A Peltier device, also known as a thermoelectric cooler or Peltier cooler, is an electronic component capable of transferring heat from one side of the device to the other when an electric current is applied. Peltier devices have several useful applications in cooling, heating, and temperature control.
Some key uses of Peltier devices include:
Precision Temperature Control
One of the most common uses of Peltier devices is for precision temperature control. The ability of Peltier devices to heat and cool with precision when current is applied makes them ideal for applications requiring stable and accurate temperature settings. For example, Peltier devices are used in scientific instruments, medical devices, and electronics to maintain specific temperature environments. When paired with a temperature sensor and control circuit, Peltier devices can adjust heating or cooling as needed to hold a temperature within a fraction of a degree.
Food and Beverage Cooling
Peltier devices are used for cooling foods, beverages, and even wine. When electricity is applied, one side of the Peltier device chilling while the other gets hot. Using a heat sink on the hot side, the cool side can extract heat from items like refrigerated food display cases, wine chillers, portable coolers, and liquid dispensers to keep contents chilled. Peltier cooling systems are quiet, compact, and do not require refrigerants compared to vapor compression refrigeration.
Electronic Component and System Cooling
Many electronic components and systems generate significant heat that needs to be dissipated to prevent overheating. Peltier devices offer an efficient solid-state cooling solution for hot electronics and processors. When a Peltier device is attached to a hot chip or circuit board, it draws heat away to keep temperatures in a safe operating range. Peltier coolers have no moving parts and do not require maintenance like fans or liquid cooling systems. They are used for cooling everything from personal computers to large servers.
Laboratory Equipment Temperature Control
Precise temperature control is critical for many lab processes and research experiments. Peltier devices enable exact heating and cooling for applications like incubation, sample preparation, and medical laboratories. For example, DNA thermocyclers use Peltier elements for rapid heating and cooling of vials during PCR amplification. Other lab equipment like microscopes, analytic devices, and environmental chambers integrate Peltier units to maintain temperatures within tight tolerances.
Laser and Photonics Cooling
Lasers and photonics equipment generate significant heat from the optics and electronics. Peltier devices offer compact thermal management for these sensitive systems. By actively cooling laser diodes, power supplies, and other components, Peltier units prevent heat buildup for optimal performance. They are also used for cooling photodetector arrays in applications like spectrometry, imaging, and telecommunications.
While mainly used for cooling, Peltier devices can also generate electricity when a temperature gradient is applied. This property allows them to be used as thermoelectric generators to convert waste heat into useful electricity. Sources like vehicle exhaust, stoves, industrial processes and more can generate electricity through a Peltier device. The small-scale power can charge batteries or power electronics.
Medical Equipment Cooling
Many medical devices like imaging systems, analyzers, and microscopes contain electronics and lasers that generate substantial heat. Peltier coolers offer precise temperature control to keep these systems operating properly while minimizing noise. MRI machines, laser scalpels, and other medical equipment integrate Peltier devices for cooling critical components. They maintain the sensitive electronics at optimal temperatures for health and safety.
In addition to heating and cooling, Peltier devices can condense moisture from the air when used as a dehumidifier. By cooling a surface below the dew point temperature, water vapor will condense out of the passing air as it touches the chilled Peltier surface. This condensed water can then be collected in a catch basin. Peltier dehumidifiers are useful for low-capacity, spot moisture removal in small enclosed spaces.
The rapid heating and cooling capacity of Peltier devices make them ideal for thermal cycling. Thermal cycling repeatedly switches between two temperatures and is useful for testing material properties. By attaching a sample to a Peltier device, it can be automatically cycled through hot and cold temperatures for heat stress and fatigue testing. Peltier thermal cycling is useful for testing in research, manufacturing, and quality control.
Thermoelectric heat pumps use Peltier devices to transfer heat and serve both heating and cooling needs. When electricity flows one way, it pumps heat from a cold reservoir to a hot reservoir for heating. Reversing the current pumps heat the other direction for cooling. Peltier heat pumps have benefits like being compact with no moving parts. They can serve as environmentally friendly HVAC systems for buildings and vehicles.
The compact size and solid-state operation of Peltier devices make them ideal for portable heating and cooling. Small beverage coolers and food warmers leverage Peltier technology for personal use. This allows cooling or warming on-the-go when electricity is available, like in vehicles. Portable Peltier air conditioners and heaters are also available for personal climate comfort.
DNA microarrays allow analyzing thousands of genes at once for genetic research and drug development. Peltier devices enable the thermal control needed for DNA microarrays. By quickly and accurately cycling through precise temperatures, Peltier units allow the DNA samples to hybridize and be analyzed. This accelerates the biotechnology workflows.
Ambient Air Cooling
Peltier junctions can also serve as heat exchangers for ambient air cooling. Warm indoor air can be passed through the hot side of a Peltier device to be chilled as it flows across the cool side, providing cold air for ventilation. This air conditioning method can be energy efficient in the right climate conditions.
Infrared detectors need cryogenic freezing for peak sensitivity. Small infrared sensor assemblies for imaging and security use Peltier elements to cryogenically cool the sensor chips. This provides the low operating temperatures needed for infrared detectors to work properly.
There are many other specialized uses of Peltier devices leveraging their solid-state heating, cooling, and temperature control abilities. New applications are still being developed as thermoelectric technology continues advancing. With their unique capabilities and compact size, Peltier devices will continue growing in usage for thermal and energy applications.