The device removes heat from one element, such as water, and then transfers that heat to another element, generally the air or water. They utilize a compressor cooling system that works in a way very similarly to air conditioning units. However, instead of cooling the air, the goal of the chiller is to cool the water. Operating the device is relatively simply. You simply need to fill up the reservoir with the fluid that needs to be re-circulated, such as water. Add the plumbing between the chiller and the application, and then provide power. The controller will handle all of the functions of the chiller.