Indirect evaporative cooling is an emerging energy-efficient air cooling technology characterized by its low energy consumption and low carbon footprint. Tubular indirect evaporative coolers serve as the commonly used air treatment devices. This study conducts a multi-objective performance comparison between two primary types of tubular indirect evaporative coolers, namely the conventional round tube design and the flat tube variant, under varying inlet air states and geometric parameters. The numerical models for each type of cooler have been established and validated to facilitate this investigation. The thermal performance of the coolers was comprehensively assessed using evaluation metrics such as temperature drop, wet-bulb efficiency, specific cooling capacity, and coefficient of performance (COP). The findings indicated that, on average, the flat tubular indirect evaporative cooler achieved a 6.2% greater dry-bulb temperature drop and a 16% higher wet-bulb efficiency in primary air compared to its round-tube counterpart when subjected to the pre-set operating conditions and the identical heat transfer areas. In addition, under equivalent geometric conditions, the flat tubular cooler demonstrated a 12% enhancement in COP while maintaining a robust specific cooling capacity. These results highlight the superior overall performance of the flat tubular indirect evaporative cooler, positioning it as a potentially efficient choice within the realm of indirect evaporative cooling technologies.

The application of moisture-conducting fibers offers a feasible solution for enhancing the wetting performance of tubular indirect evaporative coolers (TIEC). However, existing research has mainly focused on changes in the primary air state, which limits understanding of the performance characteristics of the secondary air side. This study investigates the external tube bundle of a moisture-conducting fiber-assisted TIEC and conducts a multifactor analysis of its heat and mass transfer performance. A numerical model for coupled heat and mass transfer in the external tubes is developed and validated against experimental data. Multifactor orthogonal design and sensitivity analysis reveal that the secondary air outlet conditions are predominantly governed by the inlet boundary conditions. The air outlet temperature and relative humidity exhibit the highest sensitivity to inlet temperature and inlet relative humidity, respectively. Additionally, the heat and mass transfer performance shows stronger sensitivity to flow and geometric parameters. The wet-bulb effectiveness (epsilon wb) and the cooling capacity per unit volume (Qv) are most sensitive to tube spacing (S), with range (R) values of 0.19 and 23.86, respectively. Furthermore, the predictive models established based on the multifactor analysis demonstrate high robustness, with the coefficient of determination ranging from 0.91 to 0.99 and relative errors within +/- 8%. These findings provide useful guidance for the engineering design and optimization of moisture-conducting fiberassisted IEC systems.

Hollow fiber membrane-based evaporative cooling is regarded as an efficient, energy-saving, hygienic, and versatile cooling solution. However, most existing studies simplify the calculation of evaporative area, leading to inaccurate estimates of heat and mass transfer behavior. This study proposes a theoretical model for determining evaporative area, addressing the physical phenomenon at the micro level by incorporating membrane surface morphology and hydrophobicity. Fractal theory is employed to quantify the roughness of the membrane surface, and the apparent contact angle and evaporative area calculation models are established based on the Wenzel model. The proposed model is validated through membrane material characterization and experimental testing of membrane modules. In addition, the influence of membrane properties on the evaporative area during the membrane-based evaporative cooling process is investigated. The results show that the theoretical model for evaporative area matches experimental data with a relative error of less than 5 %. Membranes with higher surface fractal dimension, intrinsic contact angle, and porosity are found to theoretically increase the evaporative area beyond the total membrane area, thereby enhancing heat and mass transfer performance. The developed evaporative area calculation method can be applied to numerical modeling of membrane-based evaporative cooling processes, enabling more accurate predictions of system behavior and providing theoretical guidance for membrane material selection and optimization.

Thin liquid film evaporation leverages latent heat and low thermal resistance to achieve superior heat transfer capabilities, making it pivotal for next-generation high-heat-flux thermal management systems. This paper presents a systematic review of the fundamental mechanisms, interfacial transport behaviors, and experimental techniques associated with static thin films and falling liquid films. This work elucidates the complex coupling of Marangoni convection, van der Waals disjoining pressure, and contact line dynamics. These mechanisms collectively govern film stability and the intensity of non-equilibrium phase change in the micro-region. The influence of surface wettability and dynamic contact angle hysteresis on hydraulic replenishment and dry spot formation is critically analyzed, offering insights into optimizing surface engineering strategies. In addition, the review categorizes advanced non-intrusive diagnostics, including optical interferometry, laser-induced fluorescence (LIF), and infrared thermography, evaluating their capacity to resolve spatiotemporal variations in film thickness (ranging from 10 nm to several μm) and temperature under complex boundary conditions. Special attention is directed toward falling film evaporation over horizontal tubes, addressing flow regime transitions and the impact of interfacial shear from external airflow. The work concludes by identifying key challenges in multi-physics coupling and proposing future directions for synchronized diagnostics and adaptive surface design.

