Secondary Chilled Water Pump Systems

Adaptive circulation for variable building demand.
Secondary chilled water pump systems are designed to distribute chilled water from a primary loop to the building's terminal units (AHUs, FCUs, fan coils), dynamically adjusting flow to match real-time cooling needs. EKG Malaysia specializes in the design, installation, and optimization of these systems, ensuring efficient, stable, and responsive cooling across all zones.

Core Function:

• Decoupled Operation: Hydraulically separated from the primary loop via a common pipe, allowing independent flow control.

• Variable Flow, Variable Speed: Pumps are equipped with Variable Frequency Drives (VFDs) and respond to differential pressure (ΔP) sensors to maintain system pressure while reducing flow (and energy) during part-load conditions.

Key System Components:

• Secondary Pumps: Typically variable speed, sized for building distribution losses.

• Common Pipe (Decoupler): A short bridge between primary and secondary loops that allows flow independence.

• Differential Pressure (ΔP) Sensors: Installed in critical locations to provide feedback for pump speed control.

• Control Valves: 2-way valves at terminal units modulate to control cooling; closed valves signal the system to reduce flow.

Why Use a Secondary System?

• Chiller Protection: Keeps flow through chillers constant, as required by most designs.

• Pump Energy Savings: Secondary pumps slow down significantly at part load, reducing energy use by 30–50% or more.

• Improved Control & Comfort: Provides stable pressure for proper control valve operation across all zones.

• Design Flexibility: Easier to zone and expand the building system independently of the chiller plant.

Critical Design & Balancing Considerations:

• Correct Common Pipe Sizing: To prevent unwanted flow "short-circuiting" or reverse flow.

• ΔP Sensor Location: Critical for representing the "worst-case" pressure drop in the system.

• System Balancing: Ensuring design flow to all terminal units under all operating conditions.

Our Secondary System Services:

• Design & Retrofit Planning: Converting constant flow systems or designing new installations.

• Pump Selection & Control Strategy: Sizing pumps and programming VFDs for optimal response.

• Commissioning & Balancing: Precisely setting flows and validating decoupler operation.

• Performance Optimization: Tuning control sequences and pressure setpoints for maximum savings.

Optimize distribution, maximize savings.
A well-designed secondary system is key to an efficient, modern chilled water plant.

Contact EKG Malaysia for expert secondary chilled water pump system solutions—from concept and design to installation, balancing, and ongoing optimization.