Swimming pool to passive house standard

Passive houses have been around for some time now – but what about passive swimming pools? Bambados, the family and sports pool centre in Bamberg, is Europe’s first indoor pool built to passive house standard, i.e. it is operated particularly energy-efficiently, in part thanks to an innovative pool edge system which makes a sustained contribution.

This innovation was developed in close collaboration between the building owner (Stadtwerke Bamberg), planning agency (pbr Planungsbüro Rohling AG based in Osnabrück) and AGROB BUCHTAL as one of the leading providers of swimming pool ceramics, and which also supplied the tiles in the other areas. Unlike a conventional WIESBADEN pool edge system, water evaporation levels using the BAMBERG system are 45 % lower. This saves valuable energy in terms of heating water and the air-handling system which is required to circulate less air, thereby reducing the energy necessary for powering the ventilators. The new system is also particularly convincing thanks to its elegant appearance and lower noise level which is attributable to gentle water intake without the formation of spray water.

Did everything go according to plan? How has it been received by visitors? How did project co-ordination work with so many people involved? Boris Schlörb from pbr Planungsbüro Rohling AG, Christoph Jeromin from Stadtwerke Bamberg and Andreas Kramer, Director Architect Service / Application Technology at AGROB BUCHTAL, provide us with the details:

AGROB BUCHTAL: Mr Schlörb, Bambados is known as the first swimming pool in Europe with certification to passive house standards. What planning approaches were decisive in order to realise this goal?

Schlörb: In physical construction terms, the particular type of building represented by an “indoor swimming pool” has a major potential when it comes to optimising energy requirements. Considering the particular use of water heated indoors all year round and at constantly high temperatures accompanied by the ensuing humidity, this task is a very demanding one. The idea and development of the passive-house design for this type of building was therefore especially exciting and challenging. What was important was the integral interaction by the Passivhausinstitut, planning in terms of architecture and technical building design, i.e. the development of an integral planning approach. Only this way and by using innovative construction materials and technical solutions was it possible to explore new paths.

AGROB BUCHTAL: Mr Jeromin, Bambados has meanwhile been in operation for more than a year. What practical experience have you gained and how is Bambados perceived by visitors and the public?

Jeromin: We have enjoyed some very positive experience with the passive-house design. During the first winter of 2011/2012, the structure was exposed to an extremely cold period with temperatures dropping as far as -20 °C which it withstood very well. The passive-house swimming pool has also easily mastered its first test in terms of dew points and condensate. The visitor numbers speak for themselves and are indicative of the fact that the facility is very popular. With the result that the target figures for the first year of operation were exceeded by 12% in the sauna landscape and on 15.11.12 – almost two weeks ahead of its first anniversary – Bambados welcomed its 250,000th visitor. Accordingly, the visitor numbers forecast for the “bathing area” were also reached. In­clud­ing clubs and schools, the pool centre was visited by around 400,000 people during its first year of operation. We are very satisfied with these figures.

AGROB BUCHTAL: Mr Kramer, what criteria were of significance for developing the BAMBERG system and how were they implemented?

Kramer: Bambados features a total water surface of 1,800 m2 and more than 400 metres of pool rims which are of particular relevance in terms of evaporation by the water flowing off. “Interfering factors” such as gratings or their supporting edges invariably cause higher evaporation rates and therefore increased energy requirements. By avoiding such disruptive influences, the aim therefore was to achieve absolutely gentle water run-off with as little evaporation as possible. So we dispensed with the classic rim cover relocating the rim to a “higher” level and integrating it directly in the moulded stone.

AGROB BUCHTAL: What made you so certain that the theoretical assumptions would actually prevail in practice?

Kramer: Our theoretical values were verified by extensive practical tests on 1:1 models of the corresponding pool edge variants. Using state-of-the-art mechanics and sensors, waves or water/air flows were generated in a climatic chamber and numerous data analysed in order to establish the influences on evaporation until finally the best variant emerged with which initial assumptions could even be exceeded by a long shot.

