Presented are the method of paint booth air feeding to paint with liquid paints (variants) and an air supply unit to realize the method (variants). Said group of innovations consists of two innovations to the method and three innovations to the installation to realize the methods. In the method (variant 1), a closed air stream is created inside the painting booth and air supply unit, after passing the painting zone it is divided into two streams, the first stream returning to the painting booth, while the second stream, containing flammable liquid vapors, is extracted to atmosphere. Simultaneously, some additional air is taken from atmosphere, mixed with return air and supplied to the paint booth painting zone. In the method (variant 2) a closed air stream is created inside the painting booth and air supply unit, and, after passing through the painting zone, is mixed with some additional fresh air and then divided into two streams, the first returning to the painting booth, while the second stream containing flammable liquid vapors, is extracted to atmosphere. The painting booth with separated units of the air supply unit (variants 1 and 2) is intended to realize the method according to claim 1 (FIGS. 1 and 4). The painting booth with connected units of the air supply unit (variants 1 and 2) is intended to realize the method according to claim 1 (FIGS. 2 and 3). The paint booth with air supply unit (variant 3) is intended to realize the method according to claim 2 (FIG. 5). A better performance and improved ecological properties are the immediate technical results of the innovations proposed.