Festool extractor with dewalt 18v tools?

This is the info (email) on differences between Class L and M Festool Midi extractor-

If an M class extractor is required then an L class will not officially suite.


We cannot recommend the use of a L class if you require M class extraction, but the bags, filter and motor are the same in an L and M machine.

The M has the alarm to basically tell you if airflow is reduced to a level that is too low, that is a requirement of an M class machine.



Regards

Customer services.

I've heard also from Festool customer services that the L is ok for example MDF, hardwood and other class M dust. Maybe if you regularly clean filter in L class it's fine for M class dust?

Keitai said:

If an M class extractor is required then an L class will not officially suite (sic)

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I find this disgraceful coming from a manufacturer. If you use L-class filters which potentially let through a lot more particles than M-class filters it is you, the user, who will eventually pay the price. It really isn't a matter of "officially" at all. More ignorant salesman b0ll0x

Your salesmsn goes on to imply that the L-class vacuum has the same filters as the M-class. Then why does the HSE make such a big play out of it? Oh yes, because respiratory disease amongst tradesmen is too high. He's right that M-class vacuums require a filter monitor, but the filters for M-class and L-class are not the same. The requirement is actually that M-class vacuums warn the user of too low a filtration level and if needs be shut down - but the requirement is also that the vacuum has higher standard of filtration

Keitai said:

Maybe if you regularly clean filter in L class it's fine for M class dust?

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No, it isn't. (or in tradesman speak, "what utter b0ll0x!"). M-class filters are able to filter smaller particles than L-class. Or did your eyes glaze over when I quoted the spec, above?

BTW, by your definition of what is OK surely it should be OK to use a L-class vacuum on asbestos, providing you regularly clean the filter?

The reply from Festool doesn't surprise me, TBH, because this is the firm that assures potential trade buyers that 230 volt tools are legal on British sites..... and we know how true that is

I'd hate to be on the wrong end of a law suit if an employee or customer challenged the use of the wrong class of machine as laid down in H&S regs.
We had guys working in a dusty environment wearing measuring devices so an expert could calculate the correct extraction systems and followed the report. Should one of those guys suffer a complaint in future we should be able to say we followed a documented recommendation from an expert. No hope if we say "but the bloke in the shop said"

JobAndKnock said:

I find this disgraceful coming from a manufacturer. If you use L-class filters which potentially let through a lot more particles than M-class filters it is you, the user, who will eventually pay the price. It really isn't a matter of "officially" at all. More ignorant salesman b0ll0x

Your salesmsn goes on to imply that the L-class vacuum has the same filters as the M-class. Then why does the HSE make such a big play out of it? Oh yes, because respiratory disease amongst tradesmen is too high. He's right that M-class vacuums require a filter monitor, but the filters for M-class and L-class are not the same. The requirement is actually that M-class vacuums warn the user of too low a filtration level and if needs be shut down - but the requirement is also that the vacuum has higher standard of filtration


No, it isn't. (or in tradesman speak, "what utter b0ll0x!"). M-class filters are able to filter smaller particles than L-class. Or did your eyes glaze over when I quoted the spec, above?

BTW, by your definition of what is OK surely it should be OK to use a L-class vacuum on asbestos, providing you regularly clean the filter?

The reply from Festool doesn't surprise me, TBH, because this is the firm that assures potential trade buyers that 230 volt tools are legal on British sites..... and we know how true that is

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Well I'm totally confused on whether to upgrade to "M' class. My L class is sitting at Screwfix waiting for me to pick it up or whether to upgrade. Festool and the customer service guy from a shop which sells the extractors are saying the same thing that the filters, bags etc are the same for both L and M. They're saying L machine will stop M class dust as long as you clean filter and u avoid the annoying alarm which is there to allow a tool to go on site and warn u it needs cleaning or something. You need the alarm to be officially accepted there I guess (by HSE) but if I work in people's houses it's not needed. I've been trying to speak to Festools technical guy but he's not called me back

Were you actually to talk to an HSE inspector you'd find their primary requirement is for the standard of filtration to be appropriate. And class L is NOT class M, regardless of how often you clean it.

