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Introduction: Hybrid ventilation systems present a promising solution for reducing cooling energy consumption in buildings, particularly in hot climates. However, while existing research highlights their potential, variability in reported cooling energy reductions underscores the need for standardized performance evaluation methods. Methods: This review synthesizes findings from 84 research articles published between 2010 and the first quarter of 2024. The studies include simulation-based analyses, experimental investigations, and real-world case studies sourced from prominent academic databases. Results: The review identifies substantial potential for cooling energy reductions through hybrid ventilation systems. However, it also reveals significant variability in energy savings across studies, suggesting that further work is needed to standardize reporting methods for accurate performance comparisons. Discussion: To address these challenges, this paper proposes a framework integrating Industry 4.0 technologies. The framework emphasizes standardized research methodologies, context-specific design considerations, and robust knowledge dissemination strategies. Artificial Intelligence (AI) is positioned as a critical enabler of innovation, driving design optimization and smart control systems. The proposed framework aims to improve performance assessments, tailor system designs to specific building types and climates, and enable real-time control for enhanced energy efficiency and occupant comfort. This approach has the potential to support the wider adoption and optimized implementation of hybrid ventilation systems, contributing to a more sustainable and energy-efficient built environment, particularly in hot climates. [ABSTRACT FROM AUTHOR]

It is commonly known that buildings in hot climate contribute to a huge amount of electricity consumption mainly due to air conditioning needs. Many countries around the world are aiming to convert buildings to net zero energy buildings (NZEB). However, buildings in hot climates require varieties of active and passive measures to adapt the concepts behind NZEB. This work attempts to resolve the challenges associated with shifting school buildings to NZEB in hot arid climates. It presents an energy performance analysis that is focused on two scenarios for new and retrofitted schools. Building thermal simulation is used to assess the implications of several energy conservation measures, and different scenarios are suggested to utilize up to 80% of roof's area for the installation of Photovoltaics (PV), and on-site wind turbines. The implemented energy conservation measures show a reduction in annual energy consumption by 35% and 21% for new and retrofitted schools respectively. Discounted payback period is used to estimate the economic feasibility of the suggested scenarios. It is found that NZEB is technically feasible at highest roof area PV installations with respective discounted paybacks of 3.55 and 5.54 years for the new and retrofitted schools. However, adding wind-turbines can delay the breakeven year of investments needed to achieve NZEB. The estimated savings in net present value (NPV) are 3273 and 4284 thousand US dollars for the retrofitted and new schools respectively, and each school's roof can generate 40.63 GWh in 25 years and avoid 29.23 kilotons of CO2. [ABSTRACT FROM AUTHOR]

This study was aimed to evaluate the influence of adding dietary three medicinal plants and vitamin E on productive performance, serum physiological parameters, immunity and antioxidant status of broiler chickens under heat stress (34 - 38) C° for 35 days. A total of 600 Ross one day old broiler chicks were distributed randomly into eight treatments with five replicates 15 birds per each replicate as follows: T1: broiler were fed standard ration (negative control); T2: 50 mg vitamin E /kg ration (positive control); T3: 5g Dill powder /kg ration; T4: 10g Dill powder /kg ration; T5: 5g Adiantum powder /kg ration; T6: 10g Adiantum powder /kg ration; T7: 5g Crataegus powder /kg ration and T8: 10g Crataegus powder /kg ration. Live body weight, feed intake, feed conversion ratio and mortality rate were measured at weekly intervals. There was a significant effect of medicinal plants on live body weight at 35 day. However, non-significant difference was noticed on feed intake, significant differences on feed conversion ratio, mortality and livability%. Regarding male chickens, T3 treatment had significantly higher carcass yield as well as each of T3 male and T4 female had higher dressing percentage. Furthermore, higher production index was found in T4 while, high value of economic figure was shown in T5 as well as significant effect on serum thyroid hormone T3,T4, corticosterone hormone and enhanced total antioxidant capacity and stable malondialdehyde all helped to reduce oxidative stress as well as boost antibody titers of ND and IBD compared with T1. It can be concluded that the supplementation of medicinal plants to broiler´s diet had a beneficial effect on most of broiler performance, improving immunity, resistance characteristics and oxidative stress particularly in T4 (Dill10g/kg) under heat stress. [ABSTRACT FROM AUTHOR]

Saudi Arabia faces significant challenges in managing the rising energy consumption in buildings driven largely by its hot climatic conditions. As a result, retrofitting building facades to enhance energy efficiency has become a critical strategy. This study assesses the effectiveness of various façade retrofit strategies in reducing cooling electricity consumption using a real-time case study in Dhahran, Saudi Arabia. The strategies explored include external wall upgrades, window replacements, and installation of shading devices. Each strategy was evaluated individually, considering the reduction in heat gains, cooling load, and payback period as key performance indicators. To further maximize energy efficiency, these strategies were also analyzed in combination using the genetic algorithm optimization method, yielding 224 possible facade configurations. The optimal solution included the use of an External Thermal Insulation Composite System (ETCIS) in walls, louvers in windows, and low-emissivity coating with Argon gas-filled glazing, achieving a cooling energy reduction of approximately 16% and a payback period of 14.8 years. This study provides several recommendations for improving the efficiency of retrofitting building façades in hot climatic conditions. [ABSTRACT FROM AUTHOR]

This paper presents a case study of energy flexibility strategies for a building located in the hot climate of Dubai, a type of climate in which energy flexibility has been under-researched. Energy flexibility is changing the routine-consumption profile and deviating from the normal operation of the building by the users to manage the variability in the load profile and cost of electricity. The three flexibility strategies being considered are based on the modulation of the indoor air temperature setpoint profile while considering different marginal costs for electricity. The main objective is to quantify the energy storage flexibility of each strategy and evaluate its impact on the system ramping and load factor. The study was carried out utilizing a grey-box, resistance–capacitance model of the building, which was validated against experimental measurements. This study is the first to use the following five indicators simultaneously: load factor, system ramping, storage capacity, peak-period demand reduction, and cost savings. Combining these indicators helps building facility managers and distribution system operators (DSOs) better understand the implications of implementing a specific flexibility strategy in a building or a group of buildings. When comparing the indicators of each strategy with each other, it was observed that depending on the amplitude of the change in the electricity cost signal during the peak period, a significant cost reduction of more than 25% could be achieved through the implementation of specific flexibility strategies compared with the normal baseline operating condition. [ABSTRACT FROM AUTHOR]

