M-class vs. L-class 'HEPA' Dust Extractors

[phased]

Hi all, period home renovator new to the forums. Australian.

I've read a couple of old threads that broadly discuss the above but would like confirmation that Festool's CT 15l HEPA Class Dust Extractor will have equal-if-not-better dust extraction filtration quality than the CTM MIDI-I 15l M Class Dust Extractor (which comes standard with an 'M Class filter').
https://www.festool.com.au/ct-15l-hepa-class-dust-extractor_574866.htmlhttps://www.festool.com.au/ctm-midi-15l-m-class-dust-extractor_576740.html

As I understand it, Festool AU have been fitting all CTs with a HEPA filters for some time now - which I understand to be a level above M Class. I assume the inclusion of the HEPA filter elevates the filtration level from 99.0% to 99.9% - but I guess this is assumes the machines are the same in other ways, too.

I've even found a Festool Aus brochure (see below) that says the use of a HEPA in an L-class machine is suitable for capturing 'lead based paint' particles. I won't be doing this explicitly - but I can't say for sure that there aren't a few nasty dusts around the site. Some painted windows sills were in pretty bad shape.

I understand there are other differences between the models but am most interested in filtration quality as the machine will likely see little use other than an initial site clean post-renovations (need to keep the missus on side!). Thanks for any help - unfortunately the Festool helpline wasn't particularly so. Cheers

(Side note: other parts of the Festool website in Aus says lead = H-class machine requirement!)

 

[bertv]

I think a lot of the confusion can be attributed to the way these are classified. In the US it is based on HEPA. In Europe they use the L/M etcetera system. I am by no means an expert, but there is some info on the subject to be found on the Festool-website., esp. the Painters’ section.

 

[AlexThePalex]

I've read a couple of old threads that broadly discuss the above but would like confirmation that Festool's CT 15l HEPA Class Dust Extractor will have equal-if-not-better dust extraction than the CTM MIDI-I 15l M Class Dust Extractor (which comes standard with an 'M Class filter').

Let's make our wording clear, you say "dust extraction" above, and not filtration.

A vac with the HEPA filter will have the best filtration. To have better filtration, you need a finer filter, and the finer the filter, the less airflow you have. So while a HEPA filter has better filtration, it will also result in slightly worse dust extraction.

As I understand it, Festool AU have been fitting all CTs with a HEPA filters for some time now - which I understand to be a level above M Class. I assume the inclusion of the HEPA filter elevates the filtration level from 99.0% to 99.9% - but I guess this is assumes the machines are the same in other ways, too.

That is correct, HEPA has better filtration than Europe's L and M class vacs.

But please note, in order for HEPA to be valid, the entire system, ie the entire vac needs to be HEPA rated in the USA. What's the point of having a HEPA filter installed if the seams in the housing leak air like crazy?

I've even found a Festool AU brochure (see below) that says the use of a HEPA in an L-class machine is suitable for capturing 'lead based paint' particles.

Also correct, a vac with a HEPA filter is suitable to capture lead particles. And so are L and M class vacs. At least, in Europe, because in Europe, lead paint dust doesn't fall in a special category. America has special rules. I don't know about your Australian rules. Does Australia even have rules?  [wink]

(Side note: other parts of their website says lead = H-class machine requirement!)

Well, not in Europe. Here, lead dust is not considered a hazard that requires an H-class vac, like for instance asbestos. That's a whole other category. L and M class will do.

 

[Coen]

Besides the flow indicator and price tag the Festool CTM and CTL are identical anyway, so the 99% vs 99.9% filtration... haha.

 

[phased]

Let's make our wording clear, you say "dust extraction" above, and not filtration.

A vac with the HEPA filter will have the best filtration. To have better filtration, you need a finer filter, and the finer the filter, the less airflow you have. So while a HEPA filter has better filtration, it will also result in slightly worse dust extraction.

As I understand it, Festool AU have been fitting all CTs with a HEPA filters for some time now - which I understand to be a level above M Class. I assume the inclusion of the HEPA filter elevates the filtration level from 99.0% to 99.9% - but I guess this is assumes the machines are the same in other ways, too.

