Pro/Forums - View Single Post - Am I crazy? Silicone amorphous waterblock

|kbn| · 03-30-2004, 05:21 PM

Mercury isnt that good though. You are all getting confused by two different groups of numbers.
Conductivity = how fast heat can move through a object. Its best to thing of the object as having no flow, so not liquid, although liquids do diffinatly conduct heat.
Specific Heat = how much heat energy it takes to make the temperature of an object rise.

If you intend to pump a coolant or have a moving coolant in any way it needs to have a high specific heat (expeption is phasechange, i dont know enough about that) so that there is the most differnce in temp between the source and the coolant.
Conduction is most important in the block/heatsink becuase it will spread the heat to a larger surface area so it is easyer to remove using coolant.

relying comleatly on a coolant (direct die, submersed system or not) is not going to get good results without jets (to maximise the use of the coolant) and high flow rates. because there would be much less spreading of heat the jets would need to be aimied well at hotspots or some areas will not get cooled aswell and be hotter.

Moving the heat away is much more effective that waiting for it to be disipated by air the normal way becuase it has a large amount of coolant which can absorb a lot of heat, with just a heatsink (although air is still a coolant) you miss that layer.

Therefore there is no point in submerging systems except to cool components which do not have a high heat output, which are pointless in cooling anyway as the stock coolers shoudl manage...

Also with a submerged system there is a lot of coolant that is not moving (= wasted) with a high heat capacity. If a waterchiller/other chiller was used it would not be able to cool it becuase of the amount of heat that the coolant holds.

Mercury is not a relistic idea. Its poisnous, expensive, not availble in quantity (and i think yo need a licence or something to buy it) and iirc has rubbish conductivity. Also it would be almost imposible to pump around. This makes it bad becuase conductivity through it would not be faster than just pumping water at moving the heat. It would basicly act like one BIG insulated metal heatsink with one of the worst thermally conductive metals you can get...
Transfer of heat needs a thermal gradient too... it wouldnt have much thermal gradient as it would reach eqilibrium.

I expect Ive made lots of mistakes, Im not an engineer and I typed this very quickly.

03-30-2004, 05:21 PM	#56
\|kbn\| Cooling Savant Join Date: Feb 2004 Location: W. Sussex, UK Posts: 329	Mercury isnt that good though. You are all getting confused by two different groups of numbers. Conductivity = how fast heat can move through a object. Its best to thing of the object as having no flow, so not liquid, although liquids do diffinatly conduct heat. Specific Heat = how much heat energy it takes to make the temperature of an object rise. If you intend to pump a coolant or have a moving coolant in any way it needs to have a high specific heat (expeption is phasechange, i dont know enough about that) so that there is the most differnce in temp between the source and the coolant. Conduction is most important in the block/heatsink becuase it will spread the heat to a larger surface area so it is easyer to remove using coolant. relying comleatly on a coolant (direct die, submersed system or not) is not going to get good results without jets (to maximise the use of the coolant) and high flow rates. because there would be much less spreading of heat the jets would need to be aimied well at hotspots or some areas will not get cooled aswell and be hotter. Moving the heat away is much more effective that waiting for it to be disipated by air the normal way becuase it has a large amount of coolant which can absorb a lot of heat, with just a heatsink (although air is still a coolant) you miss that layer. Therefore there is no point in submerging systems except to cool components which do not have a high heat output, which are pointless in cooling anyway as the stock coolers shoudl manage... Also with a submerged system there is a lot of coolant that is not moving (= wasted) with a high heat capacity. If a waterchiller/other chiller was used it would not be able to cool it becuase of the amount of heat that the coolant holds. Mercury is not a relistic idea. Its poisnous, expensive, not availble in quantity (and i think yo need a licence or something to buy it) and iirc has rubbish conductivity. Also it would be almost imposible to pump around. This makes it bad becuase conductivity through it would not be faster than just pumping water at moving the heat. It would basicly act like one BIG insulated metal heatsink with one of the worst thermally conductive metals you can get... Transfer of heat needs a thermal gradient too... it wouldnt have much thermal gradient as it would reach eqilibrium. I expect Ive made lots of mistakes, Im not an engineer and I typed this very quickly.