A properly maintained chiller can provide reliable cooling for many years. However, like any mechanical system, a chiller requires regular attention to continue operating efficiently and reliably.

Routine maintenance does more than keep a chiller running. It can help identify developing problems before they become major failures, maintain cooling capacity, reduce unnecessary wear on components, and extend the useful life of the equipment.

For businesses that depend on process cooling, preventative maintenance is especially important. An unexpected chiller failure can interrupt production, damage temperature-sensitive processes, and result in costly emergency repairs.

Whether a system uses an air-cooled or water-cooled condenser, establishing a regular maintenance program is one of the best ways to protect the investment in a chiller.

Keep the Condenser Clean

Condenser maintenance is one of the most important areas of routine chiller care.

For an air-cooled chiller, dirt, dust, debris, and other contaminants can accumulate on the condenser coils. As the coils become restricted, the system may have more difficulty rejecting heat. This can cause the compressor to work harder and may increase operating temperatures and energy consumption.

Maintenance staff should inspect condenser coils regularly and clean them as needed. The area surrounding the chiller should also be kept clear of vegetation, debris, and other materials that could restrict airflow.

Coil cleaning methods should follow the equipment manufacturer’s recommendations. Some modern condenser coils can be damaged by improper cleaning chemicals or excessive water pressure, so aggressive cleaning methods should be avoided unless specifically approved for the equipment.

Regular condenser coil cleaning can help maintain proper airflow and heat transfer while reducing unnecessary stress on the refrigeration system.

Maintain Proper Airflow

Clean coils are only part of maintaining proper airflow.

Inspect fans, fan guards, motors, and surrounding areas to ensure air moves freely through the condenser. Any obstruction around the inlet or discharge side of the chiller can affect condenser performance.

Operators should also pay attention to unusual fan noise, vibration, or changes in normal operation. These can indicate a developing problem with a motor, fan assembly, bearing, or other component.

Addressing these issues early can prevent a relatively small mechanical problem from becoming a larger repair.

Check Water Quality and Flow

Water-cooled chillers require additional attention because the quality and condition of the water moving through the system can have a direct effect on performance.

Poorly managed water quality can cause water-side systems to develop scale, corrosion, biological growth, or fouling. Fouled heat-transfer surfaces make it more difficult for the chiller to transfer heat and can reduce system efficiency.

Water treatment should be appropriate for the specific system and application. Strainers should also be inspected and cleaned as needed to prevent restrictions in the water circuit.

For systems connected to cooling towers, maintaining the cooling tower and condenser water loop is particularly important. Poor water treatment can contribute to fouling and corrosion that eventually affects chiller performance and equipment life.

Monitor Operating Temperatures and Pressures

One of the simplest ways to identify a potential chiller problem is to pay attention to how the system is operating.

Operators should establish normal operating conditions for their particular chiller and monitor for changes in:

• Supply and return fluid temperatures
• Refrigerant pressures
• Fluid flow
• Compressor operation
• Condenser temperatures
• Electrical readings
• Alarm or fault conditions

A gradual change in operating conditions can sometimes provide an early indication that something is wrong.

For example, a change in temperature difference across the evaporator could indicate a change in process load or fluid flow. Increasing condenser pressure could indicate restricted airflow, dirty coils, high ambient conditions, or another system issue.

Keeping a regular operating log can make these changes easier to identify. Manufacturer maintenance guidance also recommends maintaining operating records and monitoring pressures and other operating conditions.

Inspect Electrical Components

Technicians should inspect electrical components as part of a preventative maintenance program.

Connections can loosen over time because of vibration and thermal cycling. Motors, contactors, relays, wiring, disconnects, and other electrical components should be inspected by a qualified technician according to the equipment manufacturer’s recommendations.

Address signs of overheating, damaged insulation, corrosion, unusual electrical readings, or loose connections promptly.

Electrical maintenance is particularly important because a small electrical problem can eventually damage a compressor, motor, control board, or other expensive component.

