Thermoelectric systems are based on the scientific phenomena called the Peltier Effect. According to this phenomenon a temperature gradient is set up when an electric current is passed through the junctions of two conductors. Due to this effect heat is deposited in one junction and cooling occurs in the other junction.
Thermoelectric systems are mainly used in cooling devices but it also finds application in heating devices. In both cases DC voltage is necessary.
Use Of Thermoelectric Systems In Heating
Thermoelectric systems are used for heating under the circumstances listed below:
- If the target temperature of the heating device is lower than the melting point of the soldering material which is typically around 138°C. If special solders are used then the temperature will be around 260°C.
- If a single component of the device is responsible for heating and cooling
- If the system is equipped with a thermoelectric cooling device
- If the system requires 100% heating efficiency within a tight power budget
Use Of Thermoelectric Systems In Cooling
Thermoelectric systems are used for cooling under the circumstances listed below:
- If the amount of heat that has to be displaced is lower than the capability of a normal compressor based system
- If the system requires an environment that is not affected by position or orientation
- If the object that has to be cooled is placed in isolation
- If the exact required temperature is not achievable using thermostatic temperature control
Benefits of thermoelectric systems
Thermoelectric systems offer a number of advantages as mentioned below:
- Moving parts are absent
A thermoelectric unit does not have any moving parts. This makes the unit maintenance free.
The thermoelectric module is small and light weight. The size of a thermoelectric cooling system is much smaller than a traditional mechanical system.
It is also possible to design the unit to meet the specific requirements of different design systems.
- Heating and cooling modules are present within the same system
The thermoelectric cooler is capable of either cooling or heating the system based upon the polarity of the DC power applied.
Due to this feature, it is not required to have 2 separate modules for heating and cooling purposes.
- Exact temperature control
It is possible to set precise temperature using a closed loop circuit. It even allows changing temperature in the range of +/- 0.1°C.
- High reliability
Due to the solid state construction, thermoelectric systems are very reliable. Under ideal conditions, the life of such a system is generally more than 200,000 hours.
- Eco friendly
Traditional cooling systems use chloro-fluro carbons that are harmful to the environment. But thermoelectric systems do not use or emit any harmful gases.
Applications of thermoelectric systems
Thermoelectric systems have a wide variety of applications.
- It is used in many defense technologies as it can withstand extreme conditions.
- As thermoelectric systems are not affected by orientation, it is used in many space equipments that operate under zero gravity.
- It is used to maintain viscosity in many ink jet printers.
- It is used in laser diode arrays.