IntroductionHybrid ventilation systems present a promising solution for reducing cooling energy consumption in buildings, particularly in hot climates. However, while existing research highlights their potential, variability in reported cooling energy reductions underscores the need for standardized performance evaluation methods.MethodsThis review synthesizes findings from 84 research articles published between 2010 and the first quarter of 2024. The studies include simulation-based analyses, experimental investigations, and real-world case studies sourced from prominent academic databases.ResultsThe review identifies substantial potential for cooling energy reductions through hybrid ventilation systems. However, it also reveals significant variability in energy savings across studies, suggesting that further work is needed to standardize reporting methods for accurate performance comparisons.DiscussionTo address these challenges, this paper proposes a framework integrating Industry 4.0 technologies. The framework emphasizes standardized research methodologies, context-specific design considerations, and robust knowledge dissemination strategies. Artificial Intelligence (AI) is positioned as a critical enabler of innovation, driving design optimization and smart control systems. The proposed framework aims to improve performance assessments, tailor system designs to specific building types and climates, and enable real-time control for enhanced energy efficiency and occupant comfort. This approach has the potential to support the wider adoption and optimized implementation of hybrid ventilation systems, contributing to a more sustainable and energy-efficient built environment, particularly in hot climates.

It is commonly known that buildings in hot climate contribute to a huge amount of electricity consumption mainly due to air conditioning needs. Many countries around the world are aiming to convert buildings to net zero energy buildings (NZEB). However, buildings in hot climates require varieties of active and passive measures to adapt the concepts behind NZEB. This work attempts to resolve the challenges associated with shifting school buildings to NZEB in hot arid climates. It presents an energy performance analysis that is focused on two scenarios for new and retrofitted schools. Building thermal simulation is used to assess the implications of several energy conservation measures, and different scenarios are suggested to utilize up to 80% of roof’s area for the installation of Photovoltaics (PV), and on-site wind turbines. The implemented energy conservation measures show a reduction in annual energy consumption by 35% and 21% for new and retrofitted schools respectively. Discounted payback period is used to estimate the economic feasibility of the suggested scenarios. It is found that NZEB is technically feasible at highest roof area PV installations with respective discounted paybacks of 3.55 and 5.54 years for the new and retrofitted schools. However, adding wind-turbines can delay the breakeven year of investments needed to achieve NZEB. The estimated savings in net present value (NPV) are 3273 and 4284 thousand US dollars for the retrofitted and new schools respectively, and each school’s roof can generate 40.63 GWh in 25 years and avoid 29.23 kilotons of CO2.

The design of school building typologies, along with the use of advanced glazing systems such as suspended particle devices (SPD), is crucial for determining visual comfort for students. Recent research has focused on integrating SPD in architectural elements such as skylights, clerestories, and windows. In hot desert climates, minimizing window areas, employing shading mechanisms, and utilizing daylighting features such as courtyards and atriums are practical. This study explores the optimization of various architectural components in classroom designs, including Window Wall Ratios (WWR), Skylight Ratios (SR), floor levels, cardinal orientation, and SPD switching states. Using a detailed and comprehensive radiance simulation via Rhino-Grasshopper and Colibri 2.0, we conducted a thorough analysis and optimization of the SPD glazing system across different states on both annual and hourly bases. The results indicate that optimizing SPD transmittance states between 30–40%, maintaining WWRs from 20–40%, and incorporating a large skylight ratio significantly enhances the recommended work plane illuminance (WPI) and the uniformity index (Ui) of the tested typologies. This optimization improves glare control across various building typologies and provides a roadmap for architects aiming to design learning spaces that prioritize visual comfort and overall student well-being. [ABSTRACT FROM AUTHOR]

During the summer, air conditioning is increasingly used in commercial and residential structures to provide thermal comfort. The elevated condenser pressure caused by high ambient temperatures has led to a significant increase in electricity consumption in dry, hot climates. Therefore, this article presents the results of a numerical simulation investigation into the feasibility of enhancing the performance of a conventional air conditioning unit by applying a direct evaporative cooling system. The objective is to increase the cooling capacity while decreasing power consumption. The program used a small window-type air conditioner configured to simulate various weather conditions. The numerical findings indicate that incorporating evaporative cooling aids improved the system's ability to overcome numerous obstacles, resulting in a 10-20% increase in refrigeration capacity. Additionally, power consumption was reduced by approximately 3%, and the discharge temperature fell by 6-10°C. The predicted mean vote standard (PMV) for thermal conditions for human occupants yielded favorable outcomes (normal-type). Despite the challenging climate conditions prevailing during the five sweltering summer months, water production demonstrated good results, particularly in September. [ABSTRACT FROM AUTHOR]

The employment of electrochromic glazing can be a solution to balance circadian lighting and avoid glare. This can be achieved by controlling daylight entering the room and may be useful within the context of highly glazed facades in buildings in hot climates. Nevertheless, the use of this technology is rarely discussed in this context. In this regard, the aim of this study is to investigate the electrochromic glazing for the lighting conditions, including visual and non-visual effects within the luminous context of Brasilia, Brazil. The method consisted of computer simulations of a representative highly glazed non-residential room with the comparison of electrochromic glazing and conventional clear glass. Climate Studio was used to evaluate the visual effects of light for the entire year, and ALFA for the evaluation of melanopic daylight illuminance, vertical illuminance, and melanopic daylight efficacy ratio (mel-DER) in four days, including two solstices and two equinoxes encompassing the beginning of the four seasons. Results for the electrochromic glazing showed a better balance between a minimum threshold of 250 lux of mel-EDI without exceeding 1,500 lux of vertical illuminance in comparison with the clear glass. This was achieved in 33.33% of the hours for the north, against 27.78% of the hours for the east, 29.17% for the west, and 24.72% for the south. For the clear glass, this balance was achieved in only 9.17% of the hours for north, 10.28% for east, 12.22% for west, and 15% for south. Regarding the spectrum, higher results of melanopic daylight efficacy ratio were observed for the clear glass over the four simulated days. The main conclusion was that the electrochromic glazing was capable of providing a better balance between visual and non-visual requirements and can be a suitable solution for highly glazed facades in Brasilia. Nevertheless, particularly for the north orientation, the supply of circadian lighting can be jeopardized when the electrochromic glazing remained at the dark state. [ABSTRACT FROM AUTHOR]

