Key Concepts in Thermal Conduction — Lesson 4

The insulation of house walls provides resistance to heat flow and can significantly lower heating and cooling costs. It improves the comfort and at the same time increases the energy efficiency. In winter, for example, heat flows from all heated living spaces to the outside, which we obviously want to prevent. This is accomplished by adding a layer of low-conductivity material on the walls. These insulation materials work by slowing down the conductive heat flow. But how do engineers calculate the optimum thickness of the insulation? Or, in other words, how can we estimate the heat flow through these complex composite walls?

Heating of high-performance electronics is a problem that engineers need to consider in the design of these products. Overheating can damage the electronics components inside and that’s why cooling systems, such as a fan, are installed in laptops to output heat into the ambient air by convection. The faster we can take heat out of these electronics, the higher the performance we can get from them. So, how can we aid this heat removal process? The answer lies in the extended surfaces that you may have noticed on different electronic components inside a computer.

 

Lastly, have you ever wondered how engineers calculate the time it will take for metal molds to cool down?

 

Let’s look at the key concepts in thermal conduction and try to answer these questions.


Alternate video link.


Here are the handouts accompanying this lesson.

You can also check out our "Structures" course on "Thermal Conductivity in Heat Transfer" if you would like to learn more about Conduction.

Structures
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Thermal Conductivity in Mechanical Structures