How efficient is the plant today? The report compares annual plant electricity, cooling output, operating hours and metering boundary to form the current COP or unit cooling energy frame.
Chiller plant diagnosis
Chiller plant energy diagnosis and optimization report
kWhScan helps plant teams, facility managers and energy consultants screen chiller plant savings from baseline COP, equipment selection, chilled-water temperature, condenser-water optimization, sequencing, pump and tower control, low delta-T and multi-energy opportunities. Start with field-readable data, then add plant trend data when it improves the diagnosis.
- Estimate savings from chiller efficiency, chilled-water temperature reset, condenser-water optimization, sequencing, pumping, low delta-T correction, terminal-side issues, heat recovery, free cooling and thermal storage.
- Separate chiller-side, control-side, water-side and multi-energy measures before totals are shown, so low delta-T, pump savings, temperature reset and equipment replacement are not double counted.
- Use the free result as a pre-audit screen, then unlock the detailed engineering report only when the result is useful.
Why it matters
A chiller plant saving estimate is only useful when it separates the chiller, controls, water system and terminal-side causes.
Chiller plant energy waste is rarely caused by one isolated machine. A low plant COP may come from inefficient chillers, poor sequencing, an unnecessarily low chilled-water supply temperature, poor condenser-water control, excessive pumping, cooling tower issues, low chilled-water delta-T, bypass flow or ineffective terminal demand.
This is why a single COP calculator can be misleading. If chilled-water temperature reset, pump pressure reset, low delta-T correction and equipment replacement are added without an overlap rule, the final saving can be overstated. A report-ready diagnosis must show which part of the system owns each saving before the total is presented.
Diagnosis structure
Five checks behind the chiller plant diagnosis
kWhScan follows the same engineering report structure used across the integrated-energy workbench: baseline, equipment, control, distribution and multi-energy boundary. Each module answers a different customer question.
Are the chillers, pumps and cooling towers matched to the cooling-load profile? The diagnosis checks capacity mix, rated efficiency, operating role, temperature level and maintenance recovery signals.
Is energy wasted through chilled-water temperature, condenser-water temperature, sequencing, cycling, pump pressure or cooling tower control? Trend data can improve this module.
Is cooling wasted through low delta-T, bypass, over-pumping, valve throttling, pressure drop or ineffective terminal demand? These items are separated from chiller-side savings.
Can condenser heat, free cooling, thermal storage, PV/storage interaction or heat pump coupling reduce another utility cost? The report keeps these benefits separate from the chiller plant electricity saving rate unless they directly reduce plant electricity.
Unlock the detailed report when the free result shows a meaningful saving signal and the calculation basis is worth saving.
Data path
Start with site-readable values, then import plant trends when available.
The first diagnosis should not require a perfect metered plant. Users can start with values usually available from energy bills, plant meters, chiller nameplates, BMS screens, operator logs and maintenance records. Continuous data improves confidence, but it should refine the report rather than block the first result.
- Annual chiller plant electricity.
- Annual cooling energy, average cooling load, or chilled-water flow and temperature difference.
- Operating hours and electricity price.
- Plant electricity boundary: chiller-only, chiller plus chilled-water pumps, or full plant.
- Typical chilled-water supply and return temperature.
- Typical condenser-water entering and leaving temperature for water-cooled systems.
- Chiller type, rated cooling capacity, rated COP or rated power.
- Common running chiller count, plant control mode and chilled-water pressure differential setpoint when available.
- Pump and cooling tower quantities, power and control mode.
- Low delta-T, bypass, terminal valve position or terminal complaint indicators if known.
- Peak/valley tariff, useful heat demand, free-cooling condition or thermal storage opportunity if relevant.
- Timestamp, total plant power and cooling load.
- Chilled-water supply and return temperature, flow and differential pressure.
- Condenser-water entering and leaving temperature, flow and outdoor wet-bulb temperature if available.
- Running chiller count and per-chiller power, load percentage or on/off status if available.
- Chilled-water pump, condenser-water pump and cooling-tower fan power if available.
- Average terminal valve position if available.
Baseline and target gap
The baseline must match the cooling boundary before the target gap means anything.
Plant COP and unit cooling energy are only useful when electricity, cooling output and operating period use the same boundary. A chiller-only COP should not be compared with a full-plant benchmark that includes chilled-water pumps, condenser-water pumps and cooling towers.
kWhScan uses the baseline module to state the current energy frame: annual plant electricity, annual cooling output, current COP, unit cooling energy and target gap. The target gap is a performance frame. It does not automatically become the project saving total. Actionable savings are owned by equipment, control, distribution or multi-energy measures after overlap is checked.
