The lifetime and durability of new products.

Ageing exposure test of polymeric cover materials and antireflecting glass, particularly the product from SunArc, is a topic in the project and will continue in the work of Task 27. Moreover the project will compile the achieved knowledge that has been recognised from as-sessment of the ventilation rate of solar collectors. The experience is achieved from the fol-lowing activities:
1. The Danish assessment of the ventilation rate and its influence on condensation in the so-lar collector.
2. The CFD investigation into the pressure distribution around a solar thermal collector on a pitched roof made in the Netherlands.
3. Measurements on ventilation and moisture conditions made in Germany.
On the basis of the results achieved, the goal is to create a guideline that goes through the most essential conditions that can be of great consequence during the design of solar collec-tors. This will be of major importance to secure the solar collectors a long lifetime due to the fact that wetness and moisture is the most negative factor for the lifetime of the collector.