AGROB BUCHTAL: What made you so certain that the theoretical assumptions would actually prevail in practice?

Kramer: Our theoretical values were verified by extensive practical tests on 1:1 models of the corresponding pool edge variants. Using state-of-the-art mechanics and sensors, waves or water/air flows were generated in a climatic chamber and numerous data analysed in order to establish the influences on evaporation until finally the best variant emerged with which initial assumptions could even be exceeded by a long shot.

AGROB BUCHTAL: Mr Jeromin, what role did the jointlydeveloped BAMBERG pool rim system play in terms of energy savings?

Jeromin: As already mentioned by Andreas Kramer, complex comparative measurements were made using conventional pool rim systems in the climatic chamber at the Institut für Energie und Gebäude (ieg) at the Georg-Simon-Ohm-Hochschule, whereby a significantly lower evaporation rate of up to 45 per cent (depending on the intensity of use) was established for the innovative rim. This reduced evaporation obviously means less ventilation power and lower electricity consumption.

AGROB BUCHTAL: Mr Kramer, the BAMBERG system was used in Bambados for the first time. What challenges needed to be overcome as regards installation?

Kramer: As a general rule, ceramic tiles or even such moulded pieces only become finished “products” following expert and skilled processing – represented in this case by the swimming pool. But easy installation was very important for us even during the initial development stages to ensure that this innovative solution was convincing in both ecological and economical terms. The special shape enabling the effects already described is integrated inside the pool rim while the outer form was consciously kept “box-shaped” and simple, thereby only requiring a relatively basic recess with a 90° angle in the bare concrete. This does not make installation any more difficult than for conventional pool edge systems. Dimensionallyaccurate installation aids were supplied for the upper edge trim providing effective support during efficient and exact installation.

AGROB BUCHTAL: Mr Schlörb, how important was planning support provided by the AGROB BUCHTAL “In-house Planning Department”?

Schlörb: Support by the In-house Planning Department and Product Development at AGROB BUCHTAL was essential for developing the BAMBERG system as well as energetic optimisation of the FINLAND system for the energy-saving “sports channel”. The initial ideas and approaches were immediately picked up on there and developed to become a marketable solution thanks to the distinctive “know-how” available. For us, it was very exciting to be intensively involved in the entire process from the theoretical approach through technical development to final realisation.

AGROB BUCHTAL: Mr Jeromin, looking back, how do you rate joint development of the BAMBERG system? What do you regard as having been decisive for the success of this innovation?

Jeromin: In my opinion, what was decisive and remarkable was the great collaboration between AGROB BUCHTAL, Stadtwerke Bamberg, Planungsbüro pbr and the college in Nuremberg. By joining forces, it was possible to create such an innovation which not only saves energy but also offers new aesthetic possibilities in the area of the pool edge. The edge surface can be drawn right to the edge of the pool conveying a purist and elegant impression. Another important aspect was support by the Project Manager Jülich (PtJ) who sponsored the new development with funds from the EnOB aid programme.

AGROB BUCHTAL: Mr Schlörb, ceramic is an entirely ecological building material which therefore goes perfectly well with the environmentally-friendly alignment of Bambados. What relationship do you personally have with this material and its aesthetic and functional properties?

Schlörb: Ceramic is a material which has been proving its worth for thousands of years yet is still capable of surprising us with its amazing design potential. It is fascinating to see the development and variance undergone by this material’s properties since then. Especially in the area of pool construction, ceramic offers numerous aesthetic options for both visual and haptic experiences. At the same time, its reliable compliance with demanding functional requirements and strains, e.g. in the form of moisture or chemicals, is also very convincing. From designing a functional sporting atmosphere to a wellness ambience, a wide variety of concepts can be realised and optimally co-ordinated in terms of their effects on people. Especially here where spatial surfaces are not only experienced visually but also very intensively by means of direct contact with skin and the body. In such applications, this material offers a wealth of aspects such as roughness, smoothness, wellness, safety, variety, emotion, haptics, function, durability, sustainability or hygiene.