Under complex operating conditions, the stability of the air flow of the cross-flow duct directly influences the operational efficiency of wall-mounted air conditioners and the comfort for users. To investigate these influences, the flow field under different inlet resistance conditions were analyzed using numerical simulations. It was found that excessive resistance leads to eccentric vortex disturbances in the cross-flow duct, resulting in periodic backflow and fluctuating noise. Based on the mechanism, a gradually varying volute tongue was employed. In addition, the optimal radius and length of the volute tongue were determined experimentally, which finally enhances the fluid resistance performance of the duct of cross flow fan.

The trend towards miniaturization and high efficiency of compressors, along with the industry’s requirement for a 10-year design lifespan, has placed higher demands on the reliability of bearing systems. Focuses on the study of wear at the root of the main and auxiliary shafts of a crankshaft in a jet-integrated single-cylinder compressor. By combining theory with simulation, the key loads causing wear at the crankshaft root are identified. Further simulation analysis is conducted on aspects such as the machining quality of bearing system components and critical structural dimensions to determine the impact trend of bearing system lubrication. An optimization plan is proposed and validated through experiments, effectively solving the wear problem at the root of the main and auxiliary shafts of the crankshaft. The consistency between simulation and experimental results confirms the reliability of the simulation outcomes. The analysis method of the impact of component machining quality on shaft system lubrication and the optimization design approach can provide a reference for subsequent compressor reliability design.

People’s demands for a higher quality of life are increasing in the post-epidemic age, and they are becoming increasingly conscious of the comfort of indoor air. The health and comfort features of household air conditioners have gained significant attention in recent times, making them popular choices for air conditioning. Conventional air conditioners frequently have a mechanical air supply, cool directly with cold air rushing in, a heating head is hot while the feet are cold, and poor human comfort. The double-walled multi-spout air deflector is a new type of air guide plate that this paper proposes. It is designed using the multi-jet nozzle jet principle and diffuser principle as its foundation. To optimize the splash type interference soft wind deflector, different air guide plate porosity, soft air ring porosity, air outlet shape, and soft air ring spacing were used in the organization of the airflow numerical simulation using Fluent software. Through a comparative analysis of wind speed distribution, end face air volume, turbulence intensity, and other parameters, the best air comfort soft wind ring guide plate program was evaluated. Finally, the air comfort test was conducted to confirm the soft wind effect of the soft wind ring guide plate. According to the findings, the splash type interference soft wind deflector can effectively reduce wind speed in the area of human activity, realizing the effect of soft wind, and enhancing user experience. It can also lessen the sense of blowing while maintaining the air conditioner’s cold volume and wind volume without affecting the air conditioner’s normal cooling and heating of the air supply range.

With the integration of artificial intelligence (AI) and the Internet of Things (IoT), smart home voice interaction is evolving from functional command execution to demand understanding and proactive service. Intent Understanding is the core of this service , and its evaluation system is crucial for measuring voice assistant performance and user experience. Reviews the current status of evaluation for intent understanding in smart home voice interaction, systematically summarizing its technical evolution, datasets, and metric systems. Addressing existing limitations, it identifies three major challenges: difficulty in quantifying intelligence, insufficient coverage of complex interactions, and lack of corpus standardization. Further envisions a human-centered evaluation framework guided by user experience and emotional intelligence. Also puts forward three construction paths: standardizing data and scripts , unifying metrics and reporting protocols , and validating transferability between simulation and real-world scenarios, providing a reference for achieving human-centric intelligence evaluation.

An analysis of the reasons for speed vibration in the low-speed range of a single-cylinder compressor system in a variable-frequency air conditioning system, caused by the non-constant load during the compressor’s operating cycle, is conducted. Based on the estimation of the motor rotor position, an effective method for automatically estimating the current load condition is proposed. According to the estimated load, automatic torque current feedforward compensation is performed. A simple load torque observer is designed using an output feedback method. This observer is a simplified design of the traditional second-order Luenberger observer, featuring fast convergence and small phase delay, making it easy to implement on embedded platforms. Since the observer itself belongs to the category of adaptive control, the use of the load torque observer can avoid the frequent parameter tuning caused by open-loop compensation. Simulation and experimental verification show that this method can significantly reduce speed fluctuations at low speeds of the compressor, validating its effectiveness.

As a core heating tube in household appliances,the insulation performance of electric heating tubes directly impacts the overall safety and reliability of the oven. Based on industry standards such as JB/T 4088—2022,systematically analyzes the influence of key materials and manufacturing processes on the insulation performance of embedded oven heating tubes under high-temperature operating conditions. Through specific failure case studies,combined with elemental analysis and experimental validation,it is identified that the silicone oil sealing process leads to the generation of free carbon due to high-temperature decomposition,significantly degrading the insulation performance of magnesium oxide（MgO）powder. The carbon content increased from 2.86% to 7.2%,resulting in a sharp decline in insulation resistance. The study further reveals the mechanism by which silicone oil infiltrates high-temperature zones due to negative pressure and uneven filling during the process. Improvement measures are proposed,including optimizing the sealing process and strictly controlling material purity and filling density. It is recommended to prioritize glass sealing in high-temperature applications to enhance long-term reliability. Provides practical guidance for the manufacturing and quality control of electric heating tubes,contributing to improved product safety and industry quality standards.

To mitigate the operational noise of range hoods, it introduces an active noise control (ANC) method using multi-channel data fusion. This approach fuses signals from multiple reference sensors into a single input, creating a computationally efficient Single-Input Multiple-Output (SIMO) control system. This method not only maintains noise reduction performance but also enhances robustness against hardware variations. Experimental results show that, compared to a conventional MIMO system, our proposed method achieves equivalent noise reduction at the listener’s position with a 75% decrease in computational load. The technology has been successfully validated in commercial range hoods, proving its practical value for engineering applications..

As a core influencing factor of air volume and noise for the indoor unit of duct air conditioners, the centrifugal fan is such that the former is a key indicator for measuring the performance of duct air conditioners, and the latter is directly related to the user experience. Taking a certain type of duct air conditioner as the research object, systematically explores the matching mechanism between the height of the centrifugal fan for duct air conditioners and the size of the air inlet under the condition of a fixed air inlet size through simulation and experimental verification of multiple groups of different fan height parameters, so as to extract the optimization rules for the fan height applicable to engineering design. The study shows that when simply aiming at maximizing the air volume, there is a theoretical optimal proportional relationship between the fan height and the air inlet size; however, when considering the noise control requirements simultaneously, it is necessary to suppress the generation of large-scale eddies in the casing through structural optimization, and at this time, the optimal matching parameters will be redefined based on the aerodynamic-noise coupling characteristics.

Home appliances have evolved from traditional home appliances to networked home appliances, Internet of Things home appliances, smart home appliances, and finally evolved into smart homes. The concept of smart home has emerged with the rapid development of information technology and economy. Smart home appliances integrate home equipment through advanced network communication technology, and realize resource sharing and remote control through a unified management platform. The communication technology of smart home appliances is also constantly developing, integrating with 5G and Wi-Fi 6 technologies to develop voice interaction and AI interaction. Although smart home appliances have developed significantly, they also face some challenges. There is still a lack of unified communication quality-related standards, which limits the user experience of smart home appliances.

An experimental research was conducted on the changes in energy efficiency grades of typical commercial refrigeration appliances under the GB 26920—2024 standard, and the maximum allowable values of energy consumption and the variation range of energy efficiency grades were analyzed. The results show that, the GB 26920—2024 standard significantly raises the energy-saving requirements for vertical display freezer, horizontal display freezer and stainless steel refrigerators. Compared with the current standard GB 26920.2—2015, the maximum allowable values of energy consumption of vertical display freezer and stainless steel refrigerators decreased by 24% to 35% under the GB 26920—2024 standard, and the energy efficiency grades dropped by 2 to 3 grades. The maximum allowable values of energy consumption of horizontal display freezer decreased by 16%, and the energy efficiency grade dropped by 1 to 2 grades. The requirements for commercial ice makers under the GB 26920—2024 standard are relatively moderate. Ice makers with R290 refrigerant system can reach the energy efficiency grade 1 and with R404A refrigerant system can reach the energy efficiency grades 2 to 3.

To address the noise issue caused by resonance excitation of the natural frequency in accumulator structures, investigates the influencing factors of natural frequency in accumulator structures. Based on single-degree-of-freedom system theoretical analysis, the natural frequency is primarily determined by the structural “stiffness” and “mass”. A finite element numerical simulation model was established with less than 5% error between theoretical calculations and experimental measurements. Characteristic dimension sensitivity analysis reveals that bracket feature dimensions primarily affect the upper natural frequency: increasing bracket thickness, width and height enhances bracket stiffness and raises the upper natural frequency, with sensitivity ranking: bracket thickness > bracket width > bracket height. Bend and cylinder wall thickness dimensions mainly influence the lower natural frequency: increasing bend wall thickness, reducing bend length and thinning cylinder wall thickness improve bend stiffness and reduce cylinder mass, thereby increasing the lower natural frequency, with sensitivity ranking: bend wall thickness > bend length > cylinder wall thickness. In a practical case study with largely finalized product structure, thickening the bend wall thickness—a minimal structural modification—effectively adjusted the natural frequency and resolved the accumulator noise issue.

After the Kigali Amendment was passed in 2016, 185 countries joined and officially came into effect. The bill requires Article 5 countries to freeze the baseline of HFCs from 2023 to 2025 and begin reducing HFCs from 2026. As R32 dominates the household air conditioning market, low GWP R290 and HFOs are the main choices for reducing HFC emissions. However, due to the harm of PFAS to the environment and human health, a global ban on PFAS is being pushed forward, including some HFOs refrigerants such as R1234yf/ze, R1233zd, etc. Therefore, to meet the dual demands of GWP and PFAS, R290 is currently one of the main choices for refrigerant substitution. R290 has natural advantages and disadvantages in the field of household air conditioning. Based on the physical differences between R290 and R32, proposes the main impact of R290 replacing R32 on the system and compressor, and designs a new R290 compressor for 1.5 HP AC under this guidance.

This study investigated the effects of temperature fluctuations on the quality deterioration of frozen salmon, aiming to provide theoretical guidance for the optimization of household refrigeration temperature control systems. Salmon samples were stored under constant temperature and fluctuating temperature conditions for 0—40 days, and changes in sensory quality, color parameters (L*, a*, b*), total volatile basic nitrogen (TVB-N), total viable counts (TVC), and texture properties were systematically evaluated. Results revealed that temperature fluctuations significantly accelerated quality degradation. After 40 days, sensory scores of the fluctuating group decreased to approximately 14, with markedly higher L*, a*, and b* values, indicating pronounced surface drying and browning. TVB-N and TVC increased to 1.3-fold and 1.32-fold those of the constant group, respectively, reflecting severe tissue damage and enhanced microbial activity. Hardness and chewiness decreased by 49.5% and 51.9%, significantly exceeding reductions observed in the constant group. Mechanistic analysis suggested that repeated freeze-thaw cycles induced by temperature fluctuations promoted ice crystal recrystallization, protein denaturation, and lipid oxidation, leading to structural destruction and flavor deterioration. These findings underscore the importance of stable low-temperature control in frozen storage and provide scientific support for advancements in refrigeration technologies and cold-chain management.

An optimized defrosting control method based on the principle of hot gas defrosting is proposed to address the issues of reduced heating efficiency and operational stability caused by frost formation in heat pump air conditioners under low-temperature, high-humidity conditions. Compared to existing shutdown defrosting technologies, the hot gas defrosting technique significantly reduces system energy consumption and enhances indoor comfort by maintaining the four-way valve in a fixed position and optimizing the opening of the electronic expansion valve. Analyzed the effects of indoor fan airflow, outdoor fan speed, and compressor frequency on defrosting performance through psychrometric chart analysis and experimental validation. The results indicate that reducing the indoor fan speed can extend the defrosting duration by 14% to 40% and increase the outdoor unit coil temperature by 0.7 ℃; when the outdoor ambient temperature is above 0 ℃, activating the outdoor fan can utilize atmospheric heat sources to assist in defrosting; reducing the compressor frequency is more beneficial for defrosting performance, but indoor heating comfort should be considered when adjusting the above control parameters.

In view of the high exhaust temperature characteristic of the R32 rotary compressor, a multi-point heat flow/temperature synchronous measurement and energy conservation cross-verification method is adopted to solve the problems of difficult parameter measurement and insufficient verification in the traditional acquisition of heat transfer coefficients. This approach resolves the challenges of difficult parameter acquisition and insufficient validation in traditional heat transfer coefficient determination. High-precision sensors were installed on the compressor shell and accumulator surfaces to measure and validate heat flux/temperature distributions under typical operating conditions. The results indicate that: (1) The compressor shell temperature initially increases and then decreases from top to bottom, with the highest temperature observed at the motor outer wall. Under rated heating conditions, increased rotational speed and pressure differential lead to significantly higher temperatures and heat flux densities compared to Chinese national standard (CNS) conditions, though distribution trends remain consistent. (2) The accumulator temperature decreases progressively from top to bottom, while its heat flux density exhibits a “higher at both ends and lower in the middle” pattern . It mainly fills the gap of basic data on heat exchange of the R32 compressor housing, providing a basis for heat transfer modeling and heat dissipation design.

The connection between the compressor housing and the stator is achieved through thermal interference fit, with the resulting clamping force and deformation directly influencing the reliability and performance of the compressor. Therefore, a comprehensive study of these factors is essential. This research employs ANSYS simulation software for analysis and validates the accuracy of the simulation model. It investigates the effects of interference fit amount and temperature variation on the housing-stator clamping force and associated deformations under various loading conditions. The results indicate that the interference fit amount exhibits a linear relationship with both the clamping force and the deformation. In contrast, temperature shows a linear relationship with clamping force but a nonlinear relationship with deformation. Thus, the influence of temperature should be considered in the design of compressor interference fits. Provides both theoretical and practical guidance for the design of interference fits between aluminum compressor housings and stators.

