Calculation sequence
Step-by-step method
- Multiply equipment input power by runtime.
- Multiply electrical energy by the entered blended energy rate.
- Report the screening energy-only interval cost.
CommissioningBeginnerEnergy
Equipment Runtime-Cost Calculator
Calculate electrical energy and cost from equipment input power, runtime, and energy rate.
Why it matters: Runtime cost connects field power and hours with an explicit tariff assumption.
Calculated result
Engineering evaluation
Estimated blended-energy runtime cost (C)4,800 currency (energy only)
- Electrical energy (E)
- 40,000 kWh
Engineering interpretation
The entered runtime represents 40000 kWh and an estimated blended-energy cost of 4800 currency units.
Important limitations
- Demand, time-of-use, minimum, tax, and other tariff charges are not included unless embedded in the entered rate.
Engineering knowledge center
Understand the calculation—not just the answer
Governing relationships
E = P·t
C = E·R
Current substitution
E = 20×2000 = 40000 kWh; C = 40000×0.12 = 4800.
Equation legend
Inputs and calculated quantities
- P
- Equipment input power — kW
- t
- Runtime — h
- R
- Blended energy rate — currency/kWh
- C
- Estimated blended-energy runtime cost — currency (energy only)
- E
- Electrical energy — kWh
Applications
How this calculation is used
Building design
Screen expected operating cost.
Construction
Check power and status monitoring.
Commissioning
Calculate cost for a documented equipment operating interval.
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
- This is a preliminary evaluation and commissioning-support tool, not an automatic acceptance determination.
- Project sequences, manufacturer data, tariffs, codes, and professional review remain controlling.
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.
- 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