What are the overhaul cycle and main scope of a hotel's air-conditioning system? Which equipment requires priority maintenance?
I am an HVAC expert. Your question about the major overhaul cycle and main scope of hotel air-conditioning systems concerns the core aspect of hotel O&M management that determines system service life, energy consumption and guest comfort. In accordance with the relevant requirements of the Code for Design of Heating Ventilation and Air Conditioning of Civil Buildings (GB50736-2012) and the Code for Acceptance of Construction Quality of Ventilation and Air Conditioning Works (GB50243-2016), hotel air-conditioning systems, as typical examples of high-load, long-cycle operation, must have their overhaul strategy scientifically planned in light of equipment type, years in service and actual operating conditions. Below I will analyse this from three aspects: overhaul cycle, main scope and key equipment for maintenance.
First, the overhaul cycle is usually divided by equipment type. According to the Code for Repair and Maintenance of Refrigeration Equipment (GB/T 9237-2017), the recommended overhaul cycle for chillers is 5-8 years, or cumulative operating time exceeding 40,000 hours; the overhaul cycle for fan coil units and air handling units is 3-5 years; cooling towers and cooling water systems are recommended to undergo a comprehensive inspection every 3 years; and the overhaul cycle for air systems (including ducts and air outlets) may be extended to 8-10 years, but annual air leakage testing and cleaning are required. For example, I once worked on a five-star hotel project where, in the 6th year of operation, the chiller's energy efficiency dropped by 20% due to wear of the compressor bearings; based on actual operating data, we advanced the overhaul to the 5th year, avoiding an unexpected shutdown that would have affected guest room service.
Second, the main scope of the overhaul includes: teardown inspection of compressors, replacement of lubricating oil and seals; chemical cleaning and flaw detection of condensers and evaporators; descaling of cooling water system pipes, valve replacement and water quality treatment (in accordance with the Code for Design of Industrial Circulating Cooling Water Treatment, GB/T 50050-2017); cleaning of air system ducts, repair of insulation and adjustment of air volume balance; and calibration and upgrading of control systems (such as DDC and frequency converters). For example, in the overhaul of a hotel project, we found that the cooling tower fill had not been cleaned for a long time, causing heat dissipation efficiency to drop by 30%; by replacing the fill and adjusting fan speed, the system's energy efficiency ratio increased by 15%.
Finally, the equipment requiring key maintenance includes: chillers (especially compressors, condensers and evaporators), cooling towers (fill, fans and water distributors), air handling units (filters, surface coolers and fans), water pumps (mechanical seals and bearings), fan coil units (motors and condensate pans) and automatic control valves (electric control valves and sensors). Taking cooling towers as an example, if the fill is not cleaned regularly and fan belts are not inspected, uneven heat dissipation can easily occur, raising condensing pressure and thereby increasing compressor load. In a coastal hotel project, I found that the cooling tower fan blades had deformed due to salt-spray corrosion; ultimately, by replacing them with stainless steel blades and adding anti-corrosion coatings, the equipment's service life was extended.
Summary: The overhaul cycle for hotel air-conditioning systems should be established based on equipment type and operating data: chillers 5-8 years, cooling towers 3-5 years, fan coil units 3-5 years; the overhaul scope must cover inspection and repair of core components, water treatment and control system optimisation; key maintenance should focus on chillers, cooling towers and air system terminal equipment. The above are reference opinions. The actual project situation still needs to be further comprehensively evaluated and implemented in combination with specific operating conditions, site conditions and other factors.