Energy optimization of industrial chiller plants: monitoring and concrete levers
Baptiste
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Energy optimization of industrial cooling units: monitoring and concrete levers
In many industries (agrifood, chemicals, plastics, pharmaceuticals), cooling units are among the primary sources of electricity consumption on site. They often run continuously, 24/7, and their actual consumption is rarely monitored with precision. However, a poorly maintained or poorly regulated cooling unit can consume 20% to 40% more than necessary without triggering any visible alarm.
This is the paradox of industrial cooling production: unlike a machine breakdown, an energy drift is not visible. The setpoint temperature is maintained, production continues, and no incidents are reported. Only the electricity bill changes, and often too late to identify the cause.
This article presents the key indicators to monitor, the most common drifts, and what IIoT monitoring concretely brings to these refrigeration systems.
Why cooling units remain energy blind spots
On most sites, cooling production is connected to a main switchboard without dedicated sub-metering. Its consumption is therefore drowned in the site total, alongside lighting or compressors. Under these conditions, it is impossible to know if the system is drifting.
This is exactly the logic we describe in our article on the industrial metering plan: you only optimize what you measure. Cooling shares this commonality with industrial compressed air and steam, the three most energy-consuming and least instrumented utilities on industrial sites.
The difference between a site that controls its cooling and a site that suffers from it is rarely due to machine technology. It depends on the presence, or absence, of exploitable field data.
The COP: the central indicator of cooling units
The Coefficient of Performance (COP) is the ratio between the cooling energy produced (thermal kWh) and the electrical energy consumed to produce it. A well-maintained cooling unit operating under optimal conditions exhibits a COP of 3 to 5 depending on the technology and temperature levels. In degraded conditions, this COP can drop to 2 or less, resulting in a doubled bill for the identical service provided.
Calculating the COP continuously requires measuring simultaneously:
the electrical power absorbed by the compressor and its auxiliaries,
the flow rate and temperature of the refrigerant or the secondary circuit,
external conditions (ambient temperature) to contextualize performance.
This last point is essential: a COP of 3.2 in the middle of August does not have the same meaning as a COP of 3.2 in February. Without weather contextualization, the comparison has no value and generates false alerts.
With DAT'Power, our IIoT energy management platform, these measurements are centralized, and the COP is calculated in real time, tracked on historical curves, and compared to a baseline COP. Any degradation is detected within a few days, well before impacting production or the bill.
The most frequent drifts on industrial cooling units
Condenser fouling
Air-cooled condensers gradually foul up (dust, lint, scale on water-cooled models). Fouling increases the condensation temperature, which degrades the COP and puts more strain on the compressor. Regular maintenance can recover 10 to 15% in efficiency. Without real-time supervision, fouling goes unnoticed until a breakdown occurs.
On water-cooled condensers, monitoring the cooling circuit directly intersects with the challenges described in our article on industrial water management and 2030 regulations: consumption, water quality, and thermal performance are managed together.
Incorrect setpoint adjustment
Lowering the chilled water outlet temperature setpoint by 1 °C unnecessarily increases consumption by 2 to 3%. On an installation of several hundred kW, the effect is immediately significant. Supervision allows identifying the actual setpoints applied and comparing them to effective process requirements, which have often evolved since commissioning.
Undetected degraded operation
A compressor operating with excessive partial load (cycling) or a poorly adjusted liquid by-pass consumes energy unnecessarily. The electrical power curve reveals these behaviors: short, repetitive cycles, abnormal power peaks at startup, and excessively high consumption compared to the theoretical operating point.
Lack of intelligent load shedding
On sites where multiple cooling units run in parallel, the lack of intelligent management of startups and load allocation leads to avoidable overconsumption. DAT'Power identifies actual operating sequences and allows optimizing load-shedding logic, particularly during simultaneous power peaks that strain maximum demand.
Fixed high-pressure regulation
Many installations maintain a fixed condensing pressure, inherited from the original setting. Floating head pressure control, adjusted to actual external conditions, often recovers several COP points in mid-season. However, historical operating data is required to demonstrate this and secure the settings.
Discover DAT'Power to manage the energy performance of your utilities
Instrumenting an industrial cooling unit: what to measure
An effective instrumentation plan relies on five measurement points:
Electrical active power: energy meter on the dedicated circuit,
Flow and return temperatures of the secondary circuit: PT100 or PT1000 sensors,
Flow rate of the secondary circuit: electromagnetic or non-intrusive ultrasonic flowmeter,
Ambient temperature: essential for air-cooled condensers,
Operating status of compressors and auxiliaries: digital states retrieved via PLC or gateway.
These measurements allow calculating the actual COP, the cooling capacity produced, and the specific consumption (electrical kWh per thermal kWh).
