Falling Film / Flooded Water-Cooled Chiller – FAQ

Maintenance for Aurashu falling film and flooded water-cooled chillers is essential to ensure long-term efficiency, stable operation, and protection of key components. Because these chiller types rely on high-performance heat-exchange surfaces and precise refrigerant distribution, proper routine servicing directly affects cooling capacity, energy consumption, and equipment lifespan.Regular heat-exchanger maintenance is one of the most important tasks. For falling film evaporators, technicians must ensure that the refrigerant distribution tray and spray nozzles remain clean and free of blockages so that an even thin-film coating can form on the tube bundle. For flooded evaporators, maintaining correct liquid levels and checking for oil accumulation inside the heat-exchange chamber are critical to sustaining effective heat-transfer performance.Water-side cleaning must be performed at scheduled intervals to remove scale, sediment, and biological growth from the condenser tubes. Aurashu strongly recommends integrating a proper water-treatment program—including chemical dosing, filtration, corrosion inhibition, and periodic system flushing—to protect both falling film and flooded systems from efficiency losses caused by poor water quality.Routine refrigerant system inspections include checking for leaks, verifying refrigerant charge, monitoring oil quality, and ensuring proper superheat/subcooling levels. Compressors—centrifugal, screw, or hybrid configurations used in Aurashu systems—should be inspected for vibration, lubrication condition, bearing status, and motor performance.The control system requires periodic calibration of sensors, verification of safety protections, update of control logic, and testing of variable-frequency drives (VFDs) when applied to pumps or compressors. Electrical components, power connections, and starters should be inspected for overheating, wear, or loose terminals.Cooling tower and pump maintenance includes cleaning drift eliminators, checking fan motors, lubricating bearings, verifying pump head and flow, and confirming that tower performance remains aligned with chiller heat-rejection requirements.Finally, Aurashu recommends professional annual performance evaluations, which include chiller efficiency testing, vibration analysis, thermodynamic performance logging, and preventive replacement of critical components. With proper maintenance, Aurashu falling film and flooded chillers deliver long-term reliability, high efficiency, and stable operation even in demanding industrial and commercial applications.

Selecting the cooling tower and pumps correctly is essential to ensure the performance, efficiency, and long-term reliability of Aurashu falling-film and flooded water-cooled chiller systems. Because these chillers rely on high-precision heat exchange at the evaporator and condenser, the supporting hydronic equipment must match both the thermal load and the operating characteristics of the chiller.For cooling towers, the key factors include heat rejection capacity, approach temperature, water flow rate, ambient wet-bulb temperature, and tower configuration. Falling-film and flooded chillers typically operate at lower condensing temperatures for higher energy efficiency, so the cooling tower must provide stable performance even under varying loads. Proper tower sizing prevents excessive condensing pressure, reduces compressor power consumption, and ensures optimal seasonal energy efficiency. Aurashu typically recommends selecting towers with an approach of 3–5°C, high-efficiency fill media, corrosion-resistant structure, and drift eliminators to protect water quality and system durability.Pump selection must consider system head, flow stability, variable flow compatibility, and energy efficiency. For condenser pumps, stable flow is critical to maintain consistent condensing temperature and avoid tube scaling or insufficient heat rejection. For chilled-water pumps, especially in large central cooling plants, variable-speed pumps can significantly reduce energy consumption under partial loads. Aurashu systems support optimized pump selection through advanced controls that manage flow rate, water temperature differential, and pump sequencing.Other important considerations include water treatment system capacity, piping design, air elimination, expansion tanks, and control integration. The cooling tower and pumps must be matched to the chiller’s evaporator/condenser water quality requirements, especially for falling-film evaporators where surface wetting uniformity is essential for efficient heat transfer. Proper selection reduces fouling risk, enhances heat transfer stability, and extends the service life of core components.Aurashu provides professional engineering support for cooling tower and pump selection, including thermal calculations, system layout guidance, and recommended equipment specifications. Through accurate integration of chiller, tower, and pump systems, Aurashu ensures the entire plant operates with high reliability, low energy consumption, and long-term operational stability.