Air-source heat pump (ASHP) technology holds promise for reducing energy consumption and carbon emissions in public building heating systems. However, its widespread application is hindered by inconsistent performance across climates, coupled with the absence of comprehensive models that effectively integrate control strategy with accurate long-term performance predictions. This study investigates the adaptability of ASHP systems across different climate zones in China, with a focus on energy efficiency and carbon reduction potential. Using dynamically calibrated TRNSYS models that account for external temperature variations and frost formation, the monthly and daily operational performance of ASHP systems was evaluated in several representative public building types. Results indicate that the COP is positively correlated with outdoor temperature and significantly influenced by the supply water temperature, with the highest annual COP observed in Beijing (2.7), followed by Shanghai (2.62) and Harbin (2.58). Notably, little correlation is found between the COP and building types. Furthermore, a comparative carbon emission analysis demonstrates that ASHP systems achieve substantial reductions compared to conventional coal and gas heating systems. Specifically, carbon reduction rates reached approximately 47 % in cold regions and 28 % in severe cold regions relative to coal-fired boilers. Additionally, ASHP systems exhibited superior carbon reduction performance over gas boilers when outdoor temperatures exceeded region-specific thresholds, such as -1 degrees C in Harbin, -5 degrees C in Beijing, and 4 degrees C in Shanghai. These findings underscore the effectiveness of ASHPs as a sustainable heating solution for public buildings in diverse climates, providing valuable insights for optimizing design and operation toward carbon neutrality goals.

The increasing cooling demand in buildings, together with the urgent need to reduce carbon emissions and electricity consumption, has renewed interest in dew-point evaporative cooling system as a low-carbon alternative to conventional vapor-compression air-conditioning. However, the practical deployment of the system is often hindered by non-uniform surface wetting, dependence on grid electricity, and the lack of systematic understanding of the coupled effects of solar radiation and ambient humidity under diverse climatic conditions. In this study, a photovoltaic-driven dew-point evaporative cooling system is proposed and experimentally validated. The system dynamically couples photovoltaic power generation with fan operation to achieve supplydriven airflow control, while moisture-conductive fiber materials are employed to enhance wetting uniformity and heat-mass transfer. A transient three-module simulation framework is developed to evaluate the energy, economic, and environmental performance of the system. Results show that, across seven representative climate zones, the system achieves primary outlet air temperatures below 26 degrees C, with cooling capacities of 45-252 W per channel and wet-bulb and dew-point effectiveness reach 100% and 66%, respectively. For a commercial building case, the system achieves a 76.2% reduction in annual operating cost and a payback period of about 5.6 years compared with conventional air-conditioning. Life-cycle assessment further indicates seasonal COQ emission reductions of up to 81.1%. The proposed system demonstrates strong adaptability in both hot-dry and hot-humid climates. The main novelty lies in the dynamic coupling strategy, the application of moistureconductive fiber to ensure stable high-effectiveness operation, and the comprehensive multi-climate energy, economic, and environmental assessment, extending previous studies toward practical renewable-powered cooling solutions.

Solar interfacial evaporation technology as a sustainable clean water production solution has recently shifted its focus from pursuing high evaporation rates to constructing emerging multifunctional solar interfacial evaporation systems (MSIES) that enable the smart integration of water purification, energy utilization, and beyond. This comprehensive review explores recent advancements in MSIES, systematically analyzing the intricate interplay between interfacial mechanisms, material design, and coupled water-energy processes, along with the multi-functional synergistic effects and efficient gains achieved through material innovation and system construction. First, we critically examine state-of-the-art device design paradigms, focusing on the 2D and 3D engineering of solar interfacial evaporators tailored to optimize solar absorption, thermal insulation, and rapid capillary water pumping. Subsequently, this work highlights a pivotal paradigm shift towards the design and construction of MSIES. We systematically elaborate the deep integration of solar evaporation processes with coupled energy conversion and environmental remediation workflows, including simultaneous electrical energy harvesting (via thermoelectric and hydrovoltaic effects), thermal energy storage, advanced remediation of complex wastewater (encompassing refractory pollutant degradation and antibacterial disinfection), sustainable clean fuel synthesis (e.g., photocatalytic hydrogen evolution and carbon dioxide reduction), and high-value resource recovery (including crude oil and precious metal). Finally, we outline current bottlenecks and provide a forward-looking perspective on MSIES. Although MSIES still faces challenges in large-scale preparation, long-term stability, and functional synergy, future research through smart material design, modular system integration, and artificial intelligence optimization is expected to drive MSIES towards higher efficiency, intelligence, and sustainability, providing comprehensive solutions to address global water, energy, and environmental challenges.

