Peltier Cooler

What is a Peltier Cooler?

A Peltier Cooler can also be called a Peltier device, Peltier heat pump, solid state refrigerator, or thermoelectric cooler (TEC).  It is a solid-state active heat pump which transfers heat from one side of the device to the other. It uses electrical energy and can be used for either heating or cooling, or as a controller that either heats or cools. How? It creates a heat flux between the junctions of two different types of materials. This effect was discovered in 1834 by the French physicist Jean-Charles-Athanase Peltier.

How Do Peltier Coolers Work?

Direct current (DC) runs through the device, which has two sides. This brings heat from one side to the other. One side gets hotter while the other side gets cooler. The hot side remains at ambient temperature since it is attached to a heat sink. The cool side drops below room temperature. More than one Peltier cooler can be connected to achieve even lower temperatures.

GreenPowerScience.com makes a Peltier cooler to charge your electronic devices by campfire:

What are the Advantages and Disadvantages of a Peltier Cooler?

Peltier coolers are small and flexible in shape but the main advantages of Peltier coolers are their lack of moving parts or circulating liquid. They have a long life, no moving parts, and no chlorofluorocarbons. Temperatures can be controlled to within fractions of a degree. They can be made for applications as small as a beer cooler or as large as a bus.

Peltier Coolers

The main disadvantages of Peltier coolers are high cost and poor power efficiency. They are not as efficient as vapor-compression systems. Peltier coolers that are both cheap and efficient are being developed by several researchers and companies.

How are Peltier Coolers Used?

You may already own products using Peltier elements. They are in camping equipment, portable coolers, cooling electronic components and small instruments. Your dehumidifier may contain a Peltier heat pump to extracts water from the air. If you have a camping/car type electric cooler, the Peltier element chills your beverages or medications. They can typically reduce the temperature by up to 20°C below the ambient temperature.

On Amazon.com, a TEC1-12705 Thermoelectric Peltier Cooler 40 mm x 40mm 12V 77 Watt is available for about $10. It can be used in a wine cooler, mini-fridge, or desktop. (Be sure to buy thermo paste and apply to both sides of the cooler.)

Peltier coolers are also used in scientific devices. They are in thermal cyclers, used for the synthesis of DNA, as well as in satellites and spacecraft to counter the effect of direct sunlight on one side of a craft. Peltier elements are used in photon detectors such as CCDs in astronomical telescopes. Very high-end digital cameras are often cooled down with Peltier elements. They can also be used to cool computer components. Other applications include for fiber optics, where the wavelength of a laser or a component is highly dependent on temperature and for military use in the field.

Peltier Cooler

Build a flashlight with a Peltier, hot water, and ice:

Can I Make My Own Peltier Cooler?

Yes, you can. You need a battery, two pieces of copper wire, and a piece of bismuth or iron wire. Attach the wires to the two poles of the battery. Connect the bismuth or iron wire between the two pieces of copper wire. The Peltier effect is caused by the contact between the copper and bismuth.

The location where current flows from copper to bismuth will get hot and the location where current flows from bismuth to copper will get cold. You will see a temperature differential of around 40 degrees F or 22 degrees C. Obviously one copper/bismuth interaction isn’t enough to keep your 12 pack cold so coolers have lots of these connections.

Make a Peltier cooler: