Can a Festool Midi or Mini vacuum accept Festool HEPA filters?

[Simon O]

Staubklasse L and Staubklasse M are German standards relating to health in the workplace from an organization called BIA.

To achieve Class L an extractor must not allow more than 1% of extracted dust to pass out of the filter to a "maximum allowable concentration" (MAK value) greater than 1 mg/m^3.

To achieve Class M an extractor must not allow more than 0.1% of extracted dust to pass out of the filter to a "maximum allowable concentration" (MAK value) greater than 0.1 mg/m^3.

There are several higher categories but Class H is generally the highest for normal trade use.

To achieve Class H an extractor must not allow more than 0.1% (can be as low as 0.005%) of extracted dust to pass out of the filter to a "maximum allowable concentration" (MAK value) less than than 0.1 mg/m^3

The above copied from another thread - what i don't understand is how class M extractors achieve those MAK values if the filters, the filter bags and the suction power are the same as the L class?

As for the Hepa certification/filtration issues - it's clear to me they are more efficient, but I still don't understand why the Hepa certification/filtration is not available in Europe for Midi, Mini or Sys - whereas Hepa filters are available in Europe for models 26 and above? Does that mean these models are suitably designed to work efficiently with Hepa filters, just like their american counterparts?

'If the HEPA filters are not available in Europe how could the CT Mini/ Midi in Europe be HEPA CERTIFIED? Seems like that is a, no.  Just because they are not HEPA certified in Europe doesn't mean there are necessarily design differences.'

So a HEPA  CERTIFIED Midi in America doesn't necessarily have any design differences to a European Midi - can we get a definitive Festool answer to that? As 'necessarily' doesn't do it for me. I thought the extractors themselves had to be HEPA CERTIFIED - what does this mean in reality?

[member=48770]Magpal[/member] help out, please 

'

 

[GarryMartin]

what i don't understand is how class M extractors achieve those MAK values if the filters, the filter bags and the suction power are the same as the L class?

I think you're getting confused with the maximums allowed and the actuals. Unfortunately, not a lot of manufacturers actually list the specific technical capabilities of their filters and instead rely on the classifications that they are sold under.

If a Class L extractor allowed 0.05%, then that would meet the requirement that not "more than 1% of extracted dust to pass out of the filter". If a Class M extractor allowed 0.05%, then that too would meet the requirement of not "more than 0.1%".

The Class L extractor couldn't be certified as a Class M extractor simply because of the filtration because it wouldn't have an audible alert that is a requirement for Class M.

The main filter in a CTL 26 is the same main filter as in a CTM 26. They use the same filter bags. So read into that what you may with regard to the efficiency of the filtration of both.

What are you actually trying to ensure?

 

[semenza]

So a HEPA  CERTIFIED Midi in America doesn't necessarily have any design differences to a European Midi - can we get a definitive Festool answer to that?

The difference between the two continents is basically the filter for the US is certified for HEPA standards in the UK it is correct for L class applications. Internally the difference will be the motor due to different voltage. The seals and gaskets will be the same.
rg
Phil

  From Phil's last post.

Seth

 

[Magpal]

Staubklasse L and Staubklasse M are German standards relating to health in the workplace from an organization called BIA.

To achieve Class L an extractor must not allow more than 1% of extracted dust to pass out of the filter to a "maximum allowable concentration" (MAK value) greater than 1 mg/m^3.

To achieve Class M an extractor must not allow more than 0.1% of extracted dust to pass out of the filter to a "maximum allowable concentration" (MAK value) greater than 0.1 mg/m^3.

There are several higher categories but Class H is generally the highest for normal trade use.

To achieve Class H an extractor must not allow more than 0.1% (can be as low as 0.005%) of extracted dust to pass out of the filter to a "maximum allowable concentration" (MAK value) less than than 0.1 mg/m^3

The above copied from another thread - what i don't understand is how class M extractors achieve those MAK values if the filters, the filter bags and the suction power are the same as the L class?

As for the Hepa certification/filtration issues - it's clear to me they are more efficient, but I still don't understand why the Hepa certification/filtration is not available in Europe for Midi, Mini or Sys - whereas Hepa filters are available in Europe for models 26 and above? Does that mean these models are suitably designed to work efficiently with Hepa filters, just like their american counterparts?

'If the HEPA filters are not available in Europe how could the CT Mini/ Midi in Europe be HEPA CERTIFIED? Seems like that is a, no.  Just because they are not HEPA certified in Europe doesn't mean there are necessarily design differences.'

So a HEPA  CERTIFIED Midi in America doesn't necessarily have any design differences to a European Midi - can we get a definitive Festool answer to that? As 'necessarily' doesn't do it for me. I thought the extractors themselves had to be HEPA CERTIFIED - what does this mean in reality?

[member=48770]Magpal[/member] help out, please 

'

Not sure if I have anything interesting to contribute with, but i'll try to fill in. My understanding of the practical class M/L difference is as others have pointed out that the Festool class L/M will filter the dust equally good but that class L lacks the audible alarm when the suction drops (and probably some other minor differences defined by IEC 60335-2-69). I therefore think that the MAK values of the two classes are of less importance, since both class L and M Festool extractors seems to offer the 0.1mg/m^3 efficiency due to the filter configuration being equal for class L and M.

Although I am feeling quite confident that the class L extractors provides sufficient filtering (based on the european standards at least), I still think that the marketing and general information available could be better. For instance:

Festool (and other brands) recommend the following uses for L/M class:
Dust class L:
Simple, harmless dust such as house dust and materials such as soil.

Dust class M:
All wood dust and dust originating from repair compound, filler and clear coats, plaster, cement, concrete, tile cement and paints such as latex and oil paints or quartziferous materials such as sand and pebbles.

