Potential Energy Saving with High Δ T Chilled Water Designs Compared to the Conventional Low Δ T Designs for Office Buildings in Hot and Humid Climates

This study investigates the potential energy-saving benefits associated with high delta-T (UT) chilled water designs compared to the conventional low delta-T (4T) designs in office buildings in hot and humid climates. High $\Delta T$ systems operates with higher temperature difference between supply and return chilled water temperatures compared to conventional low $\Delta T$ systems. This high $\Delta T$ requirement is specified in the ASHRAE 90.1: 2016 under subsection 6.5.4. “Chilled Water coil selection and theoretical background of temperature difference towards energy efficiency”. Hence, the aim of the study is to evaluate the capital cost reduction and annual energy savings achievable through the implementation of high $\Delta T$ configurations and to evaluate the applicability of this configuration in hot and humid countries. The study followed a comprehensive research methodology that involved analyzing 03 chilled water ΔT options and assessing their impact on capital costs and energy consumption. The findings of the study demonstrate significant cost savings and energy efficiencies associated with high $\Delta T$ chilled water designs. A capital cost reduction of 2.8% in the $\Delta T=7^{\circ} \mathrm{C}$ system and 3.6% in the $\Delta T=8.3^{\circ} \mathrm{C}$ systems were observed compared to the conventional $\Delta T=5^{\circ} \mathrm{C}$ system. Additionally, the annual energy analysis revealed a 0.97% reduction of energy costs in the $\Delta T=7^{\circ} \mathrm{C}$ system and a higher energy cost saving of 1.93% in the $\Delta T=8.3^{\circ} \mathrm{C}$ system compared to the $\Delta T=5^{\circ} \mathrm{C}$ system. These findings highlight the potential benefits of adopting high $\Delta T$ chilled water designs in office buildings. The results not only demonstrate cost-effectiveness but also underscore the importance of energy efficiency and sustainability in building design and operation. The outcomes of this study contribute to the existing body of knowledge in the field and provide valuable insights for building professionals and stakeholders seeking optimal cooling system solutions. By embracing high delta T designs, practitioners can achieve significant benefits in terms of reduced capital expenditures and ongoing energy consumption, leading to a more sustainable and economically viable built environment.