The book outlines the basics of air conditioning theory and technology. The properties of humid air and the processes of changing its state are considered. Structural schemes and classification of air conditioning systems. Methods of calculation, as well as modes of operation and regulation of air conditioning systems. The solutions of heat and cold supply of air conditioning systems, ways to reduce energy consumption and utilization of heat and cold are shown . For students of construction universities studying in the specialty "Heat and Gas Supply and Ventilation" . Pages