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Cooling system is in charge of a high percent of total energy consumption in buildings. Different cooling systems and devices have different effects on the cooling load and energy consumption. The main objective of this paper is to study the effects of floor and ceiling temperature in comparison with other parameters including location of air diffusers and application of insulation and sealant. On the other hand, hospitals are huge buildings with high energy requirements and systems compared to other buildings such as universities, schools and offices. In this paper the impacts of these different cooling parameters on the temperature and cooling load in a room of a hospital are studied using Design of Experiments (DOE) and the Taguchi method. The experiments are simulated in Energy Plus to achieve the comfort temperature in one hospital’s room in Iran during six months of spring and summer. Using different cooling systems such as chilled floor (during night to decrease the peak load during day) and ceiling in combination with air handling unit can provide people satisfaction while optimizing energy consumption. The results show that the location of inlet and outlet diffusers has the most effect while the chilled floor (when the other systems are off) has the less impact on reaching comfort temperature. The ranking of parameters and their interactions has been discussed through the paper. [ABSTRACT FROM AUTHOR]

Multi-layered walls are commonly used building elements that have the potential to reduce cooling loads by improving thermal insulation. This paper investigates the potential of reducing cooling load using different types of multi-layered. For this purpose, a model of a small room (1.15 × 1 × 1 m) was constructed. A software code based on the radiant time series method was developed using MATLAB to extract heat gain results. The results were verified with other researchers, and there was a 0.89% error. Overall, the results show that using solid or hollow bricks in construction can be an effective way to reduce heat gain, where Wall-C achieved the minimum heat gain of 60.8 W m−2 compared to 66.207 and 71.225 W m−2 for Wall-A and Wall-B respectively. The reasons for this could be due to the insulation hollow area provided by the bricks, which tends to reduce heat transfer through the wall. [ABSTRACT FROM AUTHOR]

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An important aspect in improving the energy efficiency of buildings is the effective use of building heating and cooling load prediction models. A lot of studies have been undertaken in recent years to anticipate cooling and heating loads. Choosing the most effective input parameters as well as developing a high-accuracy forecasting model are the most difficult and important aspects of prediction. The goal of this research is to create an intelligent data-driven load forecast model for residential construction heating and cooling load intensities. In this paper, the shuffled shepherd red deer optimization linked self-systematized intelligent fuzzy reasoning-based neural network (SSRD-SsIF-NN) is introduced as a novel intelligent data-driven load prediction method. To test the suggested approaches, a simulated dataset based on the climate of Dhahran, Saudi Arabia will be employed, with building system parameters as input factors and heating and cooling loads as output results for each system. The simulation of this research is executed using MATLAB software. Finally, the theoretical and experimental results demonstrate the efficacy of the presented techniques. In terms of Mean Square Error (MSE), Root Mean Square Error (RMSE), Regression (R) values, Mean Absolute Error (MAE), coefficient of determination (R2), and other metrics, their prediction performance is compared to that of other conventional methods. It shows that the proposed method has achieved the finest performance of load prediction compared with the conventional methods. [ABSTRACT FROM AUTHOR]

Building energy consumption prediction has become an important research problem within the context of sustainable homes and smart cities. Data-driven approaches have been regarded as the most suitable for integration into smart houses. With the wide deployment of IoT sensors, the data generated from these sensors can be used for modeling and forecasting energy consumption patterns. Existing studies lag in prediction accuracy and various attributes of buildings are not very well studied. This study follows a data-driven approach in this regard. The novelty of the paper lies in the fact that an ensemble model is proposed, which provides higher performance regarding cooling and heating load prediction. Moreover, the influence of different features on heating and cooling load is investigated. Experiments are performed by considering different features such as glazing area, orientation, height, relative compactness, roof area, surface area, and wall area. Results indicate that relative compactness, surface area, and wall area play a significant role in selecting the appropriate cooling and heating load for a building. The proposed model achieves 0.999 R 2 for heating load prediction and 0.997 R 2 for cooling load prediction, which is superior to existing state-of-the-art models. The precise prediction of heating and cooling load, can help engineers design energy-efficient buildings, especially in the context of future smart homes. [ABSTRACT FROM AUTHOR]

According to the established model of a single resonance energy selective electron refrigerator with heat leakage in the previous literature, this paper performs multi-objective optimization with finite-time thermodynamic theory and NSGA-II algorithm. Cooling load ( R ¯ ), coefficient of performance (ε), ecological function ( E C O ¯ ), and figure of merit ( χ ¯ ) of the ESER are taken as objective functions. Energy boundary (E ′ / k B) and resonance width (Δ E / k B) are regarded as optimization variables and their optimal intervals are obtained. The optimal solutions of quadru-, tri-, bi-, and single-objective optimizations are obtained by selecting the minimum deviation indices with three approaches of TOPSIS, LINMAP, and Shannon Entropy; the smaller the value of deviation index, the better the result. The results show that values of E ′ / k B and Δ E / k B are closely related to the values of the four optimization objectives; selecting the appropriate values of the system can design the system for optimal performance. The deviation indices are 0.0812 with LINMAP and TOPSIS approaches for four-objective optimization ( E C O ¯ − R ¯ − ε − χ ¯ ), while the deviation indices are 0.1085, 0.8455, 0.1865, and 0.1780 for four single-objective optimizations of maximum E C O ¯ , R ¯ , ε , and χ ¯ , respectively. Compared with single-objective optimization, four-objective optimization can better take different optimization objectives into account by choosing appropriate decision-making approaches. The optimal values of E ′ / k B and Δ E / k B range mainly from 12 to 13, and 1.5 to 2.5, respectively, for the four-objective optimization. [ABSTRACT FROM AUTHOR]