The battery plays a pivotal role in the electric vehicle (EV) sector, and the advancement of this industry hinges on enhancing the thermal performance and efficiency of batteries, especially in regions characterized by high-temperature extremes. The primary objective of this study is to propose a battery configuration capable of operating efficiently in hot regions. To achieve this goal, we have selected six battery materials, each possessing distinct physical characteristics, for an in depth investigation into their thermal behavior within a mini-channel Thermal Management System. Subsequently, we conducted a comparative analysis of various volumetric flow rates and flow directions to determine the optimal combination. Once the best configuration was identified, we conducted a case study using realistic ground-based meteorological data to evaluate the performance of the selected battery configuration under real conditions. The results of this study reveal that material which is characterized by the specific heat of 830J.kg-1.K-1, and a thermal conductivity of Kx = Ky = 34W.m-1.K-1 and Kz = 3.4W.m-1.K-1, exhibits the highest thermal performance. Taking into account the power required for the system, the most efficient volumetric flow rate is 0.05 L/min which requires a power of 3e-7W, with the same direction of fluid inlet and outlet in the minichannels. The selected material, volumetric flow rate, and flow direction in this study ensure that the maximum temperature of (Tmax) of the cell is maintained at 29.21 °C, with a temperature difference (Tdiff) of 1.56 °C. Regarding the case study, applying this optimal configuration under the climatic conditions of Benguerir, Morocco, results in a Tmax of 29.36 °C and a Tdiff of 1.58 °C, confirming the feasibility of the proposed battery configuration and its BTMS in high-temperature conditions.

Goats play an important role in the agricultural business, providing valuable income sources through producing high-quality animal protein. They are widespread livestock for rural households due to their inherent resiliency, adaptability to many environments, and suitability in sustainable production systems. While goats are reared in highly diverse environments, a great portion of their population is reared in hot environments. Heat stress is known to affect goats’ productive and reproductive performance negatively. However, goats can remarkably thrive in harsh conditions due to physiological, metabolic, and molecular adaptive mechanisms. In the face of it, in the last decades, the nutrition of goats, particularly their nutritional requirements, has received special attention. Research groups worldwide have dedicated their efforts to updating feeding systems for goats. Our objective was to present the recent findings on the energy and nutrient requirements of growing and pregnant goats in hot environments. Energy and protein requirements for the maintenance and growth of goats are influenced by sex and genotype only when mature weight is not considered in the models. Sex and genotype affect the efficiency of energy use for growth but do not affect the efficiency of protein use. Major mineral requirements for maintenance and growth are not affected by sex, except for magnesium. However, the phosphorus, sodium, and potassium requirements of goats raised in hot environments differ from those in the feeding systems. This difference may be related to the adaptation mechanisms goats employ to cope with the hot environmental conditions. Regarding requirements for pregnancy, there was no effect of days of pregnancy on the energy or protein requirements. The efficiency of metabolizable energy utilization for pregnancy increased with the progress of pregnancy. Mineral accretion for pregnancy differs between single and twin pregnancies and, irrespective of pregnancy type, the mineral requirements increase as pregnancy progresses. The differences between the estimated dietary requirements of goats raised in hot environments and the most widely adopted feeding systems suggest that these goats may be using energy and nutrients to cope with heat stress and other stressors associated with hot environments. The recent findings on energy, protein, and mineral requirements of growing and pregnant goats can be an important resource of information for enhancing feeding systems worldwide.

Cricket has three unique formats - Test Cricket, One Day Internationals and Twenty20s. Each format has differing physiological and psychological demands, with the location of the match contributing to these demands. Playing conditions in India are among the most demanding of the cricketing nations. It is therefore necessary to explore the physical demands of the game and the nutritional and hydration requirements to ensure that high performance levels are maintained, and recovery is efficient to combat the short turn around between high workloads. Utilising Google Scholar and the Australian Catholic University literature databases a review of existing systematic reviews and randomised controlled trials was conducted to understand the training and match demands for fast bowlers and the physical and physiological characteristics of these athletes. Determining these characteristics allows practical nutrition, hydration, and supplementation recommendations to be made from the existing literature appropriate to the workload and level of athlete. A total of 66 sources met the inclusion criteria for this review. It was identified that fast bowlers should consume 2.0 grams of protein per kilogram of body weight (g/kg/bw) across meals containing at least 0.3g/kg/bw of protein, 6-10g/kg/bw of carbohydrates per day with 1-4g/kg/bw in the 1-4 hours pre-game, 30 grams per hour (g/hr) during sessions and 1-1.5g/kg/bw hourly for the 1-4 hours post-match. Fast bowlers should also have approximately 30% of their energy intake coming from fats, in particular polyunsaturated and monounsaturated fats. In addition, players should aim to rehydrate post-match with 1.25-1.5L of fluid for every kg of body weight lost. Lastly, 20-25g of whey protein is recommended to promote recovery post-match and if required 3mg/kg/bw of caffeine could be consumed to reduce the effects of mental fatigue. [ABSTRACT FROM AUTHOR]

