The textbook discusses the physical and hygienic basis of ventilation, sanitary and hygienic requirements for ensuring the parameters of the microclimate of premises and the protection of the air pool, the principles of operation of ventilation and air conditioning systems, their schemes, the basis for calculating and selecting ventilation equipment. Intended for students receiving the qualification of a specialist with secondary specialized education in the specialties "Sanitary equipment of buildings and structures," "Maintenance and operation of residential buildings," "Heat and gas supply, ventilation and air pool protection" and the qualification of a worker "Locksmith for the repair and maintenance of ventilation and air conditioning systems."