The foundation of energy-efficient architectural design is modeling heating and cooling loads (HLs and CLs), which defines the heating and cooling apparatus constraints necessary to maintain a suitable interior air environment. It is possible that analytical models for energy-efficient buildings might offer an accurate evaluation of the influence that various building designs would have. The implementation of these instruments, however, might be a process that requires a significant amount of manual labor, a significant amount of time, and is reliant on user experiences. In light of this, the authors of this paper present two unique methods for estimating the CL of residential structures in the form of complex mathematical concepts. These methodologies include an evolutionary web algorithm (EWA), biogeography-based optimization (BBO), and a hybridization of an adaptive neuro-fuzzy interface system (ANFIS), namely BBO-ANFIS and EWA-ANFIS. The findings initiated from each of the suggested models are evaluated with the help of various performance metrics. Moreover, it is possible to determine which model is the most effective by comparing their coefficient of determination ( R 2   ) and its root mean square error (RMSE) to each other. In mapping non-linear connections between input and output variables, the observed findings showed that the models used have a great capability. In addition, the results showed that BBO-ANFIS was the superior forecasting model out of the two provided models, with the lowest value of RMSE and the greatest value of R 2   (RMSE = 0.10731 and 0.11282 and R 2   = 0.97776 and 0.97552 for training and testing phases, respectively). The EWA-ANFIS also demonstrated RMSE and R 2   values of 0.18682 and 0.17681 and 0.93096 and 0.93874 for the training and testing phases, respectively. Finally, this study has proven that ANN is a powerful tool and will be useful for predicting the CL in residential buildings. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the effect of internal heat gains on the cooling load of a building. The house occupied by three adult men is selected as the case study for paper. The house is in the third floor of the apartment. The apartment has four flats and it has no insulation around the external walls. The heat dissipation from lighting devices, electrical equipment and the occupants are calculated by using the DesignBuilder v4 Beta release simulation program. The temperature of the house is observed during three weeks by using hobo data loggers and calibration of the measurements is made with respect to weather data file of the flat. Detailed schedule based on time of operation and occupancy is prepared to get more accurate results. Annual energy consumption and cooling load of the house is determined by using the dynamic simulation program. [ABSTRACT FROM AUTHOR]

The optimal performance of an irreversible quantum Carnot refrigerator with working medium consisting of many non-interacting harmonic oscillators is investigated in this paper. The quantum refrigerator cycle is composed of two isothermal processes and two irreversible adiabatic processes, and the irreversibilities of heat resistance, internal friction and bypass heat leakage are considered. By using the quantum master equation, semi-group approach and finite time thermodynamics (FTT), this paper derives the cooling load and coefficient of performance (COP) of the quantum refrigeration cycle and provides detailed numerical examples. At high temperature limit, the cooling load versus COP characteristic curves are plotted, and effects of internal friction and bypass heat leakage on the optimal performance of the quantum refrigerator are discussed. Three special cases, i.e., endoreversible, frictionless and without bypass heat leakage, are discussed in brief. [ABSTRACT FROM AUTHOR]

An evaporative-VCR combined AC system for providing good human comfort conditions working under hot & dry climate is proposed in this paper. The system is thermodynamically analysed for hot & dry climate of Muscat, Oman from April-July 2015 under some reasonable assumptions. The system was also compared on the basis of saving in cooling load (%) on the cooling coil for the same sensible cooling rate to the conditioned space from the conventional VCR-AC working on 100 % fresh air assumption. The saving of cooling load on the coil was found maximum (64.19%) in the month of April due to lower outside temperature and minimum (27.36%) for the month of June due to higher outside temperature. The proposed system can be made more energy efficient by utilising the exhaust air in cooling the condenser of VCR system which will improve the COP & hence reduce the power consumption of the compressor. [ABSTRACT FROM AUTHOR]

The building sector is one of the largest energy consumers worldwide. Especially in the hot-humid Southeast Asian region, this sector consumes about 30% of primary energy demand. This is mainly dominated by air conditioning systems to provide space cooling and dehumidifying. In this paper, three passive design strategies to reduce cooling energy and attain a good daylight environment in an office in Tangerang, Indonesia, will be evaluated using both measurement and simulation methods. Improving thermal insulation, natural ventilation, and solar shading are the strategies studied in this paper. The measurement result shows that the excessive daylight can be reduced by solar shading and the indoor temperature can be reduced by both solar shading and natural ventilation. The result of the simulation also validates the effects of shading and natural ventilation on lowering the indoor temperature and reducing the cooling load. Besides, it is proved that the difference in the building’s airtightness can cause an obvious difference in the effect of natural ventilation. There will be a large potential to adopt passive design even in hot and humid regions if the strategies are applied appropriately and good performance of the building, including high airtightness and proper thermal insulation, is guaranteed.

Highlights • This paper uses building structural attributes such as shapes of buildings, relative compactness(RC), glazing area(GA), roof area(RA), surface area(SA), wall area(WA), orientation(OR), overall height(OH) and glazing area distribution(GAD) for prediction of heating and cooling load. • The paper explores the data set and features to get insights with feature correlation, mutual information their association strengths etc and their relation with heating and cooling load. • The paper proposes novel group of methods based on emerging machine learning method extreme learning machine(ELM) which has shallows architecture. • The paper proposes novel method based on ELM variant online sequential extreme learning machine(OSELM) for heating and cooling load prediction in online and adaptive environment. This model also helps when data is trained in chunk by chunk fashion. • The paper demonstrates several models based on combination of learning mode, activation function and features sets and compare their results with existing work extensively. Abstract In the present day environment, smart buildings require optimization of energy consumption through monitoring, consumption prediction and making policy decisions accordingly. Attributes related to building design and structure play a vital role in heating load(HL) and cooling load(CL) of the building which directly affects the energy performance of the buildings. For prediction of HL and CL, emerging machine learning approaches can help in improving accuracy and efficiency in real time. This paper provides improvements in energy load assessment of the buildings. It is the first is the in-depth study and analysis of design and structural attributes and their correlation with HL and CL, the novel methods based on ELM and its variants online sequential ELM(OSELM) to predict HL and CL. This study also proposes OSELM based online/real-time prediction when data is coming in stream The total 24 models have been developed including 12 models based on ELM and 12 models based on OSELM with different feature sets and activation functions. Models have been compared on the basis of accuracy, computational performance and efficiency with few existing models. The experimental results show that the proposed models learn better and outperform other popular machine learning approaches such as the artificial neural network(ANNs), support vector machine(SVM), radial basis function network(RBFN), random forest(RF) and existing work in the energy and building domain. [ABSTRACT FROM AUTHOR]

Solar energy is an important source of renewable energy. In this paper, renewable energy is used to cooling purpose in the Middle East. The cooling load is calculated for major cities of the Middle East. An ammonia absorption refrigeration cycle (AARC) is used for cooling purpose. Solar energy is used as the source of high temperature. Codes are written in EES software to analysis the solar cooling cycle. In this analysis, temperature, enthalpy, and other thermodynamic properties are obtained in different cases. Weather properties information such as winter and summer design temperatures of these cities are obtained from HVAC handbooks. The variation of temperature and cooling capacity in different months and different hours of a day is calculated and is shown in different figures. Cooling ability of solar cooling system varies in the different month and different hours. Furthermore, the influence of the efficiency of heat exchanger of solar cooling system on the coefficient of performance of cycle and the cooling capacity is investigated. In this paper, different climates with summer design dry bulb between 32°C and 47°C and solar heat gain between 840 w/m2 and 890 w/m2 are considered. [ABSTRACT FROM AUTHOR]

