Journal articles on the topic 'Air conditioning in large buildings'
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1
Pan, Wen Yan, Liu Yang, and Zhu Hui Zhang. "Energy Consumption and Analysis of Air-Conditioning System of Large-Scale Public Buildings in Xi'an." Applied Mechanics and Materials 99-100 (September 2011): 388–92. http://dx.doi.org/10.4028/www.scientific.net/amm.99-100.388.
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As the main consumption equipment, the air-conditioning system of large-sized public buildings in Xi'an consumes 30%~¬60% of the total energy. Combining with the survey data and related norms, the paper analyses the energy consumption from the following aspects: basic situation of building, index of building energy consumption, ratio of energy consumption of air-conditioning system, load of air-conditioning and indoor environment. Thus, it will give a rational and scientific understanding to energy-efficiency of air-conditioning system of large-scale public buildings in Xi'an for the purpose of providing an efficient assistance to improving the energy consumption of air-conditioning system.
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Meng, Xi, Yanna Gao, Chaoping Hou, and Fen Yuan. "Questionnaire survey on the summer air-conditioning use behaviour of occupants in residences and office buildings of China." Indoor and Built Environment 28, no. 5 (August 16, 2018): 711–24. http://dx.doi.org/10.1177/1420326x18793699.
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Although occupants play a critical role in a building’s energy consumption, their air-conditioning use behaviour is often ignored, with it usually approximated as being a continuous operation. This in turn leads to a large difference between the actual and expected levels of energy consumption, raising the need to study air-conditioning use behaviour of building occupants. In this survey, 3083 questionnaires dealing with air-conditioning use behaviour were received from 34 cities distributed throughout China. The results show occupancy rates of 20% to 75% in residences and around 80% in office buildings during the period of 8:00–18:00. Air-conditioning use behaviour only meets a liveable requirement in residences and reaches a comfortable level in office buildings. This leads to daily air-conditioning operation times of between 0.85 and 4.31 hours in residences, and between 1.67 and 7.22 hours in office buildings, indicating most air-conditioning systems do not run continuously but intermittently, and that the assumption of continuous operation is far removed from reality. Based on these survey results, the large differences between the realistic (intermittent) and assumed (continuous) use of air-conditioning are employed to reveal the weaknesses in the present standards and to examine the optimization of building energy efficiency.
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Cai, Wei, Ke Jian Cai, and Zhao Hui Wu. "Dominant Factors of Central Air Conditioning System Zoning and Thermal Comfort for Large-Scale Public Buildings in China." Advanced Materials Research 171-172 (December 2010): 159–62. http://dx.doi.org/10.4028/www.scientific.net/amr.171-172.159.
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Large-scale public buildings have high energy density, which take big part of the gross energy consumption in buildings in China. It is still in attempting stage about the strategy of energy conservation in air conditioning systems. The objective of this study is to investigate that how to appropriately divide central air conditioning system zoning by using simulation software to calculate the basis dynamic temperature and load in typical large-scale public buildings. Effects of weather conditions, building envelope conditions and building structure on large-scale public building energy consumption were analyzed in this simulation. The results show that the building load is the fundamental factor involved in air conditioning system zoning. Surplus heat recovery in inner zone is also recommended to maintain inner zone comfort and energy conservation. This work provides the theoretical and technological basis for study on central air conditioning system zoning and thermal comfort for large-scale public building.
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Zhang, Guang Ming, Xue Shen, and Gui Zhong Tang. "Energy Consumption Simulation of the Air Conditioning System in Large-Scale Buildings." Advanced Materials Research 724-725 (August 2013): 1506–9. http://dx.doi.org/10.4028/www.scientific.net/amr.724-725.1506.
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The working environment of air conditioning system in large-scale building is very complex, and there is no significant linear relationship between factors affecting energy consumption and energy demand of air conditioning system. This study adopts a nonlinear regression model: ANN (artificial neural network) model as energy model of air conditioning system. Take outdoor temperature, categorical day-of-week variable, equipment efficiency and terminal load as input, energy demand as output. Use energy consumption data in 2011 for network training, and energy consumption data in 2012 to verify the reliability of model. Based on energy analysis, the operation condition and the characteristics of energy consumption of air conditioning system for large-scale buildings in Nanjing could be precisely represented.
