Energy Efficiency in Building Air Conditioning Systems using Variable Speed Drives to Minimize Carbon Footprint

Rising ambient temperatures have intensified energy demand in buildings, particularly for air conditioning systems, leading to higher utility costs and increased greenhouse gas emissions. This study investigates the application of a Variable Speed Drive (VSD) to improve the energy efficiency of the air conditioning system in an industrial airplane manufacturer’s building in Subang, Malaysia. The objectives are to analyze energy usage patterns, evaluate energy-saving measures, and assess the economic and environmental feasibility of VSD adoption through cost savings, payback period, and indirect carbon dioxide (CO2) emission reduction. Results indicate a 14–17% reduction in energy consumption following VSD installation. Correspondingly, annual CO2 emissions were reduced by 74.80 tons for cooling tower motors, 225.36 tons for the chiller’s Condenser Water Pump (CDWP) and Chilled Water Pump (CHWP) pumps, and 294.63 tons for Air Handling Unit (AHU) motors. The findings contribute to the literature by providing empirical evidence of VSD effectiveness in large-scale industrial cooling systems within a Southeast Asian context, where high cooling demand is critical. The novelty of this study lies in its dual focus on both economic performance and quantifiable CO2 reduction, establishing VSD retrofitting as a viable and sustainable strategy to minimize energy waste, reduce carbon footprints, and enhance building energy efficiency.