A compressed air supply installation for operating a pneumatic installation, especially an air suspension installation of a vehicle, includes an air supply unit and an air compression unit for supplying a compressed air supply unit with compressed air, a pneumatic connection, especially a bleeding line, comprising a bleeding valve and a bleeding port for bleeding air, and a pneumatic connection, especially a compressed air supply line having an air drier and a compressed air port for supplying the pneumatic installation with compressed air The air drier has a drier container through which compressed air can flow and which contains a desiccant. The drier container has a wall forming a desiccant-free recess, and at least part of the bleeding valve system is arranged in the recess.