Re: See the new dust collector?
> I would argue that the assumption of a distribution of particle sizes is more than?> justified in any woodworking context.
My point was not that?distribution doesn't exist, but?that it can vary widely, including real-world cases where a comparatively larger filter size will not necessarily result in higher mg/m3, such as fine sanding operations (predominantly sub micron particles) and comparing 1 to 5 micron filters.
Clearly however, for a given particle source, the lower the mg/m3, the better the filtration. ?By trying to correlate mg/m3 to filter sizes in any precise way is probably hopeless.?
Trying to correlate filter size to health protection in any precise way is hopeless too. ?What matters is how much dust ends up in your lungs, which is a lot more closely correlated to mg/m3 than to filter specs, which by themselves say absolutely nothing about the actual resultant post-filtration dust density, since that depends on other factors like the dust generation rate and the air handling in the space. ? If I pump X quantity of particles thru a filter into a 500 sqft shop, the result is a lot different than pumping it into a 5,000 sqft shop. ?And if the shop air handling has say 5 air exchanges per hour, vs. say 15, the results are very different as well.
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Re: See the new dust collector?
" You're presumably assuming a distribution of particles, including ones that are larger than than the smaller filter size.? For example, if the source includes 2 micron particles, then they will pass thru the 5 micron filter but not the 1 micron filter, so the 5 micron filter would yield a higher mg/m3 level."
I am definitely assuming a distribution of particles.? I don't know about everyone else, but when I empty my dust collector bin there is a wide range of sizes of chips and sawdust and a much smaller amount of finer stuff in the filter stack cleanout.? Clear evidence of a range of sizes, so I would argue that the assumption of a distribution of particle sizes is more than justified in any woodworking context.
On Fri, Dec 2, 2016 at 12:53 AM, murkyd@... [felder-woodworking] <felder-woodworking@...> wrote:
?
> but changing the micron level of the filter will definitely impact the mg/m3 level.? I see no? > way around that concept.? If your filter is actually filtering anything at all, then increasing > the max micron level of the filter will by definition allow more particles through which > will increase the mg/m3 level.
Not necessarily.? Suppose you have a stream of <0.5 micron particles.? A 5 micron filter won't let through more of these particles than a 1 micron filter will -- all the particles pass through either filter.
You're presumably assuming a distribution of particles, including ones that are larger than than the smaller filter size.? For example, if the source includes 2 micron particles, then they will pass thru the 5 micron filter but not the 1 micron filter, so the 5 micron filter would yield a higher mg/m3 level.
Mark ---In felder-woodworking@yahoogroups.com, I don't see how the micron level of the filter and the mg/m3 are not directly related (not necessarily a linear relationship).? Of course they are not the same thing, but changing the micron level of the filter will definitely impact the mg/m3 level.? I see no way around that concept.? If your filter is actually filtering anything at all, then increasing the max micron level of the filter will by definition allow more particles through which will increase the mg/m3 level. ?
mg/m3 is not a measure of volume, it is more a definition of "dust density".
Wood dust and health risks seems to be a controversial topic without any clear authority to draw conclusions from.
?
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Re: See the new dust collector?
> but changing the micron level of the filter will definitely impact the mg/m3 level.? I see no? > way around that concept.? If your filter is actually filtering anything at all, then increasing > the max micron level of the filter will by definition allow more particles through which > will increase the mg/m3 level.
Not necessarily. ?Suppose you have a stream of <0.5 micron particles. ?A 5 micron filter won't let through more of these particles than a 1 micron filter will -- all the particles pass through either filter.
You're presumably assuming a distribution of particles, including ones that are larger than than the smaller filter size. ?For example, if the source includes 2 micron particles, then they will pass thru the 5 micron filter but not the 1 micron filter, so the 5 micron filter would yield a higher mg/m3 level.
Mark ---In felder-woodworking@..., <jscuteri@...> wrote : I don't see how the micron level of the filter and the mg/m3 are not directly related (not necessarily a linear relationship).? Of course they are not the same thing, but changing the micron level of the filter will definitely impact the mg/m3 level.? I see no way around that concept.? If your filter is actually filtering anything at all, then increasing the max micron level of the filter will by definition allow more particles through which will increase the mg/m3 level. ?
mg/m3 is not a measure of volume, it is more a definition of "dust density".
