The Effect of Building Orientation on Energy Cost in Air Conditioning Systems

This study investigates the impact of building orientation on energy consumption in a building. It includes the analysis of cooling load using Cooling Load Temperature Difference/Solar Cooling Load/Cooling Load Factor (CLTD/SCL/CLF) method with standard design considerations and stipulated guidelines by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). The study takes the design of Nigeria Liquefied Natural Gas (NLNG) Corporate Head Office building in Port Harcourt, Nigeria as a case study, to assess the energy saving potential through building orientations that minimize the solar radiation heat gain of the walls. This would reduce the need for auxiliary cooling and consequently reduce the capacity of the air conditioning system required in the building, thereby resulting in lower energy consumption. The cooling load analysis carried out using CLTD/SCL/CLF method modelled in MATLAB program shows that the maximum load of the building occurred at 13:00 hours (1:00pm). The total cooling load of the building was found to be 359804.4W when the building is oriented North-East while it is 292993.72W when the building is oriented North. Thus, the north is a better orientation for less energy consumption and would achieve an annual energy savings of 252394.047kWh, which translates to potential energy cost savings of ₦12, 670,181.16 annually. The study validated appropriate building orientation selection as an energy efficiency strategy and architectural solution to optimized energy consumption and cost in buildings.