Heat build up testing of coloured steel panels: laboratory report for Jotun A/S

A series of painted steel panels ranging in colour from white to black have been assessed for heat build up under the Australian summer sun. The heat build up in these panels varied considerably. Two different laboratory techniques were investigated for prediction of exterior heat build up in painted substrate. Both techniques proved to have some potential, in particular the second technique involving reflectance measurements in the region of 2,400‐2,500nm. The work has also shown that a fairly good correlation exists between CIE L value and exterior heat build up in painted substrates.