Building cooling accounts for a substantial share of energy use, while conventional vapor-compression systems rely on high global warming potential (GWP) refrigerants and face efficiency penalties in hot-humid climates due to large latent loads. Evaporative cooling and shallow geothermal hybrid systems offer low-energy alternatives, but existing hybrid systems either lack effective dehumidification or suffer from soil thermal saturation and limited climatic applicability. Therefore, this study proposes an earth-to-water heat exchanger and dew-point evaporative cooling (EWHE-DPEC) hybrid system and investigates its performance through bidirectional thermodynamic coupling between shallow geothermal cooling and evaporative cooling. A coupled model, validated against multiple independent data sources, integrates sub-surface soil temperature prediction, buried pipe heat transfer, and coupled heat and mass transfer. Parametric simulations quantify the effects of water-side conditions, air-side operating condi-tions, subsurface environment, and regional climate. Results show that EWHE pre-cooling enables the DPEC unit to provide strong sensible cooling and condensation-based dehumidification under hot-humid conditions, while the high evaporative capacity of DPEC allows stable operation at elevated water temperatures, mitigating soil thermal accumulation and reducing buried-pipe length. Cooling and dehumidification are enhanced mainly at low water velocities, and the secondary-to-primary air ratio exhibits a non-monotonic effect, with maximum cooling perfor-mance at 0.2-0.3 and maximum dehumidification at 0.4-0.5. Seasonal simulations for four cli-matic zones demonstrate that supply air temperatures can be maintained below 25-27 degrees C with climate-dependent pipe lengths. The findings provide a thermodynamic basis and practical design guidance for ultra-low-energy, refrigerant-free cooling systems in hot-dry and hot-humid regions.

Membrane-based air dehumidification technology plays a pivotal role in achieving energy-efficient air conditioning. Exploring its transient characteristics under varying conditions is essential for improving system stability, optimizing performance, and reducing energy consumption, particularly in special confined spaces that require a rapid response to humidity changes. Utilizing the pilot-scale experimental setup designed for air dehumidification, this study experimentally examined the transient characteristics of membrane system for first time. Key findings reveal that both start-up and response times of membrane system are shortened as increasing the flow rate, with the maximum values of 69 s and 968 s occurring at 2 L/min. Conversely, the response time of the membrane system is greatly extended under high humidity conditions. The dehumidification rate exhibits a non-linear increasing trend with the augment of inlet moisture content. Additionally, the steady-state dehumidification performance of the membrane system was also explored under different flow rate and moisture content. The dehumidification ratio and water vapor permeance are almost constant under different inlet moisture contents with fluctuating slightly around 68 % and 2500 GPU, respectively. Notably, the system achieves an energy-saving rate of 21.5 % compared to traditional cooling methods. The findings are anticipated to offer insights and direction for the start-up strategies and dynamic regulation of membrane dehumidification systems.

This study addresses the bottlenecks faced by photovoltaic (PV) modules when applied to building envelopes, including the increase in operating temperature due to heat generation, the decrease in power generation efficiency, and the potential impact on the building’s thermal load. A solution is proposed: the photovoltaic evaporative cooling ventilated cavities (PVECVC). This solution involves installing PV on the building envelope surface, maintaining a certain distance from the building wall to form a ventilation cavity, and placing an evaporative cooling device on the PV backsheet. By constructing an outdoor test platform for comparative experiments to explore the impact of key parameters on system performance, the performance of the evaporative cooling (EC) in PVECVC was investigated. This study demonstrates that EC is an effective thermal management method for PVECVC, capable of reducing the operating temperature of PV backsheet ( T PV ), cavity backsheet ( T ca ), and cavity air ( T a ) under various environmental conditions, thereby improving system stability and efficiency. These conclusions provide a solid foundation for future research and practical applications.