The employment of electrochromic glazing can be a solution to balance circadian lighting and avoid glare. This can be achieved by controlling daylight entering the room and may be useful within the context of highly glazed facades in buildings in hot climates. Nevertheless, the use of this technology is rarely discussed in this context. In this regard, the aim of this study is to investigate the electrochromic glazing for the lighting conditions, including visual and non-visual effects within the luminous context of Brasilia, Brazil. The method consisted of computer simulations of a representative highly glazed non-residential room with the comparison of electrochromic glazing and conventional clear glass. Climate Studio was used to evaluate the visual effects of light for the entire year, and ALFA for the evaluation of melanopic daylight illuminance, vertical illuminance, and melanopic daylight efficacy ratio (mel-DER) in four days, including two solstices and two equinoxes encompassing the beginning of the four seasons. Results for the electrochromic glazing showed a better balance between a minimum threshold of 250 lux of mel-EDI without exceeding 1,500 lux of vertical illuminance in comparison with the clear glass. This was achieved in 33.33% of the hours for the north, against 27.78% of the hours for the east, 29.17% for the west, and 24.72% for the south. For the clear glass, this balance was achieved in only 9.17% of the hours for north, 10.28% for east, 12.22% for west, and 15% for south. Regarding the spectrum, higher results of melanopic daylight efficacy ratio were observed for the clear glass over the four simulated days. The main conclusion was that the electrochromic glazing was capable of providing a better balance between visual and non-visual requirements and can be a suitable solution for highly glazed facades in Brasilia. Nevertheless, particularly for the north orientation, the supply of circadian lighting can be jeopardized when the electrochromic glazing remained at the dark state.

This article examines the adoption of Battery Electric Buses (BEBs) in hot climates, highlighting the pursuit of sustainable transportation. It contrasts bus technologies and their adaptability to heat, with a focus on the operational strategies and performance metrics suited to these environments. The role of charging infrastructure is assessed, alongside the thermal tolerance of lithium-ion batteries, to establish their compatibility with BEBs in warm regions. Energy consumption patterns of BEBs are analyzed, considering the extra load from cooling systems. Additionally, the review touches on the economic implications and market acceptance, providing a succinct overview of financial impacts and consumer behavior. The paper identifies gaps in current research, particularly in relation to hot weather conditions, and validates findings to aid stakeholders in making informed decisions and spurring innovation in the field. With concise problem statements and state-of-the-art evaluations, this contribution offers a pathway for future research and a deeper understanding of electric bus operations under thermal stress.

Saudi Arabia faces significant challenges in managing the rising energy consumption in buildings driven largely by its hot climatic conditions. As a result, retrofitting building facades to enhance energy efficiency has become a critical strategy. This study assesses the effectiveness of various façade retrofit strategies in reducing cooling electricity consumption using a real-time case study in Dhahran, Saudi Arabia. The strategies explored include external wall upgrades, window replacements, and installation of shading devices. Each strategy was evaluated individually, considering the reduction in heat gains, cooling load, and payback period as key performance indicators. To further maximize energy efficiency, these strategies were also analyzed in combination using the genetic algorithm optimization method, yielding 224 possible facade configurations. The optimal solution included the use of an External Thermal Insulation Composite System (ETCIS) in walls, louvers in windows, and low-emissivity coating with Argon gas-filled glazing, achieving a cooling energy reduction of approximately 16% and a payback period of 14.8 years. This study provides several recommendations for improving the efficiency of retrofitting building façades in hot climatic conditions.

This paper presents a case study of energy flexibility strategies for a building located in the hot climate of Dubai, a type of climate in which energy flexibility has been under-researched. Energy flexibility is changing the routine-consumption profile and deviating from the normal operation of the building by the users to manage the variability in the load profile and cost of electricity. The three flexibility strategies being considered are based on the modulation of the indoor air temperature setpoint profile while considering different marginal costs for electricity. The main objective is to quantify the energy storage flexibility of each strategy and evaluate its impact on the system ramping and load factor. The study was carried out utilizing a grey-box, resistance–capacitance model of the building, which was validated against experimental measurements. This study is the first to use the following five indicators simultaneously: load factor, system ramping, storage capacity, peak-period demand reduction, and cost savings. Combining these indicators helps building facility managers and distribution system operators (DSOs) better understand the implications of implementing a specific flexibility strategy in a building or a group of buildings. When comparing the indicators of each strategy with each other, it was observed that depending on the amplitude of the change in the electricity cost signal during the peak period, a significant cost reduction of more than 25% could be achieved through the implementation of specific flexibility strategies compared with the normal baseline operating condition.

Air-source heat pumps are strongly influenced by outdoor conditions, it is expected that ongoing climate changes may impact their operation. This paper presents a predictive analysis of the behaviour of air-source heat pumps in two cities with extremely cold and warm climates in the short, medium, and long term. The seasonal coefficient of performance and heat pump seasonal energy efficiency index are evaluated over the years, considering climate change for both locations. Climate change will shorten the winter period and prolong the summer. In winter, this results in a slight softening of the seasonal coefficient of performance and a reduction in operating hours. In summer, there is a slight increase in seasonal energy efficiency ratio values and hours of operation. The work highlights how the performance of the air-source heat pump, on average, will improve in winter due to an average increase in temperature. Heat pumps are expected to be used in the future and in geographical areas where they are not currently used due to the extreme winter temperatures.

