Elephant trunk ventilation systems

Donia Conn <bookconservator [at] yahoo__com> writes

>We are in the process of designing a new 6000 square feet building
>for a private conservation practice and want to incorporate an
>elephant trunk system in the lab areas.

In the Straus Center renovation at the Fogg Art Museum, Harvard, we
used trunks manufactured by the Nederman company. They are a large,
reputable firm with a good range of equipment, in use in many labs.
In a separate room, we have a spray booth and a fume hood. The kind
of overall system you are describing will have to be designed by a
HVAC engineer experienced in these kind of installations, for it to
succeed. Particularly if you plan to maintain temp/RH conditioned
air. The variables involved are complex, having to do with tempered
make-up air being provided for when the hood/booth are on, ability
to adjust the system, OSHA requirements, your particular needs. Get
a professional involved early in the planning stages.

To deal with your questions, and some thoughts on each type of
extraction:

Our hood and booth are located in a separate, smaller room. they are
independent, but share the same make-up air supply. The make up air
is temp. conditioned, but not RH conditioned. We installed a two
speed spray booth. On low, one can work with solvents in front of it
on a large sculpture and have them pulled in, in a relatively quiet
way. Hi speed is fine for spray applications, etc, and is loud and
powerful.

The fume hood is an always on type- this may be required now. The
extraction speed is governed by how high the glass door is raised.
As it has a constant negative pressure, a solvent storage area
underneath can be vented. Our paper lab has had turbulence problems-
When the door is closed, the fan speed comes down too slowly,
resulting in a rush of turbulent air across the work surface.
Bottles of liquids and other small things, sitting on paper towels
in our hood have been knocked over and pulled to the back of our
hood. The paper lab has had theirs modified to slow it down.

The trunks are available in a variety of articulation styles and
lengths. They become more difficult and unwieldy to position as the
arm length increases. Keep them as simple and short as possible.
After a break in period, the hinging points will need to be
readjusted to keep the trunk opening where you put them. Be sure
your installer will do this, and schedule it before your warranty
period elapses. We have trunks in the objects and painting labs, on
two speed fan switches. low is fine for most things, Hi is very
powerful, loud, and therefore seldom used. Try to design and install
as quiet a system as possible, with the blowers mounted remotely if
possible. Insulate for sound if you can. Noise= stress, and if the
system is too loud, people will not use it. Keep the switching close
to the work table; on the trunk hood if you can. Walking across the
room to turn it on/off every time the phone rings or you need to
hear someone speak is irritating. We have two to three trunks ganged
on one switch. It's economical, but the noise is difficult to escape
and why have a trunk on if no one is using it? Of course all of
these conveniences can have a price tag....

Good luck,

Tony Sigel
Harvard University Art Museums
32 Quincy Street
Cambridge, MA 02138
617-496-1903
Fax: 495-9936


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                  Conservation DistList Instance 14:38
                Distributed: Saturday, January 13, 2001
                       Message Id: cdl-14-38-003
                                  ***