Secondary Chilled Water Pump Systems

Adaptive, energy-efficient distribution for building cooling loads.
Secondary chilled water pump systems are designed to circulate chilled water from a primary loop (or common pipe) to the building's terminal units (AHUs, FCUs, fan coils), independently varying flow to match real-time cooling demand. EKG Malaysia specializes in the design, installation, and optimization of these systems, ensuring optimal comfort, stability, and significant pump energy savings in commercial and institutional buildings.

Core Function & Design:

• Decoupled Hydraulics: The primary and secondary loops are separated by a common pipe (decoupler), allowing flow in each loop to vary independently.

• Variable Flow, Variable Speed: Secondary pumps are equipped with Variable Frequency Drives (VFDs) and modulate speed based on signals from differential pressure (ΔP) sensors in the building.

• 2-Way Control Valves: At each terminal unit, modulating 2-way valves open and close to control cooling. As valves close, system pressure rises, signaling the VFD to slow the pump.

Key Benefits:

• Substantial Energy Savings: Secondary pumps slow down significantly at part load, reducing energy use by 30–50% or more compared to constant-speed systems.

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

• Chiller Protection & Stability: Keeps flow through the primary loop and chillers constant, as most chillers require.

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

Critical Design & Commissioning Elements:

1. Correct Common Pipe Sizing: Prevents unwanted flow "short-circuiting" or reverse flow between loops.

2. ΔP Sensor Location: Must be placed to represent the "worst-case" pressure drop in the distribution system.

3. System Balancing: Essential to ensure design flow to all terminal units under all operating conditions.

4. Control Sequence Programming: Proper setup of VFD response, pump staging, and setpoint reset strategies.

Our Secondary System Services:

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

• Pump & Control Selection: Sizing pumps and specifying VFDs, sensors, and valves.

• Commissioning & Balancing: Precisely setting flows, verifying decoupler operation, and tuning control loops.

• Performance Optimization: Ongoing analysis and tuning of pressure setpoints and pump sequences for maximum savings.

Optimize distribution, maximize savings.
A well-designed and commissioned 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.