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Most enterprise workshop operators frequently adjust the start/stop time of air conditioning systems based on indoor and outdoor temperatures and humidity to accommodate changing demand and weather conditions. However, relying on personal subjective experience for these adjustments often leads to operational delays or energy waste due to the lack of precision in determining optimal timing. Predicting air conditioning system start and stop times is crucial for energy consumption and savings in HVAC systems. Traditional data-driven methods have been insufficient in this regard, as they mainly focus on feature mapping and overlook the dynamic coupling relationships of process variables, resulting in subpar predictions. In response to this challenge, the paper introduces a novel approach known as the Periodicity and Long-Term Convolutional Neural Network (PLCNN). This method converts one-dimensional regression prediction data into two-dimensional data containing time series features to capture the dynamic coupling characteristics of the air conditioning system while maintaining the independent variation relationships of features. Experimental results using real factory floor data have demonstrated the superior performance of the PLCNN method. Specifically, this method achieved a 14.96% lower error rate compared to the traditional method and an 8.18% improvement compared to the deep learning method. Moreover, the implementation of the PLCNN method in the optimal control of air conditioning systems led to a significant 19.43% reduction in total monthly energy consumption. In conclusion, the proposed method offers a promising alternative to traditional approaches to forecasting and provides a solution to the common challenges encountered in traditional prediction tasks. • Capture the dynamic coupling characteristics of air-conditioning systems. • Analyzing data for periodicity and long-term patterns using various methods. • Improved integration of periodicity and long-term attributes through mutual learning. • Achieved an 11.57% lower MSE compared to different methods. [ABSTRACT FROM AUTHOR]

The paper focuses on the simulation and testing of a hybrid solid desiccant‐vapor compression air‐conditioning system under different hot‐humid climates. The simulation is carried out by a BLUEJ programming framework. Air at the lowest achievable temperatures from a solid desiccant cooling system is supplied to a standard vapor compression air‐conditioning system (VCAS). The cooling capacities of the hybrid system under three modes 1, 2, and 3, indicating different supply air conditions to the cabin, are reported in the paper. This paper expresses the trade‐off between having comfort conditions and reasonable comfort conditions inside the cooling space with energy efficiency as the inflection point. The more the study is moved towards the point of energy efficiency, the higher the reduction in the cooling capacities of the vapor compression air conditioner. This is demonstrated by the cooling capacity savings when the system is operated in three modes namely 1, 2, and 3. The substantial energy savings provided by Mode 1, Mode 2, and Mode 3 are 71%, 57%, and 37%, respectively. If the system is made to provide substantial cooling and focuses deeply on cooling capacity savings, then the system could save up to 77% in the cooling capacity of the vapor compression air‐conditioning system. If the system is made to operate solely with the milestone of comfort cooling for the occupants with any substantial savings in the cooling capacity of the vapor compression air‐conditioning system, then Mode 3 would deliver the milestone and give savings in the cooling capacities from 32% to 41% which is a significant savings. From the results of the performance study, it is inferred that the hybrid system provides significant energy savings compared to a standard air conditioner, especially in hot‐humid ambient conditions. The solid desiccant cooling system thus establishes itself as an effective pre‐cooler unit for a VCAS. The hybrid solid desiccant air‐conditioning in the paper is analyzed from the aspects of savings in cooling capacities of an existing vapor compression air‐conditioning system and comfort cooling. This is a newer operational approach, especially for using this hybrid solid desiccant cooling system for ambient humidity ratios greater than 15 kg−1 d.a. [ABSTRACT FROM AUTHOR]

