The white square is the peltier element (hot side hot, cold side cold)
The silverish thing is a heat sink with a liquid line and a fan attached (featured in a previous post)
A thermal effect plate (shown above) takes advantage of the thermoelectric effect of the material. What this means is the material responds to a differential in heat between one side and the other. When the heat is different a voltage is generated. That's basically what is called the Seedbeck Effect which is described by:
That equation just says that an "electromotive force" (which is a measure of induction, Faraday's Law) can occur when there is a difference in temperature (T). The -S is the Seedbeck coefficient which is a property of the material generating the EMF--in other words different materials can be checked empiracally to see what their coefficient is. The units for S are V/K (volts per kelvin) because it's a measure of electric potential per unit temperature.
So, if I explained that horribly basically if you have a material that makes electricity when you heat it--there you go. Read about the smart girl who made a body-heat-powered flashlight for Google Science Fair.
The "reverse" of the Seedbeck Effect is the Peltier Effect. All that means is instead of making electricity with a heat gradient you can make a heat gradient with electricity!
You can figure out how much heat differential (hot side hot / cold side cold) you're going to get by:
Again, confusing Greek letters notwithstanding, this means that the heat for the junction (inside the material, more on that in a sec) is the peltier coefficients of that material multiplied by the current.
There's more to it than that but I'm not a physicist or materials engineer so this'll have to do!
Thermoelectric (sometimes called thermopower) materials are often semiconductors because you naturally have electric potential due to the materials. Semiconductors are N-type and P-type materials. N-type have extra electrons and P-type have fewer electrons. As you know this sets up an easy to exploit electric potential!
Thermoelectric semiconductors have a grid of N-type and P-type materials sandwhiched together. Current is applied on the "hot" side and inductance on the cold side drives positive and negative potentials toward the hot side. Here's a pretty picture (I splorked this one out real quick, there are better ones online I suppose):
So, I figured I'd geek out a bit and try to explain it. In any case this stuff will all be coming together... possibly this weekend. Then I'll have an A/C unit for my computer! Or whatever.
