Making things cold is usually much harder, both mechanically and physically, than heating something up due to thermodynamics. But Makers and Engineers always find a way.
In the same set of physics is a phenomenon called the Peltier Effect or the Thermoelectric effect. Driving electrical current through a semiconductor junction transfers heat from one side to another (thus cooling the side that has the heat taken away from it). Often times the junctions are sandwiched together to amplify the effect.
Peltier junctions are used for cooling small spaces, electronics, and small refrigerators. When something needs a large amount of cooling, it makes more sense power-wise to use some other cooling method often with more mechanical components like refrigeration systems.
There are a number of Peltier coolers on the market which require different methods of power and handling. For this tutorial we will use the Adafruit #1331 Peltier module. This module is powered by 5 volts. This unit has a maximum current draw of 1.6 amps. Use with Crickit is ok, as the Motor driver has current limiting to ensure the electronics are not damaged.
Using the Peltier module with two alligator to pin connection cables and a female power supply connector, you can hook the Peltier directly to a 5V 2 amp power supply. The supply must be able to provide > 1.6 amps (a supply that provides more than 2 amps at 5 volts is fine). The connections are shown below.
Assemble such that the Peltier module will not damage anything while it heats up!
You'll see one side gets rather hot and one side gets cold. Cool, literally! Note which side gets hot and which side gets cold for later.
Feel free to use the Peltier module in this manner to heat or cool any project you need.
If you'd like some variability in the heating and cooling, see the next page.