Technologies | Consumption on board

The target is to get a qualitative reasonable idea of the energy consumption of a cabin on board a vessel. To make it more detailed and also useable for other ship types than cruise liner two different designs of cabins are recorded.

Therefore a lot of information have been gathered and reviewed to provide a report that includes most of the energy inputs and outputs of a cabin. For example there is an input of electrical energy, fresh air and water consumption. On the output side there is waste water to be handled and exhaust air to be sucked off.

The result of this investigation is a list of calculated energy consumptions dependent on an estimated user profile for each type of cabin to have a baseline of energy consumption as close as possible to the reality.

At the end of the day the result is that there are high heat loads located in the cabin that have to be reduced by implementing other technologies or/and reducing the heat loads to a minimum.

Energy not used for propulsion is related to other sources of energy usage. Such as : the hotel part or the auxiliary power systems. Systems for ventilation, heating, deck machinery all contribute to energy consumption on board.

WP36 report contains the description of cabins build “state-of-the-art”. With respect to other types of vessels like dredger or other workboats also a description of crew cabins will be provided. So it should be possible to select the correct combination of passenger and crew cabins for each type of vessel.

The energy consumption of pax and crew cabins are defined based on the size and the energy consumed by: electrical, water and air-conditioning.

The two presented types of cabins are completely different in respect to space supply. Passenger cabins are much more generous than the crew accommodations. In terms of energy consumptions the different types of cabins are not that much different.
The water consumption is assumed to be exactly the same and the difference in electrical consumption is mostly depending on the smaller televisions and fewer light fixtures installed in the crew cabin. Regarding to this the heat load in crew cabins is less than in a passenger cabin but on a much smaller spaces. So the “energy density” in a crew cabin is higher than in a passenger cabin.

Actually the internal heat loads in the shown reference cabins are high. The biggest part of that is caused by the persons inside. In the first step in implementation of new technologies to reduce the energy consumption of cabins is to reduce inner heat loads such as lighting. It is necessary to have a more efficient lighting in the cabins because this has also influence on the HVAC system and its energy consumption. To swap the lighting to a more efficient LED technology should not be that complex. In this reasoning also improvement possibilities in the energy consumption of the television and refrigerator have to be investigated.

Also the external heat loads have to be in focus of further investigations. Heat loads from outside of the cabin penetrate the walls to the inside have to be prevented. One way to do that is the installation of thicker or improved insulation in walls and ceilings and the use better insulated windows.

The sizing of this system depends on e.g.:

  • The number of cabins and heat and radiation losses.
  • Energy consumption for electrical and water usage
  • Heat load for air conditioning.
  • Control parameter: required temperature