iglasgo on thu 31 may 07
questions
Very interesting information, thanks for posting it.
I've been craving a new vacuum for the house, and wondering if my old
vac would be suitable for use in the studio. It's a Eureka "true HEPA"
type that uses allergen filtration bags and has a replaceable HEPA
filter on the exhaust. A lot like this one, but older:
http://www.eureka.com/products/upright/5892bvz/5892bvz.jsp
It seems to do a very good job of keeping the dust down in the house.
What do you guys think? Is there a significant difference between this
household vac and the really expensive studio vacs?
Best,
Ivy G.
--- In clayart@yahoogroups.com, WJ Seidl wrote:
>
> Clayarters:
> John and I have been having an interesting off list conversation
> regarding what I wrote about water filtering
> the output of a wet/dry vac. I think the information is important
> enough to post to the list.
> First, some important information. OSHA standards show the following:
>
> "Respirable dust has been shown to be harmful to human health,
> especially when silica is present in the dust. It causes a disease
> known as silicosis, which can occur in three levels: chronic silicosis,
> which occurs after 10 years of exposure; accelerated silicosis, which
> occurs between 5 and 10 years of exposure; and acute silicosis,
> which can occur within a few weeks to five years of very high exposure
> to silica dust. Respirable dust consists of the dust particle size
> fraction whose median diameter is 4 microns (=CE=BCm)."
> (Note that the mention is of _dust_, especially dust containing silica.
> Not just silica, ALL dust)
>
> With John's permission, our off list conversation is shown below in
> reverse chronological order (newest post first).
> Please note the information in the second paragraph below, and compare
> it to the information above.
>
> Best,
> Wayne Seidl
>
> John:
> We use that system for commercial applications such as stores that
> generate a large amount of normal floor dust.
> We're in these places once a week each. From start to finish, each vac
> job takes about three hours. At the end of the operation, I go around
> and check to see if there has been any redeposit of dust on to surfaces,
> which is 1) an indicator that the vacuum is not performing to expected
> levels, and 2) obvious dust is not going to make our customer very
happy
> in the morning.
> To date, we haven't found any significant redeposit (I check with white
> microfiber cloths). That is the only testing I do on a regular
basis. I
> am quite sure that
> there is some dust escaping the vacuum. As to particle size, I can't
> answer because I have not had it analyzed. To our customers, if it
> isn't visible, it isn't there so for our use, keeping the customer
> happy is good enough. Of course, silica exposure is NOT a normal concern
> in vacuuming a department store.
>
> If anyone is concerned about silica exposure, they should not be dry
> vacuuming anyway. If they insist on doing so for silica removal, I
> would of course recommend a HEPA filtered vacuum. However, the caveat
> with HEPA filters is the same. It does not remove ALL particles. It
> was designed to remove allergens and bacteria, which run in the 0.3
> micron and larger range, IIRC.
>
> Here is the blurb from the Goodway HEPA vacuum site:
> --------
> HEPA Vacuum History
>
> The need for absolute filtration arose during World War II and was
> developed by the Atomic Energy Commission as part of the Manhattan
> Project to produce the first atomic bomb. There was a pressing need to
> address the health and safety issues raised by the handling of
> radioactive dust. Research and development produced the first HEPA (High
> Efficiency Particulate Air) filters for the ventilation systems used to
> deliver ultra clean air to clean rooms.
>
> In order for a filter to be certified HEPA, it must be tested and proven
> to filter particles as small as 0.3 microns to 99.97% efficiency at its
> designed air flow. To understand what a HEPA filter does, it helps to
> understand what a micron is. A micron is 1 millionth of a meter. A human
> hair is approximately 100 microns wide. Particles smaller than 10
> microns are not visible to the human eye. A particle of tobacco smoke
> averages 0.01 to 1 micron. Most bacteria range from 0.35 to 10 microns.
> Almost all viruses, however, are smaller than 0.03 microns and HEPA
> filters are not effective at trapping them.
> -------------
> So, to answer your question, if the vacuum is spitting out particles,
> they would be smaller than 10 microns.
>
> Best,
> Wayne Seidl
>
> On May 31, 2007, John Hesselberth wrote:
>
> > Hi Wayne,
> >
> > I'm concerned about this from an engineering standpoint. With the
volume
> > of air that is being handled I suspect those bubbles would be huge
and
> > there would be no effective washing out of the dust at all.