In recent decades, the energy retrofit design of buildings has been one of the most effective methods to achieve high-performance buildings. The government office buildings in Iran account for 15% of the non-residential building sector; hence, energy retrofitting of existing office buildings could effectively reduce total energy consumption and Carbon dioxide emissions. This study aims to evaluate the effect of various facade systems with cool materials on the thermal behavior and energy performance of a typical existing office building in a hot climate. The proposed hybrid retrofit method combines design and energy retrofit strategies while evaluating the effects of different workspace layouts and facade systems on external surface temperatures and total energy consumption. Applying such a method, the most optimal design and energy retrofit strategies were selected using a combination of optimization and scenario-based approaches. The results showed that using double-skin facades could reduce annual energy consumption and Carbon dioxide emissions by 63%. Moreover, the results indicated the most efficient types of cool coatings materials for reducing cooling loads. [ABSTRACT FROM AUTHOR]

Loss of homeostasis and poor egg production are common in laying hens during hot season. These negative effects of extreme ambient temperature have resulted in great economic losses to poultry farmers in the tropical regions. This study investigate d benefits of supplementing watermelon juice (WJ) and ascorbic acid (AA) to ISA Brown (IB) hens managed under hot climate on productive performance and some hormonal responses. Ninety-six IB pullets aged 34 weeks were randomly allotted to four groups (C, T1, T2, and T3), each containing 24 in triplicates. The control group (C) was given water with neither WJ nor AA. Water given to groups T1, T2 was supplemented with 20% and 40% WJ, respectively, while T3 was supplemented with 200mg AA/litre of water. The results show a significant (P ≤ 0.05) increase in water intake in T3 compared to other groups. Total egg production, daily egg production and hen-day egg production were significantly (P ≤ 0.05) improved by the supplements, as total egg weights improved in T1:(272.2 ± 35.16g) and T2:(272.1 ± 35.06g) compared to C:(212.2 ± 25.06g) and T3:(238.5 ± 19.23g). The supplements caused 24.46%, 22.70% and 9.43% rise in percentage egg production in groups T1, T2, and T3 respectively. Serum corticosterone (C:10.88 ± 1.12; T1:10.20 ± 1.06; T2:9.61 ± 0.792; T3:7.23 ± 2.36ng/mL) and thyroxine levels (C:1.45 ± 0.562; T1:0.41 ± 0.109; T2:0.39 ± 0.367; T3:0.60 ± 0.489μg/dL) decreased significantly (P ≤ 0.05) in supplemented layers, while serum prolactin and triiodothyronine differed non-statistically. In conclusion, WJ and AA supplementation ameliorated heat stress in IB layers managed under hot climate as it significantly lowered corticosterone and improved egg production. Therefore, supplementing 20%, 40%WJ or 200mg AA/litre in water is recommended for managing heat stress in IB layer chickens. [ABSTRACT FROM AUTHOR]

This study investigates the impact of building grouping patterns on enhancing shading in public open spaces, considering different solar orientations, housing densities, and the hot climatic conditions of Saudi Arabia. The study considered a set of environmental performance indicators, including the percentage of open space shaded areas, heat gains through the building envelope, open space surface temperature, and the natural ventilation potential of each grouping pattern of the buildings. The results showed that at a building height of five floors, the percentage of open space shaded areas ranged from 14% to 53%. However, using the suggested multi-criteria evaluation framework to consider the above-mentioned performance indicators revealed more in-depth observations. Configurations that included parallel rows of buildings staggered and centralized in the middle of the site offered the best performance in this regard. This shows that compact grouping patterns in which open spaces are decentralized offer more urban shading and protection against undesirable heat gains through the building envelope during summer. The results of this study will enable a wider exploration of different building grouping patterns, which are needed in the harsh hot climate of Saudi Arabia to respond to current rapid housing development plans. [ABSTRACT FROM AUTHOR]

Objective Better feed efficiency can be achieved by selecting rabbit genotypes with lower residual feed intake (RFI) under high ambient temperatures. Methods Two genotypes of rabbits (Jabali, Saudi local breed and imported, Spanish V-line) were used to derive RFI and to investigate the relationship between RFI and productive traits. In total, 250 animals (125 each) were housed in individual wire mesh cages in a semi-closed rabbitry. Growth performance, feed criteria, carcass evaluation, biochemical blood analysis, and immune responses were determined. Results Superiority in growth performance, feed efficiency, carcass characteristics, and cellular immunity was recorded in the Jabali breed compared to the V-line genotype. According to regression analysis, a significant effect of daily body weight gain was found, upon computing the expected feed intake in both genotypes. Moreover, mid-body weight0.75 had a significant effect only in the Jabali breed. Positive correlation coefficients between RFI and dry matter feed intake or feed conversion ratio were found. The same trend in this relationship between RFI and productive traits was observed in some cases for both genotypes. An opposite trend in correlations was observed in the studied genotypes for some traits. Conclusion The results suggest that the relationship between RFI and productive traits must be taken into consideration in rabbit breeding programs under the prevailing environment. However, further studies are required to investigate the effect of rabbit genotype and environmental factors on computing RFI.

Air conditioners (ACs) are more commonly used nowadays in residential and commercial buildings to achieve thermal comfort in the summer season. Due to the high outside temperature, condenser pressure was highest and ultimately resulted in high electricity consumption. One of the ways to reduce the energy consumption of AC systems and increase cooling capacity is by reducing air temperature entering the condenser by using the evaporative cooling principle. This article presents an experimental and theoretical investigation of improving the performance of the conventional air conditioning unit supported by a direct evaporative cooling system to increase the cooling capacity and reduce the consumption of power in hot and dry climates. A window-type AC unit was implemented in the experiment where the AC system is modulated to provide a wide range of various weather conditions. The results show that using evaporative cooling assist enhanced the system to overcome the many challenges by which the refrigeration capacity was increased in the range of 10–20%. Also, the results show a decrease in outlet temperature by 6–10°C, and the power consumption was reduced by about 3%. MATLAB program was used to analyze different data that were obtained. The input parameters for this program are the inlet conditions such as the weather conditions of the located city, namely the outdoor dry temperature and the outdoor relative humidity. The effectiveness and cooling capacity were calculated based on the frontal air velocity and the inlet air temperature. A comparison between the experimental and theoretical work showed a good agreement, as the relative difference is less than 9%.

The design of school building typologies, along with the use of advanced glazing systems such as suspended particle devices (SPD), is crucial for determining visual comfort for students. Recent research has focused on integrating SPD in architectural elements such as skylights, clerestories, and windows. In hot desert climates, minimizing window areas, employing shading mechanisms, and utilizing daylighting features such as courtyards and atriums are practical. This study explores the optimization of various architectural components in classroom designs, including Window Wall Ratios (WWR), Skylight Ratios (SR), floor levels, cardinal orientation, and SPD switching states. Using a detailed and comprehensive radiance simulation via Rhino-Grasshopper and Colibri 2.0, we conducted a thorough analysis and optimization of the SPD glazing system across different states on both annual and hourly bases. The results indicate that optimizing SPD transmittance states between 30–40%, maintaining WWRs from 20–40%, and incorporating a large skylight ratio significantly enhances the recommended work plane illuminance (WPI) and the uniformity index (Ui) of the tested typologies. This optimization improves glare control across various building typologies and provides a roadmap for architects aiming to design learning spaces that prioritize visual comfort and overall student well-being.

