formula.expertYour record

Chiller Efficiency (kW per Ton)

Also known as kW/ton · chiller efficiency

kW/ton=W˙ [kW]Q˙ [tons]\mathrm{kW/ton} = \frac{\dot{W}\ [\text{kW}]}{\dot{Q}\ [\text{tons}]}
kW/ton
sig figs

Worked example: 500-ton chiller at 300 kW → 0.60 kW/ton. Press Try an example to run it live, then adjust anything.

Enter your known values, leave one input blank, and solves for the missing one. Tap a variable’s symbol to see what it means, with a typical value. Change any unit and the answer follows.

Constant used: built into this formula, no need to enter
TR=3,516.8528420667 W\mathrm{TR} = 3,516.8528420667\ \text{W}Ton of refrigeration · exact

Where Chiller Efficiency (kW per Ton) fits

In this toolkit

See also

Energy Efficiency Ratio (EER): Both use compressor power input and cooling capacity.Coefficient of Performance (COP): Both use compressor power input.Heat Rejected by a Power Plant (from the Electric Output and the Thermal Efficiency): Both use compressor power input.Condenser Water Flow Rate: Both use cooling capacity.Refrigerant Mass Flow Rate: Both use cooling capacity.Tons of Refrigeration from BTU/hr: Both use cooling capacity.
Here the solver did the work. Could you?

kW per ton →

UniversityFluid Mechanics, HVAC & Refrigeration

Test your skills in the Exam Room: new numbers every attempt. Free lessons for students, no sign-up, just pure learning.

See your Report Card
Learning zone

Chiller Efficiency (kW per Ton) explained

kW/tonQW

Chiller plants are bought and argued over in kW per ton, the inverse-efficiency metric: how much electricity it costs to make a ton of cooling. Because it is inverted, lower wins. A 1970s reciprocating machine ran 1.0–1.2 kW/ton; a modern centrifugal at full load hits 0.50–0.60, and with cold condenser water on an autumn night can dip under 0.40. Relate it to the other scales with kW/ton = 12/EER = 3.5169/COP.

The number every plant engineer actually chases is plant kW/ton, which includes chilled-water pumps, condenser pumps and the cooling-tower fans: typically 0.15–0.30 kW/ton of parasitic load on top of the chiller. A "0.55 kW/ton chiller" inside a 0.85 kW/ton plant is a familiar disappointment, and it is usually the constant-speed pumps that did it. Worked example: a 500-ton machine drawing 300 kW runs 300/500 = 0.60 kW/ton, which is EER 20 and COP 5.86 (respectable, and worth about $95 an hour at $0.32/kWh when it runs flat out).

Chiller Efficiency (kW per Ton) formula

kW/ton=W˙ [kW]Q˙ [tons]\mathrm{kW/ton} = \frac{\dot{W}\ [\text{kW}]}{\dot{Q}\ [\text{tons}]}
Where
  • kW/ton\mathrm{kW/ton}= Specific power (kW/ton)
  • W˙\dot{W}= Compressor power input (kW)
  • Q˙\dot{Q}= Cooling capacity (ton)
In this toolkit

Refrigeration capacity and efficiency

6 formulasTons, COP, EER and kW per ton — the four ways the trade states the same chiller performance, and how to convert between them.

Revised 31 October 2026
Cite this page

formula.expert. (2026, October 31). Chiller Efficiency (kW per Ton) Formula & Calculator. https://formula.expert/solvers/chiller-kw-per-ton

formula.experthttps://formula.expert/solvers/chiller-kw-per-ton