LoadMatch® is a hydronic HVAC system concept developed by Bell & Gossett (a Xylem brand). It simplifies chilled and hot water distribution in buildings by using a primary-only, single-pipe system with dedicated circulators for each terminal unit (like fan coils, AHUs, etc.), rather than a traditional primary-secondary loop with control valves.

🔧 Key Features of LoadMatch:

• Single-pipe loop (instead of supply-return pair).

• Dedicated circulators (small pumps) at each terminal unit.

• No control valves – flow is controlled by turning circulators on or off.

• Designed for constant flow, not variable.

✅ Advantages:

• Energy efficiency: Dedicated small circulators use only the power needed for their terminal unit.

• Lower first cost: Fewer pipes, no control valves.

• Simplified balancing: Flow is self-regulated by pumps; no need for balancing valves.

• Better comfort: Faster response and better control at each terminal unit.

⚠️ Considerations:

• Best suited for smaller to mid-sized buildings or distributed load applications.

• Initial design may seem unconventional for engineers used to variable primary or primary-secondary systems.

• Each unit needs power and control for its circulator.

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Comparison: LoadMatch vs Traditional Primary-Secondary Variable Flow

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Traditional Primary-Secondary Variable Flow System

Diagram Summary:

• Primary Loop: Constant flow, typically includes chillers and constant-speed primary pumps.

• Secondary Loop: Variable flow, serves terminal units (fan coils, AHUs, etc.).

• Control Valves: Modulate water flow at terminal units.

• Balancing Valves: Ensure even flow distribution.

• Complex Control Logic: To coordinate between primary and secondary loops.

Pros:

• Works well in large systems.

• Established, familiar design.

Cons:

• More piping and components.

• Control complexity.

• Higher initial cost and more space required.

 

LoadMatch System (Bell & Gossett)

Diagram Summary:

• Single Pipe Loop: Water flows in one direction through a common distribution pipe.

• Dedicated Circulators: Each terminal unit has its own small pump.

• No Control/Balancing Valves: Flow is controlled by pump operation.

• Primary-Only: No secondary loop, greatly simplified.

Pros:

• Lower first cost (fewer pipes, no control valves).

• Simple to design and operate.

• Excellent zoning and occupant comfort.

• Less balancing effort.

• Ideal for retrofits and smaller buildings.

Cons:

• May not be ideal for very large buildings.

• Requires electrical connections and control for each circulator.