Single-effect absorption chillers are the most popular because of their low cost, despite their low COP. Among them, GAX-based AirCooled absorption chillers are very interesting because they have improved COP because of their ability to recover internal heat at low thermal lifts. This workshop analysed the ability of these types of chillers to recover internal heat at high thermal lifts by changing the pressure drop of an extra valve, a feature of the Robur absorption chiller when operating in subzero applications. The complete differential mathematical model analyses the components involved in heat supply and recovery and provides information on their operation. A thorough assessment of exergy destruction in the absorption refrigeration system was carried out. The main results show that when the chiller is driven at a temperature of 210 °C and an ambient temperature of 40 °C, a rise in the pressure drop of the additional valve, ΔPval1, from 175 to 700 kPa causes the extension of the vapour purification process to be reduced by 13.7% in the column of distillation and by 70.6% in the rectifier. Despite the adverse effect of ΔPval1 increase on the cooling capacity, there is no risk that the distillation column operates in weeping mode. However, this adjustment increases the internal thermal load of the generator by 26.9%. Furthermore, the mass fraction of the refrigerant flow is very similar. In addition, the occurrence of a two-phase solution flow at the input of a solution cooling absorber is the practical upper limit of ΔPval1. The refrigerant flow in the solution cooling absorber is reduced by 21.3%. Finally, the contribution of the heat recovery loop to the total exergy destruction in the refrigeration system rises slightly by 2.7% when ΔPval1 increases due to the contribution of the vapour purification system, which increases at the expense of that of the re-boiler and the SolutionCooled absorber. The results of this study show to what extent the modified GAX-based cycle can function effectively at high thermal lifts.

A modular mathematical model has been created to simulate an ammonia-water absorption refrigeration system indirectly fired and air-cooled. The model includes governing equations based on mass, species, and energy balances, implemented for the main components of the system. It accounts for both thermal and mass resistances in the transfer processes that occur in the system. The study evaluates the performance of the ROBUR® absorption refrigeration system, model ACF60-00 LB, operating under part-load conditions, driven by hot water temperatures ranging between 160 and 210 °C, while the ambient temperature remains up to 40 °C. This refrigeration system is characterised by including an extra valve that allows active control of the pressure levels of the system. The analysis focusses on the effect of its active control on the size of the system. The results show that increasing the pressure loss in this valve reduces the size of the air-cooled absorber to 37.3 % of its nominal size at an ambient temperature of 40 °C, while the reduction in refrigerant mass flow is 18.5 %, while the condenser size decreases 3.1 times. Evaporator, air-cooled absorber and condenser effectiveness are minimally affected. Additionally, contribution of condenser and evaporator to exergy destruction is balanced.

The object of research is the air-cooling system, for F4L912 direct injection diesel engine (mounted on the bench), manufactured by the Motor Enterprise (EMO). It is a naturally aspirated inline 4-cylinder engine. Maximum engine power is 49 kW obtained at maximum speed rotation of 2300 rpm. Air cooling is a critical aspect of engine performance, and studying it experimentally can provide valuable insights into the engine’s thermal behaviour and efficiency. One of the most problematic places is the high local temperature of the 4th cylinders sleeves. An innovative improvement of the cooling system is proposed. It is based on increasing the cooling air flow. It consists in the installation of new driving pulleys of the blowing turbine with different diameters. The use of these new pulleys allowed moderating the wall temperature of the liner and the cylinder head of the 4th cylinder and the thermal rebalancing of the engine. Significant improvements have been noted in cylinder wall temperature, exhaust gas temperature, and lubricating oil temperature. Drawing up the heat balance enabled us to quantify the useful work, the heat lost in the cooling water, the heat lost through the exhaust gases, the heat carried away by the lubricating oil and other losses (losses not accounted for). It is clear from the results that the high temperature in the engine has indeed been reduced and the cooling performance of the whole engine has been improved. The results show that the increase in airflow produced an improvement in cooling conditions as well as a reduction in exhaust gas temperatures which will have a significant impact on reducing NOx emissions. In future work, it is planned to improve the cooling system of the Emo F4L912 engine, by studying the effects of the geometry, number, and inclination of the turbine blades on the air flow supplied. [ABSTRACT FROM AUTHOR]

The climate change crisis has resulted in the need to use sustainable methods in architectural design, including building form and orientation decisions that can save a significant amount of energy consumed by a building. Several previous studies have optimized building form and envelope for energy performance, but the isolated effect of varieties of possible architectural forms for a specific climate has not been fully investigated. This paper proposes four novel office building form generation methods (the polygon that varies between pentagon and decagon; the pixels that are complex cubic forms; the letters including H, L, U, T; cross and complex cubic forms; and the round family including circular and oval forms) and evaluates their annual thermal energy use intensity (EUI) for Cairo (hot climate). Results demonstrated the applicability of the proposed methods in enhancing the energy performance of the new forms in comparison to the base case. The results of the optimizations are compared together, and the four families are discussed in reference to their different architectural aspects and performance. Scatterplots are developed for the round family (highest performance) to test the impact of each dynamic parameter on EUI. The round family optimization process takes a noticeably high calculation time in comparison to other families. Therefore, an Artificial Neural Network (ANN) prediction model is developed for the round family after simulating 1726 iterations. Training of 1200 configurations is used to predict annual EUI for the remaining 526 iterations. The ANN predicted values are compared against the trained to determine the time saved and accuracy. [ABSTRACT FROM AUTHOR]

