ENERGY USE AND CHILLED WATER STORAGE SYSTEM STUDIES FOR AN EDUCATIONAL FACILITY THROUGH HIGH-RESOLUTION MODELING
For an educational district that has a large number of facilities, utility cost is high, and electricity is a significant portion of the operational cost. Among the electricity end use, air conditioning system is a major contributor to energy consumption in commercial buildings, especially in hot and humid climate regions. In this research, an academic building was selected at the University of Alabama at Birmingham (UAB) campus, Birmingham, Alabama, which is in a warm and humid climate (ASHRAE 3A), to study the composition of energy use of the existing building for future building renovation, and to examine energy conservation potentials with modifying the operation settings and addition of a chilled water storage tank (CHWT). A transient system simulation program (TRNSYS) was used to perform the study. The building envelope's specifications and configurations of HVAC system were obtained from UAB Facilities Management Department. Internal loads (Lighting and Plug-in loads) and schedules were determined through long-term surveys. A baseline model of current energy consumption was verified with actual electricity consumption before executing the proposed simulations. Results showed that energy consumption varied 2% when set-point temperature increased or decreased 2°F (1.1°C) from 72°F (22.2°C). When the ambient temperature is very high, a large fraction of outdoor intake will lead to a significant increase in energy consumption. A chilled water storage tank was shown to conserve energy. With stored chilled water at 7°C (44°F) as cooling supply, an increase in tank size did not increase energy savings for the designed chilled water storage system.