At present, air-cooled refrigerators have a relatively large market share, but their refrigeration evaporators rely on electric heating for defrosting, which has problems such as high power consumption, high freezing temperature rise, and poor preservation. Therefore, new heat pump defrosting systems for single system and dual system frost free refrigerators were proposed separately. The heat pump converts less electricity into increased defrosting heat. Through system simulation theory analysis and whole machine experimental research, it was finally verified through experiments that the heat pump defrosting scheme has significant advantages over electric heating defrosting. Among them, the energy consumption of refrigerator heat pump defrosting can be improved by more than 80%, and the temperature rise in the freezing room can be reduced by more than 50%. The heat pump defrosting solution provides a new technological route for the energy efficiency upgrade of future refrigerators and the research and development of ultra efficient refrigerators.

As the construction industry undergoes digital transformation and smart home environments continue to evolve, the demand for automated layout solutions for home appliances and furniture has grown significantly. Introduces an interior layout optimization method that integrates prior knowledge with Particle Swarm Optimization (PSO) to enable efficient and intelligent spatial arrangement. Initially, major furniture and appliance objects are grouped based on spatial semantic rules, allowing a rule-driven system to generate a reasonable initial placement. A multi-objective cost function is then formulated, incorporating both object-to-object relationships and spatial constraints derived from floor plan structures. PSO is applied to iteratively optimize the layout across the entire space. By leveraging structural layout information and predefined item groupings, the method enhances both the accuracy of the initial arrangement and the convergence speed of the optimization process. The approach balances individual object placement with overall spatial harmony. Experimental results show that the generated layouts are both practical and esthetically comparable to manually designed configurations. This work exemplifies the application of artificial intelligence algorithms in the optimization of furniture and appliance layouts, and holds strong potential for deployment in smart home design systems.

With the increasingly sophisticated application of artificial intelligence technology in household appliances, smart appliances are evolving rapidly. This is especially true for products equipped with reasoning large models, which are characterized by swift changes, complex varieties, and diverse functionalities. Given the unpredictable inputs and outputs, traditional single, one-time testing methods are inadequate for scientifically evaluating the intelligence capabilities of smart appliances. This poses new and more challenging issues for the testing industry. An in-depth exploration from the three dimensions of standards and regulations, testing methods and tools, and testing personnel is conducted. Solutions such as highly adaptable testing methods, rapidly responsive intelligent testing tools, and versatile testing professionals are proposed, providing new directions and insights for the development of the smart appliance testing industry in the face of applied cross-cutting technologies.

Addressing the discrepancies between the requirements for components in household appliance whole-product standards and the specific standards for components themselves, aims to systematically analyze these differences and provide clear compliance guidance for home appliance manufacturers. Using a comparative analysis approach, the research first outlines the requirements for key components in the latest whole-product standards, such as GB/T 4706.1—2024, and highlights the concerns of relevant stakeholders in the industry chain. It also summarizes the updates and revisions of current standards for major components. Subsequently, an in-depth comparative analysis was conducted to examine the alignment between whole-product standards and component standards in terms of specific requirements, categorizing them into two types: “covered by certification standards” and “not covered by certification standards.” Finds that for most component products, their standards can adequately cover the requirements of whole-product standards. However, for certain components such as switches and relays, there are unresolved differences in key indicators like durability testing and test conditions, necessitating supplementary tests. Provides a theoretical foundation and practical guidance for enhancing standardization and compliance within the home appliance industry chain.

Addressing the defect of conventional methods in capturing dynamic friction coefficient variations during drawer sliding processes, a dynamic analysis framework for dry-friction drawer systems was established by integrating finite element numerical simulation with a modified dry friction model. Systematic experimental comparisons validate the accuracy of the method in predicting dynamic behaviors. Results show that a significant negative correlation between friction coefficient and contact pressure, revealing the non-constant nature of friction. High consistency in dynamic response trends and key amplitudes between simulations and experiments, confirming method reliability and precision. The proposed “FEM coupled with modified dry friction model” approach effectively captures nonlinear friction-structure coupling during sliding, significantly enhances push-pull force prediction capability, and provides a theoretical tool for design optimization, user experience improvement, and lifespan prediction of drawer systems.

With the wide application of rooftop in the North American market, the thermal failure of inverter controllers under high power consumption is becoming increasingly prominent, which seriously affects the stability and reliability of equipment operation. Based on the characteristics of the heat dissipation structure of rooftop, the theoretical analysis model of the heat distribution and thermal characteristics of the whole machine is established, the radiator and heat dissipation air duct of the whole machine are designed, and the temperature of the heating components is calculated by thermal simulation, and the test results verify the accuracy of the theoretical model and simulation analysis, which provides theoretical basis and engineering guidance for the design of rooftop heat dissipation system.

Indoor formaldehyde pollution poses a serious threat to health, urgently requiring efficient control. Air conditioning systems integrated with formaldehyde removal functions, leveraging their advantages of wide coverage and high frequency of use, serve as an ideal platform for the synergistic regulation of temperature, humidity, and air purification. This paper systematically reviews the sources and long-term release characteristics of indoor formaldehyde. The principles, effectiveness, and limitations of mainstream formaldehyde removal technologies integrated into air conditioners were critically examined. Moreover, the constraints on actual performance imposed by dynamic environmental parameters, complex pollution sources, system compatibility, and user requirements were analyzed. Finally, the key direction of aldehyde removal technology upgrading is prospected, which provides guidance for the research and development of the next generation of efficient and intelligent purification solutions.

With the development of artificial intelligence technology, the water heater industry has shifted from single-product research to home intelligent hot water systems, significantly enhancing water usage comfort. However, the lack of technical standards and incomplete evaluation methods have failed to meet users’ real needs and enable lateral comparisons between systems. Based on household water usage scenarios and typical water consumption patterns, proposes multiple hot water comfort technical indicators, including water temperature rise during outages, hot water temperature rise, water temperature fluctuations, hot water delivery time, and hot water volume, through literature and standards research as well as user needs analysis. It is recommended to use a weighted comprehensive scoring method to evaluate these indicators. Experimental testing and user behavior analysis verified that the evaluation system can scientifically assess the performance of different systems. Research finding provide scientific theoretical support and technical guidance for research institutions, engineering and technical personnel, and testing and evaluation agencies, promoting development of the standardization process of the industry.

A theoretical calculation method is proposed for calculating the radial force on the joint surface of interference fit for balance blocks with non-uniform thickness, based on the thick-walled cylinder theory. The effectiveness of this theoretical calculation method is demonstrated by comparison with finite element simulation results. Subsequently, the theoretical calculation method and simulation are used to explore the influence of key design parameters such as amount of interference, coupling length, coupling diameter, and thickness of the containment component on the radial force of the joint surface of the balance block, which is a containment component with non-uniform thickness. The results show that the radial force is positively correlated with the interference amount and the length of the bond, the negative correlation is nonlinear with the diameter of the bond, and the thickness of the inclusion is positively correlated. On the basis of this theoretical calculation method, a calculation tool is developed to greatly improve the computational efficiency.

Addressing the transmitted sound issue induced by four-bladed fans in top-discharge type air conditioner outdoor units, employs a combined approach of experimental testing and numerical simulation to systematically reveal the underlying vibro-acoustic coupling mechanism. Research demonstrates that system resonance originates from the coupling effect between the aerodynamic loads of the rotating fan and the structural natural frequencies. Based on this vibro-acoustic coupling mechanism analysis, a comprehensive noise reduction solution is proposed: suppressing resonant deformation modes of the fan blades through blade reinforcement, and dissipating vibrational energy using an arch-shaped bracket structure. Experimental validation confirms that the optimized design achieves a reduction exceeding 20 dB(A) in transmitted sound peak levels and a flow rate increase exceeding 1% across all fan speed settings. This study provides a novel engineering solution for flow-induced vibration and noise control in rotating machinery.

In view of the increasing demand for real-time monitoring of the closed state of the smart refrigerator door, and the traditional door magnetic or mechanical switch has some problems, such as complex assembly, easy failure of low-temperature condensation and high cost, etc., a door ajar detection method based on refrigerator operation big data is proposed. This method does not need to add new hardware, but uses a big data platform to build an off-line abnormal database with compressor status bit, evaporator temperature, refrigeration temperature, freezing room temperature, defrosting cycle and other related multi-source operation data as inputs, which provides a low-cost and landing detection solution for intelligent operation and maintenance of refrigerators.

Different thawing temperature differences affect the thawing quality of frozen meat, thus impacting food safety. The effects of four thawing temperature differences on volatile base nitrogen and microbial indexes of frozen beef were studied, and an ideal thawing method was selected and optimized to help the common scenes of family cooking. Four thawing temperature difference groups were air thawing group, high temperature with low humidity thawing group, cold storage thawing group, and low temperature with high humidity thawing group. The air thawing group had the fastest thawing rate, the highest TVB-N value and total number of colonies. The thawing rate of the low temperature with high humidity thawing group was lower than that of the air thawing group, higher than that of the other two groups, exhibiting the lowest TVB-N value and total number of colonies. Optimization of the low temperature with high humidity thawing group resulted in a 35 min thawing time with the TVB-N value and the total number of colonies reaching 11.92 mg/100 g and 4.47 lg(CFU/g), respectively. This demonstrates that the optimized thawing scheme can significantly inhibit microbial contamination during beef thawing and storage, enhancing the edible quality and safety.

The quality of PCB routing and layout in household air conditioning systems is decisive for their anti-interference performance in complex electromagnetic environments. Existing design methodologies struggle to reliably predict immunity against Electrical Fast Transient/Burst (EFT/B) disturbances due to the intricacy of electromagnetic coupling paths. To address this challenge, a PCB layout optimization method based on critical parameter analysis and co-simulation is proposed. This research establishes a quantitative mapping model between EFT coupling paths and layout parameters, resolving the opaque nature of coupling mechanisms in traditional design approaches. A closed-loop workflow integrating co-simulation, parameter quantification, and design optimization is constructed using the ANSYS toolset, enabling comprehensive digital verification from root-cause fault identification to optimization effectiveness quantification. Ultimately, an engineering-ready design scheme centering on minimizing critical loop inductance and harmful coupling is developed. Experimental results demonstrate that this approach significantly enhances EFT immunity, reduces the average number of board revisions, and improves first-pass yield in compliance testing. This methodology facilitates the digital transformation of EMC quality management in the household appliance industry toward a proactive prevention paradigm.

The development trend of refrigerator towards thin foam layer and large volume has aggravated the problem of poor foam filling. It is an effective way to optimize the density distribution by regulating the foam flow with the diversion structure. However, it is difficult to directly observe the foaming process, resulting in the determination of the scheme relying on repeated tests, which is inefficient and costly. The simulation method can be used to design the scheme in the product design stage, improve the R&D efficiency and reduce the test cost. Firstly, a foaming simulation model of a box with upper and lower structure was built under the condition of diversion, and the error between the measured and simulated average density in each area of the box was less than 5%. Furthermore, the simulation and optimization of the diversion structure are carried out. Finally, through experimental verification, the foam density range of the optimized scheme was reduced by 10%, and the foam density uniformity was significantly improved.

Investigating the temperature distribution patterns and electrothermal conduction mechanisms of magnetic components during operation holds significant theoretical and practical value for optimizing device design and enhancing system reliability. Focus on the temperature rise of magnetic components in household variable-frequency air conditioning electric control systems. Based on the electrical characteristics of magnetic elements and their loss mechanisms, establish a multi-physics coupled simulation model integrating electrical, magnetic, loss, and thermal fields to systematically analyze the electrothermal coupling process from electrical parameters to temperature distribution. Furthermore, numerical simulations and analysis are conducted to examine the temperature rise characteristics and distribution patterns of PFC inductors. The results demonstrate that coupling the electrothermal process through component loss calculations can effectively predict the thermal behavior of magnetic devices, providing a reliable theoretical foundation and technical support for design optimization and addressing excessive temperature rise issues. This approach establishes a technical basis for board-level electrothermal co-design in thermal management, thereby reducing development costs.

With the rapid popularization and promotion of smart homes and smart cars, most users have felt the convenient experience brought by smart life and travel, and they often encounter the problem that smart homes and smart car cockpits cannot be interconnected, resulting in poor user experience. Aiming at the current problems of data islands, interaction fragmentation, and weak task collaboration “between smart home and smart cockpit systems, proposes a cross-domain agent interaction technology based on MCP protocol and large model. This technology takes the automotive smart cockpit (vehicle agent) and the smart home smart home brain screen (home agent) as the core interaction nodes, relies on the MCP protocol to realize cross-system device control and state synchronization, and combines the context understanding, task splitting and continuation capabilities of the large model to build a cross-domain interaction system of scene linkage-task collaboration-service customization”. Judging from the laboratory data, the cross-domain instruction response delay of this technology is≤500 ms, the task continuation success rate reaches 94.3%, and the user scenario demand satisfaction rate has increased to 96.5%, which is 3.8 times higher than the interaction between the traditional smart home and the smart cockpit two independent systems, significantly breaking the interaction barriers between smart homes and smart cockpits, and realizing the ultimate experience of users’ smart life+smart travel intelligent interaction and non-inductive collaboration.

The sound radiation area of the sheet metal part of the air conditioner outdoor unit is large, and the vibration damping and noise reduction design can effectively reduce the noise decibel value of the outdoor unit and improve the sound quality of the experience. The valve plate is in direct contact with the external compressor pipeline of the air conditioner, which is an important part on the vibration path. In order to explore the valve plate structure with vibration damping effect, the modal, response and acoustic radiation simulation iterative optimization design was carried out. The modal and response simulation results show that compared with the single-layer valve plate structure, the double-layer valve plate structure can effectively attenuate the vibration energy transmitted to the right plate, and the best vibration damping effect can be achieved when the second layer bulge height is 6 mm. At this time, the maximum acceleration response of the right plate in the 0~200 Hz range is reduced by about 20%. It is actually measured that the acceleration and vibration value of the right plate is reduced by about 12% after using the valve plate struct. The results of acoustic radiation simulation show that optimizing the valve plate structure can reduce the radiation noise of the right plate by about 16% in the 200 Hz~400 Hz range.