Designing a
> > scrubber that really works requires generating a huge amount of
surface
> > area, i.e. extremely fine bubbles. I guess I am asking if you have
> > really tested this to be certain it is removing the dust. Or are you
> > just not seeing it blow back into your studio because it is so fine?
> >
> > John
> >
>
> >
> > On May 30, 2007, at 5:22 PM, WJ Seidl wrote:
> >
> >> Then it is a simple matter of installing a 5 gallon bucket in
the bottom
> >> of the vac, installing the pipe, and filling the bucket at least
halfway
> >> with water (or simply installing the pipe and adding water to
the vacuum
> >> so that the bottom elbow is covered to a depth of two inches or
so. The
> >> intake water bubbles through the water and exits the vacuum as it
> >> normally would, minus dust, in effect creating a water bath.
> >
>
>
___________________________________________________________________________=
___
> Send postings to clayart@...
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@...
>
WJ Seidl on thu 31 may 07
questions
Ivy:
A HEPA filtered vacuum will protect somewhat against silica if the=20
particles are large enough,
but I would again caution anyone against using a "dry" vacuum in the=20
studio, or vacuuming their studio "dry".
It only takes a few minutes to wet down the floor, and vacuum it up with=20
a wet vac, and you can
almost guarantee the safety of your lungs that way.
There are upright wet vacuums available for little money. These are=20
commonly used to
wet vac kitchen and other hard surface floors, and usually have a tank=20
for holding the chemical
or cleaner (or just plain water) that they spray, adn a collection tank=20
for whatever they suck up afterward.
Upright home carpet cleaners like the Hoover SteamVac do the same thing.
Should I tell you therefore not to use your dry vac in the studio? Well,=20
if it were me in MY studio, I wouldn't.
You really have to decide that for yourself. All we can do is put the=20
information out there.
For the record though, I hose the floor in mine. Then I wet vac it if I=20
feel the need to get the water up quickly.
But one can do that with concrete. Not always the case in a home, or a=20
studio with wood floors.
For those areas, a wet mop will do.
Emphysema, silicosis, bronchitis and other respiratory illnesses are no=20
fun. They can and will kill you.
I know that from personal experience. It's easy to avoid, why take the=20
chance?
Best,
Wayne Seidl
iglasgo wrote:
> Very interesting information, thanks for posting it.
>=20
> I've been craving a new vacuum for the house, and wondering if my old
> vac would be suitable for use in the studio. It's a Eureka "true HEPA"
> type that uses allergen filtration bags and has a replaceable HEPA
> filter on the exhaust. A lot like this one, but older:
> http://www.eureka.com/products/upright/5892bvz/5892bvz.jsp
> It seems to do a very good job of keeping the dust down in the house.
> What do you guys think? Is there a significant difference between this
> household vac and the really expensive studio vacs?
>=20
> Best,
> Ivy G.
>=20
> --- In clayart@yahoogroups.com, WJ Seidl wrote:
>> Clayarters:
>> John and I have been having an interesting off list conversation
>> regarding what I wrote about water filtering
>> the output of a wet/dry vac. I think the information is important
>> enough to post to the list.
>> First, some important information. OSHA standards show the following:
>>
>> "Respirable dust has been shown to be harmful to human health,
>> especially when silica is present in the dust. It causes a disease
>> known as silicosis, which can occur in three levels: chronic silicosis=
,
>> which occurs after 10 years of exposure; accelerated silicosis, which
>> occurs between 5 and 10 years of exposure; and acute silicosis,
>> which can occur within a few weeks to five years of very high exposure
>> to silica dust. Respirable dust consists of the dust particle size
>> fraction whose median diameter is 4 microns (=CE=BCm)."
>> (Note that the mention is of _dust_, especially dust containing silica.
>> Not just silica, ALL dust)
>>
>> With John's permission, our off list conversation is shown below in
>> reverse chronological order (newest post first).
>> Please note the information in the second paragraph below, and compare
>> it to the information above.
>>
>> Best,
>> Wayne Seidl
>>
>> John:
>> We use that system for commercial applications such as stores that
>> generate a large amount of normal floor dust.