They also form the basis for eligibility for Energy Savings Certificates (CEE) via the standard sheet IND-UT-134, which finances the installation of a measurement system for Energy Performance Indicators (IPE). This sheet explicitly covers "cooling" use for equipment with a nominal power below 10 MW, which concerns the vast majority of industrial refrigeration facilities.
What collection infrastructure?
The question of data backhaul systematically arises on existing installations. Three scenarios occur:
Equipment is already controlled by a PLC: collection is done via industrial protocol, without heavy intervention.
Equipment is legacy or isolated: deploying wireless sensors is often the fastest path. Our article on LoRa technology and industrial monitoring deployment details this approach, suited for remote utility rooms and roofs where condensers are installed.
The metering plan must be built from scratch: the combination of Carlo Gavazzi meters and DAT'Power constitutes a proven basis for quickly instrumenting multiple energy uses.
In all cases, collecting field data on a production site requires a controlled architecture. Issues of network segmentation and industrial systems protection are addressed on our dedicated industrial cybersecurity page, as well as in our article on the technical challenges of the connected industry.
Industrial cooling and regulatory obligations
Instrumenting cooling units does not only serve a cost objective. Several regulatory frameworks converge toward the same measurement requirement:
ISO 50001: cooling almost always constitutes a Significant Energy Use (UES) and must therefore be monitored by documented IPE.
Regulatory energy audit: mandatory every 4 years for large enterprises, it gains considerable relevance when the auditor has measured data rather than estimates.
BACS decree and tertiary decree: for cooling units serving commercial or service areas, obligations for automation and consumption reduction apply directly.
In other words, the instrumentation set up to optimize your costs simultaneously serves your compliance. This is the most profitable double effect of an energy monitoring project.
Predictive maintenance: the contribution of DAT'Process
Beyond energy tracking, supervising cooling units with DAT'Process paves the way for predictive maintenance. Analyzing operating signatures (pressure curves, startup profiles, superheat temperatures) allows detecting early signs of failure:
Compressor bearing wear: vibration signature or abnormal current profile,
Refrigerant charge deficiency: drop in suction pressure, rise in superheat,
Regulation problem on the electronic expansion valve.
These alerts make it possible to plan interventions outside of critical production periods and avoid unplanned shutdowns, which are particularly costly on temperature-controlled processes.
The value of these alerts multiplies when they are connected to the maintenance tool. This is the purpose of the integration between CMMS and IIoT supervision: a superheat drift detected by the platform automatically generates a work order, complete with the technical context. The technician no longer intervenes blindly.
To delve deeper into this approach, DATIVE and DIMO Maint have co-authored an e-book dedicated to transforming field data into a driver of maintenance performance.
Explore DAT'Process for the supervision of your refrigeration facilities
How much can you save?
DATIVE's field feedback on instrumented refrigeration facilities indicates recurring gains:
10 to 15% on electrical consumption after setpoint optimization and condenser cleaning,
An additional 5 to 10% after optimizing load management across multi-unit installations,
30 to 50% fewer corrective interventions thanks to predictive maintenance.
On an installation with 500 kW of cooling capacity running 7,000 h/year, a 12% gain represents approximately 40,000 to 60,000 kWh saved per year, translating to €4,000 to €8,000 depending on electricity prices. Added to this is the CEE premium on instrumentation and the reduction in corrective maintenance costs.
These orders of magnitude are found across other utilities and industrial contexts:
at Ninkasi, where DAT'Power enabled monitoring of all fluids at the new production site with savings within the first few months,
at an HVAC systems manufacturer, with multi-UES energy management structured around DAT'Power,
on an upper-tier SEVESO site, where the gradual deployment of an energy management system reconciled HSE constraints, cybersecurity, and production continuity.
How to start concretely
A cooling unit supervision project generally proceeds in four stages:
Scoping and metering plan: identify high-priority units, their capacity, and their operating regime.
Targeted instrumentation: electricity, temperatures, flow, and operating states on high-stakes machines.
Platform commissioning: construction of IPE, definition of baseline COPs, and alert thresholds.
Continuous improvement loop: analysis of drifts, corrective actions, and measurement of actual gains.
The most common mistake is wanting to instrument everything at once. A limited but correctly measured scope produces exploitable results in a few weeks and often finances the extension of the project.
The underlying mechanisms (data cross-referencing, automatic anomaly detection, and decision support) are detailed in our articles on the benefits of IIoT for energy management and on the triptyque IIoT, data, and artificial intelligence.
Summary
A cooling unit that loses 15% efficiency does not stop; it continues to run while consuming far more than necessary. Fouling, unsuitable setpoints, drifting COP: these phenomena are silent, costly, and perfectly detectable as soon as the correct parameters are measured and contextualized.
DATIVE IIoT platforms convert this field data into actionable indicators, both for your energy teams and your maintenance teams.
Have our experts assess the savings potential on your cooling units
