Air Conditioning Technology Research Articles

Developing an integrated solid desiccant dehumidifier and dew-point evaporative cooler for green air conditioning

The advancement of eco-friendly air conditioning technology has garnered significant interest in light of energy shortages and concerns regarding global warming. However, current research endeavors have encountered obstacles in addressing issues like chemical erosion and energy-intensive processes. A promising solution to overcome these challenges involves integrating a solid desiccant coated heat exchanger-dehumidifier (SDHED) with a dew-point evaporative cooler (DPEC). This innovative approach eliminates the need for condensation dehumidification, reduces compressor workload, and eliminates the use of harmful refrigerants. This study marks a pioneering effort in experimentally assessing and analyzing the performance of an integrated SDHED and DPEC system. Parametric studies have been carried out under various ambient and application conditions, yielding impressive experimental results. The DPEC achieves a dew-point effectiveness of 0.9, a DPEC COP of 15.9, and an electric COP of the integrated system reaching an impressive 6.43. The dynamic characteristics of the integrated system have been scrutinized, unveiling the underlying mechanisms of its operation. Additionally, this study outlines development methodologies for the integrated green air conditioning system, encompassing material selection and prototype testing. The findings underscore the potential of the integrated SDHED and DPEC system to enhance indoor comfort and reduce energy consumption concurrently, making it a compelling choice for future environmentally responsible building designs.

Dynamic characteristics of a climate-adaptive radiant cooling and fresh air supply integrated system with zeotrope R290/R600a

Enhancing climate-adaptability stands as a pivotal focus in the advancement of air-conditioning technology. The nuanced control over thermodynamic properties of zeotropic mixture emerging as a critical factor in effectively accommodating variable loads. This paper proposes a radiant cooling and fresh air supply integrated system, featuring dynamic adapting to various operating conditions by composition adjustment with zeotropic mixture of R290/R600a. By synchronizing the cooling capacities of dual cooling sources with indoor thermal-humidity load, the climate-adaptive operation is accomplished by tuning the secondary fluid of the liquid separation component. A physics-based dynamic model is constructed on the liquid separation condenser in the sequence of control volume-pipeline-path based on finite volume approach. The numerical analysis indicates the spatial distribution of mass fraction and thermophysical properties of the zeotropic mixture over time. To facilitate intuitive analysis of the climate-adaptive operation, the enthalpy humidity ratio (ε) that the system can handle is developed for evaluating the applicable scenarios and operating conditions of the dual cooling source system. The results demonstrate that the liquid separation component exhibits a rapid response owing to its low thermal inertia, lagging less than 30 s to adapt to the airflow step from 0.45 to 0.4–0.5 kg/s over a total duration of 120 s. The enhancement of convective heat transfer and reduction in heat capacity both lead to a decrease in thermal inertia, thereby shortening the response time. Increasing the airflow rate shortens the response time to 60 % of its initial duration. R290/R600a at mass fraction ratio of 0.6/0.4 exhibits the highest sensitivity to airflow adjustment. The capacities of the dual cooling sources respectively fluctuate between −55 % and 62.5 %, and −84.6 % and −0.02 %, as a result of the mass flow rates of the refrigerant varying between −60 % and 120 %, and −85.2 % and −48.1 %, with the mass fraction of R290 ranging from −20 % to −10 %, and −11.8 % to −5.9 %. The system can provide fresh air of 19 ± 16 %℃ and 12 ± 23 %g/kg and chilled water supply for the radiant terminal of 15 ± 20 %℃. The system is capable of handling air-conditioned spaces with ε ranging from 1450 to 20000 kJ/kg by adjusting the airflow rate within a range of ± 12 %, and offering an adjustable dehumidification capacity ranging from 0.2 to 2.5 kg/h. The system constitutes a promising prospect of thermal-humidity decoupling technology that adapts to various climatic conditions and personalized need.