In this paper, earth–air heat exchanger is examined to achieve better system operation to cool a building in the arid climate of Ouargla city (Algeria). A higher cooling power requires a big pipe size which increases the pressure losses. Based on fluid dynamics, a new approach is carried out to evaluate the air flow pressure losses that contribute to the determination of the required blower power. The mathematical model of governing equations set is presented, and its numerical solution is calculated using a Matlab program. The multi-objectives optimization between two opposite targets is adopted for achieving the compromise solutions between maximal efficiency and minimal system size. For a given cooling power, the resolution of the earth–air heat exchanger model is carried out using the weighting method to perform the bi-objective optimization. At each cooling power, Pareto curves are generated for plotting the optimal points of efficiency and lateral pipe area. Obtained results show that for a chosen cooling power range, the system operation must reach at least an efficiency of 35% but less than 90% to cover all the size-efficiency compromises. Also, the lateral pipe area must be at least 6.025 m2/kW to start with acceptable efficiency. On the hottest summer day, for 3.5 kW as cooling power, the pipe outlet temperature reaches about 26 °C at a relatively high pipe length of about 95 m. [ABSTRACT FROM AUTHOR]

Air-source heat pumps are strongly influenced by outdoor conditions, it is expected that ongoing climate changes may impact their operation. This paper presents a predictive analysis of the behaviour of air-source heat pumps in two cities with extremely cold and warm climates in the short, medium, and long term. The seasonal coefficient of performance and heat pump seasonal energy efficiency index are evaluated over the years, considering climate change for both locations. Climate change will shorten the winter period and prolong the summer. In winter, this results in a slight softening of the seasonal coefficient of performance and a reduction in operating hours. In summer, there is a slight increase in seasonal energy efficiency ratio values and hours of operation. The work highlights how the performance of the air-source heat pump, on average, will improve in winter due to an average increase in temperature. Heat pumps are expected to be used in the future and in geographical areas where they are not currently used due to the extreme winter temperatures. [ABSTRACT FROM AUTHOR]

This study investigates energy efficiency in high-rise residential buildings in Abu Dhabi, where the increased use of glass building façades has led to increased air-conditioning costs due to heat gain. The research focuses on evaluating the type of glass and the appropriate cavity between glass façades to minimize energy consumption while incorporating sustainability and innovative design principles. To achieve these objectives, this study employs a Double Skin Façade (DSF), a high-performance façade that adapts to the external climate conditions to fulfill internal cooling load requirements and meet occupants' needs. Data were collected through an online survey distributed among residents of a selected residential tower, and a combination of qualitative and quantitative approaches was utilized to analyze the gathered information. The selected case study was analyzed using Energy Plus simulation software using the existing data and available details. The analysis aimed to identify the optimal DSF design that significantly enhances energy efficiency. The findings of this study emphasize the substantial impact of the optimum DSF design on energy efficiency in high-rise residential buildings. Through modeling existing data and comparing them with new model results for each variable, this study demonstrates that a DSF with a 35 cm cavity, comprising a double-glazed single skin layer in the interior and a Low-E double-glazed single skin layer as an outer layer, can reduce overall air-conditioning energy consumption by over 25%. These outcomes provide valuable insights into implementing DSF as a solution to address the unique energy challenges presented by high-rise residential buildings in hot climates. [ABSTRACT FROM AUTHOR]

The present study aimed to assess the effects of three probiotic-supplemented diets on growth, cecal fermentation, blood biochemical, and intestinal morphological features in growing rabbits reared under summer conditions. Rabbits were allotted into four groups: G1 rabbits were fed the basal diet (control), G2 rabbits received Enterococcus faecium (EF) and Clostridium butyricum (CB) complexes (1 × 108 and 2.5 × 106 cfu/kg diet, respectively), G3 rabbits were given CB (2.5 × 106 cfu/kg diet) and yeast complexes (1 g/kg diet), and G4 rabbits received EF (2 × 108 cfu/kg diet) and yeast (1 g/kg diet). G2 rabbits exhibited the highest performances in terms of enhanced body weight and weight gain, protein efficiency ratio and feed conversion ratio (P<0.05). Serum total protein, globulin, immunoglobulin M, and highdensity lipoprotein concentrations were higher in probiotic-fed rabbits than those in controls. Additionally, lipid profile parameters were significantly reduced in the probiotic-fed rabbits, with the lowest concentrations measured in G4 rabbits (P<0.05). Rabbits given EF and CB had the highest total volatile fatty acid (VFA) and propionic acid levels and the lowest ammonia concentrations. Increased villi length and muscular layer thickness and reduced crypt depth were observed in rabbits receiving EF and CB compared with the values obtained in controls (P<0.05). In summary, supplementing fattening rabbit diets with EF and CB, as a novel formulation, might be a promising and easy method to enhance growth performance under hot climate conditions by improving the feed utilization, immune response, serum lipid profile, cecal VFA production, and duodenal morphology. [ABSTRACT FROM AUTHOR]

Objective: Better feed efficiency can be achieved by selecting rabbit genotypes with lower residual feed intake (RFI) under high ambient temperatures. Methods: Two genotypes of rabbits (Jabali, Saudi local breed and imported, Spanish V-line) were used to derive RFI and to investigate the relationship between RFI and productive traits. In total, 250 animals (125 each) were housed in individual wire mesh cages in a semi-closed rabbitry. Growth performance, feed criteria, carcass evaluation, biochemical blood analysis, and immune responses were determined. Results: Superiority in growth performance, feed efficiency, carcass characteristics, and cellular immunity was recorded in the Jabali breed compared to the V-line genotype. According to regression analysis, a significant effect of daily body weight gain was found, upon computing the expected feed intake in both genotypes. Moreover, mid-body weight0.75 had a significant effect only in the Jabali breed. Positive correlation coefficients between RFI and dry matter feed intake or feed conversion ratio were found. The same trend in this relationship between RFI and productive traits was observed in some cases for both genotypes. An opposite trend in correlations was observed in the studied genotypes for some traits. Conclusion: The results suggest that the relationship between RFI and productive traits must be taken into consideration in rabbit breeding programs under the prevailing environment. However, further studies are required to investigate the effect of rabbit genotype and environmental factors on computing RF [ABSTRACT FROM AUTHOR]

