Secondary Chilled Water Pump System

Secondary Chilled Water Pump System | Optimized Distribution & Load Matching by EKG (Malaysia) Sdn Bhd

Decouple Chiller Operation from Building Demand for Maximum Efficiency
A Secondary Chilled Water Pump System is a sophisticated hydraulic strategy that separates the primary circuit (serving the chillers) from the secondary circuit (serving the building's cooling coils). This design allows chillers to operate at a constant, optimal flow rate while the secondary pumps vary their speed to match the building's real-time cooling demand. EKG (Malaysia) Sdn Bhd specializes in the design, installation, and optimization of these systems, unlocking significant energy savings and enhancing control for large or variable-load buildings.

How the Primary-Secondary System Works

• Primary Loop: Constant-speed pumps circulate a fixed flow of chilled water through the chiller evaporators. This ensures chillers operate under stable, efficient conditions.

• Secondary Loop: Variable-speed pumps circulate water from the common piping "decoupler" (or bridge) to the building's Air Handling Units (AHUs) and Fan Coil Units (FCUs). Pump speed adjusts based on actual cooling load.

• The Decoupler: A short section of common piping that allows hydraulic separation between the two loops. It enables flow in the secondary loop to differ from the primary loop without affecting chiller performance.

Key Advantages for Large Facilities

• Chiller Efficiency: Chillers see constant, design-point flow, eliminating efficiency losses from low-flow operation.

• Massive Pump Energy Savings: Secondary pumps use Variable Frequency Drives (VFDs) to reduce speed during partial load, often saving 40-60% of secondary pumping energy.

• Improved Hydraulic Stability: Prevents interactions between different chillers and building circuits.

• Enhanced Control & Zoning: Allows different building zones or times of day to be served independently.

• Easier System Expansion: New secondary circuits can be added without redesigning the primary chiller plant.

Our Engineered Secondary Pump System Services

1. System Design & Hydraulic Analysis:

   • Sizing the decoupler and determining primary/secondary flow rates.

   • Selecting secondary pumps and designing the control strategy for optimal delta-T (temperature difference).

2. Supply of High-Efficiency Pumping Packages:

   • Providing secondary pump sets with integrated VFDs, bypass valves, and control panels.

   • Ensuring components are correctly sized for variable flow operation.

3. Professional Installation & Piping:

   • Precision installation of the decoupler bridge and associated piping.

   • Correct setup of flow meters, temperature sensors, and differential pressure sensors for control.

4. Advanced Control Integration & Commissioning:

   • Programming the VFDs to respond to building load signals (e.g., differential pressure, temperature reset).

   • Integrating with the Building Management System (BMS) for centralized monitoring and sequencing with chillers.

   • Balancing the entire system to ensure design flow in all circuits.

5. Performance Optimization & Retrofit:

   • Retrofitting constant-speed systems into efficient primary-secondary systems.

   • Tuning control sequences to maintain a wide and stable delta-T, which is critical for realizing energy savings.

Ideal Applications for Secondary Pump Systems

• Large campus-style buildings, hospitals, and universities.

• Office towers with highly variable occupancy and cooling loads.

• Buildings with multiple wings or phases added over time.

• Facilities where chiller plant is remote from the cooling load.

• Any project seeking high levels of HVAC efficiency for green building certification (GBI, LEED).

The EKG Expertise Difference

• Deep Hydronic Design Knowledge: We understand the principles behind decoupler sizing and pump selection for stable operation.

• Focus on Delta-T Performance: We engineer systems and controls to maintain the designed temperature spread, which is where real savings are captured.

• Lifecycle Cost Modeling: We demonstrate the ROI of implementing a secondary system versus a constant or variable primary-only system.

• Commissioning Excellence: We ensure the complex interaction between primary and secondary loops functions flawlessly from day one.

Unlock the Next Level of Cooling System Efficiency
Move beyond basic pumping to intelligent, demand-based distribution.

Contact EKG (Malaysia) Sdn Bhd's engineering team to discuss designing a new secondary pumped system or retrofitting your existing plant for substantial energy savings.