ABSTRACT
This chapter looks at some novel refrigeration techniques that have driven the quest of reaching as close to absolute zero as possible. One of the most common techniques of refrigeration uses the principle of so called evaporative cooling. This has been used in ancient Egypt as long ago as 2500 BC and in India even as early as 3000 BC to cool water. If a breeze of dry air were to be incident on the pot, the rate of evaporation is enhanced and so also the cooling rate. This is so, as the breeze continually replenishes the supply of dry air, facilitating the process of evaporation. A way of quantifying the efficiency of a cooling, or equivalently, a refrigerating process, is through the so called cooling power. The most important part of the refrigerator is the so called mixing chamber where the mixing and consequently also the cooling takes place.