With the continuous improvement of energy efficiency standards for household air conditioners, the traditional fan cover has been difficult to meet the energy-saving requirements. To study the parameters of the circular fan cover blades used in the outdoor units of 10-horsepower high-volume air conditioners, fluid simulation and experimental verification were conducted on the three-dimensional modeling of the fan cover. The influence of the radial spacing and twist angle of the fan cover ribs on the ventilation volume of the fan cover was analyzed. The results show that the model optimization method based on CFX three-dimensional numerical simulation can effectively optimize the structural parameters of the fan cover. After optimization, the ventilation volume of the fan cover increased by 5.2% at the same fan speed, which is of great significance for reducing the flow loss in the air conditioner duct and improving the energy efficiency of the air conditioner.

With the rapid development of artificial intelligence technologies such as large models and intelligent agents, and the utilization of large model decision-making to control smart home appliance scenarios, smart homes are evolving towards “scenario-based” and “personalized” directions through multi-agent decision-making technology. However, there are currently major issues such as complex smart home scenario configurations, fragmented communication protocols between devices, and deviations in understanding user intentions. To address these issues, a joint decision-making technology based on the large model decision-making framework is proposed, utilizing “one-click group formation” for intelligent agents. Through three innovative modules: MCP dynamic group formation, vertical domain large model interaction, and group definition-driven decision-making, dynamic generation and adaptive regulation of smart home scenarios are achieved. Experiments show that this technology is superior to traditional solutions in terms of cross-protocol communication delay, scenario adaptability accuracy, and user configuration efficiency, providing new ideas for the intelligent upgrade of smart home scenarios.

Optimizing compressor noise design represents a critical technical challenge in refrigeration equipment development, as its acoustic performance directly impacts product competitiveness and user satisfaction. Compressor operation involves refrigerant flow pulsations, mechanical structural vibrations, and electromagnetic noise. These excitation sources transmit outward through structural components such as the compressor housing and mounting brackets, ultimately generating radiated noise. Addresses the generation process of mechanical vibration noise in compressors. Key components underwent geometric model simplification, and a finite element model of the entire compressor was constructed. Modal analysis identified the natural frequencies and vibration mode characteristics of critical structures. Vibration responses simulated using harmonic response analysis served as input, with simulated noise values generated through acoustic radiation simulation. Proposes an innovative finite element simulation method for compressor noise. Validation of different design schemes demonstrates the ability to reduce noise amplitude across various frequency bands. Specifically, applying a modified shape to the upper casing reduces overall noise by 2 dB.

Accurate control of indoor temperature and humidity is essential to enhance human comfort. Aiming at the problem that it is difficult to maintain the temperature and humidity of household inverter air conditioners, proposes a cooperative control strategy for temperature and humidity. On the basis of the original indoor temperature PID control compressor frequency, superimpose the PI control increment of indoor humidity and increase the weight of dehumidifi cation; the speed of the internal fan adopts incremental PID control and adaptively adjusts the control coeffi cients according to the indoor temperature diff erence to realize the stepless adjustment of speed to control the indoor temperature and humidity. By building the air conditioning sensible latent heat neural network model and room load model simulation verifi cation, and experimental testing on the whole machine. The results show that, compared with the traditional temperature control only strategy, this cooperative control method can eff ectively suppress humidity rebound while maintaining the set temperature accuracy, stably control the indoor humidity in the comfort zone (40%~60%), and signifi cantly improve the comfort regulation eff ect of the air conditioner.

With the rapid development of smart home technology and the increasing attention to sleep quality, the demand for intelligent features in air conditioners, as essential bedroom equipment, is gradually increasing. Focus on explore the application of 24G millimeter-wave radar technology in smart home sleep scenarios. By utilizing sensors, data analysis and optimization, and machine learning techniques, aim to achieve intelligent control of air conditioners, thereby enhancing users’ sleep quality and comfort while saving energy. Experimental tests have demonstrated that the application of 24G millimeter-wave radar in air conditioner sleep scenarios is feasible and worthy of further research and promotion.

To ensure the safe application of R32 refrigerant (an A2L mildly flammable refrigerant) in air conditioning systems, investigates ignition source testing for electrical components in response to the newly added flame-retardant enclosure verification test requirements in the GB/T 4706.32—2024 standard. By analyzing the opening size limits for relay contacts and similar components specified in the standard (equivalent diameter ≤ 2.8 mm), designed and constructed an integrated test platform comprising a gas-mixing system, a high-voltage ignition device (15 kV/30 mA), video monitoring, and pH detection. This platform establishes a complete testing process for combustible gas mixing, ignition, and flame propagation. Experimental optimizations included refrigerant uniformity control (adding a circulation fan) and safety pressure-relief devices (vent holes covered with packing film on the enclosure lid), which validated the feasibility of the alternative ignition test. provides operable technical solutions for air conditioning manufacturers and testing institutions to implement the standard, effectively mitigating the risk of R32 refrigerant ignition and explosion caused by electrical arcing in components.

With the acceleration of urbanization, high-rise housing has become the mainstream form of living, and the diffusion of kitchen soot particles poses a serious threat to indoor air quality and residents’ health. The physicochemical properties, diffusion mechanism and health risk assessment methods of cooking fume particles in high-rise residential kitchens are systematically reviewed, and the pollutant propagation law in the special environment of high-rise buildings is analyzed, and the optimization path and future trend of ventilation control technology are prospected. The results show that the thermal plume effect of soot particles (pm_2.5/ufps) is dominant, and the chimney effect aggravates the cross household transmission in high-rise residential buildings; The design of air supplement system and the optimization of smoke exhaust duct structure are the key to control pollutant concentration; In the future, it is necessary to integrate intelligent monitoring, green materials and interdisciplinary research to build a healthy and safe kitchen environment.

In response to the “dual carbon” goals, China’s energy system is accelerating its transition to a new power system. The Solar photovoltaic, Energy storage, Direct current and Flexibility (PSDF) system, as an integrated energy solution combining photovoltaic conversion, energy storage, direct current distribution, and intelligent control, enhances the capacity to absorb renewable energy while also facing the challenge of coordinating indoor thermal comfort and power regulation in buildings. Systematically reviews the key influencing factors (air temperature, humidity, wind speed, etc.), underlying mechanisms, and evaluation methods (PMV/PPD models, questionnaire surveys, software simulations, etc.) in traditional thermal comfort research. It finds that existing studies primarily focus on AC power environments and lack targeted analysis of PSDF dynamic scenarios. Further exploring the limitations of existing PMV/PPD models under steady-state assumptions, it is necessary to develop a transient thermal comfort index (TTCI) by incorporating dynamic parameters such as power supply fluctuation rate and temperature change rate (dT/dt). Research indicates that while PSDF systems can achieve efficient energy utilization through flexible load regulation, it is essential to establish a quantitative evaluation system that balances power usage strategies with human comfort levels. This will provide theoretical support for the engineering application and optimization of PSDF technologies.

In response to the concept of energy conservation, emission reduction, and recycling resources under the dual carbon goals, and to promote the shift of society and households towards more environmentally friendly and economical lifestyles, household refrigerator cryogenic and fast freezing technology has garnered widespread attention in recent years. This technology enables rapid freezing at lower temperatures, better preserves food nutrients, and reduces food loss and waste. Summarizes and organizes the principles, evaluation metrics, and implementation methods of cryogenic and fast freezing technology. It also analyzes the future development directions of this technology for household refrigerators, providing a reference for subsequent research.

As a core and critical process in air conditioner manufacturing, the refrigerant charging process is widely applied in the air conditioning industry. However, the absence of corresponding entity modeling in digital simulation has hindered the effective simulation of air conditioner production lines. Utilizes the Flexsim simulation platform to conduct secondary development for modeling process equipment, production lines, kinematic mechanisms, and task allocation logic, thereby realizing full production functionality. By integrating virtual reality (VR) display technology, a dedicated simulation platform for the charging process of air conditioner production lines was developed. An immersive virtual scene and digital twin model were established, with animations implemented through Flexsim coding. By embedding production processes into the simulation system, a novel simulation paradigm featuring "virtual experience combined with simulation calculation" was created to pre-evaluate whether production line capacity meets design standards. This research lays a foundation for accurately predicting production capacity and optimizing simulation results in practical production planning and line transformation, thus expanding the application scope of digital simulation technology in the air conditioning manufacturing sector.

In practical applications, the low - wind speed mode of air conditioners has significant advantages such as quiet operation, so it is favored by many users. However, this mode has the problem of low cooling efficiency. Moreover, when the air conditioner is operating in the low - wind speed mode, the internal unit rotates at a relatively low speed, the outlet air temperature is low, and the condensation situation is severe. To ensure that the condensation meets the standards, the operating frequency in the low - wind speed mode is usually reduced, which further leads to a deterioration in cooling capacity.Solving the problem of improving the cooling capacity of air conditioners in the low - wind speed mode aims to explore effective methods, provide valuable references for the technological improvement and product optimization of the air - conditioning industry, and achieve the goal of balancing condensation and improving cooling capacity. Through in - depth analysis of each key link of the air - conditioning refrigeration system and combining theoretical research with experimental verification, feasible methods for improving the cooling capacity of air conditioners in the low - wind speed mode are explored.The results of exploring a series of feasible methods to improve the cooling capacity of air conditioners in the low - wind speed mode can provide directions for the industry’s technological improvement and product optimization. It helps to improve the cooling capacity of air conditioners in the low - wind speed mode while balancing condensation, meeting users’ dual needs for low noise and high - efficiency cooling.

China government carried out and implements the rural “coal to electricity heating” policy, air-source heat pump has been applied universally with the advantage of low-temperature heating performance. By adopting the enhanced vapor injection technology, which can effectively improve the heating capacity and the compressor operation stability in low-temperature environment, it can fully meet the needs of low-temperature heating in cold regions. But the design should also consider the coupling control of enhanced vapor injection and electronic expansion valves, so that the system fluctuation is reduced after frosting, to realize the stability in low-temperature heating and improve the heating capacity. Based on the theoretical study and experimental verification on enhanced vapor injection technique, a series of progresses have been obtained in the performance improvement and control stability of the low-temperature heating, it achieves a set of application of enhanced vapor injection technique in air-source heat pump.

The performance of the suction and discharge processes in a refrigerator reciprocating compressor is largely determined by the movement pattern of the valve plate. Traditional analytical methods generally assume uniform flow at the suction port. However, during the suction process, the geometry of the suction valve plate results in varying instantaneous flow patterns at the valve port. Different flow patterns lead to significant differences in suction losses, thereby affecting compressor performance. By applying the fluid-structure interaction (FSI) model validated through experimental studies, the influence of the suction valve assembly structure on valve plate movement and fluid performance during the compressor’s suction process was investigated. The results demonstrate that optimizing the design of the suction port and valve plate shape can effectively increase suction volume, reduce flow losses, and minimize backflow caused by delayed closure. Performance test results show significant improvements compared to the original design. The two optimized suction structure schemes achieve high-frequency cooling capacity increases of 9.9% and 8.5%, respectively, and low-frequency COP improvements of 2.2% and 3.1% over the conventional solution.

Investigates the application of progressive compression technology in low-temperature air-source heat pump systems. The technical characteristics and optimal operating conditions of progressive compression are analyzed. Based on thermodynamic analysis of an intermediate injection system with an economizer, the compression design is calculated. Under specified working conditions, the optimal intermediate pressure and volumetric ratio (high-pressure cylinder volume to low-pressure cylinder volume) are determined, and the influence of isentropic efficiency on the design parameters is evaluated. Finally, system tests are conducted by controlling the auxiliary expansion valve opening to regulate the injection state. The impact of injection on system performance under different conditions is examined, verifying the trend of system performance with intermediate pressure variation. A comparative analysis of the performance improvement potential between progressive compression with intermediate injection and single-stage compression with intermediate injection under various conditions is presented, providing a reference for future compressor design and selection.

This paper studies the energy consumption of a 300L chest freezer with a bottom-mounted evaporator in accordance with the test method specified in EN 62552—2020, and analyzes the impact of defrost power of aluminum tube heater and defrost cycle on the overall energy consumption and defrost incremental energy consumption of the freezer. The results show that under the same conditions, when the total power of the aluminum tube heater is the same, the configuration with a power per unit length of 25 W/m reduces the overall energy consumption by 0.68%~1.02% compared with the configuration of 23 W/m. Under identical configurations, with the shortest defrost cycle fixed at 12 hours, the longest defrost cycles of 48 hours reduce overall unit energy consumption by 2.61%~2.95% compared to a 24 hours cycle. Meanwhile, the longest defrost cycles of 72 hours and 96 hours increase energy consumption by 0.11%~0.72% and 0.02%~0.57% respectively compared to a 48-hour cycle. When selecting the longest defrost cycle, the 48hours option offers the best cost-effectiveness.

There is a “breathing effect” in the refrigerating operation of refrigerator, and the air between the inside and outside of the refrigerator will exchange heat and mass with the “breathing effect”. By using CFD, the influence of external airflow changes on the heat exchange of defrosting drainage pipes was studied, and the impact of drain pipe position, air hole direction, etc. on the energy efficiency of frost-free refrigerator was verified through experiments. It has been proved that when the defrosting drain pipe is far from the condenser fan and the air holes are away from the airflow of the condenser fan, it is beneficial to the power consumption of the refrigerator. Compared with being close to the condenser fan and facing the airflow directly, the average annual power consumption can be reduced by approximately 3.10%.

Traditional heat pump air conditioners experience frequent frosting and defrosting in low-temperature environments, leading to a significant decline in continuous heating performance, which restricts the promotion and application of heat pump air conditioners. In response to these issues, conducts theoretical analysis and experimental verification on the impact of system parameters such as compressor frequency, electronic expansion valve opening, and exhaust temperature during low-temperature heating operation, as well as the changes in heat exchanger tube temperature on heating performance and frosting/defrosting conditions. The results show that improving low-temperature heating performance requires a comprehensive consideration of the effects of compressor operating frequency, electronic expansion valve opening, and heat exchanger tube temperature; it is possible to appropriately increase the evaporating pressure and temperature of the air conditioning system to weaken the impact of outdoor heat exchanger frosting and defrosting on low-temperature heating performance; during the operation phase before entering defrosting, it should be avoided to continuously reduce the opening of the electronic expansion valve, which would decrease the circulation flow of the air conditioning system and thus accelerate the rapid decline of the system’s low-temperature heating performance.

