What Is a Peltier Module?
A Peltier module is a cooling device that uses a Peltier element, which is a thermoelectric element. Since it does not use refrigerant but only electricity for cooling, it is characterized by its low environmental impact.
A Peltier element is a semiconductor device that, when energized, generates a Peltier effect, causing a temperature difference between two surfaces. Generally, Peltier elements are lightweight and small plate-shaped, with a thickness of 2 mm to 5 mm.
The structure of a Peltier element consists of an n-type thermoelectric element, a p-type thermoelectric element, and electrodes sandwiched by a ceramic base.
Uses of Peltier Modules
The advantage of Peltier modules is that they are smaller than general cooling equipment and can be easily incorporated into equipment that requires cooling. Because of this advantage, they are used for cooling a wide variety of equipment.
Typical applications include cooling electronic equipment, such as computers and servers. They are especially useful in situations where there is a small cooling requirement or where heat sources are limited. For industrial equipment, they are also used in distribution boards and control panels.
Other applications include refrigerators, air conditioners, and dehumidifiers.
In recent years, Peltier coolers have also been commercialized as neck-mounted mobile coolers for heat control. There are also many smartphone coolers for smartphones that incorporate the functionality of peltier modules. They are also useful for cooling laser devices.
Cooling is essential for high-power laser devices such as laser diodes and fiber-optic lasers. Therefore, compact and motorized Peltier modules are used for cooling.
Principle of Peltier Modules
Peltier modules are made by laminating two different metals together. A potential difference is created between the two metals, and the Peltier effect is used to transfer heat from one metal to the other. The metals used are a combination of bismuth-based, silicon germanium-based, cobalt-tin-based, and iron-based.
The principle is that heat is transferred from the cooling plate to the heating plate by applying voltage to the Peltier element. Temperature can be controlled by the applied current. By reversing the polarity of the current, the cooling side and the heat-dissipating side can be reversed, making it possible to heat the object.
Since a large amount of heat is generated on the heat-dissipation side, water-cooling devices or heat sinks are often attached. There are also products with enhanced heat dissipation performance by sandwiching a heat-conductive material between the contacting surfaces.
On the heat-absorbing side, heat-absorption efficiency is maximized by attaching a cooling plate. Heat absorption efficiency is also increased by sandwiching a heat-conductive material between the contact surfaces with the cooling plate. However, the cooling temperature is limited to a minimum of 5°C.
How to Select a Peltier Module
Peltier modules can be sized according to the required capacity. In addition, products focused solely on cooling can be supplied at low and stable prices. High-performance products also exist and can be supplied with controls if precise operation is required.
Thus, the advantage of Peltier coolers is the ability to choose performance, price, and size according to the application. For consumer use, it is possible to focus on design improvements, while for industrial use, performance can be maximized to meet the required capacity.