>> We're in these places once a week each. From start to finish, each va=
c
>> job takes about three hours. At the end of the operation, I go around
>> and check to see if there has been any redeposit of dust on to surface=
s,
>> which is 1) an indicator that the vacuum is not performing to expected
>> levels, and 2) obvious dust is not going to make our customer very
> happy
>> in the morning.
>> To date, we haven't found any significant redeposit (I check with whit=
e
>> microfiber cloths). That is the only testing I do on a regular
> basis. I
>> am quite sure that
>> there is some dust escaping the vacuum. As to particle size, I can't
>> answer because I have not had it analyzed. To our customers, if it
>> isn't visible, it isn't there so for our use, keeping the customer
>> happy is good enough. Of course, silica exposure is NOT a normal conce=
rn
>> in vacuuming a department store.
>>
>> If anyone is concerned about silica exposure, they should not be dry
>> vacuuming anyway. If they insist on doing so for silica removal, I
>> would of course recommend a HEPA filtered vacuum. However, the caveat
>> with HEPA filters is the same. It does not remove ALL particles. It
>> was designed to remove allergens and bacteria, which run in the 0.3
>> micron and larger range, IIRC.
>>
>> Here is the blurb from the Goodway HEPA vacuum site:
>> --------
>> HEPA Vacuum History
>>
>> The need for absolute filtration arose during World War II and was
>> developed by the Atomic Energy Commission as part of the Manhattan
>> Project to produce the first atomic bomb. There was a pressing need to
>> address the health and safety issues raised by the handling of
>> radioactive dust. Research and development produced the first HEPA (Hi=
gh
>> Efficiency Particulate Air) filters for the ventilation systems used t=
o
>> deliver ultra clean air to clean rooms.
>>
>> In order for a filter to be certified HEPA, it must be tested and prov=
en
>> to filter particles as small as 0.3 microns to 99.97% efficiency at it=
s
>> designed air flow. To understand what a HEPA filter does, it helps to
>> understand what a micron is. A micron is 1 millionth of a meter. A hum=
an
>> hair is approximately 100 microns wide. Particles smaller than 10
>> microns are not visible to the human eye. A particle of tobacco smoke
>> averages 0.01 to 1 micron. Most bacteria range from 0.35 to 10 microns.
>> Almost all viruses, however, are smaller than 0.03 microns and HEPA
>> filters are not effective at trapping them.
>> -------------
>> So, to answer your question, if the vacuum is spitting out particles,
>> they would be smaller than 10 microns.
>>
>> Best,
>> Wayne Seidl
>>
>> On May 31, 2007, John Hesselberth wrote:
>>
>>> Hi Wayne,
>>>
>>> I'm concerned about this from an engineering standpoint. With the
> volume
>>> of air that is being handled I suspect those bubbles would be huge
> and
>>> there would be no effective washing out of the dust at all.
> Designing a
>>> scrubber that really works requires generating a huge amount of
> surface
>>> area, i.e. extremely fine bubbles. I guess I am asking if you have
>>> really tested this to be certain it is removing the dust. Or are you
>>> just not seeing it blow back into your studio because it is so fine?
>>>
>>> John
>>>
>> >
>> > On May 30, 2007, at 5:22 PM, WJ Seidl wrote:
>> >
>> >> Then it is a simple matter of installing a 5 gallon bucket in
> the bottom
>> >> of the vac, installing the pipe, and filling the bucket at least
> halfway
>> >> with water (or simply installing the pipe and adding water to
> the vacuum
>> >> so that the bottom elbow is covered to a depth of two inches or
> so. The
>> >> intake water bubbles through the water and exits the vacuum as it
>> >> normally would, minus dust, in effect creating a water bath.
>> >
>>
>>
> _______________________________________________________________________=
_______
>> Send postings to clayart@...
>>
>> You may look at the archives for the list or change your subscription
>> settings from http://www.ceramics.org/clayart/
>>
>> Moderator of the list is Mel Jacobson who may be reached at melpots@...
>>
>=20
> _______________________________________________________________________=
_______
> Send postings to clayart@lsv.ceramics.org
>=20
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>=20
> Moderator of the list is Mel Jacobson who may be reached at melpots@pcl=
ink.com.
>=20
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