Vacuum as an insulator.

[DaBit]

We are all doing a tremendous amount of effort to insulate our evaporators with Armaflex, expanding foam, whatever.

But the best insulator ever is still a vacuum. With all the CNC machines around here, did anyone ever think about making a stainless steel 'shell' around the evap, braze it on, and pull a deep vacuum in it? With the tight tolerances a CNC machine can maintain, making such a shell sounds like a trivial task.

Would this work?

[Ragnarok]

umm the surface of the evaporator would have be exposed, and hence u cannot completely cover it ?... am I missing something here?

[nas]

humm , it will be braze to the evap = it will cool aswell

[iboomalot]

this might be a better solution

http://www.aerogel.com/products.htm

[tennvols_69]

wonder whereyou could get someof that from? also a vacumm would work greatbut you couldnt braze it to theblock you wouldhave to create a seal of some kind that would sealto yhr mobo

[chilly1]

A thermos jug is made entirely out of glass it does connect with the outside but still conducts little heat. If nothing at all wouldnt this reduce the area we need to insulate and also make our evaps run cooler due to the reduced heat gain... And how about a copper box, it only needs to be sturdy enough to support itself...
And maybe a neoprene gasket seal like an o ring and nylon bolts to hold it together,,, and a small vacume pump to maintain the vacume or maybe an inert gas at a partial atmosphere?

[DaBit]

To use vacuum as a good insulator you need a pretty decent vacuum (in the range of 1-10 microns).

And sure, stainless steel conducts some heat, but not that much. Maybe plastics could be used.

[G H Z]

When your building the third stage of your -175 cascade which runs Argon, just build a sealed box and pressurize it with some Agon as well.

That might be easier than pulling and maintaining that much Vaccum. It's what they fill the expensive double pane windows with.

Originally posted by G H Z
When your building the third stage of your -175 cascade which runs Argon, just build a sealed box and pressurize it with some Agon as well.

That might be easier than pulling and maintaining that much Vaccum. It's what they fill the expensive double pane windows with.

Actually I'd recommend filling the void with Nitrogen, after trying to pull down to a vacuum. You'd have to use something with a little bit of wall thickness to it though if you're wanting to leave it in a slight vacuum.

[Tom Holck]

When I use my -112 C Cascade the hole MOB is frozen. Even the Ram is about -2 degree. The cooling is going in the cubber on the MOB.

The idea is good, we have to bouild the hole MOB in a sealed box with some gas or with dry air.

The problem is also on the AGP and the Radeon XT also condensation here from the GPU cooling.

[DaBit]

I already use the sealed box idea for ages. Works fine so far. But of course you want to reduce heat leakage into the evap as much as possible. After all it's the cpu which needs to get cold, not the mainboard.

[chilly1]

I have a solution for this problem I will post pictures as soon as we finish testing... The problem with a vacume on the whole mb is that we could have heat build up on other components on the mobo.

[pythagoras]

If you used a modified version of this cpu enclosure, you could pull a vacuum in there:



Regards

John.

(thats a 1998 kryotech cpu enclosure BTW)

[DaBit]

I was more considering the use of a vacuum as a replacement for Armaflex, neoprene, etc.

A small layer of reflective aluminium (could be aluminium foil) and a thin layer of vacuum should work much better than a thick layer of insulation. The dominating heat transfer modes are still conduction and convection, so if you can stop that by pulling a vacuum, you are doing a good job already. Aluminium foil reduces heat transfer by radiation already quite a bit.

It could be doable to put this straight into the evaporator design. For the material: stainless steel still seems the most practical material. It can be joined with copper, it is machineable, and it's heat conduction is fairly low. It also can maintain the vacuum, something rubber rings cannot.