The most commonly known design is the standard refrigerator. However, even in this basic design there are variations. Another example is the air conditioner. These two designs are applications of standard refrigeration methods. Industrial applications include the cooling tower, which makes use of the movement of falling water to provide cooling. Thermocouples allow cooling by direct application of electricity. Even the use of a wet cloth to cover earthen ware water container to cool it is a basic application of refrigeration. While, ammonia refrigeration applications are usually used for larger applications.
There are three types of heat transfer. The first is by radiation or radiative. The second type of heat transfer is by conduction. This is movement of heat through the structure of matter. The third type is convection. This covers the transfer of heat via the movement of a liquid or gas. Application of these three types of heat transfer significantly affect the efficiency of refrigeration engineering designs.