The impact of climate change on Building Energy Simulation (BES) uncertainty: Case study from a LEED building in Egypt

Climate change and global warming are two major concerns over the globe today, and the rapid
change in climate became more sensible as it impacts diverse industries and disciplines. Buildings share of the global energy use exceeds 40%, and buildings‟ Green House Gas (GHG) emissions resembles one-third of global GHG emissions; hence, Building Energy Simulation (BES) process became an essential step during building design, to study and minimize whole buildings‟ energy use, and consequently minimize buildings‟ carbon footprint. A significant and underestimated input to the BES process is the weather data; BES process normally uses historical weather data in the form of a weather file to simulate the building‟s outdoor conditions, those outdoor conditions impacts the amount of thermal load on the building, therefore they significantly impact building‟s estimated thermal comfort and annual energy use. With the rapid change in the outdoor weather
conditions year after year, using those historical weather data files must be questioned, as they impact the estimated energy use, and consequently put what‟s deemed as the “optimum energy use” in question. Using those historical weather data is hence expected to increase BES degree of uncertainty. This paper studies and quantifies the impact of weather data accuracy on building‟s annual energy performance. The paper follows an empirical research approach by simulating an office building located in Cairo, Egypt. The study relies on using a typical weather data file and real weather files to run and compare two simulations for the same case study. Finally, the paper quantifies the impact of weather data‟s accuracy on the total annual energy use by comparing
both simulation results.