Sustainability assessment of enhanced glazing compositions of commercial buildings in hot-humid climates

Saudi Arabia is experiencing a rapid growth in energy demand as a result of burgeoning population, modernization and economic development. The building sector has an import role in this respect as it accounts for almost 80% of the total national electricity consumption. Following the global trends, Saudi Arabia is also resorting to high rise and glass facade buildings especially in the commercial sector. Sustainability aspects of such buildings in terms of energy and environmental impacts, however, have not been duly addressed in the Kingdom yet. This study undertakes a sustainability assessment of glass facade of a hotel building situated in the city of Khobar that has predominantly hot and humid climate. It considers three different types of commonly used glazing compositions - low-e double glazing, solar control double glazing and laminated glass - for the facade. Building energy modelling has been conducted with the help of Ecotect software. Results indicate that the application of low-e glass can reduce the HV AC load by 25% resulting into an annual energy saving of 564 MWh. The saving is realized through a reduction of 22% and 47% in conduction and solar gain respectively. The environmental benefit is observed in the form of 22,447 ton of CO2 saving. The monitory payback period for the enhanced glazing has been calculated to be 4.5 years.