Wood dust and health risks seems to be a controversial topic without any clear authority to draw conclusions from.
On Thu, Dec 1, 2016 at 6:43 PM, John jmkserv@... [felder-woodworking] <felder-woodworking@...> wrote:
?The only filter that gets 100% is totally plugged. A filter is also at its highest efficiency just before its plugged, Hepa or not. We're splitting a hell of a lot of hairs between 0.1, 0.05, 0.03. They are all Hepa rated and considered extremely safe and typically emit air cleaner than the air we breathe.?
-------- Original message --------
From: "David Luckensmeyer dhluckens@... [felder-woodworking]" < felder-woodworking@ yahoogroups.com> Date: 2016-12-01 6:33 PM (GMT-05:00) To: felder-woodworking@ yahoogroups.com Subject: Re: [felder-woodworking] See the new dust collector?
?Brian, you¡¯ve hit the nail on the head (as usual). Whether a filter can filter down to a certain size or not is only one half of the story. It¡¯s the percentage efficiency that provides the other half. A filter that can filter down to 5 microns is definitely not good enough. But for filters that can filter down to 1 micron, or 0.5 microns, I¡¯ve never seen one that has 100% efficiency. This means that the filters are not getting all of the particles down to that size.?
I¡¯m no expert, but I think that is why Felder (and others) quote amounts/volumes, rather than sizes?
Warm regards, David
Dr David Luckensmeyer Practice Manager Luckensmeyer Medical Pty Ltd ?
and
Designer and Woodworker Original Designs in Wood ?
I guess I should have continued my train of thought¡. I didn¡¯t see anything enlightening on the Festool group. I think an engineer for these dust collector companies would have to provide more info. What micron level the filters clean to is totally separate from how many milligrams per cubic meter is emitted from the DC.?
Obviously the less volume is emitted the better, but i think the size of particles has some bearing on health issues too.
Brian we were obviously trying to find a correlation between the apples and oranges. I think if you read the Festool link you will see the connection or am I completely missing something.
?
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Re: See the new dust collector?
Haha! All good John. I'm full of 95% shit, any advances...?
Warm regards,David
Dr David Luckensmeyer Practice Manager Luckensmeyer Medical Pty Ltd ?
and
Designer and Woodworker Original Designs in Wood ?
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Re: See the new dust collector?
As a newbe I just want to say The information you have provided me so far is priceless, on the other side I like that you all can shovel out the BS too.
I had a moment to look at a few of your websites and I have to say I am impressed.
I don't know you all yet, who is who, where your at, and what you really do but you have helped me and open my eyes to that there is alot more i need to look at.
Right now im trying to close a LTL on my building.? once done I am all over you guys to help me with input to put this all together.
Thank you all
Glen Christensen
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-----Original Message-----
From: John Kee jmkserv@... [felder-woodworking] <felder-woodworking@...>
To: FOG
Sent: Thu, Dec 1, 2016 6:21 pm
Subject: Re: [felder-woodworking] See the new dust collector?
?
Its OK Lucky you can say it, I'm full of shit. LOL
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Re: See the new dust collector?
Its OK Lucky you can say it, I'm full of shit. LOL
?
Wow John. Pure entertainment huh? At least 90% of the time? I didn't know you were so knowledgeable. ?
?
I was being serious, I don't watch, read or listen to the news. 90% is pure bullshit. Those that control the media and the information only give you enough for control and manipulation. But Thanx for the articles. ? There's an old saying, ?believe none of what you read and half of what you see.?
These forums are nothing but pure entertainment and a slight diversion with maybe 10% useful information.?
-------- Original message -------- From: "'david@bestservices IMAP 2' david@... [felder-woodworking]" < felder-woodworking@yahoogroups.com> Date: 2016-12-01 8:05 PM (GMT-05:00) To: felder-woodworking@yahoogroups.com Subject: Re: [felder-woodworking] See the new dust collector?
?
David don't know what your referring to when you say fake news, please enlighten me.?
