Refrigeration:

Accurate meaning of refrigeration is the manufacture of cold confinement belongs to its surroundings. In this, under consideration temperature of the space is maintained at a temperature lower than the nearby atmosphere. To attain this, the mechanical device extracts heat from the space that ought to be maintained at a lower temperature & discards it to the nearby atmosphere that is at a comparatively higher temperature. As the volume of the space which ought to be maintained at a lower temperature is always remains much lower as comparisons with the environment, the space under consideration experiences comparatively higher change in temperature than the environment where it is discarded.

Thus the accurate meaning of the refrigeration is the following: Refrigeration is a procedure of removal of heat from a space where this is unwanted & transferring the similar to the surrounding environment where this makes little or no difference. To understand the above definition, let us take two examples from the daily life.

This is a well-known fact that the spoilage of food & several other items diminished at a lower temperature. At a lower temperature, motion of molecular slows down and the expansion of bacteria that causes food spoilage also retards. Therefore to preserve several types of perishable food products for a longer duration, we utilized refrigerators in our homes, hotels, canteens etc. The temperature of the food products ought to maintain at a level below surroundings. For this purpose we keep the food products in a refrigerator. The inside volume of the refrigerator where we hold food products or any kinds of items is much less than the volume of the room where the refrigerator is kept. In this case the room is the nearby environment. In the refrigerator food products initially were at a higher temperature than wanted temperature, meaning that it contained some unwanted heat. If its heat is reduced, its temperature shall decrease. The refrigerator eliminates unwanted heat from the food products & throws away that heat to the room - the nearby environment of the refrigerator. The amount of heat makes a large difference in temperature inside the refrigerator & almost little or no difference in the temperature of the room.