In certain harsh operating conditions,a significant amount of frost may be accumulated in frost-free refrigerators. Using conventional defrost control logic makes it difficult to completely remove the frost,which can cause the fan to stop and result in an increase in the refrigerator compartment temperature,thereby affecting cooling performance. To address this issue,based on conventional defrost logic and combined with experimental measured data,a fan defrost control method based on fuzzy logic and adaptive control is proposed. Fan operation parameters are collected and analyzed with this method and the a fan fault prediction model can be established. According to the prediction results,the conditions for entering and exiting defrost are adjusted dynamically,enabling intelligent management and maintenance of the fan. According to experimental,under high-temperature and high-humidity harsh conditions the refrigeration efficiency of refrigerators can be improved significantly compared with conventional defrost control methods. The defrost energy consumption of the tested samples are reduced by around 10%,and predicted product lifespan is extended by 30%.

In VRF air conditioning system, efficient heat dissipation directly determines the overall performance and compactness of the machine. Compared with traditional finned heat exchangers, refrigerant radiators are increasingly becoming the preferred choice for electronic control modules, especially IPM cooling solutions, due to their excellent heat dissipation efficiency, stable heat dissipation performance, and low sensitivity to environmental temperature changes. To accurately quantify its performance, conducted an in-depth analysis of a refrigerant radiator applied to practical products through a combination of theoretical modeling and experimental testing, measured the overall thermal resistance of the refrigerant during cooling, revealed the distribution of its internal thermal resistance through measurement. Based on this data, propose three optimization schemes, which provide reference technical paths for the design of next-generation high-power density and high reliability multi split products.

Human thermal comfort is influenced by various factors such as environmental temperature and humidity. Currently, most air conditioners on the market primarily focus on temperature control, with few systems capable of simultaneously controlling both temperature and humidity. To address this, analyzed the primary factors influencing human thermal comfort and the principles of air conditioner temperature and humidity control technology. Historical data from air conditioners operating in steady-state conditions were extracted, and a BP neural network model was used to establish the mapping relationship between indoor and outdoor temperature and humidity and compressor frequency and indoor fan speed. Enabled the selection of the optimal temperature and humidity control combination that ensures human thermal comfort while minimizing energy consumption, thereby enabling real-time control of target temperature and humidity levels. Experimental results show that, while maintaining the same level of human thermal comfort, simultaneous optimization control of indoor temperature and humidity can reduce air conditioner energy consumption by up to 12.3%. Provides guidance for the development of air conditioning systems based on big data for thermal comfort control.

Amid escalating market competition in the air conditioning industry, the optimization of tube-fin heat exchanger design, a critical component in mobile air conditioning systems, has emerged as a central area of research within the sector. Based on numerical simulations, introduces a novel design approach for condenser fins. Through systematic testing of individual heat exchangers and comprehensive validation using full-scale machine experiments, it is demonstrated that, compared to the original design, the implementation of the new fin configuration leads to a 3.5% to 4.2% reduction in the heat exchange capacity of individual components. However, the overall system performance degradation remains significantly lower than that of individual units, with the measured SACC decreasing by only 0.14% and CEER declining by approximately 1.2%. Additionally, the material cost of a single heat exchanger can be reduced by 8.4%. These findings offer the industry a strategic reference for achieving notable cost reductions through minimal performance trade-offs.

The reliability of electric heating was studied in accordance with the requirements of the UL 60335-2-40-2022 “Safety of Household and Similar Appliances Special Requirements for Heat Pumps, Air Conditioners and Dehumidifiers” standard for rooftop electromechanical heating exported to North America. Based on the characteristics of the roof electromechanical heating structure, the theoretical analysis model of electric heating heat transfer is established, the coupling relationship between the surface temperature and wind speed of the electric heating wire is obtained, and the wind field distribution is determined by simulation, and the test results verify the reliability of the theoretical model and simulation, which provides theoretical basis and engineering guidance for the installation design of roof electromechanical heating.

To address the issue of frequency oscillation in variable-speed air conditioners caused by elevated discharge temperatures under high ambient and high compression ratio conditions, a compressor frequency control framework is developed. The framework introduces a dynamic discharge temperature threshold and target frequency mapping based on risk levels, integrates rate limiting and anti-windup compensation in the speed regulation loop, and establishes a coordinated control and parameter tuning procedure that balances discharge temperature regulation with actuator rate and amplitude constraints. Experimental results show that, compared with conventional fixed-threshold logic, the proposed method reduces the frequency oscillation amplitude from±10 Hz to ±2 Hz ~±4 Hz, significantly shortens protection activation and recovery times, and mitigates fluctuations in airflow and room temperature while improving overall energy efficiency. Without any hardware modification, the proposed framework effectively enhances system stability and operational efficiency.

To solve the problems of reduced energy efficiency and “defrosting without frost” caused by the traditional timed defrosting strategy in air conditioners, a synergistic control strategy based on precise frost point judgment and active frost suppression with variable frequency is proposed. This strategy establishes a mapping of ambient temperature-humidity to frosting status, using the frost point temperature as the core criterion to accurately determine the timing for defrosting. Concurrently, it actively raises the evaporation temperature by dynamically adjusting the compressor frequency during different stages of frost development to suppress frost nucleation and retard frost layer growth. Experimental results show that this synergistic strategy can effectively extend the continuous heating period by 36% under the -7℃/RH70% condition, and significantly improve the comprehensive winter energy efficiency by 6.7% under the -12℃/RH65% condition. This research provides an effective technical solution for enhancing the heating comfort and energy-saving performance of heat pump air conditioners in cold and humid environments.

There is a growing concern among people regarding sleep, yet the sleep index of Chinese residents falls short of the standard. Traditional air conditioning systems have limitations in optimizing the sleep environment, highlighting the need to explore more effective thermal control strategies to enhance sleep quality. The current state of research on sleep thermal comfort and intelligent sleep systems is analyzed, considering factors such as air conditioning usage behavior, temperature, humidity, airflow, and regional variations. The results indicate that to create an ideal sleep environment, it is imperative to adjust indoor temperature and humidity according to varying outdoor temperatures and sleep cycles, while incorporating airflow organization control. Additionally, technologies like accelerometers, radar, and the Internet of Things can be leveraged for sleep monitoring and intelligent environmental regulation, ultimately enhancing sleep quality. This offers valuable insights for the design of sleep functions and scenarios in air conditioning systems.

To systematically evaluate the influence of key parameters of the multi-ion module in the floor-standing air conditioner on the negative ion release characteristics and particulate matter purification efficiency, conduct multi-dimensional optimization research on the structure, performance, hardware design, and user interaction of the emitter quantity, probe spacing, grounding method, and dual air duct structure. The results show that when the module is configured with 6 groups of negative ion emitters and each group of emitters is connected in parallel with 3 carbon brushes, the particulate matter removal rate reaches the highest; when the carbon brush spacing is controlled within the range of 15 mm to 20 mm, the negative ion number concentration reaches a peak; grounding the plastic shell through a wire can effectively suppress charge accumulation and increase the negative ion escape rate. Under the synergistic effect of the dual air duct flow field, the theoretical coverage area of the negative ion concentration is approximately 45 m². After testing by a third-party authoritative institution, the PM_2.5 removal rate of the multi-ion module within 2 hours is greater than 99%. The research results provide a quantitative basis for the engineering design of high-efficiency air purification air conditioners with negative ion modules.

In the control system of ultra-low temperature freezers, achieving precise temperature control is a key technology. To address this issue, it is proposed to use platinum resistance PT100 sensors as temperature measurement tools, ensuring high precision and reliability of temperature measurement. A PT100 temperature measurement circuit based on 1 mA constant current source control is designed to achieve precise temperature control. Based on the calibration table of the PT100 sensor, the temperature measurement circuit was simulated and analyzed using Cadence simulation software. The results verified the accuracy of the circuit and solved the problem of precise temperature control in ultra-low temperature freezers. Meanwhile, through simulation analysis, circuit performance can be evaluated in advance and circuit design can be optimized, which greatly reduces development costs and time.

With the increasing demand for energy conservation, environmental protection, comfort and health in society, the fixed operation mode of traditional air conditioning is no longer able to meet the personalized needs of users. Infrared human sensing technology provides an effective solution for the intelligent and energy-saving control of air conditioning by detecting the presence, location, movement, and quantity of indoor human bodies. Firstly, elaborates on the basic principles of infrared human sensing technology, and then studies the relationship between the installation position and detection range of infrared human sensing devices on air conditioners to determine the installation angle of infrared human sensing devices. Secondly, in order to verify the detection range and sensitivity of the human sensing device, an operation plan and detection plan for the infrared human sensing device were designed. Finally, through experimental verification, when the human sensing device is designed at a 40° angle between the middle position and the horizontal direction of the air conditioner, it can achieve effective range detection of 0.5 m to 5 m in front and back, and -50° to 50° left and right for people in different postures such as standing, sitting, and lying, ensuring the detection range and sensitivity of the air conditioner’s infrared human sensing.

For room air conditioners, the cooling capacity/heat output and performance coefficient are the core indicators, which directly affect the user’s comfort and electricity bill. Although the existing variable-frequency room air conditioners can automatically adjust the compressor frequency and the opening degree of the electronic expansion valve according to the fluctuations of indoor and outdoor conditions to improve their rationality compared to the fixed-frequency machines, due to the inability to change the refrigerant charge, the air conditioners operate inefficiently in most working conditions due to the mismatch of the charge. To solve this problem, a liquid storage module is added to the refrigeration system to achieve real-time adjustment of the charge by dynamically storing or releasing the refrigerant, thereby adding an adjustment dimension to the refrigeration system and forming a three-dimensional coordinated control mechanism with the compressor frequency and the opening degree of the electronic expansion valve. Under the precise control of the AI intelligent electronic control system, the three elements work together to optimize the operating state of the system and ultimately achieve the goal of improving the operating efficiency of the air conditioner.

Although there are already products on the market using R290, there is room to improve its annual performance factor(APF). Optimizes the heat exchange system of a 1.5-horsepower R32 household wall mounted air conditioner using R290 refrigerant as substitute to improve its energy efficiency through simulation and experimentation. Firstly, the optimal refrigerant filling amount was tested. The results showed that the system had the best performance when the filling amount was 300 g, with APF of the system reaching 4.812, and the filling amount met the maximum filling amount requirements of the specifications. Secondly, through testing, it was found that when replacing R32 with R290 refrigerant, there were two aspects that need special attention due to different characteristics of the refrigerants: (1) R290 refrigerant had higher requirements for the distribution effect of the distributor, and the problem of uneven distribution in the heat exchanger could be greatly improved by optimizing the distributors of internal and external unit; (2) R290 refrigerant was sensitive to pressure drop. By eliminating the subcooling section and replacing the connecting pipe, the system pressure drop could be effectively reduced. The APF of the prototype increased by 5.84% after optimization, reaching first level of the energy efficiency of national standard.

As an important heating equipment, researching energy-saving strategies for heat pump heating machines has significant practical significance. Propose a multi parameter correlation model based on supply water temperature, return water temperature, indoor and outdoor temperature, which avoids energy waste caused by continuous high water temperature operation by calculating the ideal return water temperature in real time. To verify the reliability and energy-saving effect of the model, experiments and field tests were conducted. The results show that this strategy can achieve dynamic adjustment of return water temperature, while ensuring comfort, the system energy saving rate is about 29%. Further field tests in Mohe City showed that under similar weather conditions and defrosting times, the average daily power consumption of the unit using this model was 45.74 kW·h, which was 19.36% lower than that of the conventional fixed water temperature (45 ℃) heating mode, and the energy-saving effect was significant. At the same time, the model effectively reduced the frequency of compressor start stop through dynamic adjustment (by 12.5%), and the indoor temperature remained stable at 26 ℃ after 24 hours of operation, achieving high efficiency and energy saving while ensuring thermal comfort, provides a reference for energy-saving optimization of heat pump heating systems in cold regions.

After 48 hours of continuous operation in a high-temperature and high-humidity environment, the air conditioner indoor unit generates a significant amount of condensation water inside the human sensing module, posing risks such as circuit board short circuits and even fire hazards. To address this issue, a moisture condition analysis was conducted for the indoor unit, and a moisture-proof method for the human sensing module was proposed. Firstly, fluid simulation analysis of the air duct structure was performed to determine the causes of condensation water and the locations prone to its formation. Subsequently, a moisture-proof method for the human sensing module was proposed, involving the optimization of the lens structure, the application of UV adhesive to improve sealing, and the addition of insulation cotton to reduce thermal conduction. Finally, validation was carried out through moisture condition testing. Results show that the proposed moisture-proof method effectively resolves the issue of condensation water formation inside the human sensing module.

The use of fluorinated refrigerants has intensified the global greenhouse effect. China has acceded to the Kigali Amendment and established a transition plan for new refrigerants. Most of the new environmentally friendly refrigerants are combustible, and research into their leakage and diffusion processes aids in advancing their wider application. Reviews the recent research developments on the leakage diffusion mechanisms and experiments of new environmentally friendly refrigerants like R32 and R290, both domestically and internationally. In response to the leakage processes and diffusion concentration distributions of flammable refrigerants, scholars and researchers have discussed theoretical models for refrigerant leakage and diffusion, corroborating these with experiments, and attaining numerous findings that unveil the leakage and diffusion mechanisms of flammable refrigerants. Offers a theoretical basis for the safe operation of household appliances, such as air conditioners and freezers, that utilize flammable refrigerants, and for the extensive promotion of these refrigerants. Also provides insights into the future directions of research on the leakage and diffusion of flammable refrigerants.

