The Peltier Effect

The Peltier effect is something that was discovered on accident. It was discovered by Jean Charles Athanase Peltier while he was investigating electricity in 1834. Peltier took copper wire and bismuth wire and connected them and then to a battery. When it was turned on one junction became hot and the other became cold. He then realized that if he put the cold junction in an insulated bag it could be a portable refrigeration device. It then occurred to him that this was simply the reversal of the Seebeck effect. This was discovered in 1821 by Thomas Johann Seebeck. He discovered that if two dissimilar metals made a circuit it would conduct electricity if the two metals had different temperatures at the connection point. This information helped him in the full development of his device. Peltier became known as the first inventor of the refrigerator, and he may not have even known.
         For the peltier effect to work the direction of the heat transfer is dependent upon current polarity. The peltier effect happens due to a electric current and heat current being together in a homogeneous conductor staying even at a constant temperature. Once this was studied and perfect the cooler was created. The peltier cooler is a heat pump that transfers heat from one side of the cooler to the other working against the temperature gradient by using an electric current. The device can be used as both a heater and a cooler. Many people that use this device today use it for its cooling properties. The device has been used by many cooler companies. They put it inside one of their insulated coolers and people can take cold food or drink with them wherever they go. Another thing it is used for is to keep instruments at a steady temperature. Certain instruments are made out of special wood and materials and need to stay at a specific temperature in order to work properly, and have the best sound quality. The military uses it to help with certain electronic devices that need to stay cool. They are also put in dehumidifiers to help with water extraction from air. Even spacecraft uses this device. It balances the effects of direct sunlight by transferring the heat form that side of the craft to the shaded side. One of the great things bout this device is that it does not have any moving parts; so maintenance is not an issue.
       The down side is that they are inefficient. Unfortunately to dissipate the heat coming from the device a fan is also needed. This adds more cost to the product. Due to the level of electricity used the device can cause overheating and in some cases condensation. The issue at the moment is creating peltier coolers that are both efficient and affordable.

Sources:

Graham, Christopher Fox, and Lindsay D. "What Is the Seeback Effect ?" WiseGeek. Conjecture, 07 Oct. 2013. Web. 30 Oct. 2013.

Ratliff, Jen. "What Is the Peltier Effect?" WiseGEEK. Conjecture Corporation, 04 Oct. 2013. Web. 30 Oct. 2013.

"The Peltier Effect." TechFAQ The Peltier Effect Comments. Memebridge, n.d. Web. 30 Oct. 2013.

Froboese, Klaus. "The Peltier Effect." The Peltier Effect. N.p., n.d. Web. 30 Oct. 2013.