© Peter Ferstl, Stadt Regensburg
© Peter Ferstl, Stadt Regensburg

Project

Multipurpose Hall Burgweinting

Product

OKALUX

Order Volume

170 m²

Architects

Tobias Ruf, "Hochbauamt" Regensburg

Completion

2004

Application

Façade | Skylight

Building Type

Sportsfacility

Multipurpose Hall Burgweinting

Burgweinting, Germany

An energetically optimized sports hall

The construction of a new sports hall in Burgweinting near Regensburg was supported by the German  Foundation for Innovations in Environmental Protection. The main reasons for this support were the development of  semi-transparent photovoltaic conversion glazing, the natural ventilating conception, and compliance with the EPBD inspite of the extensively glazed façade. Constructor of the energticially optimized sports hall is the City of Regensburg.  The Fraunhofer Institute for Solar Energy Systems in Freiburg will be monitoring the project for the next two years.

The most distinguishing feature of the school and club sports hall is the longitudinal façade oriented to the south which is a newly developed photovoltaic conversion insulating glazing construction.The silicon cells used here are not arranged smoothly but with an edge distance of 20 mm. In this way, the cells can give shade and reduce the amount of heat entering the hall. The transparent glazing between the cells allow a glare-free illumination with daylight. The development of this new glazing was optimized in building simulations and work in the light laboratory. There are a total of 56 PV-modules (glass panes) in four different variations (glass size/capacity rating) with a total power of 10 kWn in the façade.

The poly-crystalline silicon cells were bedded in a liquid resin compound between two TVC-security panes to protect them against breakage. There is a thermal protection coating on the inner side of the second TVC-pane which acts with the silicon cells to reflect the thermal radiation. The glass cavity is filled with crypton. The rim is made gas-tight with a cable. The inner pane is VSC-security glass which withstands impact from, for example, thrown balls. On the whole, the glazing achieves a solar energy transmittance (g-value) of 0.116 and a U-value of 1.1 W/m²K.

One difficulty during development was to realize and apply the light transmission values stipulated in the simulation directly and diffusely to the entire glass construction. This was made possible by using two pale, opaque 0.38 mm thick PVB-foils. This construction of the insulating glazing enabled the realization of high protection from heat radiation in the summer and a low amount of heat loss in the winter, while at the same time allowing for glare-free illumination of the hall with daylight. In addition, the power line is supplied with current produced in the façade from the sunlight.

The east and west sides were not used energetically. To achieve a glare-free illuminaton of the hall,
OKALUX K  light-diffusing glass from the insulating glass specialist OKALUX in Marktheidenfeld was installed. The double-glazing cavity of the insulating glass contains innumerable capillary tubes of plastic (PMMA) alligned perpendicularly to the pane. These tubes diffuse the incidental light and bring it to the inner pane where it is diffused again by a mat. The direct light transmission is zero. The sun as light source in not visible. Although the glazing prevents glare, its diffuse light transmission of 0.30 results in an even illumination of the hall with daylight. The extremely low g-value of 0.17 minimizes the heat input in the summer while the U-value of 0.9 W/m²K offers the thermal protection required in the winter.

The north side is constructed  of heat-absorbing glass. The three different types of glass construction allow for the conditions in the interior described and contribute to an interesting achitectural interplay in the façade.

A controlled, natural ventilating system was installed  to minimize heat input in summer and heat loss in winter when airing. The simulation showed that openings for air supply and air discharge  with a cross-section of 1.5 m² are needed on two opposite sides to air the hall in a natural manner - using thermal drive, independent of the direction or velocity of the wind.

Temperature probes are mounted on the interior and exterior of the building. The hall is cooled in the summer by airing during the night. The exposed concrete surface acts as cooling ribs and delivers delayed cooling during the day.  The air supply openings in the dado are not visible: slat windows which have louvers covered with a vacuum insulation are on the outside behind form boards of larch wood and on the inside behind the deflector casing. The air discharge flaps are flush with the west and east façade in the form of counter-sunk skylight windows. In the winter, the ventilating system allows for an exchange of air within a very short time without large heat losses.

With this interaction of the various elements, the concept of the sports hall is both innovative and economical.

 

 

References