Laboratory scale characterisation of cool roof paints
Amorphous and crystalline Y(In, Mn)O3 based pigments are employed to synthesise colourful NIR reflective coatings. Different radiation sources were tested to find the best solar simulator.
A series of cool coatings realised with three pigments displaying YIn0.9Mn0.1O3-ZnO stoichiometry and different colours (Ochre, Cyan Blue, and Deep Blue) was deposited on AA5005 aluminum substrate. Coatings were investigated by vis/NIR spectrophotometry. The colour was evaluated according to CIE-1976L*a*b* method. The innovative approach of the study aimed to compare the effectiveness of three different radiation sources (incandescent infrared emitting lamp, tungsten halogen one, and xenon arc one) to properly assess the thermal reflective performance of cool roof coatings.
Cool surface coating
These thermal evaluations were compared with the performances obtained by natural sunlight exposition. In this way was individuated the best sun simulator in terms of temperature and spectral emission, matching NIR reflectance response of the investigated cool roof materials. Considering these two last points the best solar simulator results the xenon arc lamp. Using this radiation source the Deep Blue coating was the best performing coating, as cool surface coating; the other two coatings showed promising results.
The study has been published in Progress in Organic Coatings, Volume 161, December 2021.