The flow field distribution characteristics of the refrigerator air duct system are the key factors affecting the refrigerator cooling efficiency and room temperature uniformity. In the past, air duct design mainly relied on CFD flow field simulation, which had inherent limitations, especially single-cycle air-cooled refrigerators, which were difficult to directly evaluate the rationality of room cooling allocation, and the whole room temperature field simulation faced many challenges due to the complexity of the model and the large amount of mesh. In order to accurately evaluate the air volume distribution, a single-system air-cooled refrigerator was taken as the object, and the CFD simulation results were compared with the test data to verify the quantitative relationship between the air volume distribution and the temperature field, which was verified to control the temperature simulation error of the refrigeration and freezer chamber within ±2 ℃. Based on this model, different air duct schemes can be evaluated and optimized in advance at the product design stage, reducing the dependence on physical prototypes, providing a standardized evaluation basis for the air duct design of air-cooled refrigerators, thereby shortening the development cycle and achieving better system energy efficiency matching.

A series of phosphate glasses containing antibacterial components were prepared by the melt-quenching method, and the effects of CaO content and temperature on the dissolution rate, structural characteristics, and antibacterial performance of the glasses were systematically investigated. The results showed that CaO content had a significant influence on the dissolution behavior: Ca²⁺, acting as a network modifier, enhanced the three-dimensional cross-linking degree of the glass, thereby reducing weight loss and extending service life; glasses with higher CaO content exhibited better stability against temperature variations. Antibacterial tests revealed that sample G-6 achieved the optimal balance between sustained ion release and antibacterial efficacy, with an inhibition rate of 99.9% against E. coli after 1 h of exposure, and a theoretical service life of approximately 2.5 years. Further studies indicated that an appropriate increase in ZnO whisker content allowed the maintenance of excellent antibacterial performance at a lower Ag₂O dosage, thereby improving material safety. XRD and EDS analyses confirmed that the glasses were amorphous, with Ag, Zn, and Cu antibacterial ions uniformly distributed within the glass matrix, enabling sustained release. The prepared phosphate antibacterial glasses demonstrate long-term controlled-release and efficient antibacterial properties, making them suitable for use in non-potable water systems such as washing machines, rotary floor scrubber, and humidifiers.

To address the issues of high computational cost and long cycle time associated with traditional Computational Fluid Dynamics (CFD) in simulating indoor airflow patterns, a dual-branch feed-forward neural network based on classification algorithms was constructed. This network enables the rapid prediction of indoor thermophysical fields and thermal comfort zoning under heating conditions. In view of the distinct physical characteristics of velocity fields and temperature fields, a differentiated classification strategy was proposed: a binary classification (mainstream / low-velocity) was adopted for velocity, while a ternary classification (overcool / comfortable / overheat) was employed for temperature. The research results demonstrate that the average prediction accuracy of the velocity field reaches 95.1%, which can accurately identify mainstream regions and exhibits excellent scale robustness. Meanwhile, the prediction accuracy of the temperature field exceeds 95%, enabling the precise reproduction of the spatial distribution of different temperature zones. Based on this, the prediction of the velocity field by the three-classification was studied. The results show that the cost-benefit ratio of the binary classification is the highest, which can not only meet the design requirements but also avoid the increase of computational costs. While ensuring prediction accuracy, the proposed model can achieve rapid prediction of thermophysical fields, thereby providing a basis for the optimization of air conditioning supply and energy-saving design.

In recent years, consumers have increased their demand for the health and safety performance of household appliances, especially in aspects such as sterilization, mite removal, and purification. However, existing research and standards mostly focus on enveloped viruses such as influenza and coronavirus, and do not cover non-enveloped viruses. As a non-enveloped virus, human papilloma virus (HPV) has a stable structure and strong tolerance. It may spread in the home environment through the surfaces of clothing, towels, sanitary equipment and other objects, bringing new challenges to residents ‘health. The risk of home transmission of HPV was systematically sorted out, the research progress on the virus-removing performance of household appliances was reviewed, the HPV pseudovirus model and its application in the evaluation of virus-removing performance of household appliances were mainly introduced, and the deficiencies of the existing standard system and the development trend of the industry were analyzed. It aims to provide reference for the research on health functions and improvement of the standard system in the home appliance industry, and promote the technical evaluation and industry attention of the HPV-removal function of home appliances.

Aiming at the problems of significant differences in user operation habits and insufficient energy-saving awareness in heat pump heating systems, it proposes a Model Predictive Control (MPC) strategy for heat pumps based on a data-driven hybrid model. By analyzing the operational data of 210 users in northern China, user behaviors were categorized into three types: non-adjusting, less-adjusting, and frequent-adjusting, revealing that 60% of users exhibit operational inertia or a lack of knowledge. On this basis, a hybrid model combining a 4R3C building thermal resistance-capacitance model with a BP neural network for heat output prediction was constructed. Parameters were identified using a genetic algorithm, and automatic optimal adjustment of water temperature was achieved through MPC. Experimental results show that this strategy can achieve energy savings of 6.5% to 15.7% while maintaining indoor comfort, verifying its effectiveness and feasibility in practical applications.

Human presence detection technology based on Channel State Information (CSI) is a typical application of next-generation communication technology, with broad application prospects. In real-world environments, there are often various Wi-Fi interferences, and differences in device hardware performance and environment can lead to variations in CSI data, thereby affecting the stability and reliability of CSI-based unmanned detection. Firstly, this paper analyzes various interference factors present in real-world environments and improves the stability of unmanned detection through adaptive threshold detection and subcarrier selection methods. Secondly, an electromagnetic environment evaluation method is designed to ensure the reliability of the system. Finally, the actual detection effect of the system is verified based on the ESP32 chip. This system has certain engineering practical significance in the field of home appliance intelligent perception.

With the widespread adoption of smart home appliances and the trend toward fully interconnected homes, users’ demands for seamless device interaction and enhanced after-sales customer service have significantly increased. However, traditional customer service models have long faced challenges such as insufficient intelligence and fragmented user experiences. To address these issues, proposes and reviews the innovative application of the CARE interaction model—integrating human-computer interaction and intelligent technology in smart home appliance customer service. The CARE model comprises four key dimensions: Comprehension, Agent, Rapport, and Ensemble UI, emphasizing deep understanding of user intent, autonomous agent capabilities, empathetic human-like interactions, and unified multimodal interface designs. Firstly, introduces the context and background of intelligent customer service within the home appliance industry, followed by the theoretical foundations and framework of the CARE model. It then elaborates on each design dimension with comparative analysis and summarizes typical application strategies and practical implications of the model in the industry. The research indicates that the CARE interaction model effectively enhances the humanization and intelligence of smart customer service. Furthermore, by integrating large-scale AI models and interdisciplinary design methodologies, the CARE model will play an increasingly pivotal role in shaping innovative customer service solutions within the home appliance sector.

Adding efficient clean for the filtration system in dishwashers during the washing process aims to reduce the trouble for users to disassemble and clean the filtration system. The self-cleaning technology for the filtration system is certainly the demand and expectation of consumers, and the corresponding implementation solution has become a pressing issue that needs to be addressed in the dishwasher industry at this stage. Based on the development of self-cleaning technology for the filtration system, here construct different designs of the cleaning ring component, then through the simulation analysis and comparison, the evaluations about advantages and disadvantages of different designs can be gotten and then the design can be optimized accordingly. Furthermore, it conducted comparative experimental tests to analyze and verify what the influence of different cleaning ring component designs for the cleaning performance of dishwasher is. Finally, the effectiveness of the optimization design is confirmed, leading to achieve the optimization and improvement of the self-cleaning technology for the filtration system.

after long-term grilling and cooking in the oven, the inner walls of the baking cavity often accumulate and settle a lot of grease and dirt, especially in the corners which are difficult to clean, becoming a pain point in the industry. Through the innovative design of high-temperature self-cleaning technology for the oven, the intelligent control program can rapidly heat the oven to an extremely high temperature of over 450℃ within 30 minutes, and then take about 90 minutes to incinerate or thematically crack the food residues, grease stains and other impurities inside. After cooling to room temperature, it only needs a simple wipe to shine like new and complete the cleaning. In view of the large amount of residual heat generated during the high-temperature cleaning process, an efficient thermal management system is needed to support temperature control under different modes, maintaining a dynamic balance between heat generation and heat dissipation, and avoiding excessive temperature rise under working conditions that could lead to the failure of control electronic components. This has become an urgent key technical problem to be solved. Through the analysis of the mechanism of the high-temperature self-cleaning function of the oven, a digital model of the temperature rise under the high-temperature self-cleaning condition of the oven was built. The key factors affecting the temperature rise and the technical parameters of the main components were carefully selected and optimized. Combined with CAE simulation analysis and experimental verification, the temperature rise in the space of the high-temperature self-cleaning box of the oven was reduced from 84.61 ℃ to 68.58 ℃. Ensure the safety and reliability of the electronic components of the control system and the entire machine, and effectively enhance the cleaning effect.

With the increasing popularity of wool fabrics, the problem of their complicated washing and care has gradually emerged. The wide application of household tumble dryers has provided a convenient solution for drying wool fabrics. However, consumers often find it difficult to accurately distinguish which dryers are truly suitable for wool fabrics and which ones may pose a risk of damaging the clothes. At present, the domestic standard system for the drying performance of wool fabrics is still not perfect. Only a few group standards are available for reference, and their testing methods mostly draw on the norms of the International Wool Secretariat (IWS). Therefore, select the testing method of the IWS for interpretation, aiming to provide clear R&D guidance for relevant manufacturing enterprises through in-depth analysis of this standard test method, assist in the development of wool-friendly dryers that better meet market demands, thereby enhancing user experience and promoting the overall development of the industry.

With the improvement of living standards, more and more users have purchased steam ovens that bring a lot of convenience and culinary pleasure. At the same time, while people are enjoying delicious food, steam oven also bring about some pain points such as the grilled meat becoming tough, burnt and the oil stains being hard to clean. To this end, by applying the optimization theory and building a digital technology model, the method of finding the optimal solution under given conditions is explored. The intelligent optimization control technology for steam ovens is innovated. Through precise algorithms, multiple factors such as temperature, humidity, and heating time during the cooking process are intelligently controlled for cooking verification and iterative optimization. Realize the iterative upgrade of cooking methods such as “dual control of temperature and humidity for fresh steaming, self-controlled maturity, and high-temperature self-cleaning of oil stains”, achieving the best cooking effect of deliciousness and texture. Effectively address the pain points of meat texture being tough and fat being difficult to clean for users, and enhance the level of user experience reputation.

Modern microwave ovens, in addition to basic microwave heating, integrate multiple cooking functions such as steaming, boiling, baking and air frying, aiming to provide users with a more convenient and diverse cooking experience. During the operation of a microwave system, the magnetron generates a large amount of heat by converting electrical energy into magnetic energy. In addition, the internal electronic components (such as amplifiers) consume electrical energy and convert it into thermal energy when working. Excessively high temperatures may lead to a decline in equipment performance or even damage. Therefore, effective heat dissipation is crucial for ensuring the normal operation of microwave equipment and has become one of the important demands in the industry. To this end, by leveraging artificial intelligence solutions, an innovative intelligent control dual-power enhanced heat dissipation technology was designed. The heat dissipation system was optimized from a single air duct to a dual air duct, and a digital model of microwave working condition temperature rise was established. CAE simulation calculations were carried out to continuously verify and optimize, achieving a dynamic balance among the energy input to the microwave oven, the food absorption capacity, and the heat dissipated from the residual heat, effectively improving the working condition temperature rise. The temperature has been reduced from the original 78.49 ℃ to 68.50 ℃, improving the quality of cooked food and increasing the cooking efficiency by 21.9%. This ensures that the temperature during the combined cooking operation of the microwave oven is controlled within a reasonable range, thereby extending its service life and ensuring usage safety.

With the intensification of global population aging, the demand for elderly healthcare is increasingly urgent. Traditional health monitoring systems rely on wearable devices or single-point sensors, facing issues such as low compliance, data isolation, and poor user experience. Proposes an AI-driven multi-agent healthcare system in smart home environments, utilizing smart appliances (e.g., refrigerators, mattresses, toilets) as behavior-sensing nodes to collect real-time behavioral data (e.g., usage frequency, pressure distribution, toileting patterns). The system employs the LangGraph framework for multi-agent task coordination, integrating modules for health monitoring, device control, and behavior understanding, while analyzing health trends through expert rules and machine learning. By leveraging the “appliance-as-sensor” concept and user-friendly notification mechanisms, this system significantly enhances elderly user experience and addresses accessibility and privacy concerns, offering a novel solution for integrating smart homes with elderly care.

With the rapid development and deep integration of Internet of Things (IoT), artificial intelligence (AI), big data, and cloud computing technologies, smart homes are transitioning from single-product intelligence to a new stage of whole-scene intelligence. As the core hub of the smart kitchen and a key node in family health management, the value of smart refrigerators has far surpassed traditional refrigeration and preservation functions. Their core competitiveness is increasingly focused on the intelligence level of food management capabilities. However, the isolated development of food recognition technology alone does not support the vision of smart refrigerators as the “family health management hub.” By systematically exploring the evolution of food management functions in smart refrigerators, this study analyzes the core development trends from technical, functional, and ecological dimensions, aiming to provide new directions and insights for the overall development of the smart refrigerator industry.

Full-spectrum technology has revolutionized food quality assessment through its non-destructive nature, high efficiency, and ability to analyze multiple components simultaneously. Firstly, elaborates on the basic principles and system characteristics of full-spectrum technology, then examines the limitations issue of traditional maturity determination methods, such as poor timeliness, sample destruction, and operational complexity. It focuses on discussing the application of full-spectrum technology in evaluating the maturity of food ingredients. The research further explores diverse integration pathways of full-spectrum technology with artificial intelligence algorithms and other detection technologies, while looking ahead to its industrialization prospects in intelligent food processing. Finally, identifies current challenges in technical application, including the complexity of data processing and high equipment costs, and proposes corresponding solutions and development directions.

