A Case Study

Ngee Ann Polytechnic

A Singapore case study | Tertiary institution

Located in Singapore, Block 22 @ Ngee Ann Polytechnic is a mixed-use building certified by The Singapore Building Construction Authority as a Green Mark Platinum building.

Consisting of 10 AHUs and five FCUs, the building’s air conditioning system is served by three chillers with a total cooling capacity of 570 RT (2005 kW). The system is configured with two working chillers and one chiller as standby. Four chilled water pumps were originally installed to distribute the chilled water in the facility in a Variable Primary Only System.

To uphold the building’s Green Mark credentials and push the limits of energy conservation, Grundfos retrofitted Block 22 with a Distributed Pumping system. During installation, the initial pump setting was done via the Grundfos GO REMOTE app and the flow limits were adjusted directly in the BMS for each pump.

This delivered significant time savings compared to using traditional balancing valves, control valves or PICVs (pressure independent control valves).

During operation, the distributed pumps continuously measure the air duct temperature and automatically adjust the pump speed to achieve the desired temperature – the system is autobalancing any load, providing optimal comfort for tenants. Reducing the pressure-consuming devices and replacing the balance and control valves with distributed pumps reduced the total pump energy consumption for the chilled water loop by 54%.

Results & Analysis

Detailed analysis of results before and after retrofitting to intelligent distributed systems

Based on the comparison graphs above, Grundfos distributed pumping system clearly provides the same cooling capacity as traditional valve based system with a net lower energy consumption.