I guess these statements are just copy paste from some standard/general guidance, but for the Festool extractors I dont know if this makes sense if we assume that the penetration grade for Festool class L is actually equal to class M. Who would really buy the autostarted CT class L for vacuuming house dust and soil anyway?

I think most of this gets down to pure compliance rather than actual performance. Even though the class L is allowed to have MAK values as high as 1mg/m^3 it seems like the Festool class L (and also Bosch etc.) are performing as a class M (0.1mg/m^3) in terms of penetration limits. The class L does however lack the flow alarm and thus it has to be classified as a class L extractor. This does not necessarily mean that class L is worse in terms of penetration grade, but that it is not fulfilling all requirements for the class M extractor. For the weekend warriors, this does not seem to make any practical difference as long as you change your bags before you loose suction.

If this is true, I do think that the marketing and general information on Festools website could be better at poitning out the practical difference for their class L and M extractors. But it does probably not make that much sense to push for something cheaper

Compliance is probably also the reason why we are not seeing more HEPA filters in EU. I would assume that the filters and gaskets for the HEPA extractors are more expensive, and thus it would not make sense to over-engineer the filtration for customers not requiring the HEPA-filter. 

 

[GarryMartin]

I would assume that the filters and gaskets for the HEPA extractors are more expensive, and thus it would not make sense to over-engineer the filtration for customers not requiring the HEPA-filter.

[member=41214]Phil Beckley[/member] confirmed yesterday that the seals and gaskets are the same in the EU non-HEPA and the US HEPA versions of the Midi, so it really seems to be just down to the filter as the cloth dust bags are also the same.

 

[Magpal]

I would assume that the filters and gaskets for the HEPA extractors are more expensive, and thus it would not make sense to over-engineer the filtration for customers not requiring the HEPA-filter.

[member=41214]Phil Beckley[/member] confirmed yesterday that the seals and gaskets are the same in the EU non-HEPA and the US HEPA versions of the Midi, so it really seems to be just down to the filter as the cloth dust bags are also the same.

Ahh sorry, didn't catch that. So it seems like it would be easy to offer these filters for the MIDI as well then. Questions is if this would really make any difference in practice. It would be very interesting so see some "real world" tests of class M filter vs. HEPA filter using a particle counter.

 

[antss]

You might dig into EKAT and see how many different filter part numbers there are.

Or aren't.  [wink]

That might narrow it down a bit.

 

[Simon O]

I would assume that the filters and gaskets for the HEPA extractors are more expensive, and thus it would not make sense to over-engineer the filtration for customers not requiring the HEPA-filter.

[member=41214]Phil Beckley[/member] confirmed yesterday that the seals and gaskets are the same in the EU non-HEPA and the US HEPA versions of the Midi, so it really seems to be just down to the filter as the cloth dust bags are also the same.

So why not put a Hepa filter in a European Midi - wouldn't that give better filtration?

 

[Simon O]

...a Hepa filter sourced from America of course, as they're not available here for some reason.

 

[Simon O]

what i don't understand is how class M extractors achieve those MAK values if the filters, the filter bags and the suction power are the same as the L class?

I think you're getting confused with the maximums allowed and the actuals. Unfortunately, not a lot of manufacturers actually list the specific technical capabilities of their filters and instead rely on the classifications that they are sold under.

If a Class L extractor allowed 0.05%, then that would meet the requirement that not "more than 1% of extracted dust to pass out of the filter". If a Class M extractor allowed 0.05%, then that too would meet the requirement of not "more than 0.1%".

The Class L extractor couldn't be certified as a Class M extractor simply because of the filtration because it wouldn't have an audible alert that is a requirement for Class M.

The main filter in a CTL 26 is the same main filter as in a CTM 26. They use the same filter bags. So read into that what you may with regard to the efficiency of the filtration of both.

What are you actually trying to ensure?

You're right I am getting confused, is it just me or do a lot of people see the distinction between L and M class extractors in Europe, to be one of increased efficiency where filtration is concerned - there's confusing data here and in my view, a strong implication of the above.

So in answer to your question I'm trying to ensure clarity, in an area which seems to confuse more than just me, judging by this and many other threads, I've looked at over the last few months.  [eek]

Both you and Alex, have said that there is no difference in the efficiency of the L and M extractors, so for someone who's not fussed about marketing and PR, the best option would be to access the L class extractors and simply pop a more efficient filter in - thus ensuring a safer work environment - no?

 

[GarryMartin]

Both you and Alex, have said that there is no difference in the efficiency of the L and M extractors, so for someone who's not fussed about marketing and PR, the best option would be to access the L class extractors and simply pop a more efficient filter in - thus ensuring a safer work environment - no?

Yes. If you don't have to adhere to any standards from a professional health and safety perspective (that would dictate an M class extractor), knock yourself out. If you want the best filtration (without going to H class), you can get a HEPA filter for the CT 26/36/48 in the UK/Europe (P/N 498894), and you can get a HEPA filter for the Mini and Midi in the US (P/N 496752).

 

[Simon O]

Thanks Garry - is there any reason why you would choose not to use a Hepa filter - you think it's overkill (judging by the 'knock yourself out' comment  [smile])?

 

[GarryMartin]

Thanks Garry - is there any reason why you would choose not to use a Hepa filter - you think it's overkill (judging by the 'knock yourself out' comment  [smile])?

Not at all. I have one in my CTL 26 and have discussed this many times in the past.

So if you are covered by legal requirements, you will almost certainly need the CTM. If you are a home woodworker, my advice would be to go for the CTL. If you value your health and want the best filtration, I'd also advise using the HEPA filters that come as standard in the US market. The HEPA Main Filters are 99.99% efficient at capturing particulate matter down to 0.3 microns.