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Bravo-Hidalgo, Debrayan. "Night air conditioning of buildings by external air ventilation." Revista Facultad de Ingeniería 27, no. 48 (May 5, 2018): 35–47. http://dx.doi.org/10.19053/01211129.v27.n48.2018.8462.
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Buildings contain the environment in which almost all human activities take place, and therefore, nowadays, they represent a great sink of energy. Establishing thermal comfort conditions within these buildings is responsible for a large portion of their energy demand. This paper aims at providing a theoretical framework of the performance and the trends in research and implementation of night air conditioning by outside air ventilation. The bibliographic search was conducted in the academic directory Scopus, and the information extracted was processed in the VOSviewer software, through which text mining, map of terms and networks of investigative action were carried out. The literature showed that direct ventilation has a more significant cooling potential in regions characterized by a high difference between day and night air temperatures. The effectiveness of night cooling and the reliable prediction of thermal behavior are strongly related to the model adopted for the convection algorithm. A reliable prediction of heat transfer by convection requires an approach based on computational simulations of fluid dynamics, which are much more demanding in terms of computational power, compared to simulations of the variation of energy flows as a function of time. Most studies showed that the position of the thermal mass is not significant, while the amount of ventilation air is of great importance. In particular, the energy demand for cooling a building decreases sharply if the air flow rates increase.
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Alustath, Husam, Batoul Daou, Sherif Elgohary, Mohammad Kataw, Peiman Kianmehr, and Mason Marzbali. "A Potential Solution for Solid Particulate Matter Reduction in Large Indoor Spaces." IOP Conference Series: Earth and Environmental Science 1050, no. 1 (July 1, 2022): 012026. http://dx.doi.org/10.1088/1755-1315/1050/1/012026.
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Abstract Air filtration is an essential process in indoor air conditioning and its physical removal of particulate matter is critical for enhancing indoor air quality, especially in arid regions including United Arab Emirates. In such regions, meeting indoor air quality standard is challenging during sporadic sandstorms when common air conditioning systems are unable to maintain indoor air quality properly. Such inability occurs either due to air infiltration through building’s fenestrations exposing indoor air to excessive particulate matter or the failure of inlet air filters after rapid clogging and high pressure drops. Such failure may be observed frequently in buildings with frequent openings such as public buildings and warehouses. Aerosolized pathogenic microorganisms, e.g., SARS-CoV-2 virus, can be modelled through air particle matter and be removed to a certain degree. In addition, the recent global pandemic raised more awareness towards the necessity of particulate matter filtration in indoor environment. Employing independent air filtration units might be a great solution for intermittent or emergency situations, when primary or additional air filtration process is required to attain proper indoor air quality. The main objective of this paper is to attempt designing, manufacturing, and utilizing an easy to set portable filtration unit and to assist buildings’ existing air conditioning systems in airborne dust particle elimination. The unit is designed and manufactured with additional feature accommodating easy installation of commercially available filters for further performance studies. The unit was equipped with all necessary performance monitoring sensors to detect key parameters such as air velocity, pressure differential, temperature, humidity, and particulate matter before and after filtration. The results revealed interesting information associated with the performance of commercially available filters and the feasibility of such independent filtration units.
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Wang, Jin, Jing Jing Xin, You Tao Zhou, Xin Lin Li, and Shu Sheng Li. "Cold and Heat Source Energy-Saving Reconstruction for Central Air-Conditioning System in a Research and Development Center of Shanghai." Advanced Materials Research 204-210 (February 2011): 327–31. http://dx.doi.org/10.4028/www.scientific.net/amr.204-210.327.