Energy Performance of a University Building for Different Air Conditioning (AC) Technologies: A Case Study

The study uses four AC technologies to assess the energy performance—this is a case study of an educational building in Barranquilla, Colombia. The building currently has split AC technology high-energy consumers. Therefore, it was necessary to assess a replacement with more efficient technology. Because of the non-seasonal climate in the building location, one month of monitoring of energy consumption was the reference for developing an energy model for the building using EnergyPlus and DesignBuilder software. The model was applied to forecast the building energy performance of our more efficient AC technologies available in the Colombian market, and valuable according to building specifications (Split, VRF, VAV, and Chiller). Results show a reduction in energy consumption of approximately 30% with the technology change and 15% savings in life cycle costs (LCCs), even though the building is already considered to have a low energy consumption according to national regulations. The findings of this study underscore the potential for widespread applicability across all types of buildings, regardless of their energy consumption profile, be it low, medium, or high. This extensive applicability not only highlights the adaptability and versatility of the technology but also underscores its significance in achieving substantial energy savings and cost reductions across the entire building industry, contributing to a more sustainable and economically efficient future.

Finding the gaps in design strategies and technological advancements for net-zero energy buildings development in India

The climate-adaptive net-zero energy building design is an effective trend for achieving a carbon-neutral environment and reducing global energy demand, especially, in India where building energy consumption recorded substantial growth in the past decade. This review article focuses on the development of net-zero energy buildings in tropical climates through the analysis of 44 real case studies. This study investigates the building envelope parameters, advance technologies, and their effectiveness on the building energy models. In the first phase of this study, fourteen net-zero energy buildings or high-performance buildings in the USA, China, and India considering energy-efficient design features and their significant effect on energy consumption have been examined. Moreover, the role of building simulation tools in improving energy efficiency is discussed. The second phase investigates the thirty best practices of net-zero energy buildings in tropical climates worldwide based on envelope choices, heating, cooling, and lighting features. Furthermore, this review discusses the evolving definitions, challenges, and inconsistencies in terminologies of net-zero energy building and illustrates India's initiatives towards net-zero development. The objectives of this review study are to highlight the challenges in building material research, advanced lighting, heating, ventilation, and air conditioning technologies, and integration of renewable energy compared to developed nations. Additionally, the gaps that are the barriers to the development of net-zero energy building in India have been identified. The review eventually concludes by providing policy recommendations and suggesting areas for future research to facilitate net-zero energy-building development in India.

Comprehensive Evaluation of Decarbonization Technologies: A Case Study of Residential Buildings in Zhuzhou City, China

Efficient carbon emission reduction technologies in buildings are necessary for achieving the “Dual carbon” goal in China. In this study, a comprehensive evaluation model is proposed to assess the effect of carbon emission reduction based on the analytic hierarchy process–entropy weight–coefficient of variation model which takes newly built residential buildings in Zhuzhou City as the research object. The results show that the preferred materials for the roof and exterior walls of the building’s envelope structure were flame-retardant extruded polystyrene boards, and porous shale bricks were preferred as the main materials for the exterior walls. In addition, the rooftop solar photovoltaic system and energy-saving air conditioning technology were suitable in terms of being renewable and were better utilized. In the end, carbon emissions were significantly reduced when using the building decarbonization technologies. This study provides a new reference for choosing materials and technologies for the design of residential buildings in Hunan Province and even other regions with hot summers and cold winters.

Research Status of New Energy Vehicle Thermal Management

Thermal management of new energy vehicles, as a way to break through the driving range of new energy vehicles and one of the guarantees of safety performance, has been paid more and more attention to. In order to improve the thermal management efficiency of new energy vehicles, the thermal management mode of the whole vehicle should be optimized, so that different parts can work at a suitable temperature, so as to ensure the functional safety and service life of the vehicle. Based on this, this paper analyzes the passenger cabin thermal management system through Positive Temperature Coefficient (PTC) heating air conditioning, heat pump air conditioning and other technologies. This paper introduces the new energy vehicle battery thermal management system from the aspects of direct cooling mode and heating mode, introduces the battery thermal management system through the analysis of flow charts, and introduces the cooling mode of electric control and motor, and pays attention to some cutting-edge research progress, and summarizes the automobile thermal management technology theory.

