The Stena Scandinavica is one of the biggest ships in the fleet. Stenaline is continuously improving the fuel efficiency and reducing the emissions from its fleet. In this process we were awarded a project to implement demand control for the engine air supply. The system we installed monitors and controls the pressure in the engine room within a few pascals compared to the outside. In this way, the air supply uses the minimal amount of power. The installation was carried out during ship’s normal operation.