How to hook up a heatsink to a bigger heatsink?

qviri · Post by **qviri** » Tue Jul 12, 2005 4:39 pm

Hey,

I have a rather big heatsink that will be located somewhere in the general vicinity of my new machine (<20 cm from both CPU and PSU heatsinks). I'm considering using its cooling capacities for the design revision after the one currently in production. The thing is 160x35x50 mm, the fans are 3~4 mm thick. It never gets even warm, so I hope it has some potential to help with cooling. The CPU draws 50 W max and I'm sure the whole machine doesn't exceed 100 W, so the PSU can be counted for 40 W of heat maximum.

My question is what would be the best method of attaching the forementioned heatsinks to the big one. I will use a generic PSU since I don't want to risk breaking my nice one. I could do Marko-homebrew-style MOSFET extension, but I'd rather not unless I really had to.

Would a piece of copper/aluminum/other metal clamped to the heatsink and one of the fins of the big HS work? What about the CPU? Maybe heatpipes, but how do I get them to go where I want?

Mar. · Post by **Mar.** » Tue Jul 12, 2005 6:28 pm

If you somehow attach the smaller heatsink to just a fin of the larger heatsink, I imagine that the overwhelming amount of the heat being transferred into the larger sink, would just stay in the fin and radiate from there into the ambient air, not using anywhere near the cooling potential of the entire apparatus. Probably though, the smaller heatsink and whatever you're using to attach them would bear most of the heat.

qviri · Post by **qviri** » Tue Jul 12, 2005 7:19 pm

So I'd have to get it to the base, preferably over an extended length?

Mar. · Post by **Mar.** » Tue Jul 12, 2005 8:15 pm

That may work, but you're better off just getting a better heatsink to begin with.

IsaacKuo · Post by **IsaacKuo** » Wed Jul 13, 2005 6:25 am

If we're talking PSU heatsinks, aren't some PSU heatsinks hot with plus voltage? You wouldn't want anything conductive touching that. Make sure to only attempt extending ground heatsinks.

qviri · Post by **qviri** » Wed Jul 13, 2005 6:44 am

Yeah, I saw that mentioned in Marko's write-up and I'm going to check prior to doing anything.

Tiamat · Post by **Tiamat** » Wed Jul 13, 2005 6:47 am

heatpipes - you would have to drill into the large heatsink.

I figure if you are drilling, might as well drill water inlet and water outlet and use it as a water cooling radiator.