Review of energy-efficient HVAC technologies for sustainable buildings

This review paper provides a comprehensive examination of energy-efficient Heating, Ventilation, and Air Conditioning (HVAC) technologies for sustainable buildings. The focus is on exploring the latest advancements, benefits, challenges, and future prospects in the realm of HVAC systems designed to enhance energy efficiency and promote sustainability in building operations. The review begins with an overview of the importance of energy-efficient HVAC technologies in the context of sustainable building design and operation. It underscores the critical role of HVAC systems in reducing energy consumption, minimizing environmental impact, and enhancing occupant comfort and well-being. The paper delves into various categories of energy-efficient HVAC technologies, including advanced heating and cooling systems, ventilation strategies, and smart controls. Each category is examined in detail, highlighting key features, performance metrics, and real-world applications. Furthermore, the review evaluates the benefits associated with energy-efficient HVAC technologies, such as significant energy savings, reduced operating costs, improved indoor air quality, and enhanced building resilience. It also discusses the potential challenges and barriers to adoption, such as high upfront costs, complexity of implementation, and retrofitting existing buildings. The paper explores emerging trends and innovations in the field of energy-efficient HVAC technologies, including the integration of renewable energy sources, smart sensors and actuators, and predictive maintenance algorithms. These advancements have the potential to further optimize energy performance, increase system reliability, and enable proactive management of HVAC systems. In conclusion, the review emphasizes the importance of energy-efficient HVAC technologies as a cornerstone of sustainable building practices. It underscores the need for continued research, innovation, and collaboration among stakeholders to overcome existing challenges and unlock the full potential of energy-efficient HVAC systems in contributing to a more sustainable built environment. Overall, this comprehensive review provides valuable insights into the current state of energy-efficient HVAC technologies, their applications, benefits, and challenges, while also highlighting opportunities for future advancements and their crucial role in achieving sustainability goals in the building sector.

Analysis of rainwater use in membrane-based semi-direct evaporative cooling of air

The trend of seeking solutions to reduce energy consumption in buildings is evident in the context of heating, ventilation, and air conditioning technologies. One such solution with low energy consumption is direct evaporative cooling systems. However, the use of such systems is associated with an increase in fresh water consumption in buildings. The article presents a novel approach to air cooling, taking into account the sustainable building aims of designing buildings with low energy consumption and water conservation. The proposed system is a membrane-based semi-direct evaporative cooling system, which is fed by harvested rainwater. The study analyzed the potential of rainwater harvesting for direct evaporative cooling in ten cities. The cities selected for the analysis of system operation, are located in different climates according to the Köppen-Geiger classification. Water consumption for cooling at a base temperature of 26.7 °C was estimated using a mathematical model of the membrane module. Furthermore, the number of evaporative cooling hours per year was determined for this temperature. The system under analysis achieved a high coefficient of performance (COP) and a seasonal coefficient of performance (SCOP) of up to 183 and 133, respectively. Depending on the location of the building, the annual water consumption of the system ranged from 150 to 8859 dm3. The rainwater harvesting provided up to 100 % of the evaporative cooling requirements. The proposed solution reduces tap water consumption and lowers the temperature of fresh air supplied to indoor spaces while consuming low energy.

Operational performance of PCM embedded radiant chilled ceiling using a rule-based control strategy

The increasing energy demand for space cooling, projected to triple by mid-century and surpassing a quarter of today's global electricity usage, underscores the urgent need for innovative, more energy-efficient air-conditioning technologies. The research introduces phase change material (PCM) embedded radiant cooling (PCM-RCC) as a promising solution, offering enhanced energy efficiency and indoor environmental quality. Despite its potential, PCM-RCC remains in the developmental stage, requiring further research to fully unlock its benefits. This work aims to analyse the operational performance of PCM-RCC and develop an advanced rule-based control strategy to enhance its efficiency further. The analysis was conducted using a validated PCM-RCC transient system simulation model. To quantify the advantages of PCM-RCC over typical radiant cooling and evaluate the effectiveness of the proposed control strategy, two reference cases are defined: (1) basic-controlled PCM-RCC, and (2) radiant cooling without PCM. Results reveal that PCM-RCC with advanced control demonstrates higher load flexibility (∼93% off-peak time operation), 12% less electricity usage, a 5% coefficient of performance improvement, and a 30% decrease in operational costs compared to radiant cooling. Furthermore, the proposed system shows 9% lower energy usage with a 20% improvement in thermal comfort compared to basic-controlled PCM-RCC.

