Thermoelectric cooler (TEC) is a semiconductor device which is characterized by unique heat pump performance with high efficiency, compactness and durability. The unique ability of TECs to heat and cool, permits them to lower temperature of an object below ambient as well as to stabilize temperature of objects in widely varying ambient conditions.
Here we mention some application tips that can help in optimal use of TECs.
Operation environment (ambient conditions and temperature) as well as mechanical loads affect the TEC lifetime and durability in operation and also the performance.
As most of electronic devices lifetime of TECs strongly depends on operational temperature. Lifetime of regular TECs is minimum 200,000-300,000 hours at normal conditions (25-30 °C).
Standard operational temperature conditions for TECs are given for temperature range -60...+85°C.
RMT specify operating temperature till +120°C.
TECs can withstand even higher temperatures - close to internal solder melting point (for RMT TECs - it is 230°C). But with increasing of temperature the TEC lifetime decreases gradually in accordance with Arrenius equation.
If high temperature operation is required than estimations of TEC lifetime time in the application must be done.
During temperature processing (mounting and so on) it must be taken into account that TEC high temperature heating even for short time can reduce lifetime considerable, even leads to immediate failure at long overheating.
Try to exclude redundant overheating of TECs
The presence of moisture will cause an electro-corrosion that will degrade the thermoelectric material, conductors and solders of TEC construction. Moisture can also provide an electrical path to ground causing an electrical short or hot side to cold side thermal short.
A proper sealing method or dry atmosphere eliminate these problems.
Important note is that most of standard TEC specifications (with maximal performance parameters) are given by TEC manufacturers for vacuum conditions.
But a plenty of TEC applications means gas filled environment. It must be taken into account that in gas filled ambient performance of TECs is always less than specified for vacuum conditions. Main reason of that - additional heat load to TEC by convection and thermoconductivity of gases.
Request supplier for TEC performance for you gas filled environment
Include gas ambient conditions in thermal management considerations