You may not work on site, but you ARE a tradesman and health and safety law applies to you just as much as it does to site workers working for a main contractor. You need to take this on board. I feel you are fixating on a feature which is simply not the most relevant one - the important thing, to do with your future good health and that if your clients is the filtration unit a bloody buzzer! But you believe what you will. Ignorance is bliss

JobAndKnock said:

The M-class Metabo ASR35M has two filters where if one filter starts to clog it is automatically shut down and shaken clean whilst the other filter does double duty - so no reduction in filtration whilst continuing to function normally.

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If you are using a bag, why would the filter clog in the first place? The oldest of my two Festool dust extractors (CT22) have the old paper bags, they do split from time to time when sanding cement based fillers. I do have to clean the filters from time to time. They are about 18 yrs old and still the original filters, not M class though.

opps said:

If you are using a bag, why would the filter clog in the first place?-

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Because the bags never filter as fine a dust as the primary filters can. Worst thing I have ever picked up in filters is soot - seems to be able to go right through the bags and stubbornly refuses to be washed out of filters.

Just thinking aloud...

I have two CT22, one mk1 Midi and the CT Sys. All are L class. IIRC there are HEPA class filters available for both the MIDI and SYS. Fitting the HEPA filters however will reduce the suction. BTW, I appreciate that M class covers more than just filters.

Does M class specify a minimum rate of suction? If my MIDI with a HEPA filter for example sucked up 20% less of the dust when sanding paint work, would that be worse than sticking with the L class filters in the first place?

AFAIK the regs don't specify the suction level - you are expected to have a vacuum with an appropriate extraction capacity for the tool it is attached to and it is obviously impossible to legislate this for every tool given that the extraction volume requirements for, say, a 1/4 sheet sander on gloss paint and a wall chaser on thermalite blockwork are so very different. Equally I can't recall seeing any power tool manufacturer specify the vacuum model that any given tool must be used on

Where the regs are very specific is in the filtration specification. Extract dust on an L-class vacuum and a percentage of what you suck up, the smallest particles which are the ones most likely to cause long term harm, will pass straight through the bag and the filter and exhaust out the back of the vacuum - right into the air that you are breathing. Not so bad on plaster dust - very bad on MDF (a class M dust) and potentially lethal with something like asbestos (a class H dust). That's where the real potential for harm is. One problem is that any harm doesn't become apparent for years, sometimes decades, at which time it is too late to do anything. For example, despite being a non-smoker, "builder's cough" is a phenomenon I suffer from first thing on cold sharp mornings, like this morning, and dealing with plywood, hardwood, MDF and lime plaster dusts over decades have given me allergic rhinitis as well (making mask wearing an absolute must), but at least I don't have pneumoconiosis, silicosis or COPD or any of the other respiratory diseases which can all result from long term exposure to fine dusts

In terms of higher rated filtration causing diminution of suction, the only anecdotal evidence that I can give is that a number of years back, when I had a Metabo ASR2025 L-class vacuum, I changed the filters over to M-class ones. There was no apparent change in the volume being extracted, or if there was it was minimal, but I did find that I was less affected by the dust off chipboard flooring and MDF sheets I was cutting. But that vacuum, a rebadged Starmix, has dual main filters (as does the current ASR35M - another Starmix product).

Surely if your vacuum cannot cope with the volume of dust when you change filters, that indicates that your vacuum is too low a suction capacity for the task at hand, doesn't it?

JobAndKnock said:

Surely if your vacuum cannot cope with the volume of dust when you change filters, that indicates that your vacuum is too low a suction capacity for the task at hand, doesn't it?

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Sorry, I haven't actually replaced the filters. It was more the case that by my (possibly flawed) logic, a finer filter must reduce airflow (once something other than clean air passes through it).

