What Is a Peltier Cooling System?
A Peltier cooling system, utilizing a Peltier element, provides cooling based on the Peltier effect. This effect, discovered in 1834 by Jean Charles Athanase Peltier, involves heating and cooling phenomena when direct current flows between two different metals.
Uses of Peltier Cooling Systems
Peltier cooling systems are employed in various applications where silent, vibration-free cooling is required. This includes automotive cold/warming boxes, hotel room mini-refrigerators, medical refrigerators, and CPU cooling units in personal computers. Unlike traditional refrigerators that use vaporization heat and compressors, Peltier systems offer a quieter, compact solution with no frost accumulation and are environmentally friendly, as they don’t use CFC gases.
Principle of Peltier Cooling Systems
The Peltier effect operates on the principle that when direct current is applied between two different materials, such as an n-type semiconductor, a metal, and a p-type semiconductor, one junction absorbs heat while the other releases it. This effect is reversible by changing the current’s direction. The semiconductors are used instead of metals, sandwiched between substrates like ceramics, to create separate heat-absorbing and heat-generating surfaces.
The n-type semiconductor has excess electrons, while the p-type has a shortage, causing electron movement and current flow when voltage is applied. Peltier elements produce heat on some surfaces while cooling, necessitating the use of heat sinks or fans for heat dissipation.
How to Select a Peltier Cooling System
The selection of a Peltier cooling system depends on its cooling capacity, which is the amount of heat it can remove, expressed in watts (W), and the maximum temperature difference it can create. Factors such as the cooling room’s surface area, insulation material, insulation thickness, and temperature differential between the environment and the cooling room should be considered. The cooling capacity of the system should exceed the heat entering the cooling chamber. The maximum temperature difference refers to the largest achievable temperature gap in the absence of a heat load. The selection should also account for variations in cooling capacity based on the operating environment.
Other Information on Peltier Cooling Systems
Advantages of Peltier Cooling Systems
- Extremely silent operation
- No vibration
- No frost buildup
- Compact design
- Environmentally friendly, no CFC gas usage