The current study was conducted to investigate the influence of dietary Arginine levels supplementation on broiler performance, some physiological parameters under summer conditions. One hundred and twenty, one day old unsexed of Arbor Acres broiler chicks, were randomly divided into 4 equal groups in equal 3 replicates of 10 chicks each. The first group was fed control (base diet), the 2nd ; 3rd and 4th groups fed the control diet supplemented with 0.1%, 0.3%, and 0.5% Arginine, respectively. All chicks were maintained under the same management from 1 to 38 days of age. The ambient temperature during this period fluctuated between (30-35 oC). The results were as follows: Compared to chicks given either a control diet or diets supplemented with 0.1 and 0.3% L-Arginine, chicks fed diets containing 0.5% Arginine had significantly the highest final body weight and weight gain values. The two groups received either 0.3 or 0.5 L-Arginine in their diets had recorded the best FCR ratio and the lowest amounts of feed intake at the end of experimental period. An increase in dietary arginine levels dramatically decreased TL, TC, TG, and LDL during the grower and finisher phases. As the level of Arginine supplementation rose, there was a significant rise in TP, Al, and globin, respectively. No difference in carcass traits was seen among the examined arginine levels. In general, it can be concluded that adding L-Arginine in broilers diet was useful in increasing FCR and lowering FI, blood cholesterol and abdominal fat and dietary added 0.5 L-Arginine/kg diet was more efficient in improving the performance of Arbor Acres broiler chicks under hot climate conditions. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the thermoregulatory capacity and performance of Saanen goat kids from birth to weaning in a hot climate. Twelve newborn males and female goat kids with an initial body weight of 4.17 ± 0.81 kg were used. Physiological responses, climatic variables, and biometric traits data were collected. Univariate and multivariate analysis techniques were used. Heart rate (HR) was high up to the 6th week of life, with a reduction from the 7th week on (P < 0.001). Rectal temperature (RT) was lower in the first 2 weeks (P < 0.001), with an increase and stabilization occurring in the 7th and 8th weeks. Coat surface temperature (ST) was more activated from the 5th week onwards (P < 0.001). Body weight (BW) and withers height (WH) were higher in later weeks of the calving phase with a linear effect (P < 0.001). The first principal component demonstrated the relationship of sensible heat dissipation × body area of the goat kids; the second component shows the relationship of meteorological data with RT, having a positive relationship between RT with RH and negative with AT, and the third component points to the association of RR and HR. Of the animals, 81.3% were correctly classified in their group of origin in discriminant canonical analysis, with emphasis on the classification of the kids in the 1st–2nd and 3rd–4th weeks (classification percentage Ʃ = 95.8%). It is concluded that (i) newborn kids activate latent mechanisms to maintain their homoeothermic during the first 2 weeks of life, and as they grow, they use sensitive heat loss processes, especially from the 5th week of life onwards and (ii) male and female goats do not show sexual dimorphism effect on body performance and body morphometric measurements up to 60 days of life. [ABSTRACT FROM AUTHOR]

This work treats the air ventilation and the cooling of a tunnel greenhouse. For determining the temperature of the cover surface, the energy audit is examined by the Trnsys software. The investigation of the thermal comfort inside the greenhouse is performed using the airflow conservation equations. Ansys CFD code is used to simulate indoor thermal behavior. Openings and chimneys are added for evacuating hot air and participating in greenhouse cooling. Natural ventilation of greenhouse and Rayleigh number changes are investigated to show their effects on indoor air temperature. The numeral simulation shows that the increase in buoyancy force leads to an indoor temperature decrease. But experimental tests show that the drowning up of air flow toward the chimney requires an aspirator to reinforce the buoyancy. The integration of geothermal energy shows considerable improvement in reducing indoor temperature and getting less cooling energy levels in critical climatic conditions. Daily energy of 5 kWh is needed to cool the greenhouse at an ambient temperature of 37 °C. Further energy consumption reduction can reach 50% for an ambient temperature of less than 30 °C. [ABSTRACT FROM AUTHOR]

This study investigates the impact of building grouping patterns on enhancing shading in public open spaces, considering different solar orientations, housing densities, and the hot climatic conditions of Saudi Arabia. The study considered a set of environmental performance indicators, including the percentage of open space shaded areas, heat gains through the building envelope, open space surface temperature, and the natural ventilation potential of each grouping pattern of the buildings. The results showed that at a building height of five floors, the percentage of open space shaded areas ranged from 14% to 53%. However, using the suggested multi-criteria evaluation framework to consider the above-mentioned performance indicators revealed more in-depth observations. Configurations that included parallel rows of buildings staggered and centralized in the middle of the site offered the best performance in this regard. This shows that compact grouping patterns in which open spaces are decentralized offer more urban shading and protection against undesirable heat gains through the building envelope during summer. The results of this study will enable a wider exploration of different building grouping patterns, which are needed in the harsh hot climate of Saudi Arabia to respond to current rapid housing development plans.

Sustainable architecture is a key approach for creating sustainable cities and reducing the impact of climate change. In hot, arid regions, the passive design traditional architecture is known for its ability to provide comfortable indoor environments and outdoor shaded areas, in contrast to the use of energy-intensive air conditioners in a great deal of modern architecture. Thus, this research used a qualitative methodology based on ENVI-met software to study, investigate, and compare the thermal performance of two urban fabrics as case studies (traditional and modern districts) in the hot, arid climate of the United Arab Emirates. The thermal performance of the old urban districts was better than the new ones, with a lower maximum potential air temperature and an improvement in the level of thermal comfort, measured by a predicted mean vote. Moreover, it was found that enhancing the shade in the outdoor open areas in the modern district, mimicking the traditional passive design solutions, resulted in lower air temperature and PMVs. This research is expected to be one step among many towards creating sustainable, innovative modern architecture. [ABSTRACT FROM AUTHOR]