• A solid desiccant cooling system is optimised using a response surface methodology. • Regression models were developed and showed commendable predictive capability. • Multi-objective optimisation was achieved by considering four key parameters. • Case studies demonstrated the system's applicability in Australian climates. Solid desiccant-assisted dew-point indirect evaporative cooling (SD-DPIEC) systems have gained considerable attention as a potential eco-friendly alternative to vapour-compression cooling systems in building cooling applications. However, one major drawback of these systems is their substantial water consumption during evaporative cooling. To tackle this issue, this study aims to improve the cooling efficiency and water utilisation of an SD-DPIEC system using response surface methodology (RSM). This research focuses on optimising four key parameters: supply air temperature, humidity ratio, water consumption rate and coefficient of performance (COP). The independent variables encompass the ambient temperature, relative humidity, regeneration temperature, and recirculation air ratio. Employing a multi-objective optimisation approach via the desirability function, the optimised SD-DPIEC system is subsequently tested in two prevalent weather patterns in Australia. The results demonstrated that the regression models derived from RSM exhibited commendable predictive capability, with the determination coefficient R 2 and Adequate Precision exceeding 0.97 and 40.46, respectively. The outcomes revealed that the system attained its optimal performance with a supply air temperature of 20.36 °C, humidity ratio of 12.56 g kg-1, a water consumption rate of 3.11 kg/hr, and COP of 2.03 under the ambient temperature of 33.79 °C, relative humidity of 68.48 %, regeneration temperature of 51.78 °C, and recirculation air ratio of 60 %. Based on the optimisation results, a case study was undertaken to evaluate the system's applicability in representative Australian climates. The results demonstrated that the system could uphold air conditions with the supply air temperature below 19 °C and humidity ratio below 11.51 g kg-1 under the studied Australian climates. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Refrigeration is the property of Journal of Refrigeration Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article examines the impact of air-conditioning on the history of Wuhan, a Chinese city famed for the oppressive heat of its summers. It draws upon oral history testimony, ethnographic research, and written sources, to argue that air-conditioning has played an important yet underappreciated role in changing local culture, social interactions, and the urban environment. It begins by describing how citizens of Wuhan coped with heat in the Maoist era (1949–1976), examining official heatstroke prevention techniques alongside the everyday practices of local citizens, including the use of bamboo beds and air-raid shelters. It then examines the dialectical relationship between socio-economic and technological change that occurred following the introduction of air-conditioning. This new technology, which required people to close their doors on their neighbours, arrived at the same time that older forms of communal living were becoming untenable. Finally, this article examines the role that air-conditioning has played in creating and alleviating the urban heat island problem, a process of localised climate change that makes cities hotter than their hinterlands. It concludes by exploring how locals feel about urban heating, a problem that seems intractable in Wuhan, as it is throughout much of urban Asia. [ABSTRACT FROM AUTHOR]

In comfort, air-conditioning control over the humidity is essential in applications such as pharmaceutical industries, electronic gadgets manufacturing units, the food sector, paper industries, etc. Relative humidity of nearly 50% can effectively prevent the growth and abidance of biological pollutants. There are several methods using which dehumidification can be achieved. The most common method is subcooling air up to the condensation temperature of the moisture trapped and then cooling again, and the condensate is collected. This method is time-consuming and needs to be more effective. On the other hand, desiccants' dehumidification process is suitable for maintaining humidity in air-conditioning systems and producing dry air. Desiccants with economical materials, high moisture removal rate, low regeneration temperature, and steadiness after many years make a desiccant system more successful in its performance and cost. The effect of change in process air temperature, process air humidity ratio, and regeneration temperature on the system's performance is studied. This research focuses on the functioning of various desiccant dehumidification systems and their applications. A comparative study of the different dehumidification systems found efficiency, low maintenance cost, and high sustainability. [ABSTRACT FROM AUTHOR]

In the age of noticeable climate change, enduring high temperatures is becoming a serious problem and inconvenience, which can cause health problems and even lead to death. One way to counteract the negative effects of heatwaves is to use an indoor air-conditioning system – both in residential building and in workplaces. The purpose of the article is to find an answer to the question posed in the title of the publication of whether access to an air-conditioned room can be considered, on the basis of the Constitution of the Republic of Poland, to be a human right. The considerations are divided into two segments: the right to air-conditioning in the workplace as part of the employer’s provision of safe and hygienic conditions, and the state’s responsibility for counteracting the negative effects of climate change. Indeed, it turns out that the Polish constitution makes it possible to conclude that the state has a certain obligation to provide places of rest from the heat in a situation where it threatens health and life. The article presents selected solutions for counteracting the effects of hot weather in European cities where high temperatures are more frequently recorded than in Poland. In addition, it presents the scope of the obligation to ensure adequate comfort at work in conditions with a high air temperature that also falls on employers. The aim is to draw attention to the important issue of how public authorities can counteract the negative effects of global warming. Indicating solutions used in other countries, it seeks an appropriate way for public authorities to act in Poland.

