Preventive maintenance of evaporative condensers is key to ensuring the efficient, reliable and safe operation of refrigeration equipment, according to Steve Kline, Product Applications Manager at Baltimore Aircoil Company (BAC), a Maryland (U.S.)-based manufacturer of condensers and other cooling systems.
In a recent essay written by Kline – titled “Maintaining the Mechanical Integrity of Evaporative Condensers” – he also highlighted the role of regular inspections and system upkeep for avoiding the leakage of refrigerants, such as ammonia/NH3 (R717).
“A comprehensive program of routine preventive maintenance will keep refrigeration systems performing at peak efficiency, maximize system operating life, and reduce unplanned downtime due to equipment failure,” he said. “Do not wait until the condenser fails to perform maintenance.”
According to previous analysis by Kline, water-cooled condensers that use evaporative heat rejection “significantly” reduce energy consumption compared to “similarly sized systems utilizing either air-cooled or adiabatic heat rejection.”
“A comprehensive program of routine preventive maintenance will keep refrigeration systems performing at peak efficiency, maximize system operating life, and reduce unplanned downtime due to equipment failure.”Steven Kline, BAC
In fact, his latest essay states that by lowering system condensing temperatures and compressor horsepower requirements, evaporative condensers can reduce energy consumption by up to 15% compared to air-cooling systems.
“Evaporative condensers are an efficient and cost-effective heat rejection solution for various applications, [including] food and beverage refrigeration, industrial machinery cooling and HVAC,” he added.
However, Kline urged that to maximize system efficiency as well as operational time, hygiene and safety equipment must be well maintained.
According to a 2018 brief published by the Kigali Cooling Efficiency Program (now the Clean Cooling Collaborative) in partnership with the Carbon Trust, the International Institute of Refrigeration (IIR) and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the “effective optimization, monitoring, and maintenance of cooling equipment could deliver substantial electricity savings of up to 20%.”
Effective preventive maintenance
In his essay, Kline explained that there are 10 areas of inspection that “should be part of any evaporative condenser preventive maintenance program.”
According to Kline, inspectors should look for adequate anchors and supports for unit; corrosion of enclosure, tubes, piping and supports; scale build-up on tube bundle; cracks in fan assemblies; scale or dirt build-up in drift eliminators and the water sump; safety devices; electrical connections; and spray nozzles. Shafts, bearings, motor mounts, belts, fasteners and all isolation and purge valves should also be inspected.
While the frequency of maintenance will depend on a variety of factors – such as water and air quality – Kline recommends that inspection of the evaporative condenser should be conducted on an annual basis, with more frequent examination if warranted by manufacturer guidance or other circumstances.
“For each inspection, it is important to document the process and all findings,” said Kline. This would include the date of the inspection, the name of the person performing the inspection and any actions taken. He also advised the inclusion of photographs to help document findings over time.
Paramount to the inspection is safety, explained Kline.
“Any site safety procedures must be followed prior to beginning any inspection or maintenance work [and] always follow industry best practices regarding the use of proper PPE [personal protection equipment],” he said. “Measures must be taken to confirm that there is no refrigerant left in the coil.”
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