The peltier module can be used in two ways:
The peltier module can be used for many different applications:
The module with peltier effect, is often used in coolers to produce cold or in air conditioners.
The peltier module used with the Seebeck effect can produce a voltage thanks to a heat difference of each side of the module. It can be used to light leds or any other type of components that do not require much current.
A Peltier module consists of a series of cells.
A Peltier effect cell can be defined as a ceramic plate. This one makes heat by dissipating calories and cold by absorbing them when electric current is introduced.
Two conductive materials of different natures X and W are connected by two junctions. An electric current is then imposed on the circuit.
This results in a heat release at one junction and a heat absorption at the other junction.
The Peltier coefficient relative to the couple of materials X and W is defined as the thermal power P released or absorbed by unit of current intensity I. It is expressed in volts.
There are several components to cool objects, including the compressor that allows to cool a refrigerator. We will see the advantages of the peltier module compared to the compressor:
Nevertheless, the peltier module has also disadvantages, which we will detail in the following section.
As you have seen, the peltier module seems magical, it allows to create a voltage with a temperature difference… But in reality it has its limits.
To create a current, one side must be cold and the other has to be hot.
Because the two sides are glued side by side, what happens is that the peltier module will heat more than cool and therefore the cold part will become hotter and hotter and therefore will not produce cold anymore.
That’s why in a portable cooler you will always see a fan to evacuate the hot air produced by the hot side and thus limit this effect.
Regarding the Seebeck effect, for generating a tension, there must be a heat difference between the two faces. However, as the two sides are glued together, by convection of energy, they will have the same temperature and therefore reduce the temperature difference and reduce the tension produced.
For this we need to find two sources, one cold and one hot that will keep the gap between the two plates.
In spite of these important limits, the peltier module can be useful in several cases. For the Peltier effect, its efficiency has already been demonstrated, especially in coolers and air conditioners.
For the Seebeck effect, the peltier module can be used to capture cold or hot heat that would otherwise be lost. An example of a project would be to stick a Peltier module against the wall of your house in winter. The walls would be warm because you are heating your house and the outside would be cold because of the winter. This could produce an electrical voltage to light up some of your outdoor light or Christmas lights.