Equipment
Chiller
Definition
A refrigeration machine that removes heat from water (or a water-glycol mixture), producing chilled water used to cool air in commercial buildings via air handling units and fan coil units. Chillers are rated in tons of refrigeration (TR) or kilowatts (kW) and are common in mid-to-large commercial facilities.
Why It Matters for Your Business
Chillers are among the largest energy-consuming pieces of equipment in large commercial buildings. Chiller efficiency is measured in kW/ton — lower is better. Older chillers operating at 0.7–1.0 kW/ton can be replaced with modern high-efficiency models at 0.2–0.5 kW/ton, yielding 30–60% cooling energy savings.
Frequently Asked Questions
What is a good chiller efficiency rating?
Modern high-efficiency centrifugal chillers achieve 0.2–0.5 kW/ton (6–16 COP). ASHRAE 90.1 sets minimum efficiency standards; the higher the COP, the more efficient. Older chillers often run at 0.7–1.2 kW/ton.
What is a chiller plant?
A chiller plant is a centralized cooling system comprising one or more chillers, cooling towers, pumps, and controls that distribute chilled water throughout a building or campus. Proper chiller plant sequencing and control optimization can yield 20–40% energy savings.