Heat transfer refers to the movement of heat energy through the world around us. Refrigerators, ovens, laundry machines, cars, computers, and buildings are designs that all manage the flow of heat in one way or another.
There are four major types of heat transfer:
- Conduction —The transfer of energy between objects in physical contact
- Convection —The transfer of energy between an object and its environment
- Radiation —The transfer of energy to or from a body through emission or absorption of electromagnetic radiation
- Mass transfer —The transfer of energy from one location to another as a side effect of moving an object containing that energy
Understanding the physics and thermodynamics of heat transfer will allow you to use energy more effectively by optimizing the form and materials used 
in your designs. The rate of heat transfer depends on the materials you use, and goes up as both temperature difference and surface area increase.
Here is a great Sustainability Workshop video for students explaining the fundamentals of heat transfer optimization in design: http://bit.ly/vrhDck
