Udvikling af staaltags-solfanger. (Development of solar collectors mounted on roofs of steel): Fid-Bau Portal

Udvikling af staaltags-solfanger. (Development of solar collectors mounted on roofs of steel)

P. Mikkelsen / I. Katic

The possibilities of using solar energy in connection with the renovation of roofs where steel units are laid on top of older asbestos cement sheets are investigated. Three prototypes of suitable solar collector designs are examined, and their capacities are compared with types of a more traditional design. Results showed that the capacity of collectors of a quite simple, newer, design compared well with that of traditional models when the absorbers of the former are integrated in the roof construction. This is because heat transfer from the steel roof lying under the collector reduces heat loss. It is difficult to achieve an acceptable temperature for domestic water heating based only on heat exchange between the warm air under the roof and a circulating fluid, where there is a a roof plate instead of a transparent covering over the absorber. At lower temperatures, for example in the case of heating systems for swimming pools, this design could be considered suitable. The solar collector will than be camouflaged and the absorber will be integrated as part of the roof surface. The suggested construction is aesthetically attractive, especially when compared to solar collectors mounted on top of the roof, and it is also cheaper than those of traditional design. It is concluded that this type of solar collector has good potentials for use in connection with roof renovation. (AB)