Embracing the Evaporative System in Air Conditioning Technology for Efficient Cooling Solutions

The use of an air conditioning system requires large amounts of electrical energy to carry out repeated vapor compression cycles. The use of an evaporative cooling system in this research is by spraying condensate water on the condenser, which is one solution to absorb condenser heat. Another thing that can be done is to reset the fan speed on the condenser to cool it. Resetting the fan speed on the condenser can also help improve AC performance and reduce electrical energy use. The test was carried out by modifying the 1 Pk R-410a AC split condenser by installing 6 nozzles, 2 rows of 3 columns and a DC pump to spray water on the condenser. The independent variables of this research are spraying position and fan speed. The result obtained from the research is an increase in COP by 35% and a reduction in electrical power usage by 15% by using additional water spray with a nozzle behind the condenser both when blowing the full blower and when the blower blowing speed is reduced by 75%. The use of evaporative systems in air conditioning technology is a promising solution to achieve sustainable and efficient cooling solutions.

Efficient harvesting of renewable evaporative energy from atmospheric air through hierarchical nano/microscale shaping of air-water interface

Renewable evaporative energy from atmospheric air is a recently emerged research field that demonstrates the great potential for significant energy savings in the air conditioning of buildings, data/big-data/integrated-big-data centers, agricultural storage facilities, and greenhouses. Here, we develop a method for an essential increase in the harvesting efficiency of renewable air evaporative energy by enhancing the water evaporation rate through the shaping of the air-water interface (AWI) by the menisci formed in superhydrophilic hierarchical surface nano/microstructures. Using this method, we achieve a 10-fold rise in the evaporation rate for the microscale AWI shaping. For the first time, we discover the superevaporation effect that provides an unprecedented 130-fold rise in the evaporation rate at the hierarchical nano/microscale AWI shaping. Furthermore, based on these findings, for the first time, we elaborate a novel material with an engineered AWI for a significant increase in the harvesting of renewable air evaporative energy in the dew point (Maisotsenko cycle) indirect evaporative air conditioning systems whose operation is fundamentally based on utilizing renewable air evaporative energy. The dew point cooling device fabricated using this novel material shows significantly superior cooling performance, validating the substantially enhanced harvesting of the air's evaporative energy. Our findings can essentially advance the emerging field of renewable air evaporative energy and, besides the air conditioning technology, can provide significant efficiency enhancements in water purification/desalination, thermal management, gas turbine power generation, and waste heat recovery technologies.

Exploring global accessibility of deep ocean water for sea water air conditioning (SWAC) process: Identifying feasibility areas depending on temperature source

Sea Water Air Conditioning (SWAC) technology is a highly efficient alternative to conventional air conditioning system using renewable marine energy to provide cooling to buildings. However, its implementation requires access to Deep Ocean Water (DOW) at 4–5 °C, thus SWAC is only viable in coastal regions. Furthermore, one of the major obstacles to its global development is the investment cost that remains high. This cost is strongly linked to the bathymetry of the installation location as it determines the length of the drawing pipeline, which accounts for the largest share of the investment cost. Knowing the temperature and bathymetry profiles will enable the establishment of the financial viability of SWAC technology in a specific location. This paper presents an analysis identifying areas of feasibility on a worldwide scale for standard SWAC implementation first. Then, it explores an alternative design with a higher drawing point for seawater at 12 °C (coupled with a High Temperature District Cooling), which reduces the cost by shortening the drawing pipeline and allows for more locations to be suitable for this technology. Additionally, the impact of the El Niño/Southern Oscillation (ENSO) is also considered since a shallower drawing point makes it more sensitive to temperature variations.

Experimental and numerical study of ice storage and melting process of external melting ice coil

Ice storage air conditioning technology could achieve “peak cut” by storing ice during the valley period, melting ice during the peak period to achieve the role of peak load regulation. At the same time, it can promote consumption of renewable energy. This study deals with the experimental and numerical analysis of the solidification and melting processes of coiled ice storage. From the experimental observation, it was observed that the outer surface of the lower side of the coil was the first to form an ice layer. Then the outer surface of the upper side begins to form an ice layer, and the growth rate of the ice layer is faster than that of the lower side. The average growth rates of the ice layer on the upper and lower side are 0.112 mm/min and 0.079 mm/min, respectively. The density variation of water and natural convection were considered in this analysis. The numerical simulation results well match the phenomena and results of experimental research. The influence of different directions of cooling water inlet on the melting rate was also compared in this paper. Under the same initial conditions and boundary conditions, the melting process in the Mode 1 (along the coil) cools down faster; The ice melting process in Mode 2 (perpendicular to the coil) can provide more stable cooling, and the cooling duration is 130 s longer than that in Mode 1.