Heat transfer through building envelopes constitutes the dominant part of indoor cooling load in summer. Coating building external walls with high reflectivity materials proves to be an effective way to reduce heat gains from solar radiation and save cooling energy consumption accordingly. In this paper, the transient heat transfer model of building external envelopes is established and validated through experiment, to investigate the thermal performance of building walls coated with retro-reflective materials. Moreover, taking an office building in Chengdu as an illustrative example, the cooling energy saving potential of such retro-reflective material coated building is evaluated in summer. The experiment results show that for the building box with retro-reflective coating materials (r=0.59), the average indoor air temperature is about 2.4°C lower than the reference box without coating materials, resulted from decreasing heat absorption of solar radiation for external walls. Furthermore, the illustrative example in Chengdu shows the cooling load can be reduced by about 9.1 W/m2, with such retro-reflective coating materials for building external walls, saving 15.2% electricity consumption in a whole summer. The incremental investment for coating can be paid back by 9.1 years for the studied case. Moreover, economic analysis and comparison indicate that such coating material is more applicable to southern cities in China, since the payback period is shorter due to more cooling energy saving for those with hot summer. This work can provide guidance for practical building envelope thermal design. [ABSTRACT FROM AUTHOR]

In response to the current problem of poor energy consumption control effect and overall high energy consumption of new nanopolymer materials for building exterior walls, the author proposes a thermal insulation energy consumption control technology based on the heat transfer performance model of exterior wall insulation panels. Calculate the current heat transfer performance parameters of exterior wall insulation panels using the reaction coefficient method, determine the proportional relationship between the effective heat transfer coefficients, and establish a heat transfer performance model for exterior wall insulation panels, based on the thermal conductivity index of the new nanopolymer material for the wall, the current control parameters are optimized. The optimal data algorithm is used to obtain the energy consumption decision variable value of the new nanopolymer material for the exterior wall of the building under the condition of clarifying the current heat transfer coefficient, and establish constraint conditions, based on the specific energy consumption data of new nanopolymer materials outside the current wall, establish the current thermal energy information transmission ratio relationship, analyze the current wall energy consumption hotspots, propose the K-means clustering analysis strategy, and apply it to the hot spot clustering control. Energy consumption control is achieved by locating the main cluster head parameters of the hot spot. Simulation results show that the hot spot fit of the aforementioned control methods has been improved by 29%, and the accuracy of the design method in cooling load control statistics is significantly higher than the two traditional methods used for comparison. Due to different weights, the final improvement ratio is determined to be 27%, further verifying the hypothesis. It has been proven that it can effectively improve the energy consumption control effect. [ABSTRACT FROM AUTHOR]

Air (Brayton) refrigerator has some application potentials nowadays. Based on two irreversible models of constant- and variable-temperature heat reservoir simple Brayton refrigerators established in previous references, this paper further derives exergetic efficiencies and ecological functions, and provide exergy-based comprehensive comparative analyses and optimizations for the two cycle models. Comparative studies among coefficient of performance (COP), cooling load, exergetic efficiency and ecological function characteristics are performed, including general performance analyses for fixed effectivenesses of heat exchangers and performance optimization by optimizing heat conductance distribution and optimizing heat capacity rate marching between heat-reservoir and working substance. For constant-temperature heat reservoir cycle, when select optimal pressure ratio, exergetic efficiency indicator is more reasonable than cooling load and ecological function indicators. When optimizing heat conductance distribution, cooling load indicator is almost the same as exergetic efficiency indictor. For variable-temperature heat reservoir cycle, the reasonable range of pressure ratio is that slightly larger than optimal one at maximum COP. For fixed pressure ratio, the difference between two optimal heat conductance distributions corresponding maximum cooling load and maximum exergetic efficiency is small. Various fixed design parameters have their influence features on the general performances and optimal performances of the cycle models, they should be considered specifically and pointedly. The major difference comparing with classical thermodynamic analysis is the consideration of heat-transfer loss in heat exchangers herein.

This paper introduces an original approach for the evaluation of the cooling load due to the solar radiation incident on the glazed surface of a building. This approach is based on a newly introduced parameter called Solar Response Factor , defined as the overall convective heat flux released by the building envelope to the indoor space per unit radiant heat flux acting on the outer surface of the glazing. The Solar Response Factor is a complex number, and can be calculated as a combination of the thermal and the optical properties of walls and glazing. In particular, the paper discusses how the Solar Response Factor depends on the optical properties of the envelope, on the size of the windows and on the type of walls delimiting the enclosed space. Furthermore, under steady-periodic conditions, the use of the Solar Response Factor allows an easy analytical estimation of the cooling load due to solar gains. The reliability of this approach is successfully proven by comparison with a series of simulations carried out with EnergyPlus. The results provide very useful information for optimizing the thermal response of an enclosure to periodic solar heat gains. [ABSTRACT FROM AUTHOR]

This paper presents a new spreadsheet-based cooling load design tool for underfloor air distribution (UFAD) systems developed by the Center for the Built Environment at University of California, Berkeley. After briefly reviewing previous UFAD design tools, the main characteristics of the tool are described: transformation of the zone design cooling load calculated for a standard overhead (OH) mixing system into the design cooling load for a stratified UFAD system, splits of the total UFAD cooling load into three fractions, supply plenum (SPF), zone, or room, (ZF), and return plenum (RPF); prediction of the thermal comfort in a vertically stratified environment, air temperature profiles and setpoint temperature at the thermostat; modeling of air diffusers; prediction of the design airflow rate; and modelling of commonly used plenum configurations. A practical example is reported at the end of the paper. The design tool and detailed user notes are available at: .

