M/S Silja Serenade


M/S Silja Serenade is a cruise ferry owned by Silja Line built in 1999, which operates between Stockholm and Helsinki. The ship has a length of 203 meters and a max. speed of 23 knots. It carries 2850 passengers and 450 cars. 


Our solution for M/S Silja Serenade consists of optimization and automatization of HVAC, pump control, and engine room ventilation. In addition, a new user-friendly control system with a focus on comfort and energy saving was installed. All work was performed during regular operations with no need to disrupt or dry dock the vessel.

M/S Silja Serenade

Our solutions

New control systems for HVAC, heat recovery, pumps, and chillers were installed. The system is adjusted specifically for M/S Silja Serenade and targets power consumption, comfort, and usability.


For the HVAC unit an installation of 116 drives was made for cabin-, public-, and service units each with their own individual regulation by temperature, Co2 or/and humidity. Pre- and reheating valves were installed and controlled for each unit. 45 new VDS for RW were installed with new control and 45 new RW were replaced. The control of the cabinets was rebuilt and airflow was balanced. Recirculation dampers and VVX were included in the steering to achieve the most economical drift meanwhile increasing comfort. Everything is monitored by an automatic steering system with a focus on comfort and energy efficiency.


The system is automatically controlled to regulate temperature and differential pressure in order to keep the lowest energy consumption possible while keeping the climate in the engine room areas within required values. Drives were installed for ME room, AE room, FO treatment room and for the AC room, together with different temperature-, pressure-, and differential pressure sensors and a new control system.


Pumps have both been integrated into the new control system and installed as stand-alone solutions. 


The original heat recovery system from ME Cooling water was rebuilt, valves and sensors were installed. The system was integrated in the new control system.


CO₂ (ton)




Fuel (ton)