Performance analysis of automotive air conditioning systems with electric compressors using R1234yf refrigerant: Insights into power consumption, cooling capacity, and energy efficiency

R1234yf, a low global warming potential (GWP) refrigerant, offers a promising alternative to traditional refrigerants like R134a. This study analyzes automotive air conditioning systems (AAC) equipped with electric compressors and utilizing R1234yf refrigerant. The interrelationships between refrigerant charge, compressor speed, power consumption, cooling capacity, and energy efficiency are examined. The results show that increasing refrigerant charge and compressor speed leads to higher power consumption due to increased compressor work. However, higher refrigerant charges and compressor speeds improve cooling capacity in line with heat transfer principles. As refrigerant charge and compressor speed increase, the energy efficiency, measured by the Coefficient of Performance (COP), tends to decrease, indicating a trade-off between cooling capacity and energy efficiency. Optimizing refrigerant charge and compressor speed is crucial to strike a balance between cooling performance and energy efficiency. R134a outperforms R1234yf, with an average percent difference in COP approximately 25% higher at all compressor speeds. This study contributes to the understanding of AAC system performance and guides the development of energy-efficient automotive air conditioning. Future research can further explore system components and conditions to enhance energy efficiency and advance air conditioning technology.

Development of the Life Cycle Extension Algorithm of the Air Conditioning Systems (ACS)

Introduction. The scientific problem tackled by the authors is the need to analyse and evaluate the life cycle of the air conditioning systems (ACS) for developing an optimal technology of creating the favourable indoor climate, which enables people’s productive work and rest as well as the normal flow of the technological processes. The study aimed at investigating the life cycle of an ACS as a facility of the comfortable indoor climate provision within the urban mixeduse complexes.Materials and Methods. The authors' research is based on the methods of mathematical and system analysis used to find out the solution for extending the life cycle of the indoor climate provision facilities.Results. As a result of the research, the ACS main life cycle stages were distinguished, their relations to the respective operational parameters were determined, the formulas for calculating the criteria and nondimensional indicators of the indoor climate provision system’s operation assessment were proposed. Discussion and Conclusion. The carried out analysis on distinguishing the life cycle extension capacities allowed us to conclude that the ACS operational stage provides the best opportunities for selecting the optimal layout of the system functional units and the air conditioning technology. The formulas for calculating the criteria and their respective nondimensional indicators enabling the development of the recommendations and ways of extending the ACS life cycle have been determined and described.

Towards Unlocking/Tuning the Mott Transition Temperature in Alkaline-Doped Vanadium Oxide Thermochromic Coatings and Potential Green Air-Conditioning via Room Temperature VxOy-V-VxOy Layered Coatings

In this contribution, we validate for the first time that the near infrared-infrared (NIR-IR) modulation of the optical transmission (DTTRANS = T(T<TMIT) - T(T>TMIT)) of vanadium oxide-based nanomaterials can be controlled or tuned via a genuine approach with a simultaneous drastic reduction of its Mott transition temperature TMIT. More accurately, we report a significant thermochromism in multilayered V2O5/V/V2O5 stacks equivalent to that of pure VO2 thin films but with a far lower transition temperature TMIT. Such a multilayered V2O5/V/V2O5 thermochromic system exhibited a net control or tunability of the optical transmission modulation in the NIR-IR (DTTRANS) via the nano-scaled thickness of the intermediate vanadium layer. In addition, the control of DTTRANS is accompanied by a noteworthy diminution of the Mott transition temperature TMIT from the bulk value of 68.8 °C to the range of 27.5–37.5 °C. The observed peculiar thermochromism in the multilayered V2O5/V/V2O5 is likely to be ascribed to a significant interfacial diffusion or an excessive interfacial stress/strain, and/or to an effective halide (Na, K, Ca) doping. This doping is driven by a significant diffusion from the borosilicate substrate surface towards the V2O5/V/V2O5 stacks. If the upscaling of this approach is validated, the current findings would contribute to advancing thermochromic nanomaterials and their applications in smart windows for managing solar heat and green air-conditioning technologies.

