A look along the river Spree from Humboldthafen in Berlin reveals a building between the facades with their chain-like sequence of windows that consistently breaks through the monotony of the place. Architects Richter Musikowski from Berlin have erected an exhibition and event building there. It provides an innovative solution to handle precious renewable energy. The energy concept includes a PCM storage system made by Axiotherm, a company based in Eisenberg.
Your cooperation has brought about a fascinating new building. What made your collaboration special?
Jan Musikowski: The Futurium project was not only about architecture, but also about a sustainable and efficient technical concept. Buffering heating and cooling energy in the building, which had previously been generated by solar collectors and a combined heat and power unit was one part of the project. Fortunately, after a long quest, we found Axiotherm, a manufacturer who dared to break new ground with us in this field. Our excellent cooperation brought about a latent storage system that can store hot and cold temperatures highly efficiently on the basis of paraffin phase change material. It achieves a multiple of the capacity of conventional water tanks.
Dirk Büttner: Our cooperation on the project was indeed characterised by a very positive and personal relationship. The chemistry was just right! Above all, we found the communication with the entire planning team to be very smooth and purposeful. This is important in a project like the Futurium in Berlin, where we installed a system called the paraffin latent heat storage system based on our HeatSel technology, which is still quite a novelty in the construction industry and unique in this dimension – after all, five storage tanks with a total volume of 50,000 liters. Effective planning and close cooperation are essential for the success of such a project.
Had you worked together on a previous project? And how did your collaboration come about for this project?
Christoph Richter: No, we had not met before. The contact was established by the general contractor BAM Deutschland AG, with whom we jointly explored ways to implement our storage concept. Following first discussions in Berlin and a visit to Axiotherm in Eisenberg, it became clear that we had found the right partners to implement this ambitious project.
Dirk Büttner: As a result of BAM’s meticulous and competent research, they focused on us and together we thoroughly analysed the technical feasibility. It eventually became clear that our technology was the right one for the project and so we began working with the architects. In other words, we met while the project was already underway. We were all the more pleased that the storage units, which require a lot of space in the building, had already been considered as black boxes in the drawings. This allowed us to integrate our technology seamlessly and easily.
Please tell us a short anecdote about your cooperation.
Christoph Richter: Our original intention was to set up a “glass” storage facility in the centre of the building so that visitors could see the phase change process. But we quickly learnt that the storage tanks must of course be insulated in order to work efficiently. Nevertheless, we continued to search for ways to make the process of phase change visible. At some point we got Axiotherm to experimentally fill the paraffin between two panes of glass. This was not easy for various reasons, but the result enchanted us. After many other test series – in which later even TU Dresden took part – it was eventually possible to develop a glass paraffin façade, which now surrounds the storage facility and from time to time allows a glimpse behind the scenes.
Mr. Musikowski, Mr. Richter, which concepts of a design idea or a detail do you have in mind when approaching the manufacturer?
Jan Musikowski: Usually, we start working on the brief in the form of sketches, preliminary drawings or a verbal description of our idea. And then, the feedback of the manufacturer is important to us. The more honest and transparent the discussions are, the more fun it is to work together and the greater is the chance of developing something new together
Which personal qualities of a manufacturer do you consider most important for your projects?
Christoph Richter: Being architects, we do not build for ourselves, but we are service providers and trusted partners for our clients. It is therefore crucial to us that the “chain of trust and confidence” continues through to the manufacturer. We appreciate cards on the table and working on an equal footing much more than commercial tactics.
In your opinion, up to which point should the design process be unrestricted by the feasibility and the implementation of an idea, for example, due to specific products?
Christoph Richter: From start to finish, we always try to think in options and have a Plan B up our sleeves, in addition to Plan A. All too often we have already seen manufacturers go bankrupt; product lines were sold or became unaffordable.
Mr. Büttner, at which stage in the planning process do you usually get involved in a project, and what would be the best-case scenario?
Dirk Büttner: Quite often, we are called in as a “fire brigade” if, for example, it turns out that issues such as lack of space or low temperature requirements from regenerative sources have not been consistently taken into account. Clearly, the ideal case for us is to be involved at the very beginning of the planning process. This allows optimal coordination with the trades, especially with building services. It is vital to integrate the building, the energy requirements and the options to use available energy into a common energy concept at an early stage, especially when the designing aims at achieving a high energy efficiency standard. Our PCM technology stores low temperatures in a highly efficient way. This applies to both heating and cooling. Heat or air conditioning cooling generated at the best operating points can thus be used with a phase-shift (day-night or night-day).
What are the design ideas, or the expectations with which the architects/engineers usually approach you? How often does this include ideas which require (at first) special solutions?
