I thought I could find a quick reference to the air refresh rate, or
how often a room full of air should be replaced-as in x number of
times per minute, calculated with cubic feet (or meters). I didn’t
find anything, in a quick search. Wikipedia has an understandable
post on TLV’s, or threshold limit values. All kinds of organizations
have air quality guidelines and recommendations, but again, doing a
very BRIEF search, most seemed to be about what you are screening
(carbon monoxide, particulates, sovents, etc.).
Anyway, I read Connie Fox’s blog, and below is a link to the new
hood she installed. Its out of my price range, but I thought some
here might be interested.
“SOLDERING HOOD: Kobe CH7948SQ 48 inch wire with CH1120DC adjustable
duct cover and wall mount kit. Purchased from NaturalHome.com. Also
make smaller hoods. This hood is over my soldering station. It draws
up fumes very effectively - even when I mix up liver of sulfur -
whoosh out through the hood.”
You can get extraction fans and vent hoods for kitchen ranges that
will work the same similar to the kitchen range hood you reference,
but they are not as pretty. I think there you can find them in the
kitchen bathroom section of hardware and box stores that sell
appliances. I am sure you can find comparable cmf to get better air
quality. I got a kitchen hood with the help of a friend when I first
need a vent, and more recently, I got an extraction fan (squirrel
fan) next to my soldering area since the hood is over my casting
area. Each of my fans was around $200. This has info about cmf and
more about choosing a kitchen range hood for a kitchen:
I thought I could find a quick reference to the air refresh rate,
or how often a room full of air should be replaced-as in x number
of times per minute, calculated with cubic feet (or meters).
hey you’re already getting into a profession wherein you work long
hours, undergo huge stress, and are accused by strangers of theft
(“Are you gonna switch my oh so valuable 25pt diamond?”) Why not just
not worry about air refresh rates? The stress (or robbers) will
likely kill you long before the lung cancer does.
...get extraction fans and vent hoods for kitchen ranges
Not sure about Orchid etiquette, if one is supposed to reply all
with a thank you post-some lists like to limit those. But, thanks
Melissa for the link on the hoods and CFM. Very informative, and $200
is a lot better than $7-800!
Most people arrange the exhaust system to pull UP, like a range hood
does. This, of course, brings gases and particulates right up into
the worker’s face. The exhaust should pull, strongly, from the back
of the bench, so everything goes away from the worker.
Paf—“What Me Worry” is one way to go on this issue as you suggest,
but not a good one. Setting up a fume hood, however, is actually
quite easy and can be very inexpensive. When I mentioned my solution
a while back on Ganoksin, one of the experts (I call them the Great
Ones) commented with a sniff (though I didn’t hear it, there must
have been a sniff) that my suggestion for a fume/dust hood was too
idiosyncratic. The person may have intended to say idiotic. At any
rate, what I did was to build a wooden box with apeaked “roof”, the
front slope of which is covered with a sheet of scrap plexiglass. The
lower portion of the front is left open. There is a hole in the
wooden rear slope with a fitting for a 3" vacuum cleaner hose. The
hose leads through a vent to the outside air. The air is moved by the
motor and fan from an old shop vacuum cleaner I bought at a flea
market for $6.00. The motor and fan are outdoors so that fumes and
particulates are vented outside. Location of the unit outside also
greatly reduces the noise of the motor. All together the system cost
about $40.00 (US). Most of that was for fittings to match the hoses.
I can light my acetylene torch as much as ten inches outside the
hood and the soot is pulled in to exit outdoors.
In fact the only difficulty is that the air movement may be too
great. I solved this by putting a “Y” in the vacuum hose. I can
variously block the open branch of the “Y” to produce more or less
air flow as needed. A shop vac can easily move enough air to serve a
second hood (for buffing and polishing). If my description is
confusing, I will provide a drawing or photo if you contact me
directly.
I will also say that, properly done, the ignition of an
acetylene/oxygen torch doesn’t necessarily produce a cloud of soot.
Simply open the oxygen control valve a tiny bit first then open the
fuel gas valve, then ignite the mixture. You should get a fairly long
yellow flame but no soot. Then adjust the flame by further opening
the oxygen valve. It takes a bit of practice, but it does work. By
training and education, I prefer to extinguish the flame by shutting
the fuel, then the oxygen. No pop, but it might give soot if you are
not quick. Use a fume hood such as I describe and the soot is
"sucked" away. (Yes, I know. there is no such thing as suction, just
differential pressure. I added this for the Sniffer.)
After following this thread with interest, I thought I might add a
link to an exhaust system I am installing in my studio for use with
my Glass Torch. I thought it might be an exhaust system others may
find interesting or actually need.
The design for this exhaust system was made with glass workers in
mind. It was first published in the 2006 Glass Art Magazine and is
excellent for bench torch workers. The only issue I with my set up
was the concern that it could actually pull so much air that there is
some concern I might get some flash-back from the furnace & hot water
tank exhaust, (my studio is in my basement). To fix this we just made
sure there is a relief vent on the other side of the room which
allows for fresh air to be pulled into the room.
The link to this exhaust system is:
http://www.ganoksin.com/gnkurl/1ot
That is a good system Teresa. I use the same type of inline fan
(just one fan) in my shop to ventilate three stations, kiln hood,
plating and my bench. A difference is that I have the inline fan in
my ceiling, inside the building. I put it on a dimmer switch so I
can adjust the fan speed. I also have dampers at each station so I
am only ventilating what’s in use. Agood HVAC company will help a
person decide what size fan you need to properly ventilate your
space. I hired a HVAC outit to do the whole thing (fan,make the
hoods, ducts) and it cost me less that $1700, well worth it.
I just read the posting I sent a few days ago wherein I said that to
exting uish an oxygen /acetylene torch that I recommend closing the
fuel first than the oxy. This is opposite to what I meant to say:
Close the oxygen first then the fuel to avoid a bang at the tip.
Sorry about that.
I just read the posting I sent a few days ago wherein I said that
to exting uish an oxygen /acetylene torch that I recommend closing
the fuel first than the oxy. This is opposite to what I meant to
say: Close the oxygen first then the fuel to avoid a bang at the
tip. Sorry about that.
I turn off the acetylene first TO get a bang at the tip! It cleans
the mung out of the tip. Also it prevents me having those little
black fairies that come with burning acetylene.