Experimental and Numerical Study of the Ice Storage Process and Material Properties of Ice Storage Coils

The coiled ice-storage-based air conditioning system plays a significant role in enhancing grid peak regulation and improving cooling economy. This paper presents theoretical and experimental studies conducted on the ice storage process of coiled ice storage air conditioning technology. The cooling of water is divided into two stages:10.0 °C to 4.0 °C and 4.0 °C to below 0.0 °C. Initially, the ice storage process forms an ice layer with a thickness of 2.50 mm on the lower surface of the coil, but eventually, the ice layer on the upper surface becomes 3.85 mm thicker than the lower surface as a result of the natural convection of water and density reversal at 4.0 °C. Furthermore, the impact of three coils with different thermal conductivity on the ice storage process was evaluated. It was observed that the thermal conductivity of R-HDPE (reinforced high-density polyethylene) was only 2.6 W/(m·K) higher than HDPE (high-density polyethylene), yet it reduced the freezing time by 34.85%, while the thermal conductivity of steel was 37.4 W/(m·K) higher than R-HDPE, but only decreased the freezing time by 9.40%. The results demonstrated that the rate of ice accumulation increased with thermal conductivity. However, when the coil material’s thermal conductivity surpassed that of ice, the further increase of thermal conductivity gradually weakened its impact on the ice storage rate.

Temperature, health and wellbeing in Australia

We examine the effects of temperature on general health and subjective wellbeing. We combine daily temperature data with 19 waves of panel data from the Household, Income and Labour Dynamics in Australia Survey. We find evidence of an inverted U-shaped relationship between temperature and general health. However, the effect of temperature on subjective wellbeing is less robust. We examine whether the adoption of air conditioning technology moderates the observed relationship between temperature and health. Our results show that there is no robust evidence for the role of air conditioning in moderating the relationship between temperature and health/wellbeing. Further, we conducted a mediation analysis to examine whether sleep quality serves as a channel through which the effect of temperature transmits to health. We find little evidence in support of sleep quality as a mechanism.

A novel indirect evaporative cooler with porous media under dual spraying modes: A comparative analysis from energy, exergy, and environmental perspectives

Indirect evaporative cooling (IEC), which cools the air through the physical process, is regarded as one of the high-efficient air conditioning (AC) technology. The reliable performance of traditional IEC is maintained by consistent water spraying, consuming much energy and hindering further performance improvement. In this regard, we proposed a novel indirect evaporative cooler with porous media on the secondary air channel (PIEC) to mitigate the dependence on water spraying. For the PIEC, the water storage capacity of porous media enables periodic spraying. However, the performance comparison between periodic spraying and traditional consistent spraying is rarely carried out although the two modes have been achieved, which promotes this research. In this study, the PIEC model with consistent spraying and periodic spraying was briefly described based on our previous results. According to the results from the established model, the PIEC performance was analyzed and compared under dual spraying modes from the energy, exergy, and environmental (3E) perspectives. It is demonstrated that periodic spraying can significantly improve the system COP by 58.7% at the cost of tiny temperature fluctuations. Additionally, the periodic mode can increase the exergy efficiency and lessen the exergy loss ratio in the studied cases. Eventually, the PIEC system using periodic spraying can annually reduce up to 24.2% of CO2 emissions compared with the traditional consistent mode, indicating better environmental benefits.

Correlation between cation order/disorder and the electrocaloric effect in the MLCCs of complex perovskite ferroelectrics

The physical properties (dielectric, ferroelectric, piezoelectric, etc.) of complex perovskite ferroelectrics depend on the degree of order/disorder and the scale of the ordered domains. In this study, the electrocaloric (EC) properties of three representative complex perovskite ferroelectrics, Pb(Mg1/3Nb2/3)O3–8PbTiO3 (PMN-8PT), 1mol% Sm-doped Pb(Mg1/3Nb2/3)O3–8PbTiO3 (1S-PMN-8PT) and Pb(Sc1/2Ta1/2)O3 (PST) are evaluated. Multi-layer ceramic capacitors (MLCCs) with identical structural configurations were fabricated for these three compounds, and their EC properties were characterized by direct measurement using a thermocouple. The EC temperature change ΔT of PMN-8PT, 1S-PMN-8PT and PST MLCCs under 20 V μm−1 at room temperature were found to be 1.42 K, 1.54 K, and 3.10 K, respectively. X-ray diffraction and high-resolution transmission electron microscopy data suggests that the high EC performance of PST is related to the ordering of B-site cations (Sc3+ and Ta5+) with the ordering parameter S = 0.82 and a long coherence length of ∼100 nm, such that the sample transitioned from a relaxor ferroelectric to a normal ferroelectric. These results provide pathway towards design of high performance EC materials required for solid state refrigeration and air-conditioning technologies.