Methods to Maintain Chiller Efficiency
Aside from the conventional predictive maintenance that can include rotor bar testing, infrared thermography, the potential damage to chillers can be avoided by an extensive preventive maintenance schedule.
Because of the improvements in the refrigerant, control, and equipment design, chiller efficiencies have continuously improved over the years. Now, chillers have stricter operational tolerances, so regular maintenance and services should be given more frequently. For a preventive maintenance plan, here are some things that engineering and maintenance managers should consider.
* Have an operating log for everyday activities – Chiller operators should record chiller performance every day. The log should be accurate and detailed in order to determine any potential problems. The daily log can also be used to review and analyze inefficient control setpoints. Chiller manufacturers can provide a list of suggested data points to help with chiller performance. This method can also be automated with the microprocessor-controlled building automation system.
* Maintain clean tubes – Maximizing the efficiency of chillers might not be easy if the evaporator and condenser tubes are not clean. Chillers contain several miles of tubing in their heat exchangers, so these areas must be clean to maintain high-efficiency performance. Chiller manufacturers highly suggest cleaning condenser tubes every year and they also recommend cleaning evaporator tubes at least once every three years. Scheduled inspection and cleaning is advised if the evaporator is part of an open system.
* Oil and refrigerant analysis – Analyzing the chemicals in oil and refrigerant annually can help in determining chiller-contamination problems before they become severe. The testing may involve spectrometric chemical analysis to recognize contaminants that impede efficiency and performance. A professional chemical laboratory that specializes in HVAC equipment must lead and perform the analysis.
* Have a leak-free unit – Manufacturers suggest quarterly tests of compressors for leaks. The best method for detecting leaks in a low-pressure chiller is to find purge-unit runtime and the amount of moisture in the purge unit. If one of the aforementioned is too high, the unit certainly has leaks. Other indications of leaks include high condensing temperature and head pressure.
Maintaining the efficiency of chillers should be done with the help of technicians or professionals that are equipped with knowledge and skills to handle such complicated equipment. Call a contractor as soon as you notice or suspect irregularities in the performance of your chillers to ensure proper care and handling.