Trane SYS-APM001-EN manual Application Considerations, Small Chilled-Water Systems 1-2 chillers

Application Considerations

Chiller system size affects design and control considerations. Each size comes with its own set of advantages and challenges.

Small Chilled-Water Systems (1-2 chillers)

Figure 17. Small chilled-water system schematic

Pump

Air-Cooled Chiller

Control	Load
Valve

A common design goal for the small chilled-water system with one or two chillers (Figure 17) is to minimize complexity while balancing energy consumption goals. Smaller chilled-water systems may have smaller budgets allotted for operation and maintenance and may run unattended more often than larger systems. Keeping it simple, while capitalizing on chilled water advantages, is the hallmark of a successful project.

The first cost of a small system is a common hurdle faced by a building owner. There are ways to minimize first costs without sacrificing operating costs. For example, a wider design ΔT reduces flow rates, which in turn reduces pipe and pump sizes. In addition to reducing pump and pricing costs, this may also allow the designer to avoid installing a storage tank to meet the required chiller “loop times.” (See “Amount of Fluid in the Loop” on page 79.) On a system with multiple chillers, using a variable-primary-flow design (“Variable-Primary-Flow Systems” on page 55) can reduce the number of pumps, starters, electrical equipment, and space required.

18 Chiller System Design and Control SYS-APM001-EN