Addresses the limitations of smart gas stoves that rely on temperature sensor to identify boiling states, as well as the uncontrollable cooking outcomes caused by gas pressure fluctuations during smart recipe applications. An intelligent control solution based on weighing sensor is proposed. By monitoring cookware mass changes in real-time, boiling states are precisely identified. A regression model correlating evaporation rate with burner power and gas pressure is established. For soup-boiling/braising scenarios, evaporation patterns are investigated separately. Dynamic adjustment of burner power based on evaporation rates achieves precise control over the final volume of broth in cooked dishes. Utilizing weighing sensor signal values to achieve intelligent boiling recognition and dynamic burner power adjustment for gas stoves, enabling smart and precise cooking while enhancing user experience.

With the improvement of living standards, household appliances have increasingly rich functions, and electromagnetic compatibility (EMC) has become a key design indicator. As a widely used household appliance, the electromagnetic compatibility performance of air conditioners directly affects their operational reliability and the degree of interference with other devices. Taking the electromagnetic interference (EMI) problem of the switching power supply of variable frequency air conditioners as the research core, analyzes its generation mechanism, and proposes optimization solutions. Research shows that the high-frequency switching devices in the switch power supply generate differential and common-mode noise during rapid switching, and the loop design of the power circuit, the leakage inductance of the transformer, and parasitic parameters are the main sources of interference. Through theoretical analysis and experimental verification, the following suppression measures are proposed: optimized design of the transformer, circuit improvement, shielding and layout optimization. In a case of a voice air conditioner with 600 kHz~700 kHz conducted interference exceeding standards, experiments found that the design defect of the transformer shielding layer was the main cause of interference. By optimizing the shielding structure, the peak noise was significantly reduced, verifying the effectiveness of the solution. The research results provide practical guidance for the EMC design of air conditioners and emphasize the importance of reducing interference from the source.

The issue of increased noise in refrigerators caused by compressor vibration. Through sweep frequency testing and modal analysis, the vibration characteristics of the compressor-refrigerator coupled system were investigated. The results indicate that the vibration of the compressor in three directions varies with rotational speed, which is closely related to the modal properties of the vibration isolation system composed of the compressor and rubber pads. Vibration amplitude increases significantly when excitation frequencies approach the system’s modal frequencies. In the integrated refrigerator environment, the modal frequencies of the vibration isolation system decrease to varying degrees due to the stiffness of the chassis, leading to a corresponding reduction in resonance speeds. The study demonstrates that effective noise control requires comprehensive consideration of the combined stiffness of the rubber pads and the chassis. Optimizing the parameters of the rubber pads can effectively suppress vibration and prevent excessive noise. These findings provide valuable guidance for the matching design of variable-frequency compressors and refrigerator systems.

To enhance the vibration and noise suppression performance of centrifugal fan systems, proposes a method based on optimizing the damping characteristics of rubber vibration isolators. By establishing a single-degree-of-freedom nonlinear viscoelastic model (on the Optistruct software platform), the effectiveness of using BUSH elements to simulate rubber materials is validated: when the damping coefficient increases from 0.2 to 0.5, the resonance amplitude decreases by 58.9%, revealing a strongly nonlinear energy dissipation mechanism. A coupled dynamic model of the fan-isolation system is further constructed, revealing that damping has a minimal impact (frequency response peak variation <1%) at frequencies below 100 Hz (impeller modes), while it significantly attenuates vibration transmission at frequencies above 100 Hz (volute modes), with a 16.3% reduction in peak amplitude observed at 203 Hz. Based on these findings, the experimental phase focuses on increasing the material loss factor while maintaining the isolator hardness (Shore A 50). The results demonstrate that the polyurethane rubber solution (loss factor 0.45) performs optimally, achieving a 2.2 dB(A) reduction in sound power level, a 14 dB(A) decrease in the 200 Hz noise peak, and reductions of 75% and 69% in vibration acceleration peak and RMS values, respectively. This study confirms that the strategy of “increasing damping while maintaining the same hardness” can effectively suppress high-frequency structural noise, offering a new approach for NVH (Noise, Vibration, and Harshness) design in household appliances and vehicles.

With the popularity of household air conditioners, their operating noise has increasingly attracted consumers’ attention. The noise from household air conditioners poses certain hazards to human health, quality of life, and the social environment, including sleep disturbance, hearing damage, psychological effects, and neighborhood disputes. At present, the main air conditioning noise reduction technologies are researched from four aspects: mechanical vibration control, aerodynamic noise optimization, structural improvement, and intelligent control. Research indicates that the future development of air conditioning noise reduction technology will be towards lightweight materials, intelligent adaptive control, and multi-physical field collaborative optimization, aiming to achieve lower noise emissions and higher energy efficiency. Provides theoretical basis and practical guidance for low-noise design of air conditioning products and rational use by users

For a specific outdoor unit model experiencing abnormal noise at the 6th harmonic frequency during heating operation, subjective evaluation indicated failure. Through quasi-steady-state compressor frequency sweep testing, along with modal and modal strain energy analysis of the compressor piping system, it was determined that the 6th harmonic exceedance was caused by structural resonance of the liquid receiver. An optimized solution involving reinforcement of the liquid receiver welded bracket was proposed to enhance connection stiffness and natural frequency. Experimental testing demonstrated that the optimized solution achieved a 19 dB reduction in peak noise level at the 6th harmonic compared to the original design. The abnormal noise was eliminated, and subjective evaluation results were favorable.

In order to further reduce the working noise of the range hood and improve the user experience, based on the response surface optimization technology, through the parametric modeling of the impeller, three key parameters are determined as the key optimization objects according to the previous test data. taking the range hood’s working noise, anechoic chamber noise, maximum static pressure and stir-frying air volume as targets, multi-parameter and multi-objective test optimization is carried out. The analytical relationship between the parameters and the target is determined through 13 groups of test schemes, and the impeller parameters are given when the working noise, the noise of the anechoic chamber is the lowest, the maximum static pressure and the air volume of stir-frying are maximum. This method can find the global optimal solution of the problem in a given range.

To address the challenge of predicting the noise of range hoods, a research method combining experiments and simulations is proposed. Taking a top-suction range hood as the research object, three different combinations of air cabinets and impellers are selected for the study. Noise measurements under different operating conditions are carried out within the rotational speed range of 900 r/min~1600 r/min to collect noise data. The analysis reveals that the air volume Q, power P, and operating noise L_w satisfy a multivariate logarithmic function relationship, and the final relational expression L_w=k₁+k₂·lg(P^k3·Q^k4) is proposed.

The noise of air conditioning products, as the most direct experience for consumers, directly affects their choices. Among them, sound power level can better measure the comprehensive sound impact of air conditioners on the surrounding space during operation and has been studied. Research on the sound power level of split air conditioners is conducted based on both theoretical analysis of test methods and experimental testing. The research results show that the measurement of sound power level is limited by the surrounding sound field and available instruments, and the appropriate test method should be selected based on the type, installation position, and specific dimensions of the air conditioner under test; the sound power level is positively correlated with the rotational speed of the indoor and outdoor fans, but has no obvious linear relationship with the compressor frequency. The research results aim to provide test methods for the sound power level of split air conditioners and provide data support for the dynamic relationship between the sound power level and various influencing factors.

To reduce aerodynamic noise during the operation of centrifugal fans and improve the flow adaptability and acoustic performance of the volute structure, proposes a three-dimensional curved surface volute structure based on non-uniform NURBS parametric modeling. Using a traditional volute as a reference, CFD and FW-H acoustic analogy methods are employed to conduct integrated numerical simulations of the flow field and acoustic field. The results show that the curved volute structure, by creating a “high in the middle, low on both sides” tangential flow channel, significantly improves the flow path from the impeller outlet to the volute tongue region, making the main flow more stable, reducing flow separation, and decreasing the peak turbulent kinetic energy by over 30%. Based on this, the pressure distribution on the volute wall becomes more uniform, the amplitude of unsteady fluctuations decreases, and the sound source intensity is significantly reduced. Spectral analysis shows that the sound pressure amplitude in the main frequency band below 1000 Hz decreases by approximately 4.2 dB(A), with an average reduction in total sound pressure of 3.6 dB(A), demonstrating excellent broadband noise reduction capabilities. The research results validate the comprehensive advantages of the curved volute structure in terms of aerodynamic and acoustic performance, providing theoretical basis and structural design methods for the development of high-efficiency, low-noise centrifugal fans.

To address the issue of indoor unit operating noise affecting user comfort, structural optimization was employed to reduce surging noise at the air outlet. Based on an extreme dimensional analysis of the fan and base housing assembly, it was discovered that the gap between the rear fan surface and the left end of the base housing was too large, which could easily lead to surging noise at the air outlet. The following structural optimization schemes were proposed: firstly, applying adhesive to the left air duct end surface of the base housing, and secondly, adding ribs to the right end surface of the base housing. Experimental results show that this scheme allows the rear fan surface to exceed the interior left end surface of the base housing air duct, creating a more uniform airflow channel on the left side and effectively reducing surging noise at the air outlet.

A 90° phase-shifted quadrature detection method addresses zero-crossing detection limitations in single-phase AC motor thyristor speed control systems. Conventional zero-crossing triggering suffers from grid disturbance sensitivity in optocouplers, motor inductance-induced phase lag degrading power factor, and high costs of improved alternatives. The solution generates a precise 90° phase-shifted reference signal using DSP-based grid frequency tracking, replacing direct zero-crossing detection. This approach suppresses harmonic interference and compensates load current phase lag automatically. Experimental results demonstrate stable triggering accuracy during voltage fluctuations, with enhanced noise immunity and lower cost versus conventional methods. The reliable technique proves valuable for appliance motor control applications like AC fans.

There is limited research on the impact of return duct diameters on the performance of air conditioning systems. To investigate the patterns of their influence on performance and summarize design methods, simulation and experimental studies were conducted using return ducts with diameters of φ15.88 mm and φ12.7 mm, thereby obtaining the patterns of how duct diameters affect performance under both cooling and heating conditions. The verification results indicate that using a smaller duct diameter of φ12.7 mm results in a pressure drop approximately 4300 to 4600 Pa greater than that of φ15.88 mm. Due to the different specific volumes of suction under cooling and heating conditions, changes in duct diameter have minimal impact on cooling performance but significantly affect heating performance, reducing capacity by 2%. This verification reveals the key patterns of how return duct diameters affect air conditioning systems, providing important insights for optimizing the selection of return ducts and enhancing system performance.

To enhance the flame array performance of gas water heaters, the numerical simulation method was used to simulate the internal flow field and concentration field within the flame array. The influence of flame array orifice depth was investigated. The analysis indicates that increasing the orifice depth effectively resolves the issue of airflow deflection at the flame ports, alters the magnitude and uniformity of airflow velocity at the orifice outlets, yet has minimal impact on the uniformity of methane concentration at the flame port exits. This provides valuable reference for the design of flame arrays in gas water heaters.

In terms of theory, the contact between the microchannel flat tube and the water tank is surface contact, the traditional copper tube outer-coil contact area with the out wall of the tank is line contact, it is obvious that the contact area of the microchannel is larger, which is beneficial to the heat exchange between the water and the water tank, and also enhances the energy efficiency. At present, in the market of heat pump water heaters, it is concluded that most manufacturers are using microchannel enamel outer-coil water tank, and most are high energy-efficient products, only a few manufacturers are using copper outer-coil water tank. By testing and comparing the copper tube outer-coil water tank and the microchannel enamel outer-coil water tank, it is concluded that the microchannel enamel outer-coil water tank is better than the copper tube outer-coil water tank in terms of energy efficiency and heating capacity, and reduces a certain amount of refrigerant charge. It helps to improve the heating capacity and the energy efficiency, so that finally improve the production of hot water effectively.

Through comparative experimental research on the performance of three flow path schemes of 5 mm copper tube double-row condensers, namely five-in-five-out, six-in-six-out, and eight-in-eight-out, in the air conditioner as a whole, the results show that the six-in-six-out flow path scheme of the 5 mm copper tube double-row condenser has the best performance in terms of capacity and energy efficiency when operating in a wide temperature range of outdoor ambient temperature from 35 ℃ to 60 ℃. The high pressure of the entire system is the lowest, the difference between high and low pressure is the smallest, and the operation reliability of the entire system is the best. The variance of the outlet temperature of each flow path of the condenser under different working conditions is the smallest, and the flow is the most uniform. Therefore, this scheme is the best flow path among the three flow path schemes. Through comparative experiments and tests with the prototype solution, it was found that the 5 mm copper tube double-row condenser solution can completely replace the 7 mm copper tube double-row condenser solution of the prototype. At the same time, this solution can be extended to multiple models for product development and use, which can reduce the overall machine cost by about 6% and decrease the refrigerant usage of the entire machine by up to 26%. While ensuring product quality, It can also achieve cost reduction and carbon emission reduction, contributing to the country’s dual carbon strategic goals.

As one of the core components of the air conditioning system, the expansion valve is used to regulate the refrigerant flow rate, reduce the refrigerant pressure, and meet the requirements of the air conditioning system when the load changes. However, traditional thermal expansion valves have problems such as low adjustment accuracy and poor adaptability. In order to overcome these shortcomings, electronic expansion valves have emerged. However, electronic expansion valves also have their own shortcomings. For example, under high pressure differential conditions of refrigeration and heating, the electronic expansion valve may experience out of step problems, which not only affects the performance and energy efficiency of the unit, but may even lead to excessive system pressure and damage to the compressor. To solve this problem, experimental analysis was conducted and corresponding optimization measures were proposed. The results indicate that under high pressure differential conditions, the forward flow of refrigerant is beneficial for improving the control accuracy of electronic expansion valves; Strengthening the stiffness of the electronic expansion valve spring can improve the response speed and flow control accuracy of the valve, and reduce the probability of valve out of step. This study has certain reference value for solving the problem of electronic expansion valve out of step in air conditioning systems.

