Modelling of Microclimate in collectors

Abstract It is important to avoid condensation in solar collectors, most of all because wetness of the absorber can damage the selective surface and cause corrosion on the absorber plate. During night time the cover of collectors will cool below ambient temperature due to thermal radiation to the cold sky.

In climates where the air during night time becomes saturated with humidity (the relative humidity is 100%), condensation will form on the outside and inside of the collector glazing. If too much condensation takes place on the inside of the glazing, it will start to fall off on to the absorber surface.

It is important to characterize microclimatic conditions in the collector, and at the Department of Buildings and Energy work is carried out with the improvement of a computer model. As a tool the computer model will be useful in developing guidelines to achieve the most favourable microclimate conditions for materials.

Results from the computer model will be compared to measurement of microclimatic parameters in a collector in operation.