That is correct, HEPA has better filtration than Europe's L and M class vacs.

But please note, in order for HEPA to be valid, the entire system, ie the entire vac needs to be HEPA rated in the USA. What's the point of having a HEPA filter installed if the seams in the housing leak air like crazy?

Thanks, Alex (and everyone else). I have edited my original post for clarity - I'm talking about filtration, yes.

Funnily enough, I got a call from a (far more knowledgeable) Festool rep a moment ago and he pretty much confirmed what I/we suspected. That the CT 15l HEPA Class Dust Extractor is superior in terms of filtration as compared with an M-Class machine fitted with a M-class filter. The former is missing a flow sensor / alarm, but that seems more necessary in a commercial application.

He also clarified it is a HEPA-rated machine (not just the filter). So, little-to-no leaks allover.

After all that, I'm thinking the CT 15l HEPA Class Dust Extractor is just what I need and I'll save a few hundred bucks in the process. Cheers

 

[squall_line]

But please note, in order for HEPA to be valid, the entire system, ie the entire vac needs to be HEPA rated in the USA. What's the point of having a HEPA filter installed if the seams in the housing leak air like crazy?

Festool's CT extractors are full-unit HEPA certified, housing and all.

To wit, from the FestoolUSA Website,https://www.festoolusa.com/knowledge/hepa-dust-extractors (emphasis added, but the all caps is original to the text copy):
All current Festool CT Dust Extractor models have been independently tested and certified to be FULL UNIT HEPA Dust Extractors. When you purchase a new Festool CT Dust Extractor, regardless of model, you will find a printed certificate in the box as well as labeling on the dust extractor documenting its Full Unit HEPA certification.

Lead dust doesn't make me happy.  In fact, it bothers me quite a bit knowing how many kids are around it and eating chips or even just living around people who dry-scrape lead-paint-covered homes without any thought given to the potential harm they're doing.  Obviously there are plenty of other airborne hazards that are even more insidious, like asbestos, fiberglass, and silica dust.

I don't know about your Australian rules. Does Australia even have rules?  [wink]

Well, there's "Australian Rules Football", so there's at least a few rules for that.  [wink]  Of course, their football marginally closer to America's version of football, which is completely different from Europe's version of the sport.  [big grin]

 

[phased]

Festool's CT extractors are full-unit HEPA certified, housing and all.

Thanks for the further confirmation. I'm sure the L/M/H class was introduced by those Europeans to simplify things, but when you throw HEPA variability into the mix, it sure muddies the waters. Cheers

 

[mino]

Festool's CT extractors are full-unit HEPA certified, housing and all.

Thanks for the further confirmation. I'm sure the L/M/H class was introduced by those Europeans to simplify things, but when you throw HEPA variability into the mix, it sure muddies the waters. Cheers

The European L/M/H classes is more strict in that the system must GUARANTEE sufficient filtration AND sufficient dust extraction (aka air volume).

This is unlike HEPA which addresses only the filtration part.

That way, you can have a vac which meets HEPA, but does not meet M-class. And you can also have a vac which meeds M-class yet does not meet HEPA due to a weaker filter.

Confused sufficiently ? Then read on:

All Festool L/M class use EXACTLY the same filters and have the exact same performance within series.
Still, the L-Class units cannot be sold as M-class. This is because they lacks the sensor which will alert the user that the air volume dropped below safe thresholds and the whole system performance is affected - e.g. a clogged filter. This allows the user to stop the work and remediate the issue.

There is no such flow sensor requirement in HEPA though as the "basic" HEPA standard covers only the filtration part, not the air volume part.

So, while the (basic) HEPA standard -is- stricter than both the L-class and the M-class, the "HEPA" Vacs sold by Festool are exactly same as the L-Class vacs sold by them and have exact same filters as their M-class vacs too.


This is because the vacs exceed the L-class minimum requirements, they also exceed the M-Class requirements (but cannot be sold as M-class compliant as do not have the sensor required by the standard). Well, since they exceed HEPA reqs. on filtration, that is kinda expected, right ?

The H-class vacs are a different beast though.
H-class is stricter than (basic) HEPA in both filtration and include the air-volume requirement in addition.