In this paper, I use the figure of the air-conditioner to get at the bifurcated issues of access to comfort in the Anthropocene. I think through the phenomenological relations to the air-conditioner, using as my archive Aravind Adiga’s Booker-winning novel The White Tiger. I put forth the theory of what I call subaltern discomfort, arguing that who gets to be comfortable, and why, I argue, is a matter of increasing importance as the climate warms and air-conditioning becomes much more significant in the lives of people worldwide. [ABSTRACT FROM AUTHOR]

In the age of noticeable climate change, enduring high temperatures is becoming a serious problem and inconvenience, which can cause health problems and even lead to death. One way to counteract the negative effects of heatwaves is to use an indoor air-conditioning system - both in residential building and in workplaces. The purpose of the article is to find an answer to the question posed in the title of the publication of whether access to an air-conditioned room can be considered, on the basis of the Constitution of the Republic of Poland, to be a human right. The considerations are divided into two segments: the right to air-conditioning in the workplace as part of the employer's provision of safe and hygienic conditions, and the state's responsibility for counteracting the negative effects of climate change. Indeed, it turns out that the Polish constitution makes it possible to conclude that the state has a certain obligation to provide places of rest from the heat in a situation where it threatens health and life. The article presents selected solutions for counteracting the effects of hot weather in European cities where high temperatures are more frequently recorded than in Poland. In addition, it presents the scope of the obligation to ensure adequate comfort at work in conditions with a high air temperature that also falls on employers. The aim is to draw attention to the important issue of how public authorities can counteract the negative effects of global warming. Indicating solutions used in other countries, it seeks an appropriate way for public authorities to act in Poland. [ABSTRACT FROM AUTHOR]

Objectives: Ecogeographic variation in human nasal anatomy has historically been analyzed on skeletal morphology and interpreted in the context of climatic adaptations to respiratory air‐conditioning. Only a few studies have analyzed nasal soft tissue morphology, actively involved in air‐conditioning physiology. Materials and Methods: We used in vivo computer tomographic scans of (N = 146) adult individuals from Cambodia, Chile, Russia, and Spain. We conducted (N = 438) airflow simulations during inspiration using computational fluid dynamics to analyze the air‐conditioning capacities of the nasal soft tissue in the inflow, functional, and outflow tract, under three different environmental conditions: cold–dry; hot–dry; and hot–humid. We performed statistical comparisons between populations and sexes. Results: Subjects from hot–humid regions showed significantly lower air‐conditioning capacities than subjects from colder regions in all the three conditions, specifically within the isthmus region in the inflow tract, and the anterior part of the internal functional tract. Posterior to the functional tract, no differences were detected. No differences between sexes were found in any of the tracts and under any of the conditions. Discussion: Our statistical analyses support models of climatic adaptations of anterior nasal soft tissue morphology that fit with, and complement, previous research on dry skulls. However, our results challenge a morpho‐functional model that attributes air‐conditioning capacities exclusively to the functional tract located within the nasal cavity. Instead, our findings support studies that have suggested that both, the external nose and the intra‐facial soft tissue airways contribute to efficiently warming and humidifying air during inspiration. This supports functional interpretations in modern midfacial variation and evolution. [ABSTRACT FROM AUTHOR]

Selecting suitable materials for air ductwork is essential to ensure efficient airflow distribution and reduce economic costs, as it directly impacts an air conditioning system's overall performance and functionality. The PVC-coated polyester canvas and foam materials have revolutionized the construction of air ductwork, offering numerous benefits and advantages over conventional materials. For instance, these materials have been successfully used in the construction of air ducts for large commercial buildings, resulting in significant energy savings and improved indoor air quality. Using these new-era materials has design flexibility, durability, energy efficiency, and costeffectiveness. This research has provided a comprehensive analysis of the economic cost of the new era of air ductwork compared with conventional air ductwork in Thailand, and the thorough assessment of total service life costs has improved on the financial implications of adopting this new technology. The economic analysis of PID ducts reveals their cost-effective excellence compared to other investment types. The benefit-cost ratio of 4.73 and a payback period of 1.48 years show the financial advantages offered by PID ducts. With their affordability, efficiency, and simplicity, PID ducts emerge as the most attractive option for investors seeking long-term profitability and sustainability in construction projects. [ABSTRACT FROM AUTHOR]