Not sure if you¡¯re being sarcastic or serious, but just in case . . . .
? David Best
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Re: See the new dust collector?
Wow John. Pure entertainment huh? At least 90% of the time? I didn't know you were so knowledgeable. ?
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On 2 Dec. 2016, at 11:29 am, John jmkserv@... [felder-woodworking] < felder-woodworking@...> wrote:
?
I was being serious, I don't watch, read or listen to the news. 90% is pure bullshit. Those that control the media and the information only give you enough for control and manipulation. But Thanx for the articles. ? There's an old saying, ?believe none of what you read and half of what you see.?
These forums are nothing but pure entertainment and a slight diversion with maybe 10% useful information.?
-------- Original message -------- From: "'david@bestservices IMAP 2' david@... [felder-woodworking]" < felder-woodworking@...> Date: 2016-12-01 8:05 PM (GMT-05:00) To: felder-woodworking@... Subject: Re: [felder-woodworking] See the new dust collector?
?
David don't know what your referring to when you say fake news, please enlighten me.?
Not sure if you¡¯re being sarcastic or serious, but just in case . . . .
? David Best
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Re: See the new dust collector?
That's almost as bad as bean counters and marketing departments running a company.?
For some strange reason, elected officials just entered my mind, but I¡¯ll refrain from going any further on that topic. ?:-)
David Best
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Re: See the new dust collector?
Awe David say it ain't so. Companies aren't manipulating numbers to sell products. That's almost as bad as bean counters and marketing departments running a company.?
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-------- Original message -------- From: "'david@bestservices IMAP 2' david@... [felder-woodworking]" <felder-woodworking@...> Date: 2016-12-01 8:31 PM (GMT-05:00) To: felder-woodworking@... Subject: Re: [felder-woodworking] See the new dust collector?
?
Like I said - just like dust collection specifications.
I was being serious, I don't watch, read or listen to the news. 90% is pure bullshit. Those that control the media and the information only give you enough for control and manipulation. But Thanx for the articles. ? There's an old saying, ?believe none of what you read and half of what you see.?
These forums are nothing but pure entertainment and a slight diversion with maybe 10% useful information.?
-------- Original message -------- From: "'david@bestservices IMAP 2' ?david@...?[felder-woodworking]" < felder-woodworking@...> ?Date: 2016-12-01 8:05 PM (GMT-05:00) ?To: ?felder-woodworking@...?Subject: Re: [felder-woodworking] See the new dust collector? ??
David don't know what your referring to when you say fake news, please enlighten me.?
Not sure if you¡¯re being sarcastic or serious, but just in case . . . .
? David Best
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Re: See the new dust collector?
Like I said - just like dust collection specifications.
toggle quoted message
Show quoted text
I was being serious, I don't watch, read or listen to the news. 90% is pure bullshit. Those that control the media and the information only give you enough for control and manipulation. But Thanx for the articles. ? There's an old saying, ?believe none of what you read and half of what you see.?
These forums are nothing but pure entertainment and a slight diversion with maybe 10% useful information.?
-------- Original message -------- From: "'david@bestservices IMAP 2' ?david@...?[felder-woodworking]" < felder-woodworking@...> ?Date: 2016-12-01 8:05 PM (GMT-05:00) ?To: ?felder-woodworking@...?Subject: Re: [felder-woodworking] See the new dust collector? ??
David don't know what your referring to when you say fake news, please enlighten me.?
Not sure if you¡¯re being sarcastic or serious, but just in case . . . .
? David Best
|
Re: See the new dust collector?
I was being serious, I don't watch, read or listen to the news. 90% is pure bullshit. Those that control the media and the information only give you enough for control and manipulation. But Thanx for the articles. ? There's an old saying, ?believe none of what you read and half of what you see.?
These forums are nothing but pure entertainment and a slight diversion with maybe 10% useful information.?
toggle quoted message
Show quoted text
-------- Original message -------- From: "'david@bestservices IMAP 2' david@... [felder-woodworking]" <felder-woodworking@...> Date: 2016-12-01 8:05 PM (GMT-05:00) To: felder-woodworking@... Subject: Re: [felder-woodworking] See the new dust collector?