Traditional air-conditioning (AC) systems contribute significantly to a building's total energy consumption, and improving its energy efficiency is crucial for energy conservation and carbon emission reduction. The evaporative cooling (EC) is recognized as a sustainable cooling technology to replace conventional AC systems due to its high efficiency and environmental friendliness, particularly in hot and dry regions. However, EC's high consumption of freshwater limits its application in water-scarce regions. Using saline water sources offers a promising solution to reduce reliance on freshwater and expand EC's potential, but a systematical analysis over this technology is missing in the literature. This study explores the opportunities, challenges, and solutions associated with saline water-driven EC systems. The review begins by examining the water footprint of existing EC systems to emphasize the necessity of utilizing alternative water sources. Next, potential impacts of saline water on the cooling performance and durability of EC are analyzed. Subsequently, water pre-treatment methods that can mitigate fouling and reduce contamination of saline water on EC are summarized. Finally, the possibility of integrating EC with desalination for cogeneration of both freshwater and cooling is explored. The findings suggest significant potential for saline water-driven EC and highlight the possibility of combining EC with desalination for water-cooling cogeneration. However, challenges such as biofouling and partial wetting remain to be addressed. These results provide valuable insights for the effective use of saline water in EC systems, reducing reliance on freshwater and enabling EC applications in water-scarce regions.

Direct contact membrane distillation (DCMD) driven by low-grade heat sources respresents a sustainable solution to exisitng water scarcity challenges. However, current studies primarily focus on steady-state analyses on isolated modules, limiting the understanding of dynamic behaviors for multi-component coupled systems. The present work investigates the transient performance of a solar-powered DCMD system with heat recovery (HR). A dynamic model is established and validated with experimental data. Subsequent system analyses reveal that membrane module scale significantly influences dynamic responses under various thermal perturbations. When subjected to a 20 % stepwise heat source temperature disturbance, the response time escalates by 140.8 % as the membrane length increases from 2 m to 10 m. A longer membrane module also demonstrates remarkable capability in attenuating periodic temperature fluctuations originating from intermittent solar input. Additionally, the improved thermal storage capacity mitigates the dynamic fluctuations of the system when powered by solar energy, thus prolonging high-performance operation and reducing specific energy consumption by 4.4-13.2 %. The characteristic response time of DCMD system (100-200 s) proves to be an order of magnitude shorter than conventional desalination technologies, establishing its unique advantage in rapid-response solar applications. These findings offer valuable guidance for engineering applications and the development of control strategies for solar-powered DCMD-HR system.

Traditional dehumidifiers require auxiliary heat exchangers for temperature control, incurring energy penalties from sequential heating/cooling. Desiccant coated heat exchangers (DCHE) overcome this by simultaneous sensible/latent heat removal, enabling intrinsic temperature-humidity decoupling. However, weak thermal-hygrometric coupling in conventional DCHE limits independent control. To address this critical challenge, this study proposes a dual-mode decoupling strategy rooted in adsorbent saturation characteristics. The core innovation lies in transitioning the DCHE's operational mode from active dehumidification to pure heat exchange based on adsorbent saturation detection. By developing a time-dependent simulation model in Simulink, we demonstrate the decoupled system's exceptional stability (temperature fluctuation <+/- 1 degrees C, humidity ratio fluctuation < +/- 0.4 g/kg) and rapid temperature response capability (temperature response time accounts for less than 5 % of the total dynamic time). Simulation validation reveals the strategy's robustness against sudden humidity disturbances (0.15-0.3 g/s) and temperature disturbance (27.5-42.5 degrees C). Furthermore, parameter sensitivity analysis quantifies the trade-off between control accuracy and response speed under varying humidity deviation thresholds (0.2-0.4 g/kg). This research establishes a theoretical framework for intelligent indoor environmental control systems and provides practical guidance for next-generation DCHE controller design.