Ceiling fans have been promoted as an alternative cooling technique to save energy, while their adoptions in the residential sector have yet to be investigated. This study analysed the adoption of ceiling fans in residential buildings and compared their energy-saving potential with that of air-conditioning in Building Sustainability Index (BASIX) certificated single (n = 268,558) in New South Wales, Australia, from 2011 to 2019. Four climate zones were classified according to heating and cooling hours via k-means, based on which predictive models for the relationship between cooling technologies and energy-saving levels were established via machine learning. Dwellers in the hot zone of New South Wales would be more likely to adopt ceiling fans. In the living rooms, dwellers could adopt ceiling fans alone, while in bedrooms, dwellers could adopt air-conditioning in addition to ceiling fans. This study provides empirical evidence on the adoption of ceiling fans in green buildings and helps to map out the low carbon solutions using alternative cooling in the residential sector.

In line with the waste-to-energy conservation strategies, the present study focuses on the design and analysis of a Compact Cooler Unit (CCU) that can efficiently make use of cold condensate generated from air-conditioning plants. Condensate from air conditioners with cooling capabilities of 115 kW and 175 kW, respectively, producing 23 Lh−1 and 35 Lh−1 at temperatures of 15 ℃ and 10 ℃, are used in the study to investigate cabin thermal comfort. Experimental and simulation studies are conducted to analyze the cooling performance of the CCU within a 6 m3 cabin under likely condensate temperatures. A TRNSYS model, incorporating Type 32 cooling components, assesses indoor parameters at water temperatures of 10 °C and 15 °C against EN ISO 7730:2005. Simulation studies confirmed that CCU performed better at 10 °C compared to 15 ℃, and an experiment was carried out at 10 ℃ to validate the simulation results. The simulated results had good agreement with the experiments with a variation of less than 5%. The results show that the CCU can achieve a saving of 37% with a recovered condensate quantity of 25 Lh−1 at 11 ℃, and a payback period of 4.4 years. Overall, this study provides valuable insights into the effective utilization of condensate as a sustainable resource for energy-efficient cooling in air-conditioned plants. It is recommended that CCU be fitted wherever the available condensate quantity would be more than 25 Lh−1, and it could be run along with a conventional chiller unit to achieve better thermal comfort with minimum energy consumption. [ABSTRACT FROM AUTHOR]

Phase change materials enhance the thermal comfort of buildings by utilizing stored thermal energy. In large air-conditioning systems, ice storage plays a crucial role in managing peak power loads. This experimental study explores the freezing characteristics of deionized water containing suspended iron oxide nanoparticles in spherical containers for cold storage. The synthesized nanofluid phase change material (NFPCM) was investigated for its freezing behavior under surrounding fluid temperatures of − 2 °C and − 6 °C. The uniformity in charging of NFPCM is the unique feature prevalent in the first quarter of the charging, with 50% mass frozen observed. An increased surface heat flux of 200% was achieved using NFPCM at Tsurr = -6 °C. The chiller operational time is optimally reduced by 75% by considering twice the container design's phase change materials. Adding iron oxide nanoparticles and partial charging is suitable for uniform heat transfer for the shorter freezing duration in cooling applications. The novelty of the present study is that the proposed NFPCM nearly nullifies the subcooling effects of deionized water without using nucleating agents. This NFPCM appreciably enhances power competence, yielding large-scale air-conditioning systems' desired economic impact and sustainability. The reported results align with Sustainable Development Goals (7—Affordable and Clean Energy and 13—Climate Action). [ABSTRACT FROM AUTHOR]

