# How effectively would a typical liquid CPU cooler cool a 15"x15"x1/8" sheet of aluminum?

I'm curious about whether a typical liquid CPU cooler (like, e.g., this Corsair H60) would be able to effectively cool a square sheet of aluminum with 15" sides and a thickness of 1/8".

I'm not even sure how to properly formulate the question so I'll describe the envisioned application. I'd attach the cooling plate to the bottom of the aluminum sheet and build a case for it with a cut-out for the fan. The result would (hopefully) be a refrigerated cooling pad for my constantly overheating laptop.

Is such an idea feasible? How powerful of a cooler would be needed to effectively chill such a sheet of aluminum?

Assume an ambient room temperature of 70 degrees Fahrenheit and that the bottom of the laptop is roughly 160 degrees Fahrenheit. I'd like to reduce the temperature of the bottom of the laptop to 120 degrees Fahrenheit. The bottom of the laptop is aluminum and about 15"x15". There is a gap between the aluminum sheet and the laptop bottom of about 1/8".

• I'm no expert on this subject, but I doubt such a rig would help your laptop much. You'd need conduction to cool the aluminium, conduction to transfer the "coolness" from the aluminium to the air gap, convection to cross the air gap, conduction to transfer from the air to the bottom of the laptop, and then conduction to transfer from the bottom of the laptop to the air in the laptop, to only then cool the parts themselves. That's a lot of steps which will lead to massive losses in efficiency. Then again, I'm no expert, so I might be mistaken.
– Wasabi
Mar 20, 2016 at 22:51
• @Wasabi I was thinking the same. The contact area between the cooler and the aluminum plate would be very small in respect to the overall surface of the plate. I didn't calculate it but I doubt would you get anywhere near a uniform temperature level. Besides as you pointed out you would only rely on passive cooling. What about a cooling pad? Should be cheaper, too! For the sake of completeness, I'm not a fan of these either. If your laptop overheats you should clean it, redo the thermal paste etc. Mar 20, 2016 at 23:14
• So basically the configuration goes like this: 1) the hot surface of the laptop. 2) an air gap of 1/8" thickness. 3)aluminum sheet. 4) cooler surface. Correct?
– Algo
Mar 21, 2016 at 15:59
• @Algo yep, that's the basic idea. The hope is that I can rig a cooler surface than the standard cooling pad provides. Mar 21, 2016 at 22:43

Even if the CPU cooler could make the patch of aluminum it was attached to exactly equal to atmospheric temperature, your plate would be much worse than a fan based cooler. The 1/8 inch air gap forms a very good insulator, so getting air moving along the surface of the laptop bottom is much better at cooling it than providing a heat sink 1/8 inch away.

Your best bet may be to make a hole in the aluminium sheet and mount the fan to either blow or suck the air from between the laptop base and the aluminium sheet ie using the 1/8" gap...