Production site comprising - a closed building, arranged in which are preferably several working areas, - a ventilation system a) with at least one conveying apparatus for conveying fresh air by means of a delivery stream into the building, which at least one conveying apparatus (23 - 23.3) comprises at least one air outlet pipe, arranged in the building and configured as a textile pipe, and is connected to the conveying apparatus (23 - 23.3) via a delivery line, and is subjected to a delivery air flow, and b) with an adjustable discharge air opening (31, 31.1), through which the discharge air can leave the building, c) wherein the at least one air outlet pipe is arranged at a distance interval from the at least one discharge air opening (31, 31.1) is arranged in such a way that, during operation of the ventilation system, an air flow is introduced in the building from the at least one air outlet pipe to the at least one discharge air opening (31, 31.1), - a humidifying device assigned to the ventilation system for delivering air humidity into the building, which humidifying device comprises at least one ultrasonic nebulizer arranged in the conveying apparatus (23 - 23.1) as a mist generator for producing an aerosol from a fluid with fluid droplets in a size such as can be conveyed with the air flow introduced in the building, and at least one aerosol outlet pipe, which extends parallel to the air outlet pipe and runs above it with a slight distance interval, in order for the emerging aerosol to be taken up by the air flow, - an aerosol line, by means of which the aerosol is conveyed to the at least one aerosol discharge pipe, and - working areas, which are arranged in the direction of the air flow towards the discharge air openings, wherein a working area, in which it is intended that a constant air pressure and cleanliness should be maintained, is located directly in the region of the air discharge pipe. - a closed building, arranged in which are preferably several working areas, - a ventilation system a) with at least one conveying apparatus for conveying fresh air by means of a delivery stream into the building, which at least one conveying apparatus (23 - 23.3) comprises at least one air outlet pipe, arranged in the building and configured as a textile pipe, and is connected to the conveying apparatus (23 - 23.3) via a delivery line, and is subjected to a delivery air flow, and b) with an adjustable discharge air opening (31, 31.1), through which the discharge air can leave the building, c) wherein the at least one air outlet pipe is arranged at a distance interval from the at least one discharge air opening (31, 31.1) is arranged in such a way that, during operation of the ventilation system, an air flow is introduced in the building from the at least one air outlet pipe to the at least one discharge air opening (31, 31.1), a) with at least one conveying apparatus for conveying fresh air by means of a delivery stream into the building, which at least one conveying apparatus (23 - 23.3) comprises at least one air outlet pipe, arranged in the building and configured as a textile pipe, and is connected to the conveying apparatus (23 - 23.3) via a delivery line, and is subjected to a delivery air flow, and b) with an adjustable discharge air opening (31, 31.1), through which the discharge air can leave the building, c) wherein the at least one air outlet pipe is arranged at a distance interval from the at least one discharge air opening (31, 31.1) is arranged in such a way that, during operation of the ventilation system, an air flow is introduced in the building from the at least one air outlet pipe to the at least one discharge air opening (31, 31.1), - a humidifying device assigned to the ventilation system for delivering air humidity into the building, which humidifying device comprises at least one ultrasonic nebulizer arranged in the conveying apparatus (23 - 23.1) as a mist generator for producing an aerosol from a fluid with fluid droplets in a size such as can be conveyed with the air flow introduced in the building, and at least one aerosol outlet pipe, which extends parallel to the air outlet pipe and runs above it with a slight distance interval, in order for the emerging aerosol to be taken up by the air flow, - an aerosol line, by means of which the aerosol is conveyed to the at least one aerosol discharge pipe, and - working areas, which are arranged in the direction of the air flow towards the discharge air openings, wherein a working area, in which it is intended that a constant air pressure and cleanliness should be maintained, is located directly in the region of the air discharge pipe.