The air-conditioning (AC) energy use in express hotels is stochastic with the high coupling relationships amongst AC usage, indoor temperature and energy consumption. Such complexities and stochasticity make it hard to facilitate energy saving with clear effect on indoor environment. However, lacking analyses of high-resolution occupants' energy use makes it difficult to achieve such goals due to the split form of ACs and various thermal comfort of guests in express hotels. Therefore, this study made a serial analysis on the AC energy use in a more detailed scope. The stochastic AC usage, indoor temperature and AC energy consumption were quantified by proposed typical patterns with the cluster method. The stochasticity was described by four typical patterns for each aspect. After the quantifications, the relationships amongst these three aspects were decoupled by the proposed energy use decoupling model. Two data mining methods, namely, random forest method and decision tree method, were employed to achieve this purpose, respectively. With these models, the impacts of each variable on AC energy consumption and explicit relationships of operation rules for management are presented. Strictly limiting set point temperature higher than 23°C is the effective way to save energy for most of AC usage patterns. This study can provide a deeper understanding of AC energy use in express hotels, and benefits energy saving and facility operation in express hotels. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of using a phase change material (PCM)-based latent heat storage (LHS) integrated with an air-conditioning system. The study has filled the knowledge gap regarding the dependence of melting rate and operational time of the AC system on PCM volume. Additionally, the study has examined the influences of important parameters such as inlet velocity and Stefan number on melting rates, outlet temperature, and COP. The results have revealed that higher inlet air velocity and Stefan number have led to shorter melting duration. Specifically, an increase in velocity from 1.6 to 2.14 m/sec has reduced the time required for complete melting by 19.16% at a fixed Ste value and D value of 2. Further increasing the velocity to 2.67 m/sec has reduced the time by 31.59%. However, increasing the volume of the PCM has resulted in a longer melting duration, with the total melting time increasing from 3.35 to 7.11 h. Better COP values have been obtained for low-velocity cases. For all cases examined, the COP of the AC system with PCM has been superior to the COP without the PCM at any given time. Increasing inlet velocity and Ste raised the outlet temperature of the HEX, while PCM volume had little impact. The results have also indicated that lower inlet velocity is suitable for longer working periods and lower AC cooling loads, whereas higher inlet velocity is appropriate for shorter working periods and higher AC cooling loads. [ABSTRACT FROM AUTHOR]

This paper presents a new development of an Adaptive Network-based Fuzzy Inference System (ANFIS) for a Hybrid Ground Source Heat Pump (HGSHP). The HGSHP is equipped with a supplementary heat sink composter to process organic solid waste (OSW), utilizing excess hot air from the condensing unit to aerate the compost pile. The Fuzzy Logic Controller (FLC) was developed using data collected by effective sensors installed in the HGSHP system. The main objective is to control the water flow rate with a Variable Speed Drive (VSD) to improve overall system performance. The dataset for ANFIS has been created and trained using MATLAB® software, then implemented on a Raspberry Pi nano-computer with Python coding. This paper compares the performance of ANFIS with two different cases: ANFIS with Triangular Membership Function (TriMF) and ANFIS with Gaussian Membership Function (GaussMF). After implementing ANFIS with TriMF and GaussMF, the average COP during composter operation and system cooling significantly increased. In contrast, the HGSHP system power consumption is sufficiently reduced in both case studies. Moreover, ANFIS also benefits the composting process, as evidenced by the increase in composter operation time, and vice versa for system cooling time. Ultimately, the implementation of ANFIS can improve the HGSHP system performance in both the TriMF and GaussMF cases, with the TriMF case showing a significant improvement in the HGSHP system performance compared to the GaussMF case.

Currently, a majority of global residential air-conditioning requirements are met using cooling systems based on the vapor compression cycle (VCC). To meet the future demand for space cooling and to reduce the corresponding environmental impact, there is a need for alternative cooling systems which require less resources and exhibit a higher coefficient of performance (COP). One of proposed alternatives is called the hybrid evaporative-vapor compression (HEVC) cycle, which utilizes adiabatic latent cooling in combination with the VCC. In this paper, we conducted a feasibility analysis of a HEVC system by comparing its performance to that of VCC for various global climates. To accomplish this, we developed and validated models to simulate the performance of residential VCC and HEVC systems. ASHRAE weather data and design conditions were then used to compare the performance of the two systems. In general, HEVC systems are best suited for hot arid climates with energy reduction greater than 20%. Conversely, humid climates are not suitable for HEVC adoption due to degraded performance of evaporative coolers in these climates. In addition to comparing the energy savings from HEVC systems, it is also critical to analyze their water consumption. Generally, climates that benefit the most from HEVC technology tend to also experience water scarcity issues. Thus, both the energy savings and water consumption of HEVC systems must be analyzed to guide the discussion on their adoption.