Falling film and flooded water-cooled chillers offer several high-value advantages that make them ideal for large-capacity, high-efficiency central cooling applications. Both evaporator types are engineered to maximize heat-exchange performance, reduce operating costs, and enhance long-term system reliability. Aurashu integrates optimized falling-film and flooded designs with advanced control logic, precision oil-management, enhanced heat-transfer tubing, and high-efficiency compressors to achieve superior operational performance in commercial and industrial environments.1. Exceptional Heat-Transfer EfficiencyThe primary advantage of both falling-film and flooded chillers lies in their enhanced heat-exchange capabilities. Falling-film evaporators use a thin refrigerant film over the tube surface, dramatically improving evaporation efficiency while reducing the total refrigerant charge. Flooded evaporators, on the other hand, submerge the tube bundle, maintaining maximum thermal contact even under fluctuating loads. This results in superior system COP, stable performance, and higher IPLV values.2. Lower Refrigerant Charge (Especially Falling Film)Sustainability and regulatory compliance drive the need for lower refrigerant volumes. Falling-film chillers can reduce refrigerant charge by 30–50% compared to conventional flooded units. This reduction minimizes operating cost, simplifies leak management, and supports the transition to newer low-GWP refrigerants. Aurashu’s optimized distribution system ensures an even, controlled refrigerant film for efficient operation with minimal charge.3. High Energy Efficiency & Part-Load PerformanceBoth falling-film and flooded systems excel in energy savings, especially when combined with high-efficiency centrifugal, screw, or magnetic-bearing compressors. The enhanced evaporator efficiency allows the compressors to operate at lower lift and reduced power input. With Aurashu’s intelligent VFD and adaptive control algorithms, the chiller maintains exceptional part-load performance, supporting 24/7 mission-critical environments.4. Stable Cooling Output for Large-Capacity SystemsFlooded evaporators are particularly valued for their stability in high-capacity central plants. Because the tubes are fully submerged, heat transfer remains consistent even when the load varies. This provides the operational reliability needed for industrial cooling, district energy, and large commercial buildings. Aurashu designs both evaporator types to maintain constant film thickness, optimized refrigerant distribution, and maximum surface utilization.5. Improved System Reliability & Longer Equipment LifeThanks to optimal heat-exchange efficiency and reduced compressor workload, these chillers experience less mechanical stress. Flooded systems enhance lubrication consistency, while falling-film units reduce refrigerant foaming and liquid entrainment. Aurashu’s precision oil-return design, micro-channel distribution system, and corrosion-resistant tube materials greatly extend equipment lifespan and reduce maintenance frequency.6. Lower Operating Costs & Reduced Maintenance NeedsHigh efficiency translates directly into lower energy consumption. The even thermal load on compressors prevents premature wear, and the reduced refrigerant mass lowers service cost. Aurashu integrates self-cleaning design options, anti-fouling solutions, and real-time predictive diagnostics to ensure low long-term operating expenses.7. Flexible Application Across Many IndustriesBecause of their strong efficiency and reliability characteristics, falling-film and flooded chillers are widely used in commercial buildings, data centers, industrial cooling, chemical production, pharmaceutical facilities, and district cooling systems. Aurashu customizes evaporator type, compressor configuration, tube material, and control logic based on project requirements.

Water-cooled falling film and flooded chillers from Aurashu can be configured with several compressor technologies, each chosen to match project capacity, energy-efficiency targets, refrigerant requirements, and system control strategies. The three most common compressor types used in these chillers are centrifugal, screw, and magnetic bearing centrifugal compressors—each offering unique performance advantages.Centrifugal compressors are widely used in medium-to-large capacity systems because of their high efficiency, smooth operation, and excellent performance at full and part load. They rely on high-speed impellers to compress refrigerant, which makes them ideal for chilled-water plants serving commercial complexes, industrial facilities, and data centers. When combined with falling-film evaporators, centrifugal compressors can achieve notably low approach temperatures and reduced refrigerant charge.Screw compressors provide robust performance and high reliability under varying load conditions. Their positive-displacement design delivers stable compression without the need for extremely high rotational speeds. Screw compressors are often selected for applications requiring strong adaptability to fluctuating loads, harsh operating environments, or continuous 24/7 operation. When paired with flooded evaporators, they offer excellent oil-management and stable evaporating temperatures.Magnetic-bearing centrifugal compressors represent the highest tier of efficiency and technological sophistication. Since they use frictionless bearings, they dramatically reduce mechanical losses and enable ultra-precise variable-speed modulation. This makes them ideal for premium energy-efficient installations, such as green buildings, pharmaceutical facilities, semiconductor manufacturing, and mission-critical cooling systems. Aurashu integrates magnetic-bearing technology with falling film heat exchangers to achieve exceptional IPLV performance and ultra-low vibration.Aurashu selects and engineers each compressor configuration based on project-specific parameters, including: cooling capacity, operating hours, ambient conditions, target efficiency levels, footprint constraints, noise limits, refrigerant strategy, and life-cycle cost. This ensures that every chiller—whether centrifugal, screw, or magnetic-bearing centrifugal—delivers high stability, long service life, and optimized energy performance throughout the system’s operating range.

