Energy saving potential of an air-conditioner - ice thermal storage (AC-ITS) system

Abstract

Air-conditioning (AC) systems are the most common energy consuming equipment in commercial buildings in Malaysia. An Ice Thermal Storage (ITS) application is capable of reducing the power consumption of the air-conditioning system and its corresponding costs as it transfers the peak of electricity consumption from on-peak to off-peak hours. In this study, an analysis was performed on a conceptual AC-ITS system to estimate the annual saving in operating cost when compared to an existing AC system installed at Perpustakaan Raja Zarith Sofia (PRZS) building located in Universiti Teknologi Malaysia, Johor. First, the cooling loads of the building based on the Carrier Cooling Load Method were determined. Based on the cooling loads the system equipment was selected. From the cooling load profile, the chiller-charging and -discharging scheduling of the ITS system were determined. The estimated annual operating cost of the present AC system is approximately RM 437,877. By employing the ITS-AC system, a potential saving of about RM 299,901 per year can be achieved, representing a 68.5 % saving per year.