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Exhaust Venting


#1

We’re preparing to build studio. If things work out we’ll build a 24
x 24ft two story studio.The lower level will be studio space. Comes
the question of exhaust venting. We’ll be working various types of
soldering, casting, and kiln work. We’re thinking that each work
station requiring venting would have an exhaust hood. What’s
preferred or recommended?

Thanks
Jerry in Portland


#2
                 We're preparing to build studio. If things work
out we'll build  a 24 x 24ft two story studio.The lower level will
be studio space. Comes the question of exhaust venting. We'll be
working various types of soldering, casting, and kiln work. We're
thinking that each work station requiring venting would have an
exhaust hood.  What's preferred or recommended? 

Hi Jerry, You can put a ‘hood’ over each area and connect them all to
one blower with dampers to close off the hoods you are not using at
any particular time. If you will be investing and quenching I would
make those hoods so they could never be turned off.

This would be much less expensive than a separate hood and blower for
each station.

Thanks,
Ken Kotoski
MPG Repair
www.mpgrepair.com
1-877-262-2185


#3

Dear All, I have set up eight complete workshops in the last thirty
years. Here’s my suggestion on venting. The main concerns are burnout
for casting, fume extraction for annealing & melting, wax work &
spruing, plating and maybe ultrasonic fumes.

The hoods I have used since 1980 are kitchen stove hoods. The brand
name is Vent A Hood. They make all sizes - single, double, triple and
quadruple motored. Absolutely the best product available. I am very
loyal to a good product and company. I have always installed them
myself. Except the largest, I had a four motor (four blowers)
installed by a stove hood company. I have found them used and
purchased them new. I have worn out three or four motors since 1980.
The blower motors last a long time and are easy to replace
(replacement cost about $70.00). I think the last time I bought a
single blower unit the new price was about $225.00. Again well worth
it.

In my current shop I have four individual hoods. Mounted right in a
row. I turn them on as needed. One on for annealing & melting, two on
for burnout, three on for everything. The fourth I use for plating so
I usually don’t cast and plate at the same time. The duct work is
fairly easy to install. The duct work is metal not plastic or cloth.
A bit awkward working at the ceiling. But the duct snaps together and
duc tap seals the run from the unit to the window. These vent units
have different size ducts coming out of the top. It depends on
weather they are a single or double motored unit. Make sure you
don’t reduce the size of the duct coming out of the unit. That will
restrict the air flow. At the window I have replaced a glass pane
with a board with a air flap unit which opens when the unit is turned
on. Kind of like a dryer vent on the outside of your house. Again
make sure you get the right size for your exhaust duct. You sacrifice
part of a window, but your health is the primary concern.

In my first set up. (My parents basement I just used a fan in the
window.) Better than nothing. Currently I don’t vent my bench. Good
room circulation is adequate. Don’t work in a closet. Most solders
are now cadmium free also. So there is not the same concern as years
ago. Most jewelry shops don’t vent each bench. Dental labs on the
other hand do because of all the misc grinding done.

Now I even hooked up a small in duct fan to remove wax fumes from my
spru area. Better to be safe than sorry. I’m sure the wax fumes we
breath will someday be labeled a more specific health risk so I vent
my wax working area at my shop and at school. I have also been steam
dewaxing larger casts more now than before to reduce the pollution
concerns. My shop is currently in an artist co-op building so there
are people who live above me. I burnout at night, and to keep the
neighbors happy my burnout doesn’t stink. I am mostly exhausting the
heat of the ovens.

To steam dewax all you need is a flat cake pan full of water. Heat
an oven to above 250 F. I use an old lab oven with a max temp range
of 300 F. Place flask or flasks on a oven screen in the oven on top
of the hot water in the cake pan. You know the kind of thing you cool
cookies on when they are out of the oven. Spru hole side down. The
wax will drip into the hot water. Leave them in until there is no wax
left in the flask. This can take a while depending on how big a flask
and how many items in it. This is also injection wax. I’ve had no
luck steam dewaxing carving wax so I don’t try. Preheat the burnout
oven to the same temp as the dewaxer. When ready load the oven and
start the burnout cycle. Environmentally compliant. Cool the oven
when done and throw the removed wax out.

