Colourface - Coloured Collector Facades for Solar Heating Systems and Building Insulation

摘要

Coloured absorbers are a major demand of architects for the design of facade integrated solar thermal collectors. But coloured absorbers have shown an inferior thermal performance compared to selective coatings of state-of-the-art collectors so far. Within the project Colourface selective colour coatings have been developed and ageing tests of the coatings have been performed. Four colours have been chosen as absorber coatings for test collectors. The colours were blue, green, auburn and grey. The efficiency of these test collectors was measured using the dynamic collector test method according to EN 12975-2. The blue and green coloured absorbers have shown thermal performances comparable to black solar varnish coated absorbers. The auburn coating showed less absorptivity but also less emissivity than blue and green resulting in a slightly lower efficiency curve. The efficiency of the grey coated absorber was the lowest of all tested collectors as it was expected. Seven wall constructions that are commonly used in Austria and Germany have been investigated to find out whether the direct integration of collectors into the wall is possible without harming the building materials or. Finally, two pilot systems - a newly constructed two-family house and a retrofit building - have been realised with facade collectors. Temperatures and relative humidities in the collector and inside the wall construction have been monitored and analysed. The results of the project are presented in this paper.