Air conditioning can be expressed simply as conditioning the air as per requirements, which could be with respect to temperature, moisture content, cleanliness, hygiene, odor, air motion, etc.
Refrigeration is the process of producing ‘cold’ by taking away heat. Whenever the temperature of a space or object is to be lowered below the surrounding temperature, it must be done through the process of cooling. In this chapter, we shall understand the basic requirements from air conditioning, modes of heat transfer, and factors that influence human comfort.