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Central air-conditioning energy consumption accounts for a large proportion of the buildings. And cold and heat source energy consumption accounts for about two-thirds of central air-conditioning system. For a research and development center in Shanghai, because cold and heat source capacity largely surpasses the actual demand, we propose to combine with cold sources of the two buildings. We call it "two-in-one" reconstruction. When cooling load is small, we use cold source in one building to support the two buildings. After implementation, by return on investment analysis, the average electric energy-saving rate is 9.6%. Investment can be recovered within one year.
8
Cui, Yan Qi, and Saffa Riffat. "Review of Latest Developments in Microporous Aerogel for Building Applications." Applied Mechanics and Materials 71-78 (July 2011): 1967–70. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.1967.
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Buildings are large consumers of energy in all countries. In regions with harsh climatic conditions, a substantial share of energy goes to heat and cool buildings. This heating and air-conditioning lost can be reduced through many means, such as the selection of the building thermal insulation materials. The proper use of thermal insulation material in buildings does not only contribute in reducing the annual energy cost but also helps in extending the periods of thermal comfort without reliance on mechanical heating and air-conditioning. Aerogel is one of the novel insulation these years, thermal conductivities of 0.04 W/mK less can be achieved using it. The paper is concerned with a review of Microporous Aerogel for building applications. And it also provides information about their performance.
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Strongin, A. S., and A. M. Zhivov. "Energy Efficient Air Curtains for Industrial Gates in Cold Climates." E3S Web of Conferences 246 (2021): 08005. http://dx.doi.org/10.1051/e3sconf/202124608005.
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In geographical areas with cold climates, large, massively constructed industrial and warehouse buildings and logistics complexes are large consumers of energy resources. The great height and large contained volumes of the premises, the presence of a significant number of doors, and building configurations that include many transport corridors all require the use of air-thermal curtains to increase the energy efficiency of the buildings’ heating, ventilating, and air-conditioning (HVAC) systems, which commonly produce several thousand kilowatts of thermal power. Optimization of air curtains can improve the microclimates of the premises, achieve savings in the initial construction costs, and also reduce energy consumption during operation by 10–20%.
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West, John B. "A strategy for oxygen conditioning at high altitude: comparison with air conditioning." Journal of Applied Physiology 119, no. 6 (September 15, 2015): 719–23. http://dx.doi.org/10.1152/japplphysiol.00421.2015.
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Large numbers of people live or work at high altitude, and many visit to trek or ski. The inevitable hypoxia impairs physical working capacity, and at higher altitudes there is also cognitive impairment. Twenty years ago oxygen enrichment of room air was introduced to reduce the hypoxia, and this is now used in dormitories, hotels, mines, and telescopes. However, recent advances in technology now allow large amounts of oxygen to be obtained from air or cryogenic oxygen sources. As a result it is now feasible to oxygenate large buildings and even institutions such as hospitals. An analogy can be drawn between air conditioning that has improved the living and working conditions of millions of people who live in hot climates and oxygen conditioning that can do the same at high altitude. Oxygen conditioning is similar to air conditioning except that instead of cooling the air, the oxygen concentration is raised, thus reducing the equivalent altitude. Oxygen conditioning on a large scale could transform living and working conditions at high altitude, where it could be valuable in homes, hospitals, schools, dormitories, company headquarters, banks, and legislative settings.
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Halwatura, R. U. "Effect of Turf Roof Slabs on Indoor Thermal Performance in Tropical Climates: A Life Cycle Cost Approach." Journal of Construction Engineering 2013 (November 7, 2013): 1–10. http://dx.doi.org/10.1155/2013/845158.
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Urbanization related to population growth is one of the burning issues that the world is facing today. Parallel to this, there is visible evidence of a possible energy crisis in the near future. Thus, scientists have paid attention to sustainable development methods, and in the field of building construction also, several innovations have been proposed. For example, green roof concept is one of such which is considered a viable method mainly to reduce urban heat island effect, to regain lost land spaces in cities, and to increase aesthetics in cities. The present study was aimed at investigating the impact of green roofs on indoor temperature of buildings, the effect of different types of roofs on the air conditioning loads, and the life cycle cost of buildings with different types of roofing. The study was conducted in several phases: initial small-scale models to determine the heat flow characteristics of roof top soil layers with different thicknesses, a large-scale model applying the findings of the small-scale models to determine temperature fluctuations within a building with other common roofing systems, a computer simulation to investigate air conditioning loads in a typical building with cement fiber sheets and green roof slabs, a comparative analysis of the effect of traditional type roofs and green roofs on the air conditioning loads, and finally an analysis to predict the influence of traditional type roofs and green roofs on life cycle cost of the buildings. The main findings of the study were that green roofs are able to reduce the indoor temperature of buildings and are able to achieve better heat transfer through the roof, and, thus a lower cooling load is necessary for air conditioning and has the possibility of reducing life cycle cost of a building.