Abstract: It is not feasible to apply the traditional prediction method to predict hourly building cooling load at the urban energy planning stage because of the limited building information and complexity of energy prediction. This paper presents a simplified prediction model: Hourly Cooling Load Factor Method (HCLFM) that can provide quick and fair estimate of building cooling load for large-scale urban energy planning. The paper introduces the assumptions and principles of the proposed method, as well as discussing the implication and limitation of the approach. As a verification and demonstration, the method is applied to an office building in Beijing. The predicted results show that the dynamical trend of the cooling load is reasonable. The study further analyzes the potential causes of prediction errors and the significance of various cooling load influence factors. [Copyright &y& Elsevier]

The impacts of ventilation ratio and vent balance on cooling load and air flow of naturally ventilated attics are studied in this paper using an unsteady computational fluid dynamics (CFD) model. Buoyancy-driven turbulent ventilations in attics of gable-roof residential buildings are simulated for typical summer conditions. Ventilation ratios from 1/400 to 1/25 combined with both balanced and unbalanced vent configurations are investigated. The modeling results show that the air flows in the attics are steady and exhibit a general streamline pattern that is qualitatively insensitive to the variations in ventilation ratio and vent configuration. The predicted temperature fields are characterized by thermal stratification, except for the soffit regions. It is demonstrated that an increase in ventilation ratio will reduce attic cooling load. Compared with unbalanced vent configurations, balanced attic ventilation is shown to be the optimal solution in both maximizing ventilating flow rate and minimizing cooling load for attics with ventilation ratio lower than 1/100. For attics with ventilation ratios greater than 1/67, a configuration of large ridge vent with small soffit vent favors ventilating air flow enhancement, while a configuration of small ridge vent with large soffit vent results in the lowest cooling energy consumption. [ABSTRACT FROM AUTHOR]

A model of an irreversible quantum refrigerator with working medium consisting of many noninteracting spin-1/2 systems is established in this paper. The quantum refrigeration cycle is composed of two isothermal processes and two irreversible adiabatic processes and is referred to as a spin quantum Carnot refrigeration cycle. Expressions of some important performance parameters, such as cycle period, cooling load and coefficient of performance (COP) for the irreversible spin quantum Carnot refrigerator are derived, and detailed numerical examples are provided. The optimal performance of the quantum refrigerator at high temperature limit is analyzed with numerical examples. Effects of internal irreversibility and heat leakage on the performance are discussed in detail. The endoreversible case, frictionless case and the case without heat leakage are discussed in brief. [ABSTRACT FROM AUTHOR]

Abstract: A lecture theatre with dimension 16m×8.4m×3.6m located at Roorkee (28.58°N, 77.20°E) in the northern region of India, is selected to calculate the monthly and annual cooling load (kWh) and cooling capacity of air conditioning system by a computer simulation. The paper also presents the results of a study investigating the effect of different glazing systems on windows and the reduction in building cooling load. DesignBuilder software has been used for the computer simulation for calculating the cooling load. The paper aims to investigate the reduction in thermal gains and cooling load requirements by varying the U-values of different glazing types, insulating the ceiling, providing cool roofs, interior and exterior insulation on walls, and replacing the conventional fluorescent tube lamp (FTL) by energy efficient compact fluorescent lamp (CFL). Installation of false ceiling, wall insulation, different glazing types and lighting systems are cost effective with normalized annual saving ranging from 17% to 19.8% from this retrofitting project. Furthermore, the study also highlights the potential of reducing the emission of CO2 and equivalent carbon credit. Retrofitting techniques strongly influence the level of energy saving, although the payback period is generally quite long of order 8years. [Copyright &y& Elsevier]

Abstract: This paper describes a new general method for building simulation programs which is intended to be used for the modelling of complex facades. The term ‘complex facades’ is used to designate facades with venetian blinds, prismatic layers, light re-directing surfaces, etc. In all these cases, the facade properties have a complex angular dependence. In addition to this, such facades very often have non-airtight layers and/or imperfect components (e.g. non-ideal sharp edges, non-flat surfaces, …). Therefore building planners often had to neglect some of the innovative features and to use ‘work-arounds’ in order to approximate the properties of complex facades in building simulation programs. A well-defined methodology for these cases was missing. This paper presents such a general methodology. The main advantage of the new method is that it only uses measureable quantities of the transparent or translucent part of the facade as a whole. This is the main difference in comparison with state of the art modelling based on the characteristics of the individual subcomponents, which is often impossible due to non-existing heat- and/or light-transfer models within the complex facade. It is shown that the new method can significantly increase the accuracy of heating/cooling loads and room temperatures. [ABSTRACT FROM AUTHOR]

Highlights • Taiwanese building energy conservation index (ENVLOAD) was converted to OTTV. • New models for energy efficient envelope were proposed as an adaption to the changing climate. • Coefficients of the OTTV model should be changed to reflect climate change. • Thermal insulation is gaining more concern while climate change proceeds. • Altering method of OTTV and setting new criteria in response to future climate was proposed. Abstract Changes in the climate system affect a building's energy consumption. Many countries have implemented building energy consumption indices to regulate the newly built buildings from excessive energy use. However, those indices were developed based on previous climate datasets and were incapable of responding to the changing climate. To stabilize the energy uses of future buildings as those under today's climate, regular updates of the evaluation index are mandatory to take climatic variations into consideration. This study firstly discussed the limitations in responding to future climate of current practicing building envelope energy conservation index in Taiwan. Secondly, we proposed a new index, the overall thermal transfer value (OTTV), based on the simulation results and tried to convert existing baseline criteria for the new OTTV. An approach on how to alter the OTTV index in response to the climate change was proposed. We found that because of the warming climate, the coefficient of the OTTV equation has to be changed over times to accurately respond to the changing climate. The approach presented in this paper provides a method on how to formulate a climate responsive index in pursuit of a better energy efficient building in the future. [ABSTRACT FROM AUTHOR]

The performance, lifetime, and safety of electric vehicle batteries are strongly dependent on their temperature. Consequently, effective and energy-saving battery cooling systems are required. This study proposes a secondary-loop liquid pre-cooling system which extracts heat energy from the battery and uses a fin-and-tube heat exchanger to dissipate this energy to the ambient surroundings. The liquid then passes through a chiller to complete the cooling loop. The air-conditioning system is also used to cool the battery only if the temperature of the cooling water exceeds the maximum permissible temperature. The cooling load of the air-conditioning system is thus greatly reduced. The feasibility of the proposed cooling system is demonstrated experimentally under four simulated seasonal environmental conditions, namely high summer (35 °C), mean summer (30 °C), spring and fall (20 °C), and winter (7 °C). The results show that the pre-cooling system can dissipate 1000 W of battery heat in high summer, 2000 W in low summer, 3167 W in spring and fall, and more than 4000 W in winter. In other words, the pre-cooling system greatly reduces the cooling load of the air-conditioning system, and hence significantly reduces its energy consumption. [ABSTRACT FROM AUTHOR]