To be code compliant all duct work has to have an insulation barrier
between itself and anything combustible. This can be a fire proof
sided house insulation.

I’m sure I’ll think of more later. Got to get to work.

Best Regards,
Todd Hawkinson


#4

We’re preparing to build studio. If things work out we’ll build a 24
x 24ft two story studio.The lower level will be studio space. Comes
the question of exhaust venting.

Jerry, if this is to be a commercial workspace you might find that
extraction equipment has to be “properly” designed, meaning that
there might be local or national Codes or Standards to follow. There
might also be requirements for periodic testing. Here in the UK it
works that way, if it’s provided for protection rather than just
comfort, though if it’s just a hobby shop you can do what you like.
If you’re designing it yourself don’t forget to allow make-up air to
come into the room somewhere.

Sounds as though you’ll have a nice facility when it’s completed.

Kevin  (NW England, UK)

#5

Todd,

Not to argue with you or rain on your parade. But if you asked OSHA
to examine your ventilation it would never pass.

Oven vent hoods don’t have the capacity to move enough air to remove
the toxic particles and fumes in any area of jewelry production. Just
consider investment silica you can’t smell it and can’t see it. And
fumes don’t automatically mean you can smell them or see them. The
dangerous investment silica is so small you can’t see it. The
investment you can see isn’t as harmful. (If you don’t understand
this statement contact me and I’ll explain it.)

The diseases that come from breathing silica and fumes don’t always
appear immediately. They take years to build up in your body and
during that time they slowly start creating problems. And normally by
the time you have symptoms it’s too late to reverse the damage.

You also say you don’t vent your bench. If you do any polishing at
your bench you will be breathing particles that are unhealthy. If you
do any soldering you will be breathing unhealthy fumes. Just because
there is no cadmium in solders any more doesn’t mean you should have
your face in the fumes.

You are looking at how cheap these vent hoods are compared to the
proper ventilation for what you are doing. That is wrong. You should
be looking at the cost of your life and health as compared to the
cost of proper ventilation.

If you don’t value your life then cheap is ok. But everyone I know
places a very high value on their own life and therefore even though
proper ventilation is more expensive it is much cheaper than the
medical bills you will rack up by going cheap today.

If anyone wants to know what is proper ventilation call OSHA. Don’t
ask on here. OSHA will work with you and give you the guidance to
properly ventilate YOUR shop. Be honest with them about what you are
doing. It is their job to make sure you are safe. And you don’t have
to pay for the help!

Don’t be afraid of OSHA. The only time you should be afraid of them
is if you knowingly have violated work safety laws.

I have setup ventilation on many shops from in home studios to large
manufacturing facilities and each instance is different and requires
different ventilation. The size and shape of the room matters. What
processes you are doing matters and where they are located in the
room matters.

Please value your life and health more than your money. Your health
and life are your responsibility.

Take care Orchidans,
Ken Kotoski
MPG Repair
www.mpgrepair.com


#6
We're thinking that each work station requiring venting would have
an exhaust hood.  What's preferred or recommended?  

Check with your heating/cooling expert . . . they not only build
exhaust hoods, they can recommend a venting system that will work
best with your heating/cooling system.


#7

It is a good practice to make provision to “makeup air” for all the
exhaust. Sick building syndrome results from a building that exhausts
more air than is replaced; keeping germs and toxins inside (known as
a “negative”). Bring in clean outside air in a controlled manner
through your heating and air conditioning system. It can be
interlocked with the exhaust fan so that the intake is shut
(partially) when the exhaust is off. Also design for replacement of
any combustion air (burning consumes oxygen). Keeping fresh air (more
oxygen) in and stale air exhausted (higher Carbon Dioxide). Theses
principles will help create a healthy environment. In many buildings
the air pollution is greater indoors than outdoors because of the
vapors given off by the carpeting, furnishings, glues, and the like
used in the construction and manufacture.