The unique upward airflow field of the top outlet outdoor unit of the air conditioner adds diversity to the installation scenarios of the air conditioner. The design of the top cover grille of the external unit must meet the strength requirements such as falling, trampling, and random vibration during transportation, while also considering the air volume during operation and ensuring lean manufacturing and cost control. The top out style grille is formed by sheet metal stamping, where the number of grilles determines the blade angle and blade strength. In order to improve the strength of the grille, reduce the risk of tearing at the root of the grille, and minimize the overall airflow, simulations and measurements were conducted to investigate the effects of different numbers of grilles on airflow and structural strength. Increasing the diameter of the inner circle of the grille by 20 mm and reducing the number of grilles by 5 can reduce stress by 1/2 and increase air volume by an average of 3.5%.

A comprehensive study was conducted using numerical simulation techniques on a specific model of air conditioner outdoor unit, addressing the issue of smart power module (IPM) pin cracking observed during random vibration testing, and corresponding optimization solutions were proposed.Employing Finite Element Method (FEM), a refined simulation model encompassing key components such as the electronic control box, PCB, IPM module, and heat sink was established. The failure phenomenon was accurately reproduced, and its underlying mechanism was elucidated through modal analysis, random vibration response analysis, and harmonic response analysis. Based on root cause analysis, a structural optimization scheme was proposed. Simulation validation demonstrated that the stress level at the pin crack location of the IPM module was significantly reduced. Ultimately, the optimized design passed the physical prototype’s random vibration test in a single attempt, effectively eliminating the potential product quality risk.

There is a significant temperature difference between the display temperature and the actual outlet temperature in instant electric water tap, which directly affects user experience and safety. To address this issue, this study focuses on the internal structure of the faucet and investigates the influence of different flow channel structures and temperature measurement point layouts on the temperature deviation through numerical simulation methods. The improvement effects of various schemes on temperature response speed, stability, and measurement accuracy are evaluated, aiming to reduce the temperature difference through optimized design. The results show that optimizing the flow channel to reduce flow dead zones, improving heat exchange efficiency, and precisely configuring the temperature sensor position can effectively reduce system thermal inertia and significantly minimize the deviation between the display and outlet temperatures. Based on the above, the optimal solution obtained in this study achieves a significant improvement in display accuracy while controlling cost and size, providing a practical basis for the precise temperature control and structural design of instant electric water tap.

The top-outlet wind air conditioner outdoor unit electric control box as the research object, and conducts verification on its thermal and waterproof performance. During the repeated trial and error process of the original electric control structure, the paper analyzes and summarizes the disadvantages of the original electric control design in terms of heat dissipation and waterproofing. By conducting a retrospective analysis based on the overall electric control layout, a new electric control scheme is proposed, and the revised scheme is retested. The scheme has successfully solved the original thermal and waterproof problems of the top-outlet wind air conditioner, and the revised scheme has certain referencevalue for the subsequent design of top-outlet wind type products.

Taking the drop test of a certain range hood as an example, analyzes the specific causes of outer panel deformation during the drop process. In the drop test of this range hood, obvious deformation of the outer shell occurred. Due to cost constraints, the materials of the outer shell and packaging could no longer be upgraded; thus, the only way to improve structural stiffness and prevent deformation was to modify the ribbing design of the outer shell. In traditional optimization design, the ribbing design mainly relies on the design experience of structural engineers, who modify the structure through simulation analysis and prototype verification. For the areas requiring ribbing, the topography optimization analysis method was adopted to simplify the drop simulation process. With the goal of maximizing the stiffness of the sheet metal, the ribbing design was automatically optimized and iterated, finally obtaining a structure that meets the performance requirements. This method has lower requirements for engineers’ experience. By automatically adjusting the mesh in the finite element model, the optimal design scheme is found. Compared with the traditional optimization method, this case reduces the number of simulation designs, shortens the calculation cycle, saves the corresponding prototyping costs, and has high promotion value.

Facing the global transition to green and low-carbon practices alongside environmental packaging regulations, the traditional foam cushioning packaging in the air conditioning industry is increasingly revealing issues related to resource consumption, recycling, and pollution. To adhere to green packaging principles and focus on packaging solutions for high-end cabinet air conditioners, a comprehensive application of material performance testing and simulation technology has been achieved, realizing the dual goals of enhancing foam cushioning performance and achieving green, lightweight materials. First, the key mechanical and energy absorption properties of expanded polystyrene (EPS) were systematically investigated, and its stress-strain constitutive model was established. Subsequently, a comprehensive simulation model encompassing the complete unit, foam cushioning structure, and corrugated carton was developed based on complex logistics scenarios. The model’s accuracy was validated through experiments, and evaluation criteria for drop simulation were established. The results demonstrate strong consistency between the drop/clamp simulation outcomes and experimental data, with simulations effectively identifying potential weak points in advance and enabling structural optimization during the design phase. Furthermore, material reduction was implemented in non-load-bearing paths. The optimized foam structure achieved a 27 g reduction in material usage while maintaining transportation performance, alongside a 35% improvement in clamping energy absorption and an 8% increase in drop impact energy absorption. This approach significantly reduces carbon emissions and minimizes mold modification cycles. So validating the critical role of simulation technology in green cushioning packaging design and providing a feasible pathway for innovative packaging upgrades in the air conditioning industry.

Global regulations restrict the use of halogenated flame retardants due to their harmful gas emissions upon combustion. This review categorizes four types of halogen-free flame retardants: phosphorus-based, silicon-based, inorganic hydroxides, and intumescent systems. AHP demonstrates high flame retardancy but faces migration and toxicity issues; DOPO derivatives synergize with APP to enhance epoxy resin performance, though chlorinated phosphates exhibit neurotoxicity. SiO2@DPP and POSS are applied to polycarbonate and epoxy resins respectively, requiring combination with other flame retardants. ATH and MH blends reduce additive requirements but impair mechanical properties; APP synergistic systems improve the oxygen index of unsaturated polyester. DNA offers flame retardancy but relies on phosphorus-containing components with environmental risks. In the home appliance industry, halogen-free flame retardants are widely used in critical components like circuit boards and external casings to meet safety and environmental standards. Future research focuses on nanocomposites, bio-based materials, and intelligent design to achieve efficient and eco-friendly flame retardancy goals.

At present,the transparent interior parts of refrigerators are mostly injection-molded with GPPS,and the cracking of these parts during transportation and use has become a major economic loss in the refrigerator industry. Focused on exploring the possibility of using PET material,which had better anti-cracking ability,to replace GPPS in the production of transparent interior parts for refrigerators. By comparing the key properties of PET and GPPS,the superior anti-cracking performance of PET was highlighted. Furthermore,the SWOT analysis matrix was used to demonstrate the potential opportunities and challenges of applying PET material in refrigerator transparent interior parts. Practical examples were provided to illustrate the issues and precautions to be aware of when designing and producing PET transparent interior parts for refrigerators. Finally,based on the market feedback of a certain refrigerator model that had switched to PET material,the quality improvement and economic benefits brought by using PET material were summarized.

To optimize the design of the ejector for the atmospheric burner of household gas stoves, a numerical simulation method was adopted to construct the burner flow field model. The influence laws of the throat diameter on the primary air coefficient, the average velocity of the fire outlet hole and the uniformity of mixing under different nozzle diameters were systematically studied. The results show that under different nozzle diameters, both the primary air coefficient and the average velocity of the fire outlet hole show a trend of increasing first and then decreasing with the increase of the throat diameter. For the outer ring burner, both reach the peak simultaneously when the throat diameter is 16.6 mm, and for the inner ring burner, both reach the peak synchronously when the throat diameter is 11 mm. The uniformity of gas mixing gradually improves along the flow direction of the ejector. For the outer ring burner, the standard deviation of CH₄ concentration at the outlet cross-section is the largest when the throat diameter is 16.6 mm, meaning the uniformity of mixing is the worst. For the inner ring burner, the standard deviation of CH₄ concentration at the outlet cross-section is the smallest when the throat diameter is 11 mm, meaning the mixing effect is the best. The research results can provide theoretical guidance for the optimization of ejector structure parameters.

The problem of abnormal forward opening of the check valve of gas water heater is studied. Through the analysis of dismantling parts, the components due to impurities jamming, material abnormalities and other factors, it is determined that the root cause of the problem is that the contact force between the valve stem and the rubber gasket is too large, resulting in excessive pushback resistance. Based on the theory of contact mechanics and frictional resistance, the two-dimensional axisymmetric finite element analysis method is used to simulate the existing check valve structure, and the situation of excessive contact force is clarified. Then, an optimization scheme for adjusting the cross-sectional shape of the rubber gasket is proposed, and the contact force and contact pressure are significantly reduced after optimization, which meets the design requirements. This scheme can effectively solve the problem of abnormal forward opening, and provides a reference for improving the performance of gas water heaters and reducing the failure rate of products.

Insufficient oil return in compressors can lead to reduced efficiency, increased noise, and even mechanical failures, posing a serious threat to system reliability and lifespan. Focus on the issue of insufficient oil return in compressors. It begins by thoroughly analyzing the oil return mechanism in refrigeration systems and the factors influencing compressor oil return. Based on this analysis, two improvement solutions are proposed using specific cases of insufficient oil return: optimizing refrigerant charge to improve oil temperature superheat, and adjusting startup frequency and operating platform time to establish a dynamic balance of oil circulation. Experimental validation confirms the feasibility and effectiveness of these solutions. Both approaches significantly enhance oil return performance, eliminating oil shortage periods—which previously lasted 150 seconds during cooling startup and 110 seconds during heating startup—and achieving continuous and stable oil return. However, each solution has its applicable scenarios, offering flexible choices for different engineering conditions. The research result provides a viable technical path and experimental basis for optimizing compressor oil return in refrigeration systems, offering practical reference value for improving equipment operational reliability and reducing maintenance costs.

With the deepening of the global “dual carbon” strategy, the material selection of household appliance components has become one of the key factors affecting the overall carbon footprint of products. Based on the significant low-carbon advantage of PP material over ABS, developed a modified PP material with excellent mechanical strength, heat resistance, and low molding warpage characteristics through the synergistic modification technology of glass fiber/talc powder. Its tensile strength, flexural strength, flexural modulus, and thermal deformation temperature are 47.5%, 35%, 100.5%, and 26.1% higher than heat-resistant ABS, respectively. By further combining the design of the snail shell structure with the regulation of the melt flow path, the warpage and deformation of the parts can be effectively improved. Reliability tests have confirmed that it can replace heat-resistant ABS for the snail shell of mobile air conditioning fans. Using this PP material to manufacture the snail shell can achieve a component weight reduction of about 4.3%, and reduce product costs and carbon footprint.

As a critical structural component in wall-mounted air conditioner indoor units, the base traditionally utilizes high-impact polystyrene (HIPS) for its exceptional material properties. With advancements in material technology, novel plastic alternatives have emerged. A modified HIPS material is investigated, synthesized by blending recycled polystyrene (PS) waste from air conditioner casings with virgin HIPS through crushing, sorting, and melt extrusion processes, achieving significant improvements in resource circularity. To validate its performance, specimen testing evaluated strength fluctuations, while high-low temperature cycling tests assessed extreme environmental adaptability. Results indicate that the modified HIPS exhibits comparable or superior comprehensive properties to conventional materials, with minimal strength variations confirming stable performance. Post-cycling tests revealed no deformation or cracking, meeting stringent operational requirements. This innovation provides the home appliance industry with a high-performance material solution that synergizes resource efficiency and technical viability.

With the growing user base of washing machines, personalized home appliances are also increasing. To enhance space utilization and aesthetic appeal, designers innovatively installed clothing care devices in countertop form, meaning the washing machine is mounted on kitchen counters or in confined spaces. This design not only saves space but also integrates seamlessly with the kitchen or balcony environment, improving overall aesthetics. However, due to the limited installation space for clothing care devices, the requirements for displacement caused by eccentricity are higher. When the device experiences significant displacement due to eccentricity, it may collide with surrounding objects or even fall off the countertop, increasing operational safety risks. Therefore, anti-fall technology is proposed for small washing machines. By analyzing the relationship between acceleration squared data and displacement, the risk of machine movement is predicted in advance, achieving a detection rate of over 94%. This method is reliable and enhances user experience.

The progress of resonant microwave sensors is investigated aiming to explore their application potential in home appliances and industry, such as smart kitchen devices and environmental monitoring systems. Methods include summarizing developments in electromagnetic field regulation, surface functionalization, and design optimization, supported by simulations and experimental data. Results show that these sensors offer advantages like non-contact measurement and high sensitivity for appliance energy management and safety monitoring. The conclusion highlights that integration with AI and flexible designs will core promote smart homes and precision medicine, though standardization and cost issues remain.

addresses electromagnetic radiation from 5G communication, smart appliances, and wearable devices by studying asymmetric structured electromagnetic shielding composites to overcome the drawbacks of traditional metal-based shields. The characterization methods for EMI SE are outlined, and progress is systematically reviewed regarding multilayer, fiber, porous, and segregated structures. Results indicate that these materials achieve a synergistic “absorption-reflection-reabsorption” mechanism via their designed structures, enhancing shielding effectiveness while reducing secondary reflection pollution. Their advantages in lightness and flexibility make them highly applicable for electromagnetic protection in smart household appliances and wearable electronics. Future work should focus on interdisciplinary design, intelligent regulation, and green sustainability to overcome challenges like interfacial stability and scalable production for achieving high absorption, ultra-low reflection, and environmental friendliness.

This review systematically summarizes the development status, key manufacturing technologies, corrosion mechanisms, and application progress of all-aluminum heat exchangers in the field of household appliances. Comparative analysis shows that full aluminum substitution offers significant advantages in cost and environmental performance; however, long-term corrosion resistance and adaptability to complex operating conditions remain major technical bottlenecks. Future research is expected to focus on new corrosion-resistant aluminum alloys, green brazing technologies, anti-frost structures, and full life-cycle reliability evaluation, providing technical references for high-efficiency, energy-saving, and sustainable development in the home appliance industry.

Based on the national-level proficiency testing project, an in-depth analysis was conducted on the proficiency testing results of the 50 W horizontal flame test for non-metallic materials of electrical products. Through a systematic assessment of the participating laboratories’ performance in terms of test equipment, environmental conditions, and the understanding of the standard and practical operation skills of the test personnel, the overall capability level of the laboratories in this testing project and the main existing problems were revealed. The results show that most laboratories can complete the test in accordance with the requirements of GB/T 5169.16—2017 standard, while a few laboratories have deviations in key test links, ultimately affecting the consistency and comparability of the proficiency testing results.

