Influence of building orientation on cooling load: A comparative study

Reducing the cooling load for buildings is a key sustainability measure. Factors effecting buildings’ cooling load are air conditioning (A/C) system outdoor temperature, humidity, and building configuration etc. Here, transient system simulation is used to compare the impact of building orientation on cooling load in three different MENA regions. The findings revealed that west-oriented buildings demand the highest cooling load (1950.85 Ton.hr in UAE, 1566.14 Ton.hr in Jordan, and 1653.69 Ton.hr in Tunisia) contrary to north-west orientation that require the least (1405.57 Ton.hr in UAE, 376.04 Ton.hr in Jordan, and 521.04 Ton.hr in Tunisia). The percentage disparity between the maximum cooling load of west-oriented buildings and the minimum load of the north-west oriented was 1.54%, 2.33%, 2.03% for UAE, Jordan, and Tunisia, respectively. It emphasizes Jordan greater susceptibility to orientation compared to UAE and Tunisia. The research also compared annual electricity bills and CO₂ emission extrapolated for larger households to each region. The Gross domestic product (GDP) per capita comparison lead to potential savings through different orientations, with Tunisia demonstrating the highest savings-to-GDP per capita ratio at 0.013375, Jordan at 0.012655 and UAE at 0.002666. The CO₂ emission due to orientation resulted in a reduction of 0.00654, 0.00264 and 0.00320 tons per m² in the UAE, Jordan, and Tunisia, respectively. This study employs Life Cycle Assessment (LCA) to investigate the influence of building orientation on CO₂ emissions. It uncovers variations of up to 2.47% (Jordan), 1.91% (Tunisia), and 1.56% (UAE) linked to regional energy mix for electricity generation. Therefore, proper building orientation would offer both economical and CO₂ emission benefits. Sustainable Index is also introduced to account for building orientation by integrating Cooling Load Efficiency (CLE), Economic Savings (ES), and CO₂ Emission Reductions (CER). Finally, Analysis of Variance (ANNOVA) sensitivity analysis explores the effects of ambient parameters on cooling loads, revealing that orientation significantly contributes 16.6% to the variance in the UAE, 10.8% in Jordan, and 15.85% in Tunisia. The findings can serve as valuable guidelines for design of energy-efficient buildings and future sustainable cities.