Check for Refrigerant Problems

The refrigeration circuit should be periodically inspected by a qualified technician.

A properly operating system should maintain the refrigerant pressures and temperatures expected for its operating conditions. Unexpected changes can indicate issues such as a refrigerant leak, restriction, metering problem, or abnormal operating condition.

Refrigerant leaks should never simply be addressed by repeatedly adding refrigerant. The source of the leak should be identified and repaired by a qualified technician.

This is particularly important with newer A2L refrigerants such as R454A and R454C. Equipment designed for A2L refrigerants has specific installation, service, and safety requirements, and technicians should follow the applicable procedures for the specific chiller.

Inspect Filters, Strainers, and Fluid Circuits

Restrictions in the fluid circuit can reduce flow and affect chiller performance.

Water or fluid strainers should be inspected and cleaned according to the requirements of the system. Filters used in associated process equipment should also be maintained as recommended.

The fluid circuit should be checked for signs of leaks, unusual pressure drops, or changes in flow.

We design chillers to operate under specific conditions, so proper fluid flow is essential. A change in flow can affect heat transfer and may cause the equipment to operate outside its intended range.

Check Pumps and Associated Equipment

The chiller is only one part of a complete cooling system.

Pumps, valves, piping, tanks, controls, and other associated equipment should also be maintained. A problem somewhere in the process loop can appear to be a chiller problem even when the refrigeration system itself is operating properly.

Pumps should be checked for unusual noise, vibration, leakage, and changes in performance. Valves should operate correctly, and piping should be inspected for leaks or signs of damage.

Keeping the entire cooling system properly maintained helps the chiller operate under the conditions for which it was designed.

Pay Attention to Alarms and Changes in Performance

Do not ignore alarms or repeatedly reset a chiller without determining why the alarm occurred.

Modern chillers use controls and safety devices to identify abnormal operating conditions. An alarm can be caused by something relatively simple, but it can also indicate a developing mechanical, electrical, refrigeration, or fluid-side problem.

If an alarm repeatedly returns, the underlying cause should be investigated.

Operators should also take note of changes that may not immediately generate an alarm. Increasing operating temperatures, unusual noises, longer run times, reduced cooling capacity, or increased energy consumption can all be reasons to have the equipment inspected.

Schedule Professional Preventative Maintenance

Some maintenance tasks can be performed by trained facility personnel, but many chiller maintenance procedures should be performed by qualified HVAC or refrigeration technicians.

A professional preventative maintenance inspection can include checking refrigeration pressures, electrical components, controls, compressor operation, motors, fluid circuits, safety controls, and other components specific to the chiller.

The appropriate maintenance schedule depends on the specific model, operating conditions, environment, and application. A chiller operating in a clean indoor environment may have different maintenance requirements than equipment operating outdoors in a dusty, dirty, or corrosive environment.

Following the maintenance requirements provided for the specific chiller is therefore essential.

Maintenance Helps Protect Your Chiller Investment

Chiller maintenance is ultimately about preventing avoidable problems.

Cleaning condenser coils, maintaining proper water quality, monitoring operating conditions, checking electrical components, inspecting the refrigeration system, and addressing unusual performance early can all contribute to dependable long-term operation.

Preventative maintenance also provides an opportunity to identify worn or deteriorating components before they cause an unexpected shutdown.

For facilities where cooling is critical to production, maintaining the chiller should be treated as part of the overall process maintenance program rather than something that only happens when a problem occurs.

Legacy Chillers: Built for Long-Term Process Cooling

Legacy Chillers manufactures process cooling equipment for a wide range of commercial and industrial applications. Proper maintenance is an important part of getting the most from any chiller, regardless of the manufacturer.

Legacy Chillers can help customers select equipment based on their application, cooling requirements, and operating conditions. Once the system is installed, following the recommended maintenance procedures for the specific equipment can help maintain performance and reliability throughout its service life.

If you are installing a new process chiller or need help determining the right cooling system for your application, contact Legacy Chillers to discuss your requirements.