This experimental study is a contribution to the search for solutions to reduce indoor heat gain through sheet metal roofing in hot weather. It has evaluated the thermal impact of two different sheet metal roofs insid...This experimental study is a contribution to the search for solutions to reduce indoor heat gain through sheet metal roofing in hot weather. It has evaluated the thermal impact of two different sheet metal roofs inside of two identical test buildings in sunny weather and cloudy weather conditions. Test building 1 has a single sheet corrugated roof and the building 2 is covered with roof made from top to bottom with corrugated sheet metal, a 12 mm thick serpentine copper tube in which water is circulated, a sheet of aluminium foil acting as a heat reflector, a 4 cm thick polystyrene panel and a 1.5 cm thick plywood. A maximum reduction of 15.1˚C in the temperature of the inner face of the test Building 2 roof was obtained comparatively to the temperature of the inner face of the test Building 1 roof consisting of a single sheet of metal at the warmest hours. In addition, the simple corrugated sheet metal roof of the test building generates high and varied temperatures inside the building. Whereas the proposed heat recovery roof favours low and relatively uniform temperatures inside the building. The proposed sheet metal roof construction technique is very effective in reducing the heat gain through the roof considerably;thus improving the thermal comfort inside sheet metal roofed dwellings. Hot water has been produced by recovering heat from the metal sheet of the roof of test building 2. The temperature of the hot water produced reached of 39˚C. This study could be also an alternative for the reduction of energy consumption due to the use of mechanical means for cooling of sheet metal roofed houses and the reduction of the use of fossil fuels for domestic hot water production.展开更多
Now one of the main cash crops in Côte d’Ivoire, the cashew tree feeds an entire industrial sector based on the processing of its fruit. This processing generates a large volume of waste, consisting of cashew nu...Now one of the main cash crops in Côte d’Ivoire, the cashew tree feeds an entire industrial sector based on the processing of its fruit. This processing generates a large volume of waste, consisting of cashew nutshells, the management of which poses environmental problems. With the aim of replacing charcoal and firewood with more environmentally friendly fuels, several studies are currently being carried out into the optimal use of cashew shells in fuel briquettes. To assess the environmental sustainability of these briquettes, this study calculates the environmental impacts associated with their life cycle, compares them with those of charcoal and firewood, and identifies the processes that contribute most to environmental pollution, with a view to improving them. Analysis of the results showed that cashew nutshell briquettes emit a range of pollutants over their life cycle that damage the environment and are responsible for the 7 impact categories considered: acidification, eutrophication, freshwater aquatic ecotoxicity, global warming, human toxicity, photochemical oxidation and terrestrial ecotoxicity potential. However, they are more environmentally friendly than charcoal and firewood for 5 impact categories: freshwater aquatic ecotoxicity, global warming, human toxicity, photochemical oxidation and terrestrial ecotoxicity potential. The 3 elementary processes, i.e. transport of biomass raw materials, production, and combustion of briquettes, emit pollutants that contribute most to the creation of environmental impact categories. The most relevant pollutants are nitrogen oxides (NOx), sulphur oxides (SOx) and particulate matter (PM).展开更多
文摘This experimental study is a contribution to the search for solutions to reduce indoor heat gain through sheet metal roofing in hot weather. It has evaluated the thermal impact of two different sheet metal roofs inside of two identical test buildings in sunny weather and cloudy weather conditions. Test building 1 has a single sheet corrugated roof and the building 2 is covered with roof made from top to bottom with corrugated sheet metal, a 12 mm thick serpentine copper tube in which water is circulated, a sheet of aluminium foil acting as a heat reflector, a 4 cm thick polystyrene panel and a 1.5 cm thick plywood. A maximum reduction of 15.1˚C in the temperature of the inner face of the test Building 2 roof was obtained comparatively to the temperature of the inner face of the test Building 1 roof consisting of a single sheet of metal at the warmest hours. In addition, the simple corrugated sheet metal roof of the test building generates high and varied temperatures inside the building. Whereas the proposed heat recovery roof favours low and relatively uniform temperatures inside the building. The proposed sheet metal roof construction technique is very effective in reducing the heat gain through the roof considerably;thus improving the thermal comfort inside sheet metal roofed dwellings. Hot water has been produced by recovering heat from the metal sheet of the roof of test building 2. The temperature of the hot water produced reached of 39˚C. This study could be also an alternative for the reduction of energy consumption due to the use of mechanical means for cooling of sheet metal roofed houses and the reduction of the use of fossil fuels for domestic hot water production.
文摘Now one of the main cash crops in Côte d’Ivoire, the cashew tree feeds an entire industrial sector based on the processing of its fruit. This processing generates a large volume of waste, consisting of cashew nutshells, the management of which poses environmental problems. With the aim of replacing charcoal and firewood with more environmentally friendly fuels, several studies are currently being carried out into the optimal use of cashew shells in fuel briquettes. To assess the environmental sustainability of these briquettes, this study calculates the environmental impacts associated with their life cycle, compares them with those of charcoal and firewood, and identifies the processes that contribute most to environmental pollution, with a view to improving them. Analysis of the results showed that cashew nutshell briquettes emit a range of pollutants over their life cycle that damage the environment and are responsible for the 7 impact categories considered: acidification, eutrophication, freshwater aquatic ecotoxicity, global warming, human toxicity, photochemical oxidation and terrestrial ecotoxicity potential. However, they are more environmentally friendly than charcoal and firewood for 5 impact categories: freshwater aquatic ecotoxicity, global warming, human toxicity, photochemical oxidation and terrestrial ecotoxicity potential. The 3 elementary processes, i.e. transport of biomass raw materials, production, and combustion of briquettes, emit pollutants that contribute most to the creation of environmental impact categories. The most relevant pollutants are nitrogen oxides (NOx), sulphur oxides (SOx) and particulate matter (PM).
