Reducing energy consumption: what’s next?

 – a blog by Sigbjørn Tyssen

Currently, reducing the energy consumption on board passenger vessels is a hot topic. It is known that HVAC is one of the largest energy guzzlers on board of these type of ships. And with a growing focus on the environment and operational costs, it is an exciting time to work in the marine HVAC business. In lowering the energy on board via HVAC we are already quite far and can promise a big reduction.
For more information about this issue, I would like to invite you to our Seatrade stand 1594.
In this blog I will try not to talk about Artificial Intelligence (AI), machine learning, neural nets and other modern concepts. Which savings topics will come up next?

There has been a lot of development in the HVAC field in recent years. On the air side there has been development in the field of VAV systems, the use of local cooling and heating (fan coil units) and on-demand ventilation in the accommodation and cabins. On the water side, used for cooling and heating the air, a similar development has been seen. Commonly used are more efficient chillers, frequency-controlled pumps and chillers and pressure-dependent 2-way valves.

Obviously, the systems, both the design and the operation, are becoming more and more complicated. You can easily lose the overview in both cases and partially optimize the systems. When minimizing energy consumption you will need to see the sources for heating and cooling, the pumps, the fans and the local cooling and heating equipment as one.

Predict

An excellent HVAC system should do its job in operation without being too dependent on too many manual operations. But even with an excellent system, the system will usually respond to input from other independent input devices. These input devices can be very diverse, from temperature sensors in the accommodation to the outside temperature, from the heat load under the galley extraction hoods, to key card readers.

Often a number of schemes are built in for different public areas, so that they can be put into energy-saving mode as soon as they are assumed not to be in use. With the exception of planning, the system mainly responds to what is happening at that moment. But what if the system could predict, plan and respond to the future before things happen? With a location system we can see where mobile phones, key cards or ID cards are on board. With the weather forecast we know what the outside temperature will be and which hours the sun shines. Based on the sailing route, we have an idea of the available residual heat. A quick adjustment could be to work with a heat map based on where the mobile phones are on board. This allows you to react faster than temperature and CO2 levels.

See patterns

More interesting is the possibility to find patterns based on this and to plan the HVAC scheme. Predict when the guests are in the pool, restaurants, shops, cabins and on private balconies. And to check whether the pattern is different when the weather is nice or less beautiful (never bad on a cruise ship). And does the pattern behave differently for a full day at sea than when it is in the harbor or on short trips?

We believe that the future HVAC system will not only respond to imports but will learn from historical data combined with predicting the future. The future HVAC system will react faster, but also move energy to where it is needed, plan when it is needed and produce in the most energy-efficient way.

The traditional HVAC skills such as fan curves, noise calculations and knowledge about refrigeration cycles will not go out of style. Automation is already important. But knowledge of systems that I promised not to talk about, such as AI, machine learning and neutral networks is something we need to learn more about. The technology is there and the data must be collected. Whether we want it or not.

Sigbjørn Tyssen has been working in the marine HVAC business for over 20 years. During his career he mainly worked on systems for navy, cruise and passenger ships. Started as a CAD and commissioning engineer, and he is now project manager at our HVAC-department in Bergen.