Dirk Büttner: New technologies such as ours are of the nature to break new ground in a particular project. Hence, in principle, every idea is a special case. But for us, dimension and application temperature are the most important factors, not the basic technology. Architects like to associate it with the idea of a seasonal storage facility. However, this has nothing to do with our technology. We offer short-term storage solutions ranging from minutes (e.g. industrial applications) to two or three days (e.g. building services). This is due to the constantly low temperatures that we can store and retrieve. It enables us to use the (renewable) energy resources available all year round. And thus, results in smaller storages for high cycle counts.
Mr. Büttner, which traits do you appreciate most in architects?
Dirk Büttner: Their intellectual freedom and agility, and their open-mindedness for new solutions. This interest in innovation leads to a sustainable development of building services engineering and thus advances the construction industry in general. In future, the combination of architecture and new technologies will constitute a sustainable and unique selling proposition for planners. The prerequisite for this is, of course, that the client provides financial leeway to support these options.
How does the building respond to the different framework conditions?
Jan Musikowski: With regard to energy storage, it was important to us that the futurium opened up new opportunities beyond the combustion of earthly resources. In addition to energy generation from sustainable resources (sun, rainwater), for us local energy storage is a key concern. Our design aimed at presenting technology aesthetically and thus raising awareness in society. This is how the ideas were born, for instance the accessible roof with a view onto the sun awning, or the paraffin store, which is located in the centre of the building.
What exactly was the brief and which specific solution did you find?
Dirk Büttner: To qualify for the sustainability rating, the building had to be ranked according to the “Sustainable Building Rating System” (BNB). The building’s energy concept envisages the primary use of renewable energy, which can be used, for example, for lights, illumination or building services to minimise the use of fossil fuels. The Futurium is designed to be a very low-energy building in which – roughly speaking – thermal cooling energy that cannot be used directly is stored in the PCM storage tanks so that it can be reused for air conditioning later on to compensate peak loads. Ultimately, the planning team succeeded in achieving BNB Gold status.
Christoph Richter: The Futurium will also serve as a central location in Berlin for presentations and to promote the dialogue between research and development. Exhibitions and events are intended to highlight future-oriented developments of national and international interest. In the context of the competition, we submitted a variety of specific proposals, which fortunately met the jury’s approval: large public forecourts, numerous entrances to the building, an accessible roof and an ingenious, sustainable energy concept.
Which changes did this project undergo from the first design to the completed building?
Christoph Richter: It always depends on the scale by which change is evaluated. If you compare the renderings from the design competition with the current building, you will hardly notice any differences at first glance. But if you look at the floor plans and the facade details, there are countless changes. This is quite natural, because all the functions of a building interact with each other in a complex way. It would be fatal for all parties if an architect wanted to insist on building the first draft immediately.
Was the project influenced by current trends in energy planning, construction, or design?
Christoph Richter: Yes, of course! Particularly when it comes to this building, there is no getting around the need for comprehensive information and a look around. But in view of the flood of information, it is important to develop one’s own visions, even if the journey is not immediately obvious. We also like to look off the beaten track, immerse ourselves in an antique painting or a futuristic film set. Sometimes there is more future in it than you would guess. After all, we are always amazed at what we can accomplish with technology and know-how today.
Dirk Büttner: In terms of energy, this project is a first. It is true that there are already large cold stores in buildings (for example in Japan), but these are ice stores. From an energetic point of view, this is a major disadvantage, as the generation of temperatures well below 0 °C greatly reduces the efficiency of the chillers. A lot of energy is wasted. The futurium is the first building where a large PCM storage tank was installed, which has a constant charging and discharging temperature at 12 °C (adjusted to the absorption chiller). This allows highly efficient operation with small temperature differences between cooling generation and energy consumption. Water storage tanks do not reach viable capacities at such small temperature differences. And right there is the opportunity: For reasons of efficiency, future energy storage systems will only work with these small temperature differences. The futurium’s name gives it away: This is where the energy technology of the future takes place.
Where did you have to pay particular attention, concerning the installation of the storage system on site?
Jan Musikowski: The paraffin storage system comprises five large tanks of approx. 10,000 litres each, which must be stacked at a central point in the building in a kind of heavy-duty high rack at a height of 20 metres. Due to their weight, we first had to lift in the empty tanks before the roof could be closed by crane on the construction site. Axiotherm then filled the patented, macro-encapsulated paraffin elements using the injection openings.
Dirk Büttner: Starting from the “Cave” (basement), a storage tank was installed on each floor. The logistics were therefore decisive as the storage tanks were installed through the still open roof. Since each storage tank was followed by the next one on the floor above, coordination with the subsequent trades was equally important. Theoretically, we could have built a tank with a volume of 50,000 litres, but from an architectural point of view, the concept of the building is geared to several levels. The macro-encapsulated PCM (storage material) was therefore inserted in five “sessions”. This was done using manholes in the floor and the dome areas of the tanks. Special care had to be taken to ensure that there was sufficient space between the storage dome and the floor above it.
Thank you very much, Mr. Richter, Mr. Musikowski and Mr. Büttner.
This interview was conducted by: Thomas Geuder, World-Architects
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