The impact of the air-conditioning systems on the urban microclimate of beirut city

Abstract

The urban heat island consists of the increase in the ambient temperature in urban areas with respect to their rural surroundings, due to artificial modifications of the natural land cover. As a result, significant increase in the demand on cooling loads occurs in cities during summer, inducing more energy consumption in buildings. Furthermore, air-conditioning systems release anthropogenic waste heat to outdoor intensifying the urban heat island. Therefore, an interactive relation exists between the heat islands formation and the cooling systems as well as mutual impacts. Hence, the contribution of the air-conditioning systems to the urban heat island is assessed through an appropriate numerical simulation for Beirut city. It is found that the intensive use of air conditioning systems in Beirut during summer could rise the street air temperature of about 0.8°C in the daytime and up to 4.7°C in the nighttime.