Contribution Of Dark Brown Pakis-Stem To Mitigate Thermal Solar Irradiation Of A Heated Environment

摘要

In the era of global warming issues areal most happening every time and day in many countries, one of the possible way to apply brown and white-pakis blocks as high-albedo heat insulation in the urban cities is on the flat concrete rooftops. The brown-pakis blocks will absorb much incoming global solar irradiation and emit less longwave solar heat to space in contrast, the white-pakis blocks could not only handle well the incoming solar irradiation but it also lessens the outgoing longwave solar irradiance by simply emiting much irradiation to atmosphere and performing as insulator to the flat concrete rooftop. This research is concentrated on the ability of brown Pakis-stem blocks to reflect less outgoing solar irradiation to space, to absorb and to emit as much possible of longwave solar heat irradiation. The results of brown Pakis-stem blocks are proved to reflect an average 18.2 W.m-2 compare to white Pakis blocks 71.7 W.m-2 of outgoing global solar irradiance to atmosphere. The average surface bottom temperature of one-piece brown-Pakis block is 34.8oC compare to 33.9oC white-Pakis block. The contribution of brown-Pakis blocks lessen the over heated environment, and act as solar irradiation controller and temporary container.