Our partner is a leading bank in sustainability, and they have committed to driving climate action not only through its financing and investment portfolios but also through the decarbonization of its own operations. In alignment with the Singapore Green Plan 2030 and the bank’s net-zero ambition, retrofitting existing buildings represents a critical and immediate opportunity to reduce operational carbon emissions, enhance energy efficiency, and demonstrate environmental leadership within the financial sector.

The bank’s building Air Handling Units (AHUs) were originally equipped with AC belt-driven centrifugal fans powered by IE2 (High Efficiency) motors. Electric motors are classified into efficiency classes (IE1, IE2, IE3, etc.), with each higher class representing improved energy performance.

As shown in the photos, each AHU typically contains one large AC belt-driven centrifugal fan assembly. These units are bulky, relatively noisy, and less energy-efficient compared to modern alternatives. Due to their size and mechanical configuration, dismantling and maintenance of the AC fan system (e.g. belt replacement) is also time-consuming and labour-intensive.

We begin with retrofitting the Air Handling Unit (AHU) from AC to EC fans. Beyond their well-documented energy efficiency gains, EC fans offer a significant advantage that is often overlooked, their integrated electronics make them far more compatible with IoT systems, simplifying future integration.

For many building owners, this retrofit alone is a meaningful step forward. However, for those looking to push energy efficiency even further, smart energy management systems become the logical next move. Here's why: high-efficiency equipment like EC fans can only do so much on their own. To truly optimise performance, we need to go beyond the hardware and understand how and when these fans should operate, including the speeds at which they run, which directly impacts energy consumption.

This is where occupant behaviour becomes critical. Understanding the needs and patterns of a building's occupants requires real data on occupancy. Smart energy management systems collect and analyse this data, enabling informed decisions on when to run the fans and at what speed, ensuring your equipment operates efficiently in response to actual building demand.

In the first step, the existing AC belt-driven centrifugal fan was replaced with multiple EC centrifugal fans, resulting in significant operational and performance improvements.

Key benefits include:

• Higher Efficiency: EC fans are inherently more efficient than conventional AC fans. They also maintain superior efficiency under part-load conditions, where systems typically operate most of the time.
• Lower Noise Levels: The EC fan system operates more quietly compared to the previous AC configuration, contributing to an improved acoustic environment.
• Reduced Maintenance Requirements: As fully integrated and highly durable units, EC fans eliminate maintenance tasks associated with belt-driven systems, such as periodic belt replacements and tension adjustments.
• Operational Redundancy: With multiple EC fans installed, airflow can be maintained even if one fan fails. The remaining fans compensate for the reduced output — a level of redundancy not possible with the previous single-fan AC setup.
• Fewer External Components: Unlike AC fans, which require external variable speed drives for speed control, EC fans feature integrated variable speed control. This reduces system complexity and simplifies installation.

In the second step, equipment that enables smart energy management are installed.

The intelligate Mesh, which serves as the heart of this system, functions as both a sensor (carbon dioxide, temperature and humidity) and a gateway, removing the need for an additional gateway device.

Additional devices such as heatmap sensors and Wi-Fi routers work together to enable data transfer to the server. This allows information to be displayed on a web dashboard, accessible from any workstation by the bank’s facility management team.

The heatmap provides insights into the occupancy rate of the surveyed location that the AHU ventilates. Using this data, airflow can be adjusted in real time based on occupancy levels. This delivers additional energy savings on top of those already achieved through the AC fan to EC fan retrofit.

Through this two-step approach, a total energy saving of 65.2% was achieved.

The first phase , retrofitting from AC to EC fans , delivered approximately 37% energy savings. The second phase , integrating the EC fan system with an IoT platform , contributed a further 28% reduction.

Together, these measures significantly enhanced overall system efficiency and performance, bringing the bank one step closer to achieving its net zero ambition.