General Heat Transfer Guide
What This Guide Is
This content was originally featured on Amdmb.com and has been converted to PC Perspective's website. Some color changes and flaws may appear.What this guide is:
An introduction to the science behind heat transfer.
An explanation of power, energy, conduction, convection, and other related terms.
A discussion of fans, chips, and materials.
An exposé on the heat transfer properties of air, water, and other materials.
A guide designed specifically with air cooling in mind.
A text intended to dispel some of the myths associated with PC cooling.
What this guide is not:
A guide to specific cooling equipment.
A complete in-depth analysis of all things associated with heat transfer.
An engineering text designed to educate while gentling lulling to sleep(although if you try to read it all at once, ZZZZZZ.).
A sure-fire means to transform you into an all-knowing thermal guru.
A guide designed to discuss water or Peltier cooling in fine detail.
The specific purpose of this guide is to take the science associated with heat transfer and translate it into a meaningful document that will allow the reader to understand how heat transfer works and how it applies to computers. Far too often I see statements posted that range for a little off base to completely false. Hopefully by explaining the basics of heat transfer, everyone will be better equipped to handle their particular cooling requirements.
This guide will not discuss any equipment by manufacturer or model. The primary reason for this is that the available equipment changes too frequently. A secondary reason is a desire to avoid a subjective bias. The equipment available in the computer field changes daily. The equations that drive heat transfer do not.
A brief word about the author’s qualifications; I’m a mechanical engineer with a degree from UW-Madison. I spent more hours than I care to recall designing heating and cooling systems related to the paper industry. I’ve tried to condense bits from a few 3-credit engineering classes into a single document without burying the reader. I will not claim to be an all-knowing thermal and PC master and can’t guarantee that everything I write applies 100% of the time. I will claim a solid knowledge of the topics I discuss and leave it to you to believe or not. If you believe any part of what follows to be in error, I would appreciate hearing about it. Be forewarned, however, that I’ll expect you to back up your assertion with published information from reliable sources. Unsubstantiated claims stated on someone’s web site do not pass muster.
What else should you know about engineering? Engineering is primarily an empirical science. This means that it relies upon measurements to determine material properties and physical phenomenon. Based on these measurements, engineers create tables of material properties and equations governing behavior. An engineer’s ability to predict performance is limited by the engineer’s ability to accurately measure and determine operating conditions. As such, engineers often sacrifice accuracy of the results for speed and simplicity of calculation. They also create rules-of-thumb that handle the majority of situations, but don’t analyze any specific situation in great detail. You will note the emphasis of this document is on concepts and not hardware-specific analysis.