bart wrote:
Hi all,

I hope I'm not too way off base here in asking for advice, but you
guys seem to know everything!! :-)


Boss at work bought a $99.00 environmental chamber and told me to
"make it work".
( this one's sibling:
http://cgi.ebay.com/AES-ENVIRONMENTA...8 6.m20.l1116)

When we recieved it, it didn't "do" anything.
I kept flipping the switch back & forth and eventually some sticky
relays started "working", that is, the heater /fan started working and
the gas solenoid clicked in - depending on the temperature dial.

A label on the back says it is to be cooled with liquid CO2.
Somebody retrofitted it with a 300PSI solenoid - We have since then
gotten a 1000PSI liquid CO2 solenoid.
The wiring in it is OLD and BRITTLE, BTW.

A few hours ago my boss is on my ass to get the cooling working by
next week.
Now I have a basic oxy/acetylene rig at home, but have never played
with liquid CO2.

I'm not exactly sure of what fittings/tubing to use ( copper,
stainless, double flare??).

I think any 1/4" metal tubing should handle it fine. it is about 900
PSI in the bottle. Do you use this without a regulator? I guess so.
Any, you want a siphon-tube bottle for the CO2.
Also, the boss says that CO2 isn't toxic, so therefore we aren't going
to vent it.
(it's setup in the back of a kitchen, where I work {our "lab"}- with
zero ventilation)

It is a small chamber, unless the room is SEALED, I wouldn't worry about
it. If you DO worry, just get a window fan and set it in the open door
while it is running, should be plenty of ventilation.
I don't mind doing potentially dangerous stuff in my own garage ( with
the door open), but this is an office full of people.

Am I way off base telling him to hire a professional to do the gas
fitting ( and leave the premises when he runs it without ventilation?)
I don't know about your regulatory environment, if there are OSHA
inspectors popping in every week, you'd better go legal.

Jon