Membrane distillation (MD), combining phase-change purification with membrane separation, is a promising technology for treating industrial hypersaline wastewater with complex organics and residual oxidants (e.g., H2O2). However, membrane fouling remains a prominent challenge that limits both productivity and durability. To address this challenge, a superhydrophobic membrane capable of in situ micro-bubble generation is developed at the membrane-liquid interface, effectively mitigating salt accumulation while enhancing vapor transfer. This is achieved by applying a surface coating of γ-MnO2 and perfluorodecyltrichlorosilane (FDTS) on a commercial polyvinylidene difluoride (PVDF) membrane, which facilitates the decomposition of H2O2 in the feed solution. The modified membrane evinced a flux enhancement of up to 35% for desalinating sodium chloride (NaCl) solution under various operating conditions, and its resistance to gypsum (CaSO4) fouling nearly doubled compared to the unmodified membrane. These improvements are attributed to the synergistic effects of the superhydrophobic property and the dynamic micro-bubbles, which intensified turbulence and acted as nucleation barriers. Compared to recent studies, the developed membrane demonstrated superior productivity, antifouling, and cost-effectiveness across various scenarios. The work provides a scalable and efficient approach for MD applications in hypersaline wastewater treatment.

Membrane dehumidification technology has gained significant attention for its efficiency, energy savings, and simplicity. Enhancing the performance of membrane dehumidification is crucial as it directly impacts energy efficiency and indoor comfort, promoting wider adoption of this innovative approach. Significant advances have been made in enhancing membrane dehumidification performance from the perspectives of materials, modules, and systems. This review delves into recent developments, focusing on enhancement methods, dehumidification effects, and limitations. Innovations in membrane materials, such as the use of nanoparticles and hydrophilic functional groups, improve permeability, selectivity, and durability. Moreover, novel module designs, like porous or spiral-wound configurations, increase the surface area and optimize flow dynamics, thereby boosting the dehumidification efficiency. Connecting multiple modules in series or parallel enhances performance but introduces manufacturing complexities, higher flow resistance, and fouling risks. At the system level, integrating membranes with heat recovery or renewable energy systems can reduce energy consumption by over 20 % compared to traditional methods. In this review, the optimization recommendations for membrane materials, modules, and systems were proposed. Combining molecular-scale modeling with experimental testing provides a precise path for upgrading membrane properties. The mass transfer characteristics within modules, along with multi-objective optimization, support a more efficient and rational design of the membrane module. Additionally, the exergy analysis can identify energy-intensive areas, refining the system design strategies for greater efficiency.

To address the efficiency enhancement of vacuum membrane dehumidification, this study innovatively substitutes traditional circular fibers with elliptical hollow fibers. A three-dimensional flow and mass transfer model was developed for elliptical membrane modules arranged in staggered and linear configurations, enabling a detailed comparison of dynamic behavior and performance improvements with circular fibers. The results demonstrate that elliptical fiber membranes significantly outperform circular fibers, particularly as the axial ratio (major to minor axis) increases, resulting in enhanced mass transfer efficiency. Notably, the staggered elliptical fiber modules mitigate the flow stagnation zones, significantly enhancing dehumidification efficiency. Additionally, the impact of inlet humid air conditions and structural parameters on the dehumidification efficiency and flow resistance was thoroughly investigated. The variations in inlet air humidity have slight effect on the dehumidification rate and pressure drop. An axial ratio of 0.5 strikes the optimal balance between high dehumidification performance (10.2 %) and low flow resistance (4.04 Pa). Moreover, an elongated flow channel for humid air by increasing the fiber spacing (SL/d) significantly boosts the mass transfer with minimal fluid resistance increase. These findings provide valuable insights for the design of elliptical hollow fiber modules, highlighting the potential to greatly enhance the effectiveness of membrane-based dehumidification systems.

To evaluate the impact of fluid resistance on the performance of tubular indirect evaporative coolers (TIECs), a mathematical model of secondary air channel resistance was developed. An experimental setup was created to study the effects of factors such as secondary air flow rate and water spray flow rate on R2 under actual conditions. The model used the same conditions to analyze how factors like air flow, water flow, and droplet size influenced R2. The relationship between R2 and wet-bulb effectiveness (epsilon wb) was also examined experimentally. The data from the experiments were compared to the model's predictions, showing a maximum relative error of 10 %, confirming the model's accuracy. It was found that R2 and secondary air flow rate (V2) are positively correlated, and epsilon wb increases with R2. The experiments yielded secondary air resistances ranging from a minimum of 548.2 Pa to a maximum of 554.26 Pa. These results are valuable for selecting appropriate fans for the secondary air channel. Additionally, simulations were conducted to predict and calculate energy losses in the secondary air channel under real working conditions, providing a useful basis for future fan selection.

