in the mixer the cooled air heated air during the winter mode is mixed with the stream of atmospheric air to form a joint air stream with a required temperature which is then supplied to an object to be air conditioned each end surface can have one or more window pairs the device shown in fig2 has a dust filter 1 a distributing valve 2 pipes 3 and 4 a drum with passages 5 an end surface 6 with a window 7 for low pressure air supply and window 8 for compressed pressure withdrawal an end surface 9 with a window 10 for high pressure air supply and a window 11 for expanded air withdrawal a compressor 12 an electric motor 13 an air cooler 14 a bypass pipe 15 a mixing unit 16 this device operates in the following manner in contrast to the device shown in fig1 the airstream supplied after the distributing valve 2 into the pipe 4 is subdivided into two partial airstreams one of the partial airstreams is supplied into the passages of rotatable or immovable cylindrical drum through the windows 7 for low pressure air supply formed in the movable or rotatable end surface 6 where it is compressed by compression waves to a desired pressure at one stage and exits through the window of compressed air withdrawal and the pipe connected to it the second partial.