Due to global temperature increases, terraced house (TH) residents face a threat to their health due to poor indoor thermal environments. As buildings are constructed by low-income residents without professional guidance, this study aims to investigate the indoor thermal comfort and energy resilience of THs under the future climate and determine the optimal passive design strategies for construction and retrofitting. By exploring the effects of building envelope structures, adjusting the window-to-wall ratio (WWR) and designing shading devices, EnergyPlus version 22.0 was used to optimize the thermal environment and cooling load of THs throughout their life cycle under future climate uncertainties. Unimproved THs will experience overheating for nearly 90% of the hours in a year and the cooling load will exceed 60,000 kWh by 2100 under the Representative Concentration Pathways (RCP) 8.5 scenario. In contrast, optimization and improvements resulted in a 17.3% reduction in indoor cooling load by increasing shading devices and the WWR, and using building envelope structures with moderate thermal insulation. This study can guide TH design and renovation, significantly reducing indoor cooling load and enabling residents to better use active cooling to combat future overheating environments. [ABSTRACT FROM AUTHOR]

The majority of the population in Indonesia lives in naturally ventilated and unconditioned residential buildings because they cannot afford energy services. This situation is common in many countries in tropical regions, negatively affecting the occupants' health due to overheating. Therefore, housing types that can cool down indoor temperatures to the extent possible using a passive approach, rather than an active approach, should be developed. This study aims to improve naturally ventilated houses by considering the louver area and insulation of houses. First, we employ an on-site measurement for collecting data such as the indoor/outdoor temperature and relative humidity in an Indonesian city, Lhokseumawe. In addition, the experimental data are used to validate a numerical simulation model. Second, the numerical simulation is utilized to establish energy-efficient design solutions for houses in 14 Indonesian locations. The results show that, compared with the insulation cases, different louver areas insignificantly change indoor air conditions by approximately 0.3 to 1 °C. Additionally, the application of a combined performance improvement for both louver areas and building envelope insulation levels can reduce the indoor air temperature and relative humidity by 2.2 °C and 8%, respectively. Moreover, the daily cooling demand for the proposed improvement plan is reduced by 18.90% compared with that for the existing case. Furthermore, the annual cooling loads for the entire simulated regions are reduced by 46.63 GJ/year (23.09%). This study is a potential starting point for achieving zero-energy housing and occupants' sufficient thermal comfort in unconditioned and naturally ventilated houses in Indonesia. [ABSTRACT FROM AUTHOR]

Highlights • The infiltration is responsible for more than half of the total cooling load. • A direct method is developed for measuring the transient infiltration airflow rates. • The method is validated by the experiments of tracer gas decay technique. • The measurement errors of infiltration airflow rates are distributed between ±10%. • The practical application of the proposed method is discussed. Abstract The measurement of the infiltration airflow rates can support the calculation of the infiltration cooling load for the better understanding and optimizing the energy consumption of cold stores. However, the large temperature difference and the intense transient features make it difficult and complex to measure the airflow rates accurately. In this paper, a simple and practical method to measure the transient infiltration airflow rates is developed by using the local air velocity linear fitting. The proposed method is validated by the measurement results of the tracer gas decay method. It is concluded that the proposed method shows a good performance on the transient infiltration airflow rates measurement. The measurement errors are between ±10%. To enhance the application of this method, the layout of the measuring points of the air velocities are analyzed. The results show that, along the vertical layout direction, air velocity measuring points around the neutral level (where the cold and the warm air separate, about the middle height of the door) are not preferred when using this method. What’s more, the calculation of the infiltration cooling load by using this measuring method is also discussed. [ABSTRACT FROM AUTHOR]

This paper investigates the climate change impact on cooling energy consumption of office buildings in four major architectural climate zones in China. The results show that there are apparent differences in the responses of monthly or yearly cooling loads to climatic change in different climates. Dominant factors affecting monthly cooling loads change from dry bulb temperature (DBT) to wet bulb temperature (WBT) with the climate zones changing from severe cold to hot. The yearly cooling load was mainly afftectd by DBT in severe cold climate, whereas the WBT had the dominant effect in the other climates. With the continuous warming climate, the yearly cooling load did not rise significantly for any climate zone except for severe cold climate zone where cooling load had a significant increase ( p  < 0.01). More importantly, the cooling load showed a weak decrease in Guangzhou. These results suggest that different measurements for buildings cooling energy conservation should be made in different climate zones. The humidity effect should be fully considered to improve buildings energy efficiency, especially in the hot climate zones. The continuous increase of temperature in the future does not necessarily increase cooling loads of buildings in the cold, hot summer & cold winter and hot summer & warm winter climate zones, and change trendency of humidity in the future need to be considered to predict cooling energy consumption. [ABSTRACT FROM AUTHOR]

Configuring the number and size of chillers in a multiple-chiller plant properly is an efficient way to improve the plant energy efficiency. At the design stage, the optimal configuration can be achieved through matching the capacity to load as closely as possible across the full-load profile. However, in spite of the fact that current literature offers practical recommendations, a systematic method to optimize the configuration of multiple-chiller plants is lacking. Due to the lack of accurate information at the design stage and only limited knowledge of the eventual realization it is hard to predict the building’s cooling load. Moreover, there is no operational data to predict the system performance. Both explain the existence of uncertainty in the HVAC plant design process. This paper, therefore, proposes a strategy to optimize the configuration of multiple-chiller plants, which takes account of the load side uncertainty as well as the COP uncertainty and selects the optimal configuration through a life-cycle analysis. Both the load side uncertainty and the COP uncertainty are quantified using statistical distributions. To facilitate applications, the distributions of the cooling load profile of different types of buildings under different weather conditions are investigated and are classified into four categories, and the optimal configuration schemes under each type of cooling load distribution are analyzed and summarized in a tabulated form. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the impact of the thermal insulation on the cooling effectiveness of the Earth-to-Air Heat Exchanger systems under hot and arid climate. For that, the dynamic behaviour of two identical buildings submitted to the same exterior solicitations and equipped with an EAHE is presented in detail. To achieve the objective of this study, two transient models are developed; one for modelling the EAHE and the other for describing the thermal behaviour of buildings. The set of differential equations corresponding to different components of the system is solved using the technique of Complex Finite Fourier Transform. The findings indicate that when the insulated building is equipped with an EAHE, the effect of the thermal insulation will be combined with that of EAHE and the resulting effect will be more important, so that the reduction in the indoor air maximal temperature can be greater than 11°C and the reduction rate in the amplitude of the indoor air temperature increases until 91%. In addition, it is found that the thermal performances of the building outer walls represented usually by the decrement factor and the time-lag can be more improved using insulation layers within these components. On the other hand, the investigation conducted on the effect of the building materials showed that in Saharan climate, the light buildings such as those constructed with autoclaved aerated concrete blocks are more performing compared to the heavy buildings in which the outer walls must be judiciously insulated with a material of high thermal resistance. However, it is shown that the insulation with air cavities is an effective and economic solution for the light buildings in hot and arid regions. [ABSTRACT FROM AUTHOR]

