Energy audit of individual air conditioners: A case study

Individual systems are extensively used in residential areas and commercial buildings with old design and where centralized systems are not feasible. Air-conditioning systems account for 60-65% of total energy consumption in commercial areas making it an important area to study energy consumption. In this study, an energy audit was conducted on 109 air conditioners. The performance of air conditioners was evaluated using operating parameters - air flow rate and enthalpy difference across the evaporator coil as described by Bureau of Energy Efficiency. Major findings were - 55 units did not conform to star labelling specifications and 50% units performed below 75% of their rated capacity. Common air-conditioning issues such as low refrigerant charge, unclean filters, non-evident insulation, infrequent maintenance and improper installation have been discussed along with energy conservation measures as a step to explore future energy management opportunities for individual air-conditioning systems in India.