Definately w/ LN2 you need alot of insulation. On my tube I use 3/4" foam. Sorry don't know metric. I spray the back of my mobo and nailpolish the front. Make sure to seal around the caps real well. If you get a lock up and need to wait for temps. to drop anything nearby will have condensation on it. I would worry about the metal brackets they will surely be covered in frost.