Tuesday, October 25, 2016

Cascaded thermoelectric (Peltier) modules

A lot of engineers are impressed with thermoelectric (Peltier) coolers and most of them thought about getting ultimate freezing (negative) temperatures. Thermoelectric cooler -conceptually- is a heat pump, so it takes electric power and pump heat from one side (source) to the other side (sink).

To get ultimate negative temperatures, you have to cascade Peltier module on the top of another, but how this will work. The first principle is: the dissipated heat of thermoelectric module from the hot side is the summation of the input electric power and the absorbed heat from the cold side. Therefore, the dissipated heat is always large and around 3 times the absorbed heat.

So... when stacking Peltier modules on top of another, you have to make sure that the dissipated heat of the top one is less than or equal the cooling power of the lower one. You can stack different Peltier modules of different sizes in pyramid layout from largest size in the bottom to smallest size on the top.

Also, you can stack Peltier modules of different cooling powers but with the same size. The following is a list of Peltier modules that have the same size, but different cooling powers:

If there are no more options for Peltier modules in your country (one model only is available in your country), then you can use array layout for cascading them like the image below:


Cascaded thermoelectric (Peltier) modules|elments|tiles

Thermoelectric (Peltier) cooler on the top of another

Thermoelectric (Peltier) stacking

Minimum thermoelectric (Peltier) cooler temperature

Ultimate cooling|freezing temperature in thermoelectric (Peltier) cooler

Dissipated heat of thermoelectric (Peltier) modules|elments|tiles

Heat sink power of thermoelectric (Peltier) modules|elments|tiles

Thermoelectric (Peltier) modules|elments|tiles in Egypt