Cool roofing systems use paints and membranes with high reflectance to reflect a portion of the incident solar radiation resulting in lower exterior surfaces temperatures in relation to conventional/black roof systems. This study directed at the energy performance of the roof system that is being used in factories in the Cooperation Council nations when this roof is exposed to hot and humid climatic conditions in India. The long-term moisture performance of white and black roof systems was investigated in a previous study with results showing no risk of condensation and mould growth in roofs with different values ​​of rooftop solar reflectance and with different initial construction humidity happened. . With similar environmental conditions used in a previous study, the focus of this paper is on assessing the energy performance of white and black roof systems for a wide range of thermal insulation thicknesses and on estimating roof solar reflectivity. In addition, the idea is given in this study to develop a practical design tool that can be easily used by engineers and architects to determine all pairs of insulation thicknesses and the associated solar reflectivity of reflective roofing materials/coatings who’s this results in similar levels of energy performance as for black roof systems of thicker insulation thickness. The effects of this research, collectively with the practical drawing tools developed, could be used in the future to upgrade Indian construction codes to use less insulation in roofs when a white Cool Roof Paint system is installed.

Background

The phenomenon of global warming and its consequences are some of the issues that we are currently facing. This has resulted in several environmental problems such as increased rainfall intensity, increased greenhouse gas emissions as well as higher atmospheric temperatures. Research studies in China have indicated that the urban heat island effect has contributed to about 30% of climate warming. Low-wave solar radiation is one of the foremost drivers of urban heat lands. For example, urban surfaces reflect less solar radiation back into the atmosphere than vegetation and another natural land cover. Instead, they absorb and store more solar energy resulting in an increase in the surrounding temperature EPA, 2010, 2018a. According to USEPA 2018, the annual mean air temperature in a city with one million or more people can be 1-3°C warmer than its surroundings. However, during the evening, the difference can be up to 12 °C as the built environment radiates the heat absorbed during the day. It is important to point out that higher surrounding temperatures basically mean more demand for not only air conditioning A/C systems but also the lower coefficient of performance of A/C systems appearing in more energy loss to run these systems. it befalls. As a result, thermal power stations burn more fossil fuels and thus generate additional carbon emissions. Urban heat islands are hotter and more polluted. This is because smog is formed by photochemical reactions of pollutants in the air, and the rate of these chemical reactions is likely to increase at higher air temperatures. In some cities, the incidence of smog increased by 3% for every degree, with the increase in temperature above 21 °C

The results of this research study have shown the potential for using different coatings and reflective roofing materials to increase the energy performance of roofing systems for a given insulation thickness and to use a smaller amount of insulation resulting in similar energy performance. Levels have been achieved. Of black roof systems of thicker insulation thickness. Additionally, they obtained results in this research study that could be used to upgrade India building codes in the future to allow less roof insulation to be used when a white roof system is installed.