Instead of insulating....

Not every part of the computer likes being at -193C.

I heard idiots that have tried it and killed their rigs.

EDIT: thought you referred to LN2

Even a purged case would have problems with condensation. It's physically impossible to remove all of the water from the atmosphere, especially considering that water can be made anywhere ozone can be made, like your PSU.

You could...but why? Pure CO2 would cost a lot more than just insulating properly and also pure CO2 is toxic so if a leak did occur it would be very unhealthy.

all in all i think it would be waste of money and resources.

um what about all the air cooled components how would you remove the heat from them ?

by the way its' FAR cheaper and simpler to just insulate the socket like everyone else does

You can get a 20lb tank of co2 from gas/welding stores for about 20 bucks, which allow you to purge a box for something like this hundreds if not thousands of times. I was thinking about keeping the psu, pump, radiators outside the box and simply installing them through holes cut in the top with airtight grommets. Purity of the gas is around 99.995, and i dont know about co2 specifically but i know for oxygen you get get 'extra dry' oxygen which is less that 2 ppm, I think aviation oxygen is 3 ppm or less of water. The reason I ask is I have a tank of co2 already with a regulator, and it wouldnt be too much work to built the tank; just thought it might be a cool experiment. It would require water cooled video cards and chipset cooler. Would 3 ppm really be enough water to short out the board?

i highly doubt it would and try it out! if it works then awesome, should have a build log or something, this is something that seems very interesting

The only concern is for components that need to dissipate their heat. I would say that it could potentially be a problem but other than that I would say go for it. Don't forget about the possible health effects though as CO2 is quite toxic.

Just get a CO2 detector and keep it close to the case. Seal any holes for cables with silicone sealant and keep HDD PSU etc. out of the case. I'd love to see this build log but I would stress the CO2 detector.

you should use pure nitrogen instead.

Experiment if you want to.....but you will need to seal the case.

it is all very well watercooling specific parts to extract that heat from the sealed case but what about the other bits ????

The mobo itself will generate a fair bit of heat how do you plan to cool that ??
In a small sealed box the temperature will rise exponentially and completely negate any benefits of using a TEC to cool below the dew point.

If you really wanted to try this I think chielscapes suggestion of nitrogen is better. But whatever you do without any means to remove heat from all the components it is an almost certain fail and is a ridiculous amount of effort just to go below the dew point.
What is it with all you people wanting to use to use TECs to go just below the dew point.

it would be a waste. Also you could kill your rig.