Selective, coloured façade collectors – Colourface

A survey among architects showed that the availability of coloured solar collectors would enhance the application facilities in the building sector. As there are only black absorbers on the market, the project has the target to develop spectral selective coloured coatings for absorbers of facade collectors with similar features as the conventional ones. The developed colours shall be easy to apply to absorbers and also repair of the absorbers afterwards shall be possible. The binder of the colours shall be environmentally friendly and suitable for the use in glazed collectors. The absorption of the coating shall be above 80%, while the maximum emissivity shall be below 50%. Therefore, a compromise between the costs for pigments, the optical properties and the architectural requirements has to be found.

The main work packages of the project are the following:

• Development of a set of aesthetically coloured solar absorber paints based on environmentally friendly binder and pigment systems suitable for solar facade collectors with a solar absorption of 80%+ and a thermal emission limit of 50% maximum.
• Development of appropriate life cycle test for the coatings and test of the coatings
• Analysis of questions of structural physics (stagnation temperatures, moisture transport in the system wall/collector, thermal bridge effect)
• Measurement and comparison of test facades
• Production of guidelines for the application of solar facade collectors as part of the building envelope based on experimentally validated studies of their energetic performance, architectural appearance and impact on the building physics.
• Construction of two pilot plants to implement and monitor the findings of the project.