Cityplaza is a shopping mall owned by Swire Properties, which is adjacent to Taikoo MTR station and divided into North and South wings. The central bridge is located at 2/F of Cityplaza, which connects these two wings. Central Bridge of Cityplaza has an area of approximately 130 m2 serving 10 AHUs, with 5 AHUs on east and west sides. Due to the pyramid-shaped glass window at the ceiling, the indoor temperature is affected by climate conditions.
Apart from the pedestrian walk, the central bridge is also served as functional area to become a place for organizing exhibitions or small market. An increase on occupancy rate and subsequent rise in cooling load led to concerns on customer’s comfort at the central bridge. Therefore, the objective of this Retro-commissioning (RCx) project is to optimize energy consumption and occupancy’s thermal comfort by enhancing the AHUs at the Cityplaza’s central bridge area.
The key elements of this project include the application of the EcoStruxure Building Advisor (BA) offered by Schneider Electric for real-time monitoring and energy management. BA analyzed the data and suggested to reduce the use of AHUs from 10 to 6-7 units and achieved 42% of energy saving. To further investigate energy saving and visualize the environment of the central bridge, we decided to attach wireless environmental sensors in the exhibition booths and on patrolling robots. Beexergy Consulting Limited (BXG) then performed computational fluid dynamics (CFD) integrated with operational data to demonstrate heat distribution under different scenarios. Together with weather data, A.I. analysis will be performed to suggest AHU scheduling. By installing modular motorized double deflection discharge grill in the AHU outlet, A.I. can control the direction of air flow. With the above solutions, A.I. spot cooling can achieve a further 12% energy saving, and better people comfort at the central bridge.