On Dec 11, 10:15*pm, Eric Greenwell wrote:
On 12/11/2010 9:07 PM, brianDG303 wrote:



Just as a discussion, I have had some experience trying to make even
quite small containers (art exhibit display cases) dust tight with a
notable lack of success, both by me and others I have observed. *As
you seal the container, you don't actually change the amount of air
circulation, I suspect; you just change the velocity of the air at the
inlet points you can't close up. *I am sure there is some benefit to
sealing, but to make a display case dust tight you seal up what you
can, then provide positive pressure through a lot of filters, or in
less critical situation just provide a lot of filter surface area to
lower the resistance of the filtered air. *The problem is that
temperature differences inside to outside create air pressure
differences that push the air in and out. *Perhaps a solution is to
seal up the trailer really well and then provide a source of inlet air
that is drawn across a long desiccant tray or something.

Maybe you need "ballast". Make the trailer airtight, but run a vent tube
from it to a plastic garbage bag half full of air: when the trailer
"breathes" it just moves air in and out of the garbage bag, and soon the
dehumidifier has all the trailer air (and bag air) dry, dry, dry!

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

Andy, a few years ago, you were reputed to be moving to Arizona.
Maybe it's time to reconsider where you live? I can confirm that you
are very unlikely to have severe condensation issues here.

However, if we can't talk you into moving to a more sensible climatic
zone, I had to solve a similar situation many years ago when I needed
to maintain a dry atmosphere inside an outside 4'x4' metal cabinet
with sensitive electronic equipment. We ran two 60-watt light bulbs
in series - worked great! About six to ten 60-watt bulbs operated at
60 V should do the trick.

Mike