It will not be a mistake to say that air conditioning and refrigeration belong to the paramount achievements of engineering of the 20th century. These inventions make our life easier, comfortable and beneficial. Air conditioning embraces such processes as cooling, heating, sterilization, humidification and dehumidification of the air. Refrigeration is the process of cooling of the enclosed space. What is more, refrigeration maintains stable low temperature in this space. Why are these inventions so notable? They enable people to enjoy their life creating suitable environment for them. Let us observe the strong sides of air conditioning and refrigeration on the specific examples.