The study shows that native-born neighbourhoods occupy a large portion of Abu Dhabi's landscape, with 55.2% of the total land designated for development. Even though 18% of the total Abu Dhabi's population lives in these neighbourhoods, they consume 47.8% of total domestic electricity demand in 2014, or almost six times more than the average per capita electricity consumption. This paper explores potential building energy reduction and solar heat gains by focusing on urban density of one typical Emirati neighbourhood in Abu Dhabi. Results show that building energy demand can be reduced by up to 10.5%, while solar heat gains can be reduced by more than 50%, depending on the urban density. Results in general reveal how urban density can affect solar heat gains and reduce building cooling demand for low-rise Emirati neighbourhoods. [ABSTRACT FROM AUTHOR]

In an earlier paper [1], the authors had comprehensively reviewed the climate change impacts for commercial buildings and their technical services in the tropics, and it revealed that numerous studies have been conducted to assess the climate change impacts in terms of energy consumption of a building. However, only few studies were carried out in the tropical region. This study aims to project the future cooling load needed for the years of 2000, 2020, 2050 and 2080 in the tropics using the TRNSYS simulation. Based on the simulation results, the total cooling load increases as the temperature changes. The total maximum cooling loads required in the years of 2000, 2020, 2050 and 2080 are 297000 kJ/hr, 305000 kJ/hr, 321000 kJ/hr and 332000 kJ/hr, respectively. When compared with the year 2000, the maximum cooling load needed in the years of 2020, 2050 and 2080 increases by 2.96%, 8.08% and 11.7% respectively. Based on the simulation results, in the next 70 years, the efficiency and durability of the existing system is predicted to decrease. [ABSTRACT FROM AUTHOR]

Climate Change is known to have a great impact on the energy consumption in buildings. This paper studied the cooling load of a residential building in Jinan, China, in 2020, 2050, 2080 by considering the impacts of climate change on the influential parameters for cooling loads. The Hadley Centre Coupled Model 3(HadCM3) was employed to investigate the impact of climate change on the outdoor temperature, solar radiation and wind speed. In addition, this study also differentiated the cooling loads according to occupants’ age, since the energy usage patterns and the requirements on cooling loads are closely related to occupants’ age. The results suggest that climate change will create significant impacts on the cooling loads in residential buildings. Regarding occupants’ age, the impact on the occupants under 55-year-old is larger than the people older than 55. [ABSTRACT FROM AUTHOR]

In summer, a large amount of heat is transfer from outdoor circumstance into indoor space through building external wall in tropical and subtropical zones and much energy was consumed to remove the surplus heat to maintain a comfortable indoor environment. In order to save energy, a concept of evaporative wall was presented in this paper. The structure and principle of evaporative wall was described. To investigate the energy saving potential of evaporative wall, a mathematical model was developed. With the climatic design information of Guangzhou, the cooling load temperature (CLT) and cooling load per unit wall area of evaporative wall were computed by using the model developed. It was found that the CLT of evaporative wall is 5~7℃ lower than that of dry wall. A cooling load reduction of 83%~93% can be achieved by evaporative wall compared with dry wall. In addition, evaporative wall has the ability to reduce the hourly swing of CLT and cooling load. [ABSTRACT FROM AUTHOR]

The heating and cooling energy consumption levels of urban buildings account for a large and rapidly growing proportion of the total end-use energy consumption of society. The urban heat island (UHI) effect is an important factor influencing the spatiotemporal variations in the heating and cooling energy consumption levels of buildings. However, there is a lack of research on the impact of the UHI on the heating and cooling energy consumption of buildings in cities of different sizes in the Beijing–Tianjin–Hebei urban agglomeration, which is the most urbanized region in northern China. We selected rural reference stations using the remote sensing method, and applied an hourly data set from automatic weather stations, to examine the impact of the UHI on the typical residential building heating and cooling loads in three cities of varied sizes in the Beijing–Tianjin–Hebei urban agglomeration through building energy simulation. The main conclusions were as follows. As the UHI intensity (UHII) increased, the heating load difference between urban and rural areas decreased, while the cooling load difference between urban and rural areas increased in the cities. The average daily heating loads in the urban areas of Beijing, Tianjin, and Shijiazhuang were 8.14, 10.71, and 2.79% lower than those in their rural areas, respectively, while the average daily cooling loads in the urban areas were 6.88, 6.70, and 0.27% higher than those in their rural areas, respectively. Moreover, the absolute hourly load differences between urban and rural areas were significantly larger during the heating periods than during the cooling periods, with the former characterized by being strong at night and weak during the day. During the peak energy load period, the contribution of the UHI to the peak load of residential buildings varied between the cities. During the stable high-load period, from 18:00 to 07:00 the next day in the heating periods (from 18:00 to 05:00 the next day in the cooling periods), the hourly loads in the urban areas of Beijing, Tianjin, and Shijiazhuang were 3.15 (2.48), 3.88 (1.51), and 1.07% (1.09%) lower (higher) than those in their rural areas, respectively. Our analysis highlights the necessity to differentiate the energy supplies for the heating and cooling of urban buildings in different sized cities in the region. [ABSTRACT FROM AUTHOR]

The air conditioning demand varies significantly in the hot and desert climates of the UAE due to diurnal temperature variation, seasonal shifts, and occupancy patterns. One of the challenges faced by the relatively higher energy-consuming UAE building stock is to optimize cooling capacity utilization and prevent excessive energy loss due to undesired cooling. A potential route to achieving such a goal involves cooling energy storage during low demand and releasing the stored cooling at peak demand times via thermal energy storage (TES). Latent heat thermal energy storage (LHTES) employing phase change materials (PCMs) provides impactful prospects for such a scheme, thus gaining tremendous attention from the scientific community. The primary goal of the current article is to provide a comprehensive state-of-the-art literature review on PCM-based TES for cooling applications to understand its efficacy, limitations, and future prospects. The article involves various applications, designs, and validations. The article emphasizes the importance of material innovations and heat transfer augmentation strategies to render this technology feasible for real-life integration into cooling systems. [ABSTRACT FROM AUTHOR]

