Index

Index

• Index• Goes• Here

Slide 1: The Chemistry of Cooling a PC

Computer Processors (CPUs) generate heat

Transistors are semi-conductors contained within

the CPU core

Resistance creates Heat

Moore’s Law dictates that transistor count in CPUS

will double every couple of years.

Generally Speaking:More transistors = More Heat

The Chemistry of Cooling a PC

Slide 2: The Chemistry of Cooling a PC

Heat creates “Electro-migration” which destroys

sensitive circuits.

Heatsinks are used to dissipate the heat from

computer CPUs

Performance has changed dramatically over the years

Slide 3: The Chemistry of Cooling a PC

Heatsink design has gone from simple passive aluminium to actively cooled copper or aluminium/copper hybrid.

However, Aluminium is 1/3rd of the weight soPer unit volume, Copper can absorb more heat.

But: Aluminium looses heat faster then Copper.= Good Hybrid Heatsinks.

Why?

• Heat Conduction of Copper = 380J s-1 m-1 K-1

• Heat Conduction of Aluminium = 200J s-1 m-1 K-1

• Specific Heat Capacity of Copper =  0.902J g-1 K-1

• Specific Heat Capacity of Aluminium = 0.385J g-1 K-1

Slide 4: Water cooling: From Enthusiast to Mainstream

Greater cooling potential, less noise, less stress on the system.

Why?• Specific Heat Capacity of Water =  4.179J g-1 K-1

• Specific Heat Capacity of Air (1atm) = 1.01J g-1 K-1

Water cooling: From Enthusiast to Mainstream

Slide 5: Water cooling: From Enthusiast to Mainstream

However, problems with the water system now occur.

Problems with water systems:

• Water and Electricity = Bad• >1 metal systems creates an electrochemical cell = erosion of water blocks.

• All Copper systems are now primarily used.

Slide 6: Water cooling: From Enthusiast to Mainstream

Many argue the water system should use distilled or deionised water.

Deionised water • Advantages: Removal of reactive ions.• Disadvantages: Still solvated solids remain

Distilled Water (Boiled Water)• Advantages: Pure water – nothing else solvated• Disadvantages: A “void” in the water causes ions

from the Copper blocks to restore ionic equilibrium

Slide 7: Water cooling: From Enthusiast to Mainstream

What can be done about it?

Possibly use a Copper solution in distilled water

• Common Ion Effect inhibits further ionisation.

Possible solutions:• Copper Hydroxide• Copper Nitrate• Copper Carbonate• Copper Oxide

Problems• Lower heat capacity.• Possible crystal growth if flow is slow.• Chemically “active” Copper solutions.• How soluble are they?

Slide 8: Water cooling: From Enthusiast to Mainstream

What can be done about it?

Use a completely different liquid like PFC’s(Per-fluoro-carbons)

C6F14 : Bpt: 56ºC

• Non toxic, non corrosive, non electrically conducting.

Problems with PFCs

• Lower heat capacity

• If the pump fails – PFC boils

• Expensive and possible restricted use.

Slide 9: Summary

Summary

Type summary in here

Slide 10: Acknowledgments

• University of Alaska Physics Dept.• University of Indiana Northwest• CSL Metallurgical and Materials Engineering Department• Bit Technologies• Wizard Designs• Pro Cooling

Thank you for your attention!

Acknowledgments