A fire suppression system comprising: a gas source comprising a plurality of cylinders coupled in parallel via a supply manifold ; each cylinder having an outlet and one or more control valves and/or control pressure regulators between the outlet and a corresponding port on the supply manifold ; a controller ; the supply manifold having an outlet port connected to a main feed line which, in turn, connects to an inlet port of a distribution manifold ; the distribution manifold having outlets feeding individual end points (36A-G) through respective delivery lines (40A-G); some of the endpoints forming second outlets configured to merely discharge the inert gas supplied by the gas source as a suppressant, these endpoints forming a first type of endpoints of the distribution manifold ; wherein the controller is configured to control the control valves and/or control pressure regulators and to effect a pressure regulation from 50 bar to 75 bar; wherein each of the delivery lines (40A-G) comprises a respective selector valve connected to and controlled by the controller ; wherein at least another endpoint that forms a second type of endpoints of the distribution manifold has a vessel containing a body of liquid agent and having a headspace configured to be pressurized via the associated delivery line to drive or propel the liquid agent into an inlet of a discharge conduit , said inlet immersed well below a surface of the liquid agent , and through the discharge conduit to a distribution manifold and therefrom as discharge flows from first outlets of nozzles ; and wherein the delivery line to the at least one endpoint being of the second type of endpoints of the distribution manifold comprises a pressure regulating device being configured to limit downstream pressure to a value in the vicinity of 10 bar to 45 bar. a gas source comprising a plurality of cylinders coupled in parallel via a supply manifold ; each cylinder having an outlet and one or more control valves and/or control pressure regulators between the outlet and a corresponding port on the supply manifold ; a controller ; the supply manifold having an outlet port connected to a main feed line which, in turn, connects to an inlet port of a distribution manifold ; the distribution manifold having outlets feeding individual end points (36A-G) through respective delivery lines (40A-G); some of the endpoints forming second outlets configured to merely discharge the inert gas supplied by the gas source as a suppressant, these endpoints forming a first type of endpoints of the distribution manifold ; wherein the controller is configured to control the control valves and/or control pressure regulators and to effect a pressure regulation from 50 bar to 75 bar; wherein each of the delivery lines (40A-G) comprises a respective selector valve connected to and controlled by the controller ; wherein at least another endpoint that forms a second type of endpoints of the distribution manifold has a vessel containing a body of liquid agent and having a headspace configured to be pressurized via the associated delivery line to drive or propel the liquid agent into an inlet of a discharge conduit , said inlet immersed well below a surface of the liquid agent , and through the discharge conduit to a distribution manifold and therefrom as discharge flows from first outlets of nozzles ; and wherein the delivery line to the at least one endpoint being of the second type of endpoints of the distribution manifold comprises a pressure regulating device being configured to limit downstream pressure to a value in the vicinity of 10 bar to 45 bar. <EOS>