Construction and operation of buildings are responsible for about 20% of the global energy consumption. The embodied energy of conventional buildings is high due to the utilization of energy-intensive construction materials and traditional construction methodology. Higher operational energy is attributed to the usage of power-consuming conventional air-conditioning systems. Therefore, moving to an energy-efficient cooling technology and eco-friendly building material can lead to significant energy savings and CO2 emission reduction. In the present study, an energy-efficient thermally activated building system (TABS) is integrated with glass fiber reinforced gypsum (GFRG), an eco-friendly building material. The proposed hybrid system is termed the thermally activated glass fiber reinforced gypsum (TAGFRG) system. This system is not only energy-efficient and eco-friendly but also provides better thermal comfort. An experimental room with a TAGFRG roof is constructed on the premises of the Indian Institute of Technology Madras (IITM), Chennai, located in a tropical wet and dry climate zone. The influence of indoor sensible heat load and the impact of natural ventilation on the thermal comfort of the TAGFRG system are investigated. An increase in internal heat load from 400 to 700 W deteriorates the thermal comfort of the indoor space. This is evident from the increases in operative temperatures from 29.8 to 31.5 °C and the predicted percentage of dissatisfaction from 44.5% to 80.9%. Natural ventilation increases the diurnal fluctuation of indoor air temperature by 1.6 and 1.9 °C for with and without cooling cases, respectively. It reduces the maximum indoor CO2 concentration from 912 to 393 ppm.

Widespread adoption of air-conditioning significantly enhances indoor thermal comfort in summer, but the heat dissipation from these outdoor units contributes to an increase in ambient air temperature, exacerbating urban heat island effects. Consequently, as outdoor thermal conditions worsen, the energy consumption associated with air-conditioning is likely to escalate. The spray system becomes a suitable choice due to the obvious advantage of heat absorption through the droplet evaporation. To assess the effectiveness of the spray system in reducing heat release, a comparative study was conducted between two identical buildings with the same air-conditioning system, but only one of which incorporated the spray system. Three installed locations are considered with the spray location in inlet (Case 1), outlet (Case 2) and both inlet & outlet (Case 3) of outdoor units. The results demonstrated the average temperatures of air outlet were reduced by 4.0 °C, 6.3 °C, and 7.9 °C for Cases 1–3, respectively, accompanied by a reduction in energy consumption of the air-conditioning system by 18.8%, 13.9%, and 37.3% respectively. The most significant benefits were observed when the spray location was installed in both outdoor unit inlet and outlet (Case 3). The spray system established a virtuous cycle in heat dissipation improvement, evaporation enhancement, and air temperature reduction.

The world is warming, and the demand for cooling is increasing. Developing a future green hydrogen economy will also increase the demand for cooling for hydrogen liquefaction. This increase in cooling demand will happen mainly in tropical and developing countries due to their increase in population, improvements in quality of life, and the export of their renewable potential with liquid hydrogen. To solve this increase in demand for cooling, this paper proposes the use of ammonia airship cooling (AAC). AAC extracts cold from the tropopause (−80 °C) with airships and ammonia refrigeration cycles. The liquid ammonia is then transported back to the surface to provide low temperature cooling services (−33 °C). This cooling service is particularly interesting for lowering the electricity consumption in hydrogen liquefaction plants. If all the technological challenges mentioned in the paper are addressed, it is estimated that the cost of cooling with the technology is 8.25 USD/MWht and that AAC could reduce the electricity demand for hydrogen liquefaction by 30%. AAC is an innovative renewable cooling technology that has the potential to complement other renewable energy sources in a sustainable future. [ABSTRACT FROM AUTHOR]

Germany is obliged to report emissions of fluorinated greenhouse gases annually under the UNFCCC. This includes emissions of fluorinated refrigerants when decommissioning RAC equipment. To obtain this information, data on the recovery, recycling, and disposal of fluorinated greenhouse gases is necessary, but such data are scarce. The VDKF-LEC database contains information on the recovery of fluorinated refrigerants from decommissioned RAC equipment in Germany and an extracted dataset was used to obtain real-world information for the years 2017 to 2021. Recovery rates for different fluorinated refrigerants from decommissioned commercial and industrial refrigeration as well as stationary air-conditioning equipment were derived. Furthermore, average lifetimes of equipment for the different sectors were calculated. In the analysis, a dependency of charged refrigerant and age of the unit at decommissioning could be observed. Results from the analysis of the VDKF-LEC dataset were compared with reported data under the UNFCCC for Germany and other available data sources. [ABSTRACT FROM AUTHOR]