Equipment selection
Chiller selection is about load profile, rated condition and real operating efficiency.
A plant can have enough installed cooling capacity and still be inefficient. The chillers may be oversized for low-load operation, poorly matched to demand variation, operated outside their efficient temperature range, or inefficient compared with current performance references. Low performance may also come from heat exchanger fouling, refrigerant issues, non-condensables, water-side problems or sensor errors.
For each chiller, the diagnosis can use type, capacity, rated COP or power, commissioning age and common operating role. Trend data can improve the diagnosis by showing part-load behavior, actual COP, operating hours and sequencing. Final equipment replacement or retrofit selection still needs supplier validation, but the pre-audit report can show whether the current fleet deserves deeper review.
Plant control
Chilled-water and condenser-water control must be evaluated as a system.
Raising chilled-water supply temperature can reduce chiller power, but only when the terminal or process requirement allows it. Lowering condenser-water temperature can improve chiller efficiency, but tower fan and condenser-water pump power may increase. The correct answer is a net plant optimum, not the lowest water temperature.
Sequencing is also plant-specific. A low-load condition may be better served by fewer machines, a high-efficiency unit, or a different staging rule. Poor control can create excessive cycling, unnecessary parallel operation, poor load sharing, high chilled-water differential pressure or inefficient pump and tower operation.
Distribution and terminal-side
Low delta-T and terminal-side issues can make a good chiller plant look inefficient.
Low chilled-water delta-T can increase flow, pump energy and the number of running chillers. Bypass flow, poor hydraulic balance, clogged filters, heat exchanger pressure drop, valves that remain nearly closed and ineffective terminal demand can all shift the problem away from the chiller itself.
Distribution and terminal-side measures should not be counted twice under plant control. If low delta-T correction reduces flow and allows pressure reset, those savings need one owner. If terminal HVAC measures reduce cooling load, the cooling baseline should be corrected before chiller plant savings are calculated.
Heat recovery and storage
Multi-energy opportunities should be valuable without being mixed into the wrong saving rate.
A chiller plant may offer condenser heat recovery, free cooling, thermal energy storage, PV/storage coordination or heat pump coupling. These opportunities can be valuable, but they do not all reduce chiller plant electricity in the same way.
Condenser heat recovery may offset hot water, process heat, space heating, steam or boiler fuel. Thermal storage often reduces demand charges or shifts electricity cost before it reduces physical energy. Free cooling can reduce chiller runtime when wet-bulb temperature, supply temperature requirement, heat exchanger approach and auxiliary pumping allow it. The report keeps these boundaries explicit so the integrated-energy total remains credible.
Report unlock
Free chiller plant screening first. Detailed report when useful.
The free diagnosis is intended to answer whether the chiller plant has a meaningful saving signal. It shows the baseline, opportunity direction and top findings. The paid unlock adds the full chiller plant engineering report.
- Chiller plant baseline and saving signal.
- Current COP or unit cooling energy indicator.
- Top findings across equipment, control, water-side and multi-energy modules.
- Project-level view of whether detailed diagnosis is worth continuing.
- Full chiller plant diagnosis report.
- Measure-by-measure calculation basis.
- Five-module contribution table.
- Evidence labels and overlap notes.
- Implementation and measurement recommendations.
- Download access.
FAQ
Common questions
Is this only a chiller COP calculator?
No. COP is only the baseline frame. The diagnosis also checks chiller selection, chilled-water temperature, condenser-water optimization, sequencing, pumping, low delta-T, terminal-side issues and multi-energy opportunities.
Do I need a cooling meter?
No. A cooling meter improves confidence, but you can start with annual cooling energy, average cooling load, or chilled-water flow and temperature difference when available. The report states the data basis.
Can the tool diagnose low delta-T?
Yes. The diagnosis can flag low chilled-water delta-T, over-flow, bypass, pressure differential issues and terminal valve signals when the required data is entered or imported.
Can it recommend chiller replacement?
It can flag replacement, maintenance recovery or sequencing opportunities when capacity, rated efficiency, operating pattern or trend data indicates a mismatch. Final equipment selection still needs supplier validation and site constraints.
How does the report avoid double counting?
The report separates baseline gap, equipment selection, plant control, water-side distribution and multi-energy measures before totals are shown. Measures that affect the same load or operating condition are grouped before the final saving is calculated.
Run the free chiller plant diagnosis.
Use it as a pre-audit screen before spending time on detailed measurement or supplier review.