The book deals with the fundamentals of commercial air-conditioning, ventilation, heating and cooling system design. It is the first Russian book of this kind, a memorial one to a certain extent, which describes all modern initial data in full details: requirements for engineering systems, thermodynamic, climatologic, hygienic, aerochemical and technological information, basic standards and numerous methods. The book includes numerous examples and control questions for a better understanding of the material. It gives full description of thermal loads for heating and hot water supply systems, the methods of heat, humidity and harmful emission calculations in air-conditioning, ventilation, heating and cooling systems. In addition to detailed description of individual components, specific air, heat, heating, cooling loads, methods of their analysis and synthesis are given in the book. The method of heat, moisture, vapor, air-gas balances of the rooms is described in full details. Harmful emissions of paint and coatings, welding, galvanic, chemical etc. industries are considered as a basis for calculation of commercial ventilation systems. The book includes basic standards and numerous methods and practical examples. The book is supposed to be of great use for designers, researchers, scientists, members of teaching staff, under and post graduate students of the civil engineering, polytechnic, energetic, technological etc. colleges and universities in their researches and diploma projects concerning general task of improving and optimization of air-conditioning, ventilation, heating and cooling systems.