What is a Peltier Cell (Peltier Cell) and How It Works

The cooling of our components is very important, especially the processor. Any heatsink and graphics card have a lower thermal limit, which is determined by the ambient temperature. Breaking this barrier is possible, but we need certain accessories, such as a Peltier cell. In this article we will explain in a simple way what a Peltier cell is and how it works.

What is a Peltier cell

A Peltier cell is an electrothermal device that allows to generate cold from electrical current. This acts as a solid state heat pump, or what is the same, allows heat to be transferred from a cold focus to a hot one, generating an opposition to the temperature gradient.

When a Peltier cell works, one side starts to heat up while the other side cools down. There are other much more efficient systems to generate heat, that is why it is normally used for cooling.

How a Peltier Cell Works

Its operation for thermoelectric cooling is relatively simple. Basically it is a sandwich of two ceramic plates whose filling is two semiconductors. These two semiconductors are usually:

• Type P: boron, indium, gallium
• Type N: Phosphorus, arsenic, antimony

When a current is circulated between the two ceramic plates, one of them cools. All the heat lost by one of the ceramic plates is collected by the second, which increases in temperature.

The heat of the Peltier cell is not dependent on the ambient temperature, so we can have a liquid below the ambient temperature. Thermodynamics prevent any air sinks or liquid cooling from dropping below ambient temperature. This system allows to obtain a better cooling of our components.

Why it is not used in the cooling of electronic components

Its use in the world of hardware, despite the benefits, is quite limited. By requiring high currents, this system is much more inefficient than liquid cooling and let's not talk about air-cooled heatsinks anymore. We must bear in mind that the heat generated by the hot plate must also be dissipated. So we must install a heatsink to reduce excessive heat generation.

We must bear in mind that the difference between the two faces of the Peltier cell is usually around 70ºC. After this point the cell becomes inefficient and the cold plate begins to heat up. In addition, both plates are very close and the heat tends to rise, so it affects the cold part of the cell.

A small 40x40cm plate can generate 60W of heat that we must cool, which adds to the inconvenience of requiring electricity to function..

Advantages of Peltier cells

• They lack moving parts, reducing wear
• They require little maintenance
• They do not have chlorofluorocarbons (CFCs)
• Allows temperature regulation by regulating the current
• They can be quite small and compact
• They have a fairly long operating life
• They can be useful to cool our hardware

Disadvantages of Peltier cells

• The amount of dissipable heat is limited
• They cannot be used in high heat generation systems
• Highly inefficient as they consume a lot of electricity
• Risks of burns
• Risk of direct electrical contacts
• Generates condensation
• The heat generated by the cell must be dissipated