Guidelines for heating, ventilation, and air-conditioning systems have been developed for different settings. However, there is a lack of up-to-date evidence providing concrete recommendations for the heating, ventilation, and air-conditioning systems of an isolation room, which is essential to appropriately guide infection control policies. To highlight the guidelines for heating, ventilation, and air-conditioning systems in isolation rooms to inform relevant stakeholders and policymakers. A systematic search was performed based on Joanna Briggs Methodology using five databases (CINAHL, Embase, Joanna Briggs Institute, Medline, and Web of Science) and websites. Eight articles published by government departments were included in this review. Most studies recommended controlled airflow without recirculation, 12 air changes per hour, high-efficiency particulate air filtrate to exhaust contaminated air from the airborne isolation room, humidity ≤60%, and temperature in the range of 18–30 °C. This review provides further evidence that there is a need for interdisciplinary collaborative research to quantify the optimum range for heating, ventilation, and air conditioning system parameters, considering door types, anterooms, and bed management, to effectively reduce the transmission of infection in isolation rooms. [ABSTRACT FROM AUTHOR]

The temperature changes of grain piles during rice storage in high-temperature and high-humidity grain storage areas were studied under the air-conditioning temperature control mode with a temperature of 22 ℃ and a daily opening time of 13 h and a temperature of 24 ℃ and a daily opening time of 24 h. The changes of rice moisture and fatty acid values ​​before and after temperature-controlled storage were compared, and the differences in temperature changes in each layer in the horizontal direction of grain piles at different depths were analyzed. The results showed that the average temperature and the maximum grain temperature of the grain pile increased slowly under different air-conditioning operation modes. Air-conditioned temperature-controlled grain storage had a greater impact on the surface temperature of the grain pile, but less impact on the middle layer grain temperature. During the air-conditioned temperature-controlled storage period, the lower layer grain temperature may be affected by the floor temperature. The temperature control mode that lowered the temperature control temperature but shortened the temperature control time was more economical and efficient. The temperature control mode of 22 ℃ + 13 h could save about 12.4% of electricity costs compared with the temperature control mode of 24 ℃ + 24 h. At the same time, the control effect of the warehouse temperature, surface grain temperature and average grain temperature of the grain pile with a lower basic grain temperature was more obvious, and the basic grain temperature of the grain pile played an important role in the implementation of temperature-controlled grain storage technology.

Tractors are manufactured without air-conditioned cabins in Pakistan. This leads to thermal discomfort for tractor operators working under direct solar exposure. Therefore, this study aimed to design and install an air-conditioned cabin on a tractor. Experiments were undertaken to evaluate the installed cabin performance under two scenarios i.e., conventional (S–I) and enhanced (S-II) air distribution. Computational fluid dynamics (CFD) simulations were used to analyze airflow and calculate thermal comfort indices. The results showed that the air-conditioned cabin attained optimum thermal conditions under the enhanced air distribution scenario (S-II). In this scenario, the inside cabin temperature was an average of 27.4 °C, compared with 30.4 °C in S–I. The relative humidity remained similar in both scenarios, around 53 %. The temperature difference between the cabin and the ambient environment was 11.09 °C in S-II, aligning with the thermal comfort conditions outlined in ISO 14269–2. Furthermore, the CFD simulations showed a predicted mean vote (PMV) index of 0.61 and the percentage people dissatisfied (PPD) index of 26.5 %. These results also confirm the provision of optimum thermal conditions for operator inside the cabin. The simulations also demonstrated good agreement with experimental data, with a small difference in air temperature (2 °C) and relative humidity (5.8 %). In the light of these findings, this study recommends installation of air-conditioned cabin on tractors with enhanced air distribution (S-II) in Pakistan to improve thermal comfort of operators.