Now, in practice it is like this:
- all Festool vacs are sealed to (be able to) comply with both European H-class and HEPA requirements
- the actual filtration level will depend on what filter you use (they are interchangeable)
- if you need the flow sensor -> get the M-class units

If you are a commercial operation, also make sure to get a unit that meets whatever regulatory requirement is applicable in your jurisdiction.

If you just want best possible filtration at lowest cost, get a simple CTL 26 and buy a set of H-class bags and a H-class main filter for when you expect to work with really dangerous stuff (think asbesthos dangerous).

If you are happy with "HEPA vac", then any Festool vac will do per above.

If you want your vac to tell you when the air flow is getting too low, for whatever reason, get an M-class with the flow sensor.

 

[AlexThePalex]

And then when you realise how much dust escapes at the source you understand it doesn't matter if you have an L, M or HEPA filter.

 

[phased]

If you just want best possible filtration at lowest cost, get a simple CTL 26 and buy a set of H-class bags and a H-class main filter for when you expect to work with really dangerous stuff (think asbesthos dangerous).

Thanks for the thorough response, mino. That all made sense.. with perhaps the exception of the above part ^

The H-class main filter, at least on the Aus website is Designed to trap particles down to 1 micronhttps://www.festool.com.au/ct-extractor-h-class-main-filter_498995.html

While their HEPA filters are Designed to trap particles down to .03 micronshttps://www.festool.com.au/ct-mini-midi-2-hepa-extractor-main-filter.html

I would have assumed the H-class main filter to be some sort of 'super' HEPA filter, perhaps capable of trapping to below .03 microns - particularly given the 99.995% particle capture claim. Can you elaborate?

The CT 26L is substantially more expensive down here than the CT 15l HEPA, and aside from the inability to fit an H-class bag (instead is uses a SELFCLEAN filter bag), is there really much difference in terms of filtration?

Again, I'm not looking to start a HAZMAT cleaning service, I just want a solid 'site clean' vacuum after all the trades have left and the proverbial (and literal) dust has settled. There was some minor remediation work done to some all painted windows, hence the mild paranoia. The painter assured me they used Festool HEPA extractors at the time.

Update

Spoke to Festool Rep again. He said H-Class filters (in Aus at least) are HEPA filters. So, effectively the same as what comes with the CT 15l HEPA (although a different size, I'm guessing). Said the main 'filtration' difference between L class and M/H class machines (assuming they are all fitted with HEPA filters) is the ability to use a H Class Safety Bag in the latter.

He said their SELFCLEAN bags capture up to 0.5 micron anyway - so no big deal - unless I'm looking to vac asbestos, etc.

He endorsed the CT 15l HEPA for my purposes. Thanks

 

[Johnyhof]

Does Selfclean really capture 0.5um?  There is little of this information on the intranet, I found a mention of 5 um somewhere, but it is true that they are wary of official information.

Johny

 

[mgrobins]

The requirement on commercial sites to use a specific class for insurance / safety means L/M/H are important for trades, however a person using in a non-commercial setting isn't hamstrung by this requirement.

This means you are free to choose a less expensive model and have the same filtration without the naming convention.
I find the way Festool describe and distinguish between models here a bit duplicitous given use of common parts and filters on models. I think of the Dust Extractor range as being one of those scenarios where a profession is hit with higher pricing because of the legislated provisions (L/M/H) not the actual product.

 

[squall_line]

The requirement on commercial sites to use a specific class for insurance / safety means L/M/H are important for trades, however a person using in a non-commercial setting isn't hamstrung by this requirement.

This means you are free to choose a less expensive model and have the same filtration without the naming convention.
I find the way Festool describe and distinguish between models here a bit duplicitous given use of common parts and filters on models. I think of the Dust Extractor range as being one of those scenarios where a profession is hit with higher pricing because of the legislated provisions (L/M/H) not the actual product.

It's not duplicitous if the extractors are actually a higher quality than the legislation requires.  The primary difference between the L and the M models is the inclusion of a low flow alarm on the M models, which is required to meet regulations.  That the L class filters just as well as the M class is not duplicitous, it's actually quite generous considering the alternative would be to not even bother to try.