Why Chiller Efficiency Matters
Water-cooled centrifugal chillers are the backbone of cooling in large commercial and industrial facilities, including high-rise offices, hotels, hospitals, universities, and manufacturing plants. These systems can account for 20–40% of a building’s total energy consumption.
Even small inefficiencies add up. For example, a typical 600-ton chiller operating at 15–30% efficiency can result in $5,000–$24,000 in wasted energy per year.
Learn more about the fundamentals of chiller systems on Chiller Basics.
How to Diagnose and Fix Common Chiller Issues
The Role of Chillers in Medical Equipment: Ensuring....
Essential Chiller Maintenance: Preventing Downtime
Technical Articles
How to Diagnose and Fix Common Chiller Issues
The Role of Chillers in Medical Equipment: Ensuring....
Essential Chiller Maintenance: Preventing Downtime
How to Diagnose and Fix Common Chiller Issues
The Role of Chillers in Medical Equipment: Ensuring....
Essential Chiller Maintenance: Preventing Downtime
How to Diagnose and Fix Common Chiller Issues
The Role of Chillers in Medical Equipment: Ensuring....
Essential Chiller Maintenance: Preventing Downtime
Condenser Issues
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Fouled or blocked condenser tubes
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Non-condensables trapped in the system
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Division plate problems
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High or low condenser water temperature
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Low or high condenser water flow
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Metering device issues
Evaporator Issues
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Low refrigerant or contaminated charge
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Fouled evaporator tubes
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High evaporator approach temperature
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Low or high evaporator water flow
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Division plate problems
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Metering device issues
Common Causes of
Chiller Efficiency Loss
How Do You Calculate Condenser Approach?
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When Condenser
Tubes Are Clean
When Condenser
Tubes are Dirty
Scale, bacteria, and sediment act as insulation, which results in a higher condenser approach temperature.
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Other Causes of High Condenser Approach
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Blown division plate gaskets
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Warped division plate
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Eroded division plate support channels
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Blocked
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New internally enhanced tubes
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Spiral groves
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Expanded tube surface
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Very efficient
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Tubes fouled with microbiologicals due to poor water treatment
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Reduced efficiency = wasted energy $$$
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Only discoverable by recording data AND knowing how to analyze it
Dirty Tube (microbiological fouling)
Water Flow & Temperature Challenges
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Low condenser water flow: Higher temperature rise reduces efficiency by up to 2% per 1°F rise.
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High inlet condenser water temperature: Above 85°F can reduce efficiency ~2% per degree.
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Low evaporator setpoint: Each degree below design increases energy use by up to 2%.
Chiller Instrumentation Issues
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Accurate instrumentation is essential for chiller performance monitoring.
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Instruments should be calibrated regularly or upgraded if inaccurate.
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Annual calibration checks by service contractors ensure reliable data.
Logging the data on paper or in your BAS does not get the job done
Chiller logs are routinely taken but data analysis is difficult, and problems may not be identified in a timely manner
The Cost of Ignoring Efficiency Loss
Without proper monitoring and analysis, many chiller plants operate 10–30% less efficiently than they could, leading to:
Increased energy costs
Reduced system reliability
Shortened equipment lifespan