?
David don't know what your referring to when you say fake news, please enlighten me.?
Not sure if you¡¯re being sarcastic or serious, but just in case . . . .
? David Best
|
Re: See the new dust collector?
David don't know what your referring to when you say fake news, please enlighten me.?
Not sure if you¡¯re being sarcastic or serious, but just in case . . . .
? David Best
|
Re: See the new dust collector?
Hahaha!
Warm regards, David
Dr David Luckensmeyer Practice Manager Luckensmeyer Medical Pty Ltd ?
and
Designer and Woodworker Original Designs in Wood ?
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Wood dust and health risks seems to be a controversial topic without any clear authority to draw conclusions from.
I¡¯m pretty sure this is where the current ¡°Fake News¡± trend started - around dust collection specs.
David Best
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Re: See the new dust collector?
David don't know what your referring to when you say fake news, please enlighten me.?
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Show quoted text
-------- Original message -------- From: "'david@bestservices IMAP 2' david@... [felder-woodworking]" <felder-woodworking@...> Date: 2016-12-01 7:33 PM (GMT-05:00) To: felder-woodworking@... Subject: Re: [felder-woodworking] See the new dust collector?
?
Wood dust and health risks seems to be a controversial topic without any clear authority to draw conclusions from.
I¡¯m pretty sure this is where the current ¡°Fake News¡± trend started - around dust collection specs.
David Best
|
Re: See the new dust collector?
Wood dust and health risks seems to be a controversial topic without any clear authority to draw conclusions from.
I¡¯m pretty sure this is where the current ¡°Fake News¡± trend started - around dust collection specs.
David Best
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Re: See the new dust collector?
>? I¡¯m no expert, but I think that is why Felder (and others) quote amounts/volumes, rather than sizes?
Presumably the reason they use mg/m3 is because that's the standard medical exposure metric. ?For example, OSHA doesn't specify filter size, it specifies the maximum quantity (in mg) of dust that can be present in each cubic meter of air in the workplace. ? This metric does not factor particle size, but I believe the threshold assumes a typical particle size distribution -- that is to say, if you are under the threshold, you can assume you are safe regardless of the particle size distribution. ?
Fwiw, the NIOSH exposure limit is 1mg/m3.?
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Re: See the new dust collector?
I don't see how the micron level of the filter and the mg/m3 are not directly related (not necessarily a linear relationship).? Of course they are not the same thing, but changing the micron level of the filter will definitely impact the mg/m3 level.? I see no way around that concept.? If your filter is actually filtering anything at all, then increasing the max micron level of the filter will by definition allow more particles through which will increase the mg/m3 level. ?
mg/m3 is not a measure of volume, it is more a definition of "dust density".
Wood dust and health risks seems to be a controversial topic without any clear authority to draw conclusions from.
On Thu, Dec 1, 2016 at 6:43 PM, John jmkserv@... [felder-woodworking] <felder-woodworking@...> wrote:
?
The only filter that gets 100% is totally plugged. A filter is also at its highest efficiency just before its plugged, Hepa or not. We're splitting a hell of a lot of hairs between 0.1, 0.05, 0.03. They are all Hepa rated and considered extremely safe and typically emit air cleaner than the air we breathe.?
-------- Original message --------
From: "David Luckensmeyer dhluckens@... [felder-woodworking]" < felder-woodworking@yahoogroups.com> Date: 2016-12-01 6:33 PM (GMT-05:00) To: felder-woodworking@yahoogroups.com Subject: Re: [felder-woodworking] See the new dust collector?
?
Brian, you¡¯ve hit the nail on the head (as usual). Whether a filter can filter down to a certain size or not is only one half of the story. It¡¯s the percentage efficiency that provides the other half. A filter that can filter down to 5 microns is definitely not good enough. But for filters that can filter down to 1 micron, or 0.5 microns, I¡¯ve never seen one that has 100% efficiency. This means that the filters are not getting all of the particles down to that size.?
I¡¯m no expert, but I think that is why Felder (and others) quote amounts/volumes, rather than sizes?
Warm regards, David
Dr David Luckensmeyer Practice Manager Luckensmeyer Medical Pty Ltd ?
and
Designer and Woodworker Original Designs in Wood ?