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Liang, Na, and Rui Li. "Air Conditioning System Water Quality and Equipment Condition Investigation and Analysis of Energy Saving Measures." Advanced Materials Research 516-517 (May 2012): 1224–28. http://dx.doi.org/10.4028/www.scientific.net/amr.516-517.1224.
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Due to energy reserves reduces gradually and uneven distribution, all countries pay more and more attention to energy saving and improve the effective utilization of energy, China also attaches great important to this. Energy saving of buildings is a necessary development trend. Air conditioning system as a large important part of building energy consumption has a huge energy-saving potential. This article mainly introduced the related strategies of energy saving in central air conditioning water system from the following three points of view: the water treatment, the cooling tower, and the variable frequency pump.
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Peri, Giorgia, Gianfranco Rizzo, Gianluca Scaccianoce, and Giancarlo Sorrentino. "Role of Green Coverings in Mitigating Heat Island Effects: An Analysis of Physical Models." Applied Mechanics and Materials 260-261 (December 2012): 251–56. http://dx.doi.org/10.4028/www.scientific.net/amm.260-261.251.
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Worldwide, governments are introducing several rules and standards in the aim of limiting the quantity of primary energy for air conditioning of buildings and supporting the use of renewable source of energy for generating thermal and electric energy to be utilized in buildings such as the European Directive on the Energy Performance of Buildings [1]. Along with these interventions, another important action takes currently place in the building sector, that is the introduction of passive structural components of the envelope, able to reduce the requirements of energy for air conditioning purposes. Among these building components, the so-called green roofs are becoming more and more interesting for designer and buildings owners. This simple technical solution, in fact, apart its effectiveness in lowering particularly the summer cooling loads, could make more attractive the shape of each single building and, when adopted on a large extension, of an entire city district, reducing the risks for urban heat island phenomena that represent a severe problem in urban contexts. In this work, a short review of the literature models for computing the energy balance of roof coverings will be proposed, with particular reference in modelling the heat exchange of a canopy.
14
Wang, Jun, and Hai Xia Wang. "Air Flow in Large Space Building with CFD Model and Local Test." Advanced Materials Research 213 (February 2011): 260–66. http://dx.doi.org/10.4028/www.scientific.net/amr.213.260.
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Simulation with CFD and local test are two main methods in study on air flow in large space building. This paper tests and simulates thermal comfort and air distribution of existing air- conditioning mode of some exhibition center. Through comparison and analysis on existing and simulated air-conditioning pattern, draw a conclusion that it’s feasible to simulate thermal comfort and air distribution of air-conditioning. And the research is important to guide energy efficiency and design optimization of air-conditioning system in large space building.
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Zhang, Yunqian, Jun Lu, Xin Jiang, Shuren Shen, and Xin Wang. "A study on heat transfer load in large space buildings with stratified air-conditioning systems based on building energy modeling: Model validation and load analysis." Science Progress 104, no. 3 (July 2021): 003685042110361. http://dx.doi.org/10.1177/00368504211036133.
