Once an exotic component, solid state heat pumps or Peltier devices are now pretty mainstream. The idea is simple: put electricity through a Peltier device and one side gets hot while the other side gets cold. [DroneBot] recently posted a video showing how these cool — really cool — devices work. You can see the video, below.
Many things in physics are reversible, and the Peltier is no exception. The device is actually a form of thermocouple, and in a thermocouple a temperature difference causes a voltage difference. This is known as the Seebeck effect as opposed to the Peltier effect in which current flowing between voltage differences causes a temperature difference. It was known for many years, but wasn’t very practical until modern semiconductor materials arrived.
The problem is that all the heat has to go somewhere, so there is need for some way to move heat away from the hot end. The experiments in the video use a TEC1-12706. That number may look cryptic, but it actually identifies the parameters of the module as explained in the video.
These coolers are not terribly efficient but for places where you need to get an area cold with very little extra volume and mass, these are just the ticket. We love seeing these used in odd contexts. For example, using a peltier instead of dry ice in a cloud chamber. While it isn’t very efficient, you can use one to make a kind of air conditioner.