Cooling load refers to the amount of energy to be removed from a space (or consumed) to bring that space to an acceptable temperature or to maintain the temperature of a space at an acceptable range. The study aimed to develop a series of models and determine the most accurate ones in the prediction of the cooling load of low-rise tropical buildings based on their basic architectural and structural characteristics. In this context, a series of machine learning (regression) algorithms were tested during the research to determine the most accurate/efficient prediction model. In this regard, a data set consisting of ten features indicating the basic characteristics of the building (floor area, aspect ratio, ceiling height, window material, external wall material, roof material, window wall ratio north faced, window wall ratio south faced, horizontal shading, orientation) were used to predict the cooling load of a low-rise tropical building. The dataset was generated utilizing a set of generative and algorithmic design tools. Following the dataset generation, a series of regression models were tested to find the most accurate model to predict the cooling load. The results of the tests with different algorithms revealed that the relationship between the predictor variables and cooling load could be efficiently modeled through Histogram Gradient Boosting and Stacking models. [ABSTRACT FROM AUTHOR]

In hot arid climates, air conditioning in the summer dominates energy use in buildings. In Kuwait, energy demand in buildings is dominated by cooling, which also determines the national peak electricity demand. Schools contribute significantly to cooling demand, but also suffer from poor ventilation. This paper presents analysis of a ventilation and cooling system for school classrooms using a wind catcher for natural ventilation and evaporative cooling. A school classroom in Kuwait with single-sided ventilation was modelled using the DesignBuilder V5.4/EnergyPlus V9.1 software and calibrated using field data. The model was used to analyse the performance of a wind catcher, with and without evaporative cooling, in terms of energy use, thermal comfort and indoor air quality. Compared to the baseline of using air-conditioning only, a wind catcher with evaporative cooling was found to reduce energy use by 52% during the summer months while increasing the comfortable hours from 76% to 100% without any supplementary air conditioning. While the time below the ASHRAE CO2 limit also improved from 11% to 24% with the wind catcher, the indoor air quality was still poor. These improvements came at the cost of a 14% increase in relative humidity. As the wind catcher solution appears to have potential with further development; several avenues for further research are proposed. [ABSTRACT FROM AUTHOR]

The renewed attention paid to raw earth construction in recent decades is linked to its undoubted sustainability, cost-effectiveness, and low embodied energy. In Italy, the use of raw earth as a construction material is limited by the lack of a technical reference standard and is penalised by the current energy legislation for its massive behaviour. Research experiences, especially transoceanic, on highly performative contemporary buildings made with natural materials show that raw earth can be used, together with different types of reinforcements, to create safe, earthquake-resistant, and thermally efficient buildings. On the basis of experimental data of an innovative fibre-reinforced rammed earth material, energy analyses are developed on a rammed earth building designed for a Mediterranean climate. The paper focuses on the influences that different design solutions, inspired by traditional bioclimatic strategies, and various optimised wall constructions have in the improvement of the energy performance of the abovementioned building. These considerations are furthermore compared with different design criteria aiming at minimising embodied carbon in base material choice, costs, and discomfort hours. Results have shown the effectiveness of using the combination of massive rammed earth walls, night cross ventilation, and overhangs for the reduction of energy demand for space cooling and the improvement of wellbeing. Finally, the parametric analysis of thermal insulation has highlighted the economic, environmental, and thermophysical optimal solutions for the rammed earth envelope. [ABSTRACT FROM AUTHOR]

Cooling load accounts for more than 70% of the electric energy used in buildings in the Middle East. This paper presents a passive method to reduce the cooling load in buildings. The proposed concept includes adding an external solar shield enclosing an air gap between it and the outer wall of the building. This external solar shield layer would absorb the solar radiation incident on the outer walls of the building and get heated inducing a convective airflow in the gap between the layer and the building. This is an example of solar chimney in a flat geometry with a superficial resemblance to Trombe wall. Conventional Trombe wall channel heats the building external wall and creates a convective flow in-between a transparent glass layer and the heated wall. This hot flow is used either as a warm inlet air to the building in winter or help inducing airflow from inside the building for ventilation in summer. However, in the present work, the solar chimney induced airflow is purely external to the building. The proposed external solar shield starts with a glass layer from outside followed by an opaque porous metallic layer followed by an air channel before the building outer walls. The absorbing porous layer would get heated up quickly and transfer its heat to the air in the gap effectively due to its large surface area. The porous layer thickness is optimized at 15 cm while the air gap is optimized at 0.3 m. Numerical simulations based on finite volume analysis using ANSYS Fluent were carried out for a wall of 3 m height. Comparisons of the performance of buildings with its outer walls shielded by white painted, black painted and glazed walls are presented and discussed with respect to that of buildings with bared outer walls as a control. Putting glazing alone after an air gap, expectedly, increases the heat gained by 47–56% compared to 0.7 emissivity simple bared wall. Single black and white solar shielding walls reduce the heat gain by 30 and 67%, respectively. However, the proposed design of a solar chimney with a glass outer wall followed by a porous foam metal layer on its inner surface, reduced thermal gain by 67–79%. This results in electrical cooling load reduction by about 28%. Furthermore, the heated airflow induced by a solar chimney formed with a 20 × 3 m south wall can be utilized to induce water evaporation of 625–1046 kg/day allowing active evaporative cooling and/or water desalination under solar irradiation condition of Dhahran, Saudi Arabia [ABSTRACT FROM AUTHOR]

This paper aims at investigating the effect of combining thermal insulation with high thermal inertia on building’s thermal performance in a hot semi-arid climate. The impacts of these passive techniques on the cooling/heating loads and the indoor comfort are analyzed by means of dynamic simulation as well as on-site monitoring of a two floor detached house located in the Green City of Benguerir in Marrakech region (Morocco). This house, mostly built using local materials, integrates many other passive and hybrid systems. The present study focuses on the hemp-gypsum, the double slab technique for thermal insulation, the double glazing and the high thermal inertia of the walls. Thermal performance of these techniques are assessed by comparison to a hypothetical reference case of the house lacking the considered techniques and built with regular classic construction materials. The results show that the investigated passive systems have a remarkable effect on the indoor air temperature, the thermal comfort and the cooling/heating loads of the building. When the three systems are integrated into the studied house, better comfort conditions are achieved compared to the reference case as its indoor air temperature minimum is up to 5 °C higher in winter while the indoor air temperature maximum is reduced by up to 9 °C in summer. In addition, the daily air temperature amplitude (peak-to-peak difference) is drastically reduced compared to the reference case. Moreover, the discomfort hours based on an acceptable thermal comfort zone of 16 °C–28 °C are reduced by 62% compared to the reference case. Furthermore, the house performs up to 81% of reduction in the annual cooling and heating load compared to the reference case. [ABSTRACT FROM AUTHOR]

