By Tony Kordyban

Now Available.  Order Your Copy Today.

More Hot Air is the long-awaited sequel to the author'sprevious ASME Press book, Hot Air Rises and Heat Sinks: Everything YouKnow About Cooling Electronics Is Wrong. This new bookcontinues in the same humorous and easy-to-read style of theearlier book, with all-new, original case studies in the field ofelectronics cooling. Each case study, told as an anecdote, isdesigned to teach a basic concept of heat transfer, as applied tokeeping electronics from overheating.

Because of the constantly shrinking size of electronics, the job ofcooling electronics continues to get tougher. Many people nottrained in the basics of heat transfer have been roped into doingthis job out of necessity. For those who lack any formal trainingin heat transfer, the case studies explode many of the myths aboutcooling electronics and replace these flawed practices with soundengineering, based on actual heat transfer theory.

The case studies and humor in this book are also entertaining tothose well versed in electronics cooling. A must-read book for allengineers and their managers concerned with electronicspackaging.


Table of Contents

Introduction

Measurement and Test: Getting the WrongAnswer Direct from the Lab

Chapter 1.1 The Best Worst Case

The requirements say to measure the product temperature underthe "thermal worst case environment."  But the ReliabilityDepartment, the Safety Compliance Department, the Thermal Engineerand the Customer all have different ideas of what the thermal worstcase should be.

Chapter 1.2 Blowing the Rel Test

The blowers in the Reliability Test Chamber makes the air flowbackward through your chassis.  Does that seem like a fairtest?  Or does it actually tell you something useful aboutyour product design?

Chapter 1.3 The Five-Finger Thermometer

Why your hand is not a good thermal sensor.  It not onlyhas calibration problems, but you might literally get burned.

Chapter 1.4 T-types Fried My Brain

There is a reason why different types of thermocouple wire haveunique color codes.  You can't always tell the differencebetween the types by just using common sense.  It takesbrains.

Chapter 1.5 Permutations and Combinations Add Up to JobSecurity

Maybe it makes sense to stack shelves up in a rack and use onebig fan box to cool all of them.  But there are lots ofthermal reasons not to like that design.  Endless combinationsof hardware can keep you doing thermal testing for years.

Chapter 1.6 Power Confuses, and Variable Power ConfusesAbsolutely

For some types of components, power dissipation depends on thecomponent temperature.  Sometimes it goes up, sometimes downas the temperature increases.  In that case a room temperaturetest can give you results exactly opposite to what you'd get at anelevated ambient.

Chapter 1.7 How to Get Percent Error 100%Wrong

A story about metrics, and how you can use percent error to getwhatever result you want.  The important metric for thermaldesign is the one that measures how well the process isworking--usually a temperature difference--not the absolutetemperature.

Fans:  Increasing the Air Flow and theTrickiness of Your Cooling System

Chapter 2.1 Elbow Room