags for the Bosch machine at about £500 they seem to vary from £4 to £6, so I guess they are much of a muchness.

Definitely one to think about. Thanks.

 

[mbartlett99]

It seems that there are onlh a couple of manufactuers of quality vacuum cleaners - Nilfisk and Numatic - both of whom make for others. It was on post sometime last year. Either of those brands are pretty bulletproof; I tend to go for Nilfisk because their parts are available worldwide.

Shopvac err no, just no. Might be ok for cleaning your garage but thats it.

 

[weekend_woodworker]

Thanks for the recommendations about Numatic and Nilfisk. This seems like a good price for a Numatic TEM390A M Class vac at £400. It is more expensive than the Fein one, but comes certified as M Class. It is also interesting that the bags are available at about only £1 each rather than £4 each for the other vacs. So does anyone have experience of using a Numatic TEM390A?

 

[MikeJhn]

At only 650 watt and 18lt capacity I can see this being underpowered and forever being emptied, why do you specifically want M Class when most larger machines can have the exhaust ducted wherever you want, even into a outside filter box, additionally at only 650watt its not going to suck away a lot of the harmful dust, its only class M when the dust gets to the unit, but I do find these class of filters a bit pointless in a home workshop, debatably different if you have to conform to H&S legislation in the workplace for a client and their employees, someone still has to empty and clean the class M and other filters, bags do take most of the dust away without contact, but Class M fine dust still gets on the filters you have to clean and don't forget that filtering through something that fine will reduce the suction.

This would be my choice: https://www.axminster.co.uk/numatic-nvd ... r-ax782721 at 2400Watts (will take away a lot more dust) and a 30Lt capacity with ducting facility and four filters when used with a bag more expensive, but what value your health.

EDIT: Even though it says Axminster on it, it's actually a Numatic.

 

[siggy_7]

Sorry, just seen this - as I've been asked to comment, I offer the following thoughts in the interests of providing information (categorically not taking sides in an online debate).

Filters work by trapping particles as a fluid passes through a membrane with lots of tiny holes in it. A filter is specified based on the size of particles you want to trap (i.e. the size of perforations in the membrane) and the flow rate through the system for a given pressure drop across the filter (more surface area of a filter reduces the pressure drop across the filter for a given flow rate).

Let's think about what happens during operation. As the filter works, particles become trapped on the filter surface. This starts to block up the perforations in the filter media. In terms of the filter's ability to capture particles, it's obvious that the blocking of the filter pores will aid rather than hinder the filter's ability to capture more particles. However, this comes at the expense of more flow resistance. Over time, the increase in flow resistance will starve your extraction system of flow rate. It's pointless having a filter that is capturing all of the dust passing through it when due to a restricted flow rate most of the dust isn't getting to the filter in the first place. It's worth stating that any correctly specified filter should capture the required size of particles even when brand new; relying on the filter blocking up to provide the required filtration efficiency would be considered poor practice. Running a filter with the required efficiency and keeping it clean to maximise flow rate through the system (and thus dust-capturing ability) is a better approach.

 

[SammyQ]

Thank you Siggy, I am grateful for you sharing your knowledge and bringing clarity to bear.

I, in no way, wish to initiate, perpetuate or accentuate, any debate; I seek only empirical fact, in the face of which, "debate" is superfluous.

Sam

 

[MikeJhn]

Debate is never superfluous, plus you can read siggy's post any way you like, as a filter starts to do its job it blocks even more dust, therefore becoming in effect more efficient than its intended filtration, this obviously can not go on for ever as the flow rate will decrease to a point of inefficiency, the only way to keep the whole of you filter working at its intended filtration particle size is to clean it every minute of the day, this is not what happens in the real world and filters are always partially blocked.

 

[SammyQ]

"relying on the filter blocking up to provide the required filtration efficiency would be considered poor practice. Running a filter with the required efficiency and keeping it clean to maximise flow rate through the system (and thus dust-capturing ability) is a better approach."