Out of interest, my two CT22 vacs have an outlet port that you can plug a hose in to. It enables you to vent post filtered air out of a window if you want. I have only ever used it on extremely hot days to vent the warm exhaust air outside. On reflection, bad for the environment (and anyone outside), but better for my lungs?

Isn't it all about volume, though? The air capacity in a 12 x 10 x 8ft room is 960 cubic feet, the air in a 50 x 30 x 16ft hall is 24,000 cubic feet, and outside? Blow10g/min of dust into any of these environments and what will the effect be? Dependingbon the dust, in the small room it' could soon become intolerable without a mask, in the hall it will take quite a while to get to that stage (possibly days as dust will settle out of the air onto the floor over time, especially at night when there is no air movement caused by people walking, etc), but outside surely it'll only really make a difference of you are standing within a few feet of the end of the hose because of dilution in the air.

OK, let's put a few of the misconceptions to bed.

Before all the EU nonsense we had basically three grades of vacuum cleaner - ordinary ones, ordinary ones with extra HEPA filtration, and Type H which are (and still are) built to a (non-harmonized) British Standard (BS 5415-2.2:Supplement No. 1:1986) and are sold with individual machine test certificates - this BS is still specified by MOD and Nuclear industry.

Then along came EU directive BS-EN 60335 - BS because we harmonized it, and which, incidentally, is called "Household and similar electrical appliances — Safety". This is where all the L, M and H Class (note not Type H, but H Class) b*******x came from. Ignoring Type L, which is basically an "ordinary vacuum", M and H Class introduced the filter clog indicator - which doesn't have to be a light, or a buzzer - just an indicator - a simple gauge with a red section is enough. But here's the killer - Vacuum cleaners of dust class M and class H shall be provided with an indicator which operates before the air velocity, through the largest hose (or tube) supplied by the manufacturer, falls below 20 m/s, referring to the largest section in the hose. - It's Bx because if multiple hose diameters and lengths are available the indicator is useless (yes you could have some means of adjusting the indicator - and the standard says if one is necessary it must be adjustable without tools but it's all EU Bx because they only refer to hose diameter - it doesn't consider that the airflow might be different in a 15m hose to a 3.5m one!). And in any case, stick the nozzle into a pile of dust, kill the flow, indicator goes off.

Secondly, of course, L, M and H class specify different filtration grades. In reality many M and H class machines have exactly the same filter - the main difference is that H Class units are certified and technically require re-certifying to maintain their rating.

Thirdly, M and H Class have to collect into a disposable bag. Great if it's a personal machine, but totally useless and impractical for a real commercial/industrial vacuum with a 60-80 litre collection tank - ever tried lifting 80 litres of carp? A disposable bag strong enough to contain, yet still possible to filter is a very expensive item - hardly disposable, and the reason real Industrial machines don't use them - and are neither M or H rated!

There is no substitute for power. Flow and Vacuum are interdependent. You get maximum vacuum with zero flow (think hand over the nozzle) and maximum flow with no vacuum. If you want both for heavy duty applications, you need power, which is why Industrial machines designed for use in factories, industrial plants etc are typically 4-15kW on 3PH. many have HEPA filtration, many are ATEX rated. Most are not M Class or H Class.

Cutting to the chase, an M rated machine has to have "better" filtration than an L Class, BUT a fairly powerful vacuum + a very fine HEPA filter is likely to blind very quickly with very fine dust, so yes, use M or even H to protect yourself from fine dust in a personal environment, but it isn't the be-all and end-all. It is the actual filtration system overall that matters, and that has to be appropriate for the application. If you are working in a dusty environment, the exhaust air from a vacuum can stir more dust into the air than passes through a filter, so wear a mask!

Also, even HSE is confused - some of the publications on working with asbestos wrap Type H and H Class together "H Class, sometimes called Type H" - even though the classifications arise from two completely different BS with completely different filter test specifications....