kW/ton

kW/ton stands for kilowatts per ton — the standard chiller efficiency unit, expressing electrical input (kilowatts) divided by cooling output (tons of refrigeration, where 1 ton = 12,000 BTU/hr). Unlike EER, where higher is better, lower kW/ton is better — it means the chiller is consuming less electricity for the same cooling output.

Reference points for commercial chillers in 2026: a 20-year-old standard centrifugal unit at full load runs 0.6 to 0.7 kW/ton. A current high-efficiency centrifugal runs 0.45 to 0.55 kW/ton. A magnetic-bearing variable-speed unit hits 0.35 to 0.40 kW/ton at full load and can drop below 0.30 kW/ton at part-load conditions. Absorption chillers (which use heat rather than electricity as the primary energy input) measure efficiency differently and typically aren't compared on kW/ton.

For financing decisions, kW/ton is the input to the operating-cost math. A 500-ton chiller at 0.65 kW/ton consumes 325 kW continuously when running at full load; at 0.45 kW/ton it consumes 225 kW. Over 2,000 annual cooling hours at $0.12/kWh, that's the difference between $78,000 and $54,000 per year in electricity — $24,000 in annual operating savings that goes straight to the bottom line and supports the financing payment on a more efficient unit.