Central chilled water systems represent the largest capital and energy expenditure in commercial building projects. Selecting between Air-Cooled and Water-Cooled chillers requires a holistic evaluation of climate, water availability, and lifecycle operating costs.
1. Efficiency Comparison (IKkW / TR)
Water-cooled chillers rejected heat via cooling towers at wet-bulb temperature, enabling lower condensing pressures and superior efficiency:
- Water-Cooled Centrifugal/Screw Chiller: 0.55 to 0.65 kW/TR (COP 5.4 to 6.3)
- Air-Cooled Screw/Scroll Chiller: 0.95 to 1.15 kW/TR (COP 3.0 to 3.7)
2. When to Choose Air-Cooled Chillers
Air-cooled chillers are preferred where raw water availability is scarce, water treatment costs are prohibitive, or roof space allows seamless outdoor package placement without dedicated plant rooms.