Thermoelectric coolers … TECs ... solid-state heat pumps … micro-coolers ... Peltier cooling ...

Several terms are commonly used to describe the cooling technology discovered and developed by Seebeck, Peltier, and Lenz in the early 1800s:

• Thermoelectric cooler / TEC
• Peltier cooler
• Solid-state refrigerator
• Solid-state heat pump
• Micro-cooler

The term thermoelectric originates from Seebeck’s discovery relating to the operation of thermocouples, while the term Peltier module / Peltier coolers stems from Peltier’s observations, known as the Peltier Effect. (For more details regarding these discoveries and associated analysis, reference “Infrared System Engineering” by Richard D. Hudson, Jr., John Wiley & Sons, New York, 1969.)

Early in the 20th century cryogenic cooling was commonly used to stabilize the temperature of detectors.

• The use of thermoelectric coolers - commonly abreviated as TEC - was explored at that time, but it wasn’t until later in the 20th century when smaller, more efficient systems were required and manufacturing costs were reduced that the use of thermoelectric coolers became common.

Many of the terms currently used for thermoelectric coolers originate from the application of the cooling module.

The term solid-state refrigerator touts its advantage over cryogenic cooling and provides a clear explanation that the device is used for cooling.

• Solid-state refrigerators use a crystal material called bismuth telluride for the thermocouples, eliminating the need for cryogenic gases deemed unfriendly to the environment.
• However, many users soon discover that the device not only pumps but generates heat that needs to be dissipated for efficient operation.

The term solid-state heat pump characterizes the function of a device that pumps heat from one object or space to another, again using the solid-state material bismuth telluride.

• Many users choose solid-state heat pumps to stabilize the temperature of a component such as a detector and understand that the heat from the component is dissipated to the heat pump.
• What users often don’t understand is that the heat pump itself generates a small amount of heat.
• The heat from the component and the heat pump need to be dissipated to an object such as a heatsink or a background environment that is lower than the temperature being dissipated. See Operating Precautions for more information.
• Operated in the reverse current mode, heat pumps can also be efficiently used to heat components or stabilize them at an elevated temperature.

Today, many applications are designed to use less space resulting in lighter weight systems.

• Solid-state heat pumps are becoming smaller and more efficient through the use of higher-grade bismuth material and improved assembly processes.
• The term micro-cooler is often used to describe these smaller modules that use less power while providing more cooling to microelectronic packages and systems. Micro-coolers are finding their way into more applications as costs are reduced through higher volume production.

From time to time we are asked why we refer to our product as a solid-state heat pump rather than a TEC or thermoelectric cooler. Now you know - we chose the more descriptive term rather than the generic thermoelectric cooler.