Calculation sequence
Step-by-step method
- Convert SI cooling kW to refrigeration tons when required.
- Divide electrical input by cooling tons.
- Compare kW/ton with the user-entered screening value and show COP for reference.
MechanicalBeginnerCentral Plant
Chiller kW per Ton Calculator
Calculate chiller kW per refrigeration ton and COP from capacity and electrical input.
Why it matters: kW/ton is a common operating-efficiency metric for chillers.
Calculated result
Engineering evaluation
Chiller operating efficiency (E)0.6 kW/ton
- Coefficient of performance (COP)
- 5.861 ratio
- Cooling capacity (Qton)
- 500 ton
Engineering interpretation
The entered operating point is 0.6 kW/ton with COP 5.861. The efficiency field and result remain kW/ton in both unit views.
Important limitations
- Keep thermal-capacity and electrical-input boundaries consistent. Plant kW/ton may also include pumps, towers, and auxiliaries.
Engineering knowledge center
Understand the calculation—not just the answer
Governing relationships
Qton = Q
E = P/Qton
COP = 3.51685284/E
compare E with Emax
Current substitution
Qton = 500; E = 300/500 = 0.6 kW/ton; COP = 5.861; Emax = 1 kW/ton.
Equation legend
Inputs and calculated quantities
- Q
- Cooling capacity — ton or kW
- P
- Chiller electrical input — kW
- Emax
- Entered maximum screening value — kW/ton in both views
- E
- Chiller operating efficiency — kW/ton
- COP
- Coefficient of performance — ratio
- Qton
- Cooling capacity — ton
Applications
How this calculation is used
Building design
Compare scheduled capacity and input power.
Construction
Check metering boundaries.
Commissioning
Calculate field kW/ton and COP from simultaneous measurements.
Quality controls
Assumptions and limitations
Assumptions
- Entered data describe one stable operating condition and use consistent measurement boundaries.
- Time, energy, and performance values are representative of the stated interval.
Limitations
- The efficiency input and result remain kW per refrigeration ton in both I-P and SI capacity views.
- Plant kW/ton may also include pumps, towers, and auxiliaries; use a consistent metering boundary.
Field use
Verification procedure
- Confirm the operating mode, test boundary, and instrument calibration.
- Collect simultaneous readings or a documented trend interval.
- Compare the result with the approved sequence, submittal, and project criteria.
Common engineering mistakes
- Combining measurements from different operating modes or time intervals.
- Ignoring sensor uncertainty, trend sampling, or the defined equipment boundary.
Technical basis
References and source standards
- U.S. Department of Energy—Better Buildings Solution CenterFederal HVAC energy-management and equipment-performance guidance.
- ASHRAE Handbook—HVAC Systems and EquipmentHVAC equipment, central-plant, air-system, and control-performance context; verify the licensed current edition during professional review.
- NIST Measurement and Calibration ResourcesFederal measurement, calibration, timing, and unit-system context.
Engineering calculation disclaimer
These engineering tools are provided for educational, preliminary evaluation, field verification, and commissioning support. Results depend on the accuracy of user-entered information and the assumptions stated for each calculation. Every colored status and comparison is a screening indicator only; project criteria, contract requirements, applicable codes, manufacturer instructions, measurement uncertainty, and authorized engineering judgment govern. The tools do not replace project-specific engineering analysis or the judgment of a licensed professional engineer.
Read the full use and limitation statement