Falling film and flooded evaporators are two advanced heat-exchange designs widely used in high-efficiency water-cooled chillers, especially in large-capacity systems such as Aurashu’s falling-film and flooded water-cooled chiller series. Although both serve the same function—extracting heat from chilled water by evaporating refrigerant—they operate in fundamentally different ways and offer unique advantages for various applications.A falling film evaporator distributes refrigerant as a thin, uniform liquid film over the outer surface of the heat-exchange tubes. The refrigerant evaporates almost instantly due to the large surface contact area, resulting in rapid heat absorption, reduced refrigerant charge, and lower energy consumption. Its high heat-transfer coefficient enables excellent part-load efficiency, making it especially suitable for projects requiring energy savings, compact structure, and fast response. Because only a small refrigerant volume is needed, falling film evaporators are often considered more environmentally friendly and cost-efficient in large HVAC systems. In addition, improved oil return, reduced pressure drop, and easier maintenance further enhance system stability.In contrast, a flooded evaporator submerges the heat-exchange tube bundle in a refrigerant pool. As warm water flows inside the tubes, the surrounding refrigerant absorbs heat and boils. Flooded systems maintain a very high wetted surface area, delivering consistent and stable heat transfer under full-load conditions. This design is widely used in high-capacity industrial and commercial chillers requiring exceptional reliability, smooth operation, and long-term durability. Flooded chillers typically operate with higher refrigerant quantities, but they deliver superior thermal performance, particularly when load demands remain steady or when the chiller is part of a centralized plant that prioritizes constant high output.Comparing the two, falling film evaporators offer lower refrigerant charge, superior part-load performance, and higher energy efficiency, making them ideal for green buildings, premium commercial facilities, and projects seeking long-term energy cost reduction. Flooded evaporators excel in large, steady-load environments, such as industrial cooling, process plants, data centers, and district energy systems. Falling film systems are more compact with faster heat-exchange response, while flooded systems are favored for their robustness, stable operation, and strong full-load capacity.Aurashu applies both technologies depending on project requirements. For customers prioritizing energy efficiency and environmental sustainability, Aurashu’s falling film chillers provide excellent seasonal performance, reduced operating cost, and modular optimization. For heavy-duty, continuous operation environments, Aurashu’s flooded chillers deliver unmatched reliability, stable cooling output, and long service life.

A Falling Film / Flooded Water-Cooled Chiller is a high-efficiency central cooling system designed for large-scale commercial, industrial, and process applications requiring stable, high-capacity chilled water. It utilizes a flooded evaporator design, where refrigerant fills the evaporator shell at a low level and continuously wets the tube surfaces. In falling-film configurations, refrigerant is evenly distributed over the tube bundle in a thin film, significantly enhancing heat transfer compared with traditional dry-expansion evaporators.This design provides greater heat exchange efficiency, higher evaporation temperature, and reduced compressor power consumption. As a result, falling film and flooded chillers deliver exceptional performance in medium- to high-tonnage systems and achieve lower kW/ton values, making them one of the most efficient water-cooled chiller technologies.Aurashu falling-film and flooded chillers are engineered with optimized heat-exchanger geometry, precise refrigerant distribution, high-efficiency screw or centrifugal compressors, and advanced control algorithms to maximize system performance. The flooded evaporator ensures more surface area is actively utilized, allowing the unit to run with lower lift and reduced energy consumption, especially under part-load conditions.These chillers are widely used in large commercial complexes, industrial manufacturing, data centers, pharmaceuticals, electronics production, automotive plants, chemical processing, and other environments where long-term stable cooling and low operating cost are essential. They also support integration with free-cooling systems, thermal storage, heat recovery, and intelligent building automation.Aurashu provides extensive project customization options, including capacity range, refrigerant selection, heat-exchanger configuration, corrosion-resistant materials, high-efficiency variable-speed compressors, and optimized system control strategies. With advanced safety protection, redundant monitoring, and professional engineering support, Aurashu ensures reliable long-term operation, high system stability, and reduced lifecycle cost for mission-critical cooling applications.