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The characteristics of heat transfer load from the non-air-conditioned (NAC) area can help to understand the complex airflow movement and thermal physical mechanisms inside large space buildings. Based on building energy modeling, the indoor thermal environment and building energy consumption of a plant for computerized numerical control (CNC) machine tools are studied. Considering the form of the stratified air-conditioning system and the phenomenon of heat retention near the roof in the plant, the double zone and triple zone models are established. The vertical air temperature, the parameters of the terminal of the air-conditioning system and the heat/cool source system of the plant in summer and winter were measured on site, which verifies the accuracy of the established model. Based on the validated model, the proportion of heat transfer load from the NAC area is calculated, at the range of about 60%–85%. The positive influence of the roof heat transfer coefficient on the sensible heat load in the NAC area is revealed. The recommended value of the non-dimensional zone-mixing flow rate between the air-conditioned (AC) and NAC areas is given, with 30% (in summer). The results of this work can help understand the composition of the stratified air-conditioning load in large spaces and optimize the design of air distribution.
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Cui, Yan Qi, and Saffa Riffat. "Review on Phase Change Materials for Building Applications." Applied Mechanics and Materials 71-78 (July 2011): 1958–62. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.1958.
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Buildings are large consumers of energy in all countries. According to the statistic, more than 40% of final energy is used in buildings. A reduction of the energy consumed in buildings is, for that reason, one of the priorities of the world. To achieve this goal it is necessary to reduce the heat loss by the selection of the building thermal insulation materials. Phase change materials could absorb or release a large amount of heat before melting or solidifying. And this unique property could help PCM in building applications to maintain the thermal comfort without using mechanical heating and air-conditioning. The paper is focus on a review of different types of phase change material for building applications. And it provides more information in this aspect.
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Dang, Wei Kang, Guo Qiang Xia, Yu Liang Zhong, Lin Yang, Chun Hua Sun, and Hua Yang. "Risk Assessment and Control Measures of Air Conditioning System in Large Commercial Building." Applied Mechanics and Materials 694 (November 2014): 266–71. http://dx.doi.org/10.4028/www.scientific.net/amm.694.266.
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The risks of air conditioning system were found out by analyzing safety accident in recent years, and the derivative and secondary disasters were identified about air conditioning system. On the basis of the theory of man-machine-environment-management of system safety analysis, the risk index system of the possibility and consequences severity was established by identifying the possibility and the consequence severity factors resulting in the occurrence of air conditioning. The risk grades were determined by using the risk matrix to conduct the risk assessment for air conditioning system of a Commercial building in Tianjin. The preventive measures and control safety measures were proposed for air conditioning system Security.
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Peng, Xiao Yong, Fen Wan, Jing Fang Xie, Lin Yao, and Zhen Hao Liu. "Numerical Simulation of Indoor Airflow and Poison Gas Diffusion in Air-Conditioning Buildings with Large Space." Advanced Materials Research 243-249 (May 2011): 5810–17. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.5810.
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The numerical simulation of indoor airflow and poison gas diffusion and transport process is given for different air systems of air-conditioning in large space buildings in this paper. The numerical results show that the poison gas diffusion is affected by indoor airflow, and the variety air systems make the characteristics of poison gas diffusion differently. After arriving at the air return, the poison gas will soon be sprayed from the air inlet of the air system to the whole space which is serviced by the air system.
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Wang, Zhi Wei, Qiu Li Yang, Lei Min Zhang, Li Ping Han, and Jie Sun. "Study on the Optimization of Multi-Factor Influencing Ice Thermal Storage Air Conditioning System Economy." Advanced Materials Research 443-444 (January 2012): 333–39. http://dx.doi.org/10.4028/www.scientific.net/amr.443-444.333.
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On the basis of dynamic hourly cooling load, an optimal target function was taken as the minimization of sum of system fist cost and operation cost etc., within life cycle for ice thermal air conditioning system, the mathematics model of system optimization was established, and solved based on the external point penalty function method with step accelerate algorithm, using VB.NET for writing calculation program, taking ice thermal air conditioning systems for typical public buildings (an office building, a 4 star level hotel, a large scale store) as study objectives, the optimal calculations and analysis were carried out to multi-factor such as building load profile characteristics, discharge rate, and electrical price structure. Results in this paper provide technical information and reference for designer and operator.
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Moskvitina, A., M. Shyshyna, and M. Korchminskyi. "Feasibility study for the use of variable air volume systems for office buildings." Ventilation, Illumination and Heat Gas Supply 36 (February 8, 2021): 62–79. http://dx.doi.org/10.32347/2409-2606.2021.36.62-79.