I guess I should have continued my train of thought¡. I didn¡¯t see anything enlightening on the Festool group. I think an engineer for these dust collector companies would have to provide more info. What micron level the filters clean to is totally separate from how many milligrams per cubic meter is emitted from the DC.?
Obviously the less volume is emitted the better, but i think the size of particles has some bearing on health issues too.
Brian we were obviously trying to find a correlation between the apples and oranges. I think if you read the Festool link you will see the connection or am I completely missing something.
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Re: See the new dust collector?
The only filter that gets 100% is totally plugged. A filter is also at its highest efficiency just before its plugged, Hepa or not. We're splitting a hell of a lot of hairs between 0.1, 0.05, 0.03. They are all Hepa rated and considered extremely safe and typically emit air cleaner than the air we breathe.?
toggle quoted message
Show quoted text
-------- Original message -------- From: "David Luckensmeyer dhluckens@... [felder-woodworking]" <felder-woodworking@...> Date: 2016-12-01 6:33 PM (GMT-05:00) To: felder-woodworking@... Subject: Re: [felder-woodworking] See the new dust collector?
?
Brian, you¡¯ve hit the nail on the head (as usual). Whether a filter can filter down to a certain size or not is only one half of the story. It¡¯s the percentage efficiency that provides the other half. A filter that can filter down to 5 microns is definitely not good enough. But for filters that can filter down to 1 micron, or 0.5 microns, I¡¯ve never seen one that has 100% efficiency. This means that the filters are not getting all of the particles down to that size.?
I¡¯m no expert, but I think that is why Felder (and others) quote amounts/volumes, rather than sizes?
Warm regards, David
Dr David Luckensmeyer Practice Manager Luckensmeyer Medical Pty Ltd ?
and
Designer and Woodworker Original Designs in Wood ?
I guess I should have continued my train of thought¡. I didn¡¯t see anything enlightening on the Festool group. I think an engineer for these dust collector companies would have to provide more info. What micron level the filters clean to is totally separate from how many milligrams per cubic meter is emitted from the DC.?
Obviously the less volume is emitted the better, but i think the size of particles has some bearing on health issues too.
Brian we were obviously trying to find a correlation between the apples and oranges. I think if you read the Festool link you will see the connection or am I completely missing something.
|
Re: See the new dust collector?
Brian, you¡¯ve hit the nail on the head (as usual). Whether a filter can filter down to a certain size or not is only one half of the story. It¡¯s the percentage efficiency that provides the other half. A filter that can filter down to 5 microns is definitely not good enough. But for filters that can filter down to 1 micron, or 0.5 microns, I¡¯ve never seen one that has 100% efficiency. This means that the filters are not getting all of the particles down to that size.?
I¡¯m no expert, but I think that is why Felder (and others) quote amounts/volumes, rather than sizes?
Warm regards, David
Dr David Luckensmeyer Practice Manager Luckensmeyer Medical Pty Ltd ?
and
Designer and Woodworker Original Designs in Wood ?
toggle quoted message
Show quoted text
I guess I should have continued my train of thought¡. I didn¡¯t see anything enlightening on the Festool group. I think an engineer for these dust collector companies would have to provide more info. What micron level the filters clean to is totally separate from how many milligrams per cubic meter is emitted from the DC.?
Obviously the less volume is emitted the better, but i think the size of particles has some bearing on health issues too.
Brian we were obviously trying to find a correlation between the apples and oranges. I think if you read the Festool link you will see the connection or am I completely missing something.
|
Re: See the new dust collector?
I guess I should have continued my train of thought¡. I didn¡¯t see anything enlightening on the Festool group. I think an engineer for these dust collector companies would have to provide more info. What micron level the filters clean to is totally separate from how many milligrams per cubic meter is emitted from the DC.?
Obviously the less volume is emitted the better, but i think the size of particles has some bearing on health issues too.
toggle quoted message
Show quoted text
Brian we were obviously trying to find a correlation between the apples and oranges. I think if you read the Festool link you will see the connection or am I completely missing something.
|
David Luckensmeyer
David P. Best