This is the nub of what I was trying to articulate earlier, but failed miserably. I have a twin-bag, leaky, HVLP Axi 'blower'. I use it to extract CHIPS from my AGS saw and my Elecktra 260C planer/thicknesser. The bag weave 'separation' between strands is smaller than the average chip, so I find very little dust exfiltration from either tool, and my asthma remains dormant, even in a closed shed.

My Record HPLV 'dustbin' has a much finer filtration 'weave' where this distance is significantly less; that deals effectively with sub-micron router dust; you can tell from the change in motor note when its paper bag is clogged.

If I reversed the usage, the Axi would initially cast loads of dust out, then the bag fabric would 'load up' with dust and the extraction failure Siggy refers to would happen. The Record dalek/dustbin would probably soldier on for a bit, but its capacity for chips is limited, about a third of the twin-bagger's capacicity.

Returning to the quotation from Siggy at the top of this post, if I had a pools (that dates me!) or a Lottery win, I would invest in a H.D. Bosch, self-cleaning beastie in a heartbeat. I've seen what it can do in terms of " Running a filter with the required efficiency and keeping it clean to maximise flow rate "attched to an R.O.S., and it was a revelation. Certainly, i'd back using one for domestic installations where airborne dust is a concern for either health or finishing, (or both!!).

This is just my tuppence worth - 0.85p in Newspeak - and 'your mileage may vary'.

Be safe, breathe easily and deep. Sam

 

[SammyQ]

"the only way to keep the whole of you filter working at its intended filtration particle size is to clean it every minute of the day, this is not what happens in the real world and filters are always partially blocked"

I refer the Right Honourable gentleman to my two posts re the Bosch/Hilti systems.

I further refer the Right Honourable Gentleman to my post immediately subsequent to his last one and I claim, not 'The Chiltern Hundreds', but the the discretion to 'agree to disagree'.

Signing off, Sam

 

[MikeJhn]

I would love to know how they self clean and where the dust they clean off the filter goes?

 

[SammyQ]

Me too!! Didn't get a chance to pull either apart and suss that out...but the point was, no airborne allergens. They rock.

Sam, really signing out this time.

 

[siggy_7]

I would love to know how they self clean and where the dust they clean off their filters goes?

I have a Nilfisk Alto shop vac with a filter cleaning facility - you hit a big button on the top of the vacuum a few times and it cleans out the filter. The filter itself is a cylindrical element which is held into the vacuum by a central plastic assembly. This central assembly has a plastic weight that can slide up and down. I think how these work is that when the vacuum is on, the plastic weight rises to the top. The big button completely blocks the flow off, and the plastic weight drops down which then acts like a tap to a blocked filter, knocking the dust off. The dust just falls back into the collection chamber. It's surprisingly effective - if the filter is restricted, you notice an immediate drop in pitch from the motor after cleaning (indicating it's less blocked). I think the automatic machines by Bosch use a similar principle, it's just automated on a timer.

 

[MikeJhn]

So in effect the dust is re-cycled back to the filter and eventually you are knocking off the same dust each time you activate the devise. #-o

 

[siggy_7]

Well some of the dust will undoubtedly end up back on the filter, but most of it should fall away and end up in the pile of collected debris. Once the dust falls out of suspension of the airflow, it will settle out. It's not going to be as effective as cleaning out the filter with a compressed air line of course, but these systems do work allowing you to keep going with good airflow through the extractor (in the case of the fully automated ones, with no operator intervention at all). That these systems do work is evident in the immediate increase in air flow which only then gradually reduces with ongoing use as new dust accumulates on the filter. And at some point, you're probably going to empty out all that dust into a bin!

 

[MikeJhn]

So just delaying the inevitable emptying process, sounds like giving the vacuum unit a good shake before each use may be of benefit.

 

[SammyQ]

The Bosch and Hilti I experienced, both had some form of automatic cleaning. Sounded very like reverse airstream, probably to do the same job as Siggy proposed. Whatever it was, it worked, without any physical intervention from the operator. Super useful when up a step ladder with a wall tracker or ROS.

Sam