Article Heating Performance and Energy Efficiency Analysis of Air-Source Heat Pumps in Public Buildings Across Different Climate Zonings Junbao Fan 1, Yilin Liu 1,*, Jing Ma 2, Ying Cao 1,2, Zhibin Zhang 1, Xin Cui 1 and Liwen Jin 1,* 1 School of Human Settlements and Civil Engineering, Xi’an Jiaotong University, No. 28 Xianning West Road, Xi’an 710049, China 2 China Architecture Design and Research Group, Beijing 100044, China * Correspondence: ylliu@xjtu.edu.cn (Y.L.); lwjin@xjtu.edu.cn (L.J.) Received: 11 July 2024; Revised: 3 September 2024; Accepted: 5 September 2024; Published: 20 September 2024 Abstract: Public buildings exhibit the highest operational energy consumption and contribute the most to carbon emissions compared to other types of building. The electrification of energy terminals in public buildings is crucial for the energy conservation and emission reduction, especially the energy-saving retrofitting of heating systems. Given the significant impact of climate on the performance of air-source heat pumps, this study explored the performance and energy efficiency of air-source heat pump systems in public buildings across different climate zonings. Using Design Builder software, the physical models of three types of public buildings (commercial, hotel, and office) were constructed, and the annual variations in the building load was analyzed. Considering the effects of defrosting and low-temperature conditions, an air-source heat pump heating system models were developed using TRNSYS software. The simulation results showed that the average COP of the heat pump system on the coldest day in Harbin, Beijing, and Shanghai were 1.7, 2.46 and 2.49, respectively. Moreover, the analysis factor correlation analysis reveals that the COP of the heat pump system is positively correlated with the dry-bulb temperature, negatively correlated with the building load. Surprisingly, the COP is not affected by the types of public buildings. The findings of this study are expected to provide valuable guidance for the application and regulation of air-source heat pumps in the public buildings.

The countercurrent hollow fiber membrane-based evaporative water cooler (MEWC) offers an eco-friendly and compact solution for cold water generation. This study introduces a random sequential addition algorithm to model the real-world irregular fiber filling within the MEWC. Inspired by the honeycomb structure, the developed 3-D numerical model adopts a calculation unit featuring a hexagonal prism comprising multiple fibers. Validation against experimental data reveals an average relative error of 2.81 % concerning outlet water temperature. The effects of fiber filling patterns (regular layout and random layout) on the velocity and temperature fields of the MEWC are investigated. Comparisons of outlet water temperature, cooling efficiency, consumptive electric power ratio, and heat and mass transfer resistance composition between these layouts under various operating conditions are conducted. The results indicate that the random layout fosters severe channeling effect and large flow dead zones, impairing air side heat and moisture transfer. The random layout exhibits over 15.9 % reduction in cooling efficiency and 36.3 % decrease in consumptive electric power ratio compared to the regular layout. Irregular fiber filling leads to a notable 158.6 % increase in air side heat transfer resistance and a 35.9 % rise in mass transfer resistance. Although irregular filling compromises the cooling performance, it demonstrates potential for energy savings under certain conditions. Design schemes should be carefully tailored to meet specific application requirements by considering these trade-offs.

Modern digital developments have propelled data center (DC) to prominence, with the cooling requirement being an important driver of its energy consumption. This study explores the climate application potential of indirect evaporative cooling (IEC) technology, which utilizes water evaporation for cooling. The IEC technology is considered as a promising avenue for energy-efficient DC cooling system. This study reveals essential insights for optimizing DC cooling performance by analyzing different IEC operation modes, including dry mode, wet mode, and cascading hybrid mode. The selection of operation mode is closely related to climatic conditions, DC working conditions, and IEC cooling efficiency. Higher DC supply air temperatures extend dry mode cooling hours and decrease cascading hybrid mode hours. It enhances energy savings through better utilization of natural free cooling resources. Elevating IEC cooling efficiency expands dry mode cooling hours while reducing reliance on mechanical cooling, contributing to improved power usage effectiveness (PUE) and energy conservation. The analysis is based on a typical data center and considers representative cities in different climate zones of China, emphasizing the importance of reducing the PUE and energy consumption of the DC by adjusting the DC supply air temperature and improving the IEC cooling efficiency. This work provides a useful reference for customizing DC cooling strategies according to various climate differences, optimizing energy efficiency and promoting sustainable development.