This paper presents experimental and thermodynamic investigations of the performance of commercial refrigeration systems with capacities varying from 6 to 26 tons of refrigeration. The analysis considers a critical comparison between the conventional and widely used single-phase approach with the actual multi-phase methodology. The tests were performed under practical conditions with state-of-the-art experimental setups using variable cooling loads. The tests were performed in a climate chamber with advanced ambient temperature and humidity control equipment, where temperature can be raised up to 65 °C, and humidity can vary from 10 to 90%. This enabled us to simulate a wide range of operating modes to validate the performances of the proposed two-phase refrigeration system with theoretical results obtained from single-phase modeling. It was also found that the refrigeration system with a larger cooling capacity exhibited an operational performance close to two-phase theoretical results more than the small refrigeration system capacity. The experimental results were found to comply with the theoretical results with an error of approximately 10% for the two-phase approach compared to an error of approximately 20% for the single-phase approach. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Cereals, Oils & Foods is the property of Science & Technology of Cereals, Oils & Foods Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Heavy-duty trucks emit >25% of the CO2 of the European road transport sector despite representing ≈2.5% of its fleet. Escalating temperatures associated to global warming will increase the use of air-conditioning (AC) in heavy-duty trucks, further raising their fuel consumption and emissions. Thus, sustainable solutions are needed to reduce the thermal loads affecting the truck cabins, to minimize the need for AC and decrease the sector's costs and environmental footprint. We assessed the economic and environmental impact of AC use in the European heavy-duty transportation fleet, for realistic environmental conditions throughout the year, across the different European regions. Potential reductions were estimated for various changes in the optical properties of the cabin external paints and glazing elements (windshield and side-windows). The use of high-reflectivity paints in the cabin external surfaces and low-transmissivity glazing can reduce fuel costs by ≈€195 million/year across Europe (i.e., ≈0.1% of the total fuel costs of the European heavy-duty fleet), and decrease CO2 emissions by 1% of the reduction target set for 2025. These potential reductions highlight the importance of engaging with transportation stakeholders (e.g., workers unions, vehicle manufacturers, policymakers, and regulating bodies), to raise awareness about the potential benefits for the European transportation sector and the environment, and to promote the necessary adaptation in the transportation fleets. [ABSTRACT FROM AUTHOR]

The energy consumption status and energy saving potential of the air-conditioning systems of data centers in seven typical cities in China (Xinjiang, Beijing, Jinan, Shanghai, Nanning, Guilin, and Haikou), representing diverse climate regions, were studied. The power usage effectiveness (PUE) and cooling load factor (CLF) were taken as the evaluation indicators. First, the energy consumption situations of the existing air-conditioning systems were analyzed using an internship survey. Second, the meteorological data throughout the year for the seven cities were statistically analyzed. Then, two energy saving renovation schemes were proposed. The operating hours under different operating modes in the seven cities were calculated, and the PUE and energy saving potential of the two energy saving schemes were evaluated by taking the production of 15 °C chilled water as an example. This study provides an overall picture of the energy utilization status in the current Chinese data center market and provides solutions for improving the design of air-conditioning systems, with energy saving benefits. [ABSTRACT FROM AUTHOR]

In this paper, the optimal refrigerant mass charge amount of R417A, as a substitute for R22, was experimentally investigated in a split‐type air‐conditioner with no changes in system configuration. Experiments were conducted for both refrigerants over a range of mass charge from 500 to 850 g in a 12,000 Btuh−1 split air‐conditioner as the case study which is a conventional refrigeration system in residential sector of Iran. In order to study the effect of refrigerant mass charge on performance of refrigeration cycle, energy and exergy analysis were performed to determine cooling capacity, energy efficiency ratio (EER) and exergy efficiency. Results showed that the maximum EER for R22 and R417A are 2.48 and 2.41, and the maximum exergy efficiencies obtained for R22 and R417A are around 7.3% and 7%, respectively. Based on both EER and exergy efficiency, the optimum mass charge for R22 and R417A refrigerants are around 640 g and 650 g, respectively. In addition, it was found that under optimal charge conditions, the cooling capacity, EER and exergy efficiency of the system while working with R417A are lower than R22, just by 2.5%, 3%, and 4.5% respectively. Comparison results indicate that R417A can be considered as a suitable substitute for R22, which can almost provide the same performance without need to change the system components. [ABSTRACT FROM AUTHOR]