# Heat transfer

```                     == Conduction ==
```
• Conduction can be defined as the heat transfer through a substance because of a temperature gradient. The rate of heat transfer by conduction between two regions of a substance is proportional to the temperature difference between them. The constant of propotionality is called thermal conductivity of the material.
• Mathematically, it can be described by using the Fourier's law:
$Q_{Conduction} = -k*A*dT/dX$

Where

```     k = Thermal conductivity of the material (W/m-K)
```
```     A = Cross-sectional area of the object parallel to heat conduction
```
```     T = Temparature (K)
```
```     X = Length of the object
```