The microbial contamination of the refrigerator freezer has a great impact on the health of users. In order to investigate the situation of salmonella contamination in commercial fresh eggs and the influence of cold storage on the contamination in refrigerator freezer, salmonella detection was carried out in commercial fresh eggs. The contaminated fresh eggs were put into the refrigerator freezer and a controlled experiment was designed to detect salmonella in the refrigerator freezer. The results showed that salmonella was present in the batch of fresh eggs, and the contaminated fresh eggs caused salmonella contamination in the refrigerator freezer. The main biochemical characteristics of Salmonella were analyzed. The research results a direction for the development and design of refrigerator, and provided reference for the application of antibacterial materials, sterilizing modules and related tools in refrigerator. At the same time, it also provides guidance for the daily use and maintenance of refrigerator in families.

In order to provide readers with a deeper understanding of “technical requirement and test method for low temperature washing performance of washing machines”, to introduce the definition of washing machines low temperature washing and the scope of application of this standard, expounds the technical requirements of washing performance, rinsing performance, abrasion performance and color protection performance and test methods of color protection performance, and emphatically analyzes the reasons and purposes of setting each index of low temperature washing. In addition, the background of RZB 044—2019 “technical specification for characteristic product certification technical requirements for washing machine cold water washing performance certification” is introduced, and the performance indicators of the two are compared. Compared with the ordinary washing machine washing performance standards, the technical indicators of evenness of washing, rate of rinse and rate of abrasion in this standard are more stringent, and the performance indicators of color rate are increased. Finally, the advantages of low temperature washing are demonstrated through experimental data from some sample machines, providing guidance for the future development direction of the washing machine industry.

The GB/T 4706 series of standards is currently in the transition period of version change. GB/T 4706.1—2024 Annex R introduces several major technical changes, primarily including a shift in the software evaluation framework from “Type A, B, C classification” to “Table R.1 / R.2 measures”, along with practical challenges arising from new process documentation requirements. Based on testing and certification practice, this study systematically analyses the main differences of Annex R between the new and old versions of the standard, clarifies its correspondence with GB/T 14536.1 Annex H, and distinguishes between the boundaries of safety responsibilities and the collaborative implementation pathways for complete appliances and components. In response to the common industry challenge of applicability determination, practical solutions and implementation paths are proposed—covering risk-oriented design processes, documentation system improvement, and simplified assessment methods—supported by typical case studies. Aims to provide practical guidance for household electrical appliance enterprises in adapting to the new standard requirements and to facilitate a smooth transition for the industry.

Systematically interprets the key contents of the group standard T/CAS 991.5—2025 “Specifications for Quality Grading of Home Building Materials Products, Part 5: Smart Cameras for Household and Similar Purposes.” It focuses on analyzing the technical requirements of the standard’s basic, key, and featured indicators, and clarifies its quality grading logic and evaluation methods. By summarizing the appendix testing content, including App operating experience, night vision capabilities, image clarity, and minimum illumination, it helps companies understand the standard’s implications and promotes product quality improvements in the smart camera industry.

An accurate measurement method based on thin wire thermocouple is proposed to solve the problem of lack of measurement method for freezing point temperature of test package in performance test of refrigeration appliances. By comparing the measurement results of platinum resistance and thermocouple, it is found that platinum resistance is easily disturbed by the environment because of its size, and the thin-wire thermocouple can significantly reduce the data deviation when it is arranged in the geometric center of the test package, which is more suitable for measuring the freezing point temperature. The method of determining the stable condition in the freezing process is clarified, and it is suggested that the stable condition of temperature fluctuation limit per unit time should be used to screen representative data, and the freezing point temperature should be obtained by calculating the average value. In addition, it is proposed to correct the measurement results based on the freezing point of pure water to eliminate the influence of equipment and environmental factors and ensure the comparability of cross-laboratory data. Experiments show that this method can effectively improve the accuracy of freezing point temperature of test packages, and provide technical support for standardization and reliability of refrigeration appliance testing.

Poor system sealing has two main impacts on air conditioning: firstly, air can enter the system through leakage points, leading to reduced cooling performance; secondly, refrigerant leaks can result in decreased cooling efficiency, reduced compressor lifespan, and even environmental pollution issues. Research on the sealing performance testing methods of air conditioning outdoor units, in accordance with the national standards related to the sealing requirements of refrigeration and air conditioning equipment. Various methods such as gas tightness tests, vacuum tests, and halogen leak detection are employed to effectively identify air conditioning units with poor seal integrity, thereby preventing them from entering the market.

Refrigerant leakage in an air conditioner will affect its cooling capacity or even cause it to fail to cool. Therefore, air conditioners must undergo refrigeration system leak testing before leaving the factory. Some air conditioning manufacturers select refrigerant as a tracer gas, charging it into the indoor unit evaporator for system leak detection. In air conditioners, the refrigerant pressure at the indoor unit evaporator is higher than atmospheric pressure. During installation, the refrigerant (including tracer gas in the indoor unit) is released into the air. This results in issues such as cost waste and increased carbon emissions. A study on leak detection in the indoor unit system of air conditioning refrigeration equipment was conducted by referencing relevant sealing standards. Through theoretical calculations and experimental testing, the minimum charge level required for effective system leak detection was determined, thereby achieving cost reduction and carbon emission reduction.

In the field of room air conditioner performance testing, the air enthalpy measurement device is one of the core equipments. Its measurement accuracy directly determines the reliability of the test results for air conditioner performance parameters. To ensure the accuracy and long-term stability of the air enthalpy measurement device, GB/T 7725—2022 Room Air Conditioners requires that a calibration test must be conducted at least every 6 months. Based on this requirement, a calibration test device was developed. Data verification and analysis were carried out on a set of air enthalpy measurement devices that have passed the inspection of authoritative institutions. It has been verified that when the temperature difference between the inlet air and outlet air is within the range of 6 ℃~15 ℃, the calibration test device can complete the calibration test accurately. When the temperature difference exceeds this range, the calibration result is unqualified.

Focusing on three 2024 editions of standards (GB/T 4706.1—2024, GB/T 4706.32—2024, and GB 4343.1—2024) as the basis for mandatory certification of air-conditioners, the core technical differences between the new and old standards regarding safety protection and electromagnetic compatibility requirements are systematically reviewed, with particular emphasis on distinguishing special provisions for non-flammable and A2L flammable refrigerant products. Clarifies the phased transition arrangements for certification updates and the implementation procedures enterprises must follow, covering key steps such as gap assessment, supplementary testing, and document updating. The analysis reveals that successfully addressing this standard transition requires tripartite collaboration among manufacturers, testing institutions, and certification bodies: manufacturers should establish compliance management systems and optimize testing strategies; testing institutions need to enhance capabilities and technical services; certification bodies should streamline processes and provide guidance. Collaboration among these three parties is crucial for ensuring a smooth industry transition and enhancing overall safety standards.

Recently, the World Health Organization has proposed for the first time in its vaccine refrigerator series standards the requirement for an Vaccine Cold Chain Equipment Monitoring System (EMS), with the aim of achieving standardization and interoperability of vaccine cold chain equipment data collection to support national EPI programs. The EMS monitoring system requirements proposed by WHO indicate that WHO’s control of the vaccine cold chain will adopt intelligent means towards data electronification, remote monitoring, and system integration. The WHO standards are not only applied in WHO projects, but also highly recognized in some countries and regions in Africa and Southeast Asia. They are one of the standards that are widely used in the export of vaccine refrigerators in China. This standard upgrade involves the upgrading of product hardware and software, which has a significant impact on enterprises. In order to facilitate relevant personnel to quickly familiarize themselves with and understand the standards, the WHO vaccine refrigerator EMS requirements were analyzed through literature analysis and standard interpretation methods. The WHO vaccine cold chain related standards and requirements required to achieve EMS requirements were sorted and summarized using comparative analysis methods. Examples were given to illustrate their verification methods, experimental equipment requirements, and issues to be noted in the experiments, providing reference for vaccine refrigerator enterprises to complete product development and pass verification smoothly. We also hope to provide reference for China to achieve full chain supervision of vaccine cold chain and improve the vaccine cold chain standard system for long-term development through the research of WHO vaccine cold chain series standards.

To study personalized demands for kitchen appliance replacements and upgrades, this paper propose an image-processing-based visualization system. By analyzing semantic information and structural features (e.g., line textures) from user-submitted kitchen images, the system identifies spatial relationships between key components (e.g., cabinets) and applies empirical kitchen layout principles to derive optimal appliance placement rules. Even with imprecise user input, it predicts ideal positions for target appliances (e.g., dishwashers, refrigerators, ovens) and simulates virtual installations. The results are visualized as augmented images, significantly enhancing the convenience and realism of DIY kitchen design.

Usage dimensions are designed across multiple scenarios, and quantitative and qualitative research methods are integrated. The Analytic Hierarchy Process (AHP) is applied to determine the weight of each indicator based on its importance, and the comprehensive score for efficacy evaluation is calculated. This serves as the basis for judging the core efficacy claims of household beauty devices, aiming to establish a systematic, scientific, and objective user experience evaluation system. It not only provides data support for household beauty care appliances enterprises to optimize product design and improve service quality, but also offers theoretical support for the subsequent development of efficacy evaluation standards, while helping consumers more accurately select products that meet their own needs.

Refrigerator odor is a key issue affecting user experience and food preservation. To address the inadequacy of traditional methods in real-world scenarios, aimed to empirically compare the actual efficacy, user experience, and safety of three deodorization technologies: compound bio-enzymes, activated carbon, and ozone generators. Seventy-five households were recruited and randomly assigned to three groups for a four-week field test. Data were collected via odor intensity scales, user satisfaction, and safety questionnaires. Results showed that the compound bio-enzyme group achieved an 81% reduction in odor score, the ozone generator group 72%, both significantly outperforming the activated carbon group (39%). The bio-enzyme group led comprehensively in satisfaction (4.5/5.0), perceived safety (4.8/5.0), and convenience (4.9/5.0). While the ozone generator was effective, it received lower ratings for safety and convenience (2.9/5.0). It is concluded that compound bio-enzymes offer a safe, efficient, and imperceptible solution for daily use, whereas ozone generators are more suitable for rapid emergency treatment, and activated carbon technology shows limited effectiveness. Provides direct user-experience-based evidence and selection criteria for optimizing deodorization functions in the home appliance industry.

Currently, high-end floor-standing air conditioners widely use acrylic for exterior panels. However, traditional solutions require an additional transparent backing plate for assembly, leading to high comprehensive costs in materials, molds, transportation, and labor. By eliminating the transparent backing plate and adopting an integrated assembly process, the manufacturing and transportation costs of exterior components can be significantly reduced. Through validation of acrylic dimensional changes under different temperature and humidity conditions, static suspension tests, various laser engraving techniques, and lamination protection processes, issues such as significant dimensional variations in storage and transportation, double-sided tape adhesion failure, uneven assembly gaps, and stress cracking during lamination—caused by the removal of the backing plate—have been resolved. This successfully achieves a stable first-pass yield rate of over 95% for high-end floor-standing air conditioners with acrylic panels assembled without a backing plate. This solution provides a new technical approach for high-end floor-standing air conditioner acrylic exteriors that is low-cost, highly reliable.

Under the “dual carbon” goals, systematically examines the current status, challenges, and countermeasures of low-carbon transformation in China’s home appliance industry. Industry data from 2024 shows that the main business revenue of home appliances reached 1.95 trillion yuan, with production rebounding but carbon emissions remaining a prominent issue. Corporate carbon emissions exhibit a divergent trend: for instance, Haier Smart Home reduced its emissions by 23.86% in 2023, while TCL and Midea saw increases exceeding 50%. The industry faces challenges such as reliance on energy structure, insufficient technological innovation, and weak supply chain collaboration. Both domestic and international experiences indicate the need for policy guidance and technological innovation to drive transformation. Domestic research primarily focuses on technological innovation, environmental regulations, and industrial chain collaboration. Recommendations include: strengthening R&D in energy-saving and emission-reduction technologies, optimizing the energy structure, and striving to achieve zero growth in manufacturing sector carbon emissions by 2030; improving the carbon trading market by expanding coverage and enhancing carbon price effectiveness; enhancing talent cultivation, promoting technological transformation, and industrial upgrading; expanding green foreign trade to elevate value chain status.

The study aims to address the complexity of program settings in current smart washing machines. Based on user experience, a simplified interaction model is constructed by analyzing questionnaire surveys and user behavior data to identify key factors affecting operational efficiency. Proposals include optimizing interface hierarchy, applying scenario-based recognition technology, and implementing multi-channel feedback mechanisms. Prototype testing verifies the optimization effects, showing a significant reduction in user operation time and a notable improvement in satisfaction. The research results provide theoretical support and practical guidance for human-computer interaction design in smart home appliances.

With the advancement of technology, there is an increasing demand for enhanced culinary experiences using advanced kitchen appliances. In Chinese cuisine, a single dish often includes multiple ingredients to achieve nutritional balance and rich flavors. However, simultaneously processing multiple ingredients while ensuring uniform heating is a significant challenge. Addressing this challenge by analyzing the impedance characteristics of various ingredients and proposes a principle for simultaneous multi-ingredient cooking using solid-state sources. The principle leverages the ability of solid-state sources to adjust heating power based on ingredient impedance, achieving precise heating control. A control program has been developed to guide the operation of a solid-state source microwave steam oven. Through comparative experiments, the results demonstrate that the solid-state radio frequency source microwave-steaming-baking integrated machine produced superior outcomes in the preparation of five multi-ingredient recipes, with internal temperatures consistently exceeding the required cooking temperature of 120%. This validates the superior performance of the solid-state radio frequency source microwave-steaming-baking integrated machine in simultaneous cooking of multiple ingredients and confirms the feasibility and effectiveness of the proposed principles and control logic.