The work reported in this paper is focused on the performance of a thermoacoustic refrigerator under various operating conditions. The experiments were conducted with various stack geometries fabricated with epoxy glass and Mylar material. Four stacks with different pore sizes are used to evaluate the performance of the refrigerator. Stack 1 has parallel plates of Mylar material 0.12 mm thick spaced 0.36 mm apart. Stacks 2, 3 and 4 are made of epoxy glass with pores of circular cross-section having 1, 2 and 3 mm diameter, respectively. The entire resonator system was constructed from aluminium material coated with polyurethane material from inside to reduce conduction heat losses. Helium gas was used as a working fluid. The experiments were conducted with different drive ratios ranging from 1.6% to 2% with varying cooling load from 2 to 10 W. For the experiments, operating frequencies from 200 to 600 Hz with mean pressure varying from 2 to 10 bar in steps of 2 bar each were considered. The temperatures of the hot end and cold end of the heat exchangers were recorded using RTDs and a data acquisition system under various operating conditions. The coefficient of performance (COP) and relative COP (COPR) are evaluated. Results show that COP of the refrigerator rises with increase of cooling load and decreases at higher drive ratio. It was also observed that the temperature difference between the hot end and cold end of the stack is higher at 2 W cooling load for 400 Hz operating frequency. The temperature difference between the hot end and cold end of the stack was observed to be 19.4, 17.2, 14 and 12.4°C for stacks 1, 2, 3 and 4, respectively, for 10 bar mean pressure and 2 W cooling load. The temperature difference and COP of the parallel plate stack are better compared with other stack geometries. [ABSTRACT FROM AUTHOR]

Numerous experiments have shown that trees can reduce the energy consumption of adjacent buildings, but little research has been carried out on how leaf area density (LAD) and the distance between walls and trees (DW-T) in different orientations affect the energy consumption of rural houses. Using an investigation method, a simulation method, and a remote sensing information extraction method, the impact of different tree-planting scenarios on the energy consumption of typical rural houses was analyzed. The results show that the energy-saving effect becomes more prominent with a higher leaf area density of trees in summer. Under the same conditions, Osmanthus fragrans is the most effective tree, followed by Koelreuteria paniculata, and then pomegranate. Moreover, the energy-saving rate of the rural house increases with a decrease in the wall–crown distance of the tree. For instance, when a Koelreuteria paniculata is planted on the west side of the rural house with a wall–crown distance of 1–3 m, the energy-saving rate ranges from 4.38% to 9.81%. Additionally, the planting orientation of the tree affects the energy-saving rate, with the west-facing orientation being the best and the north-facing orientation being the worst under the same conditions, and the energy-saving rate of the best orientation (west-facing) ranging from 2.11% to 14.98%. By establishing a comprehensive model, it was found that planting Osmanthus fragrans on the west side of a rural house with a 1 m wall–crown distance yields the best energy-saving effect. The results of this study can provide theoretical support for planting trees around rural houses from the perspective of energy saving. [ABSTRACT FROM AUTHOR]

The potential of natural materials is becoming more and more important as concerns about the environmental impact and energy efficiency of the construction sector grow. Incorporating waste from fiber sub-products seems like a wise choice, in line with the circular economy model. Despite the fact that date palm materials have been extensively researched and developed for use in modern buildings, the potential of using date palm fibers has not been widely explored. This research intends to examine how date palm fibers thermal insulation affects a building's thermal efficiency in an Atlantic climate. An analysis using a numerical simulation using the TRNSYS software is conducted to determine the effect of this passive approach on cooling/heating loads and indoor comfort. This technique is measured against a hypothetical reference case of homemade traditional building materials without thermal insulation. The results show that insulation with date palm fiber materials has a significant effect on the indoor air temperature and the cooling and heating loads of the house. In comparison to the reference case, the studied house achieves better comfort conditions when thermal insulation is adopted since the indoor air temperature is increased by up to 3 °C in winter and decreased by up to 5 °C in summer. In addition, annual cooling and heating requirements can be reduced by 25% and 18%, respectively, by insulating the roof and walls with date palm fiber materials. On the other hand, it allows financial savings and a reduction in CO2 emissions. [ABSTRACT FROM AUTHOR]

A louver is a traditional environmental control device and passive architectural element based on an ecofriendly concept. Louvers are architectural elements that can be used to regulate natural lighting, thermal environment, and building energy use. To realize these integrated functionalities of louvers, they must be designed considering the climate and geographical characteristics of the target region. However, these aspects are typically not considered during building design in Korea, resulting in lovers being used as design elements with simple natural lighting control functions. Therefore, the objective of this study was to promote the integrated use of louvers by optimizing the louver angle according to the microclimate in Korea from the viewpoint of thermal energy use. We performed load and energy simulation planning and calculation and conducted optimization studies for the louver angle and range of motion for each region. The energy consumption in central and southern Korean regions was minimized when the angles of the fixed louvers were 45°–75° and 60°–90°, respectively. Kinetic louvers could enhance thermal energy management when installed at 30°–75° in spring, 135°–165° in summer, 75°–165° in autumn, and 45°–75° in winter. These findings can promote the realization of integrated functionalities of louvers from the perspective of indoor environment comfort based on the microclimates of the Korean regions. [ABSTRACT FROM AUTHOR]

This paper presents the results obtained during the synthesis of nonlinear predictive controllers dedicated to the energy management of centralized air conditioning systems in the rooms from two city hotels. The model for predictions is based on the Radiant Time Series (RTS) method. To satisfy the thermal comfort required by the occupants, an adaptive model is considered explicitly in the economic objective function of the predictive controller. Historical records of electrical consumption from the two hotel facilities are used for comparing the performance of the controllers. Results obtained in simulation using real data as inputs show an improvement in energy consumption while maintaining the thermal comfort. [ABSTRACT FROM AUTHOR]

A dew point evaporative-vapour compression based combined air conditioning system for providing good human comfort conditions at a low cost has been proposed in this paper. The proposed system has been parametrically analysed for a wide range of ambient temperatures and specific humidity under some reasonable assumptions. The proposed system has also been compared from the conventional vapour compression air conditioner on the basis of cooling load on the cooling coil working on 100% fresh air assumption. The saving of cooling load on the coil was found to be maximum with a value of 60.93% at 46 °C and 6 g/kg specific humidity, while it was negative for very high humidity of ambient air, which indicates that proposed system is applicable for dry and moderate humid conditions but not for very humid conditions. The system is working well with an average net monthly power saving of 192.31 kW h for hot and dry conditions and 124.38 kW h for hot and moderate humid conditions. Therefore it could be a better alternative for dry and moderate humid climate with a payback period of 7.2 years. [ABSTRACT FROM AUTHOR]