In the spring of 2013 DFDS Seaways decided to upgrade the HVAC system onboard m/s Pearl Seaways by having the control system replaced. CATC (short for “control at sea”) won the project. The old system of ABB type suffered from communication problems and low availability of spares. DFDS also saw a potential to save energy in the process. The switch was carried out while the ship was sailing.
The first step was to install frequency drives and pressure/ temperature control on the engine room ventilation. A separate touch-screen was installed in the engine control room where the temperature and pressure in the engine room can be controlled and monitored. As the ship was built to cope with a much warmer climate than the Scandinavian area, the actual average use of the fans is greatly reduced.
Accommodation & public rooms
Next task was to replace the HVAC controls in the accommodation and public areas. A new fiber optic Ethernet was installed in order to allow the new controllers to communicate with the new HVAC ViewPort PC. All 30 Air handling units were refitted with a new PLC and new software.
Numerous new frequency drives were installed for more efficient fan operation. Since the ship travels on a fairly predictable schedule, time controlled energy modes were tuned to the actual use of each public room. CO2 sensors were installed in some public area. The PLC:s were refitted one-by-one and this allowed the ship to operate the not-yet-modified AHU:s on the old system, and the modified ones from the new system in parallel, thus the downtime of the monitoring for each AHU was only about one day. All the existing field equipment was tested when the new PLC was commissioned and thus many minor problems were tracked down. The conference area was fitted with a separate touch screen, where the staff can control the climate and energy usage in the conference rooms. Drawings and manuals were updated, and the project was finalized in November.
Passenger comfort and energy conservation
By running the HVAC system based on the actual temperature, pressure and CO2 levels, accurate inside temperature were confirmed. Benefits such as lower average noise levels and lower emissions can also be contributed to the new control system. All that aside the investment can easily be justified from an economic standpoint. It’s hard to imagine any sizable onboard project with a better ROI.
2.4 Tonnes of fuel savings
daily, according to customer.
ROI < 1.5 years.