Dan Wellman


#8

Dear Ken & All,

Some added comments…

    Not to argue with you or rain on your parade. But if you asked
OSHA to examine your ventilation it would never pass. 

Here we go… I HAVE and Do work with OSHA at the Minneapolis
Community & Technical College where I teach jewelry repair and
manufacturing. I worked closely with the contractor building our lab
and work facility. The local jewelry advisory group approves any
recommendation. Our shop at school is set up identical to the
manufacturing facilities in our region. We do pass inspection. We
pass inspection currently. We keep up with ongoing inspection. What I
do in my own shops is exactly what I do at school. I just don’t
invite inspectors in my shop. In fact I think my own shop is even
better that any other place safety wise. The local fire marshal was
taken through by the landlord last month and the shop passed with the
exception of one too many extension cords for the camera area.

    Oven vent hoods don't have the capacity to move enough air to
remove the toxic particles and fumes in any area of jewelry
production. 

Vent A Hood is not a cheap hood. It is the best I have found
whatever the price. The larger Vent A Hood unit was purchased from a
national jewelry supplier and installed by the local distributor.
Just because it is sold as a kitchen hood doesn’t mean it is not an
excellent product that goes to many markets. Look them up and see. I
would not buy any other brand ever. They make small one blower units
and industrial size for several industries. Again I like this brand
because I can add additional units as needed. And it DOES move
adequate amount of air to be code compliant.

    The diseases that come from breathing silica and fumes don't
always appear immediately. 

I didn’t talk about the investment hood I recommend. It is sold by
Gesswein and used in combination with a dust mask for investment. Now
if you are a smoker… well that’s a different lecture.

    You also say you don't vent your bench. If you do any
polishing at your bench you will be breathing particles that are
unhealthy. 

No I do not do any polishing at my bench. I do not like to get the
stuff in my face and in my breathing chamber. I polish like the
industry does, in a separate area. This doesn’t have to cost a
fortune either. The smallest Handler dust collection unit is only
about $500.00. This is also a unit with adequate air flow for health
and safety concerns. With the bench set up like industry my bench top
is at about my shoulder level. So I sit lower than my work. Again
this is as industry sets up work stations in our region. So the air
circulates above my breathing area. My head is never above my work
where the air rises. Anything stinky or smoke generating I go to a
vented area. General jewelry repair and manufacturing bench work
TRADITIONALLY is not vented. Again not in a closet setting but in a
room that has some air circulating. Dental labs grind and polish at
the bench so their benches are much better vented. Maybe all jewelers
should take a lesson from that industry. At the present time jewelry
benches are not vented in most shops.

    You are looking at how cheap these vent hoods are compared to
the proper ventilation for what you are doing. That is wrong. You
should be looking at the cost of your life and health as compared
to the cost of proper ventilation. 

My former business partner and best friend died five years ago from
Cystic Fibrosis. Probably one of the finest jewelry designers on
God’s green earth. He educated my on the value of my health. I do not
take good health for granted. His every breath was a struggle. He was
the God Father to both of my children. I value every breath I take
with my healthy lungs. A concern of mine is the asbestos I worked
with back in the early 70’s. Now I am as safe as I can be. Doesn’t
EVERYTHING cause some sort of health problem?

    If anyone wants to know what is proper ventilation call OSHA.
Don't ask on here. OSHA will work with you and give you the
guidance to properly ventilate YOUR shop. Be honest with them about
what you are doing. It is their job to make sure you are safe. And
you don't have to pay for the help! 

My hesitancy here is just my own issues of privacy. I don’t ask an
IRS auditor to help me with my taxes either. I have a CPA do them
every year. I’m compliant without any government help. After building
an addition onto our home this last year, I’m convinced I work the
right way. Even the building inspectors don’t know all the rules and
regulations! My advice is only to help work the safest and most
profitable way possible. The small beginning jewelry doesn’t have to
spend a fortune to be safe and compliant with health and safety
regulations.

Again Best Regards,
Todd Hawkinson