In the centre of the Hamburg metropolis there is a unique location which combines creativity, chances, contrasts and suspense. The Elbe islands of Wilhelmsburg and Veddel and the Harburg inland harbour are the venue and subject matter of the international building exhibition IBA Hamburg. Alongside the main themes of “metro zones” (development of inner city limits) and “kosmopolis” (development of the international community of a city) the IBA has written “City in a Climate Change” on its’ flags, with the goal of a CO2-neutral city development.On this backdrop projects are to be realised here which will enable renewable energies to find a wide area of usage. The importance of this theme should be expressed not only by the symbolic character but also by the transferability of the applied technologies to other projects. The IBA information centre, where building began in 2009, the IBA_Dock, was planned according to this motto; this signifies that air conditioning is possible without conventional energy sources such as oil and gas.
The IBA_Dock is a steel-constructed floating pontoon. In terms of static and weight requirements, the superstructures are made in a modular construction and assembled on location on the pontoon. This also influences the choice of outgoing heat systems. Conventional walls and underfloor heating do not come in to consideration because neither floor fill nor plastered walls are used. The better choice is the usage of ready-made heating and cooling ceiling elements to be installed in the entire building.
The fact that the IBA_Dock is a floating building made the type of energy supply a challenge for engineers, geologists and the responsible authorities. Multiple possibilities were covered in cooperation with the company IMMOSOLAR to provide an energy supply for the IBA_Dock from the water temperatures of the Elbe combined with solar thermics. This comprises both the heating requirements of the building including water heating and the cooling requirements for air conditioning the rooms. The energy source is a heat transformer built in to the pontoon in the form of meander-like extended pipes. These pipes enter in the sol plate of the pontoon and are laid over the entire space. The choice of the heat source depends on the quality of the water and the biological conditions of the Elbe. In this case a water-water heat pump would lead to the iron clogging of the filter and the presence of multiple algae and mussel growth in the suction tubes which in turn would lead to high maintenance intervals. The low temperatures of the Elbe in winter would also have a negative effect on the yearly working figures of the heat pump.
There are three offload levels for solar energy which are hydraulically controlled and regulated according to priority. The process water preparation has the highest temperature requirements and thus the highest priority. At the second level a heating buffer is controlled which works at an average temperature range.
Temperatures lower than 30°C which cannot be used for warm water and heating are fed to and saved temporarily in the third offload level, the closed brine system. A further buffer, installed between the heat pump and the heat transformer on the pontoon, saves the solar energy. During the heating period the saved energy is raised to a temperature level suitable for heating purposes by means of a heat pump and is fed to the heating surfaces or water heating. This clearly maximises the solar yield and the yearly working figures and hence the efficiency of the entire system.
The solar offload levels are part of the IMMOSOLAR EnergyManager which represents the hydraulic and regulation core components of the IMMOSOLAR EnergyManagementSystem. It forms the point of intersection for the linking of the solar collectors and the heat pump as well as for the incorporation of the reservoir components in the system. The IMMOSOLAR EnergyManager makes sure that all energy fluxes are utilized according to temperature and requirement. Solar energy is passed on to the consumer immediately in accordance with requirements or is temporarily saved for use at a later stage.
A 44kW IMMOSOLAR Sole-Water heat pump is used to both heat and actively cool the building. The installed heating and cooling ceilings are used to either heat the rooms or to remove heat during a cooling process. The flow temperatures will be limited to 35°C during heating and 16°C during cooling processes. This ensures an optimal room temperature in both cold and warm months.
The IBA_Dock was designed as an information centre both for busy public traffic and for exhibitions and thus there are given hygienic requirements for the quality of the air. Air exchange throughout the entire building is ensured by means of a ventilating machine which recycles the heat it recovers. A photovoltaic unit is used to guarantee CO2-neutrality, the size of which is determined by the amount of energy used by the heat pump unit and also it’s’ auxiliary power units.
Ultimately the usage of green electricity for all electrical loads emphasizes the hidden goal.
The photovoltaic unit is located on the roof terrace level and is positioned at an angle of 30°.facing south. The 63 polycrystalline solon modules require a surface area of approx. 103 m2 and achieve a delivery rate of 14,8 kWp. The technical room is being made accessible so that the energy supply is clear for the interested visitor, and in this manner it is being integrated into the exhibition.
The single components are presented for all to see behind a Plexiglas wall and are explained with the aid of info tables. The monitor informs visitors about yields, consumption, temperatures and the condition of the unit. Monitoring can be selected remotely and hence it can be individually adjusted and readjusted as required.
1. EnergyManager and heat pumps
Energy concept and engineering