Towards the Renovation of Energy-Intensive Building: The Impact of Lighting and Free-Cooling Retrofitting Strategies in a Shopping Mall

One of the most energy-intensive types of buildings is commercial. Several works investigated the optimizations of Heating, Ventilation and Air Conditioning (HVAC) systems for achieving thermal comfort and indoor air quality. On the other hand, lighting systems play also a crucial role in minimizing energy consumption rates in a shopping mall and increasing its sustainability. Despite the relevant scientific research in the literature, to the best of our knowledge, there is no study that analyzes the impact of HVAC systems with and without the free-cooling option applied to a commercial building combined with lighting solutions. The combination of HVAC systems with free cooling and lighting retrofit strategies defines four energy scenarios, where the most efficient one is detected. The results show that the use of advanced technologies in lighting control systems has a double benefit: direct savings due to the better performance of the lighting fixtures and indirect savings due to the reduction in the thermal load with a consequent reduction in consumption levels for air conditioning. Additionally, a reduction of 51.7% in lighting consumption levels generated a 17.4% reduction in air conditioning levels. A total reduction in energy consumption rate of 33% was achieved. Since the lighting strategy demonstrates a relevant impact on reducing the global energy consumption of the shopping mall, a feasibility analysis is also presented.