An installation for the production of pressure in a pressure medium, the installation being switchable between a delivery operation and an idle operation, the installation having at least two compression chambers that are arranged in at least one compressor,
- each compression chamber being assigned at least one switchable inlet valve, each of said switchable inlet valves having a rest position which allows said pressure medium to flow into the associated compression chamber in said delivery operation of said installation,
- each of said switchable inlet valves also having an idling position which allows said pressure medium to flow into and out of the associated compression chamber without being substantially compressed in said idle operation of said installation,
- wherein at least one inlet valve can be switched to its idling position independently of the at least one other inlet valve to switch said installation to a partial delivery operation,
- at least one of said compression chambers being assigned at least one non-switchable inlet valve.