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The main factor contributing to greenhouse gas emissions is the building up of the surrounding area. Studies have shown that buildings globally consume 30-40 % of energy use and release 40-50 % of global carbon dioxide emissions. Among all systems in houses, heating, ventilation and air conditioning (HVAC) systems are by far the most energy intensive. They consume approximately 50 % of the total energy demand of buildings. However, the systems are some of the most important systems in today's buildings. The number of these systems that are being installed has increased dramatically over the past few years. This is mainly due to the increasing demands for thermal energy, comfort and climate change. This paper presents a feasibility and ecology study between two ventilation or air-conditioning systems: constant air volume (CAV) and variable air volume (VAV). One of the purposes of this work is to determine the energy costs for each of the systems. An air conditioning system that saves operating costs usually requires a large initial investment. In this case, engineers must decide whether it is worth paying the additional upfront costs for a system that has lower operating costs. Despite the low attractiveness from the point of view of the investor, the VAV systems reduce the amount of greenhouse gas emissions and the amount of energy resources for servicing the commercial sector. Such system have less metal consumption. Thus, the cost of metal processing is also reduced. The results of this study can contribute to the future selection of ventilation systems, as well as contribute to the design and improvement of the systems under study. Energy saving is one of the main reasons why VAV systems are very popular today for the design of ventilation and air conditioning systems for office buildings and in many industries abroad. With these systems, the volume of transported air is reduced as soon as the operating load falls below the maximum projected load. The calculation of emissions of harmful substances into the environment was made while ensuring the operation of CAV and VAV systems.
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Wang, Qian Kun, Zhan Liang Zu, and Si Lun Liu. "Study on the Use of Geothermal Energy in Large Space Stadium." Applied Mechanics and Materials 368-370 (August 2013): 1415–20. http://dx.doi.org/10.4028/www.scientific.net/amm.368-370.1415.
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With the development of economy and the rising of public awareness on environmental issues, building energy consumption, especially the energy consumption of public buildings represented by large space stadiums, has received an increasing public attention. Geothermal energy, as a green energy, is widely used in large public buildings as a replacement of traditional energies. This article compares the respective economic and environmental benefits of ground source heat pump system and traditional air-conditioning system. First of all, the article discusses the feasibility of building geothermal wells and utilizing geothermal energy in large space stadiums. Then, the article illustrates the determination of the parameters of the geothermal wells and geothermal utilization strategy (deep + shallow geothermal) through software stimulation on Dest. Finally, the article evaluates the environmental and economic effect of geothermal energy system applied in large space stadium.
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Narayanan, Ramadas, Abeer Abdullah Al Anazi, Roberto Pippia, and Mohammad G. Rasul. "Solar Desiccant Cooling System for a Commercial Building in Kuwait’s Climatic Condition." Energies 15, no. 11 (June 2, 2022): 4102. http://dx.doi.org/10.3390/en15114102.
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The use of air conditioning in buildings to provide a comfortable environment accounts for up to 75% of the electricity consumed in Kuwait for the hot season from April through to the end of October. The widespread adoption of air conditioning systems in buildings has resulted in an increased demand for electricity. This has led to an increased peak load demand that has resulted in a larger carbon footprint and placed the electricity grid under significant strain. Heat-driven air conditioning systems that use solar energy are now emerging as alternatives to electricity-driven conventional refrigerated air conditioners. These systems are more energy-efficient, with lower carbon emissions while also ensuring better indoor air quality and comfort when optimally designed. Among the heat-driven air conditioning systems, the desiccant cooling system is among the systems with the most potential. This paper presents a numerical investigation of the design optimization of solar desiccant cooling systems for Kuwait’s climate. The numerical model of the system is developed using validated components. The various design configurations analysed include a solar heating system and regeneration air for the desiccant wheel. It is found that an evacuated tube solar collector in conjunction with return air from the building to regenerate the desiccant wheel provides the best results.
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da