For really large systems an air compressor can feed all your rooms. Just calculate how many CFM you need and run a good sized pressure tank to prevent excessive cycling on and off. Scroll compressors can be very quiet and supply constant large volumes, properly sized they are the way to go for large commercial grows that use DWC. Kaeser comes to mind. You can even run an air to air or air to water aftercooler (intercooler) if you wanna drop the temp on the compressed air. Pipe in high pressure lines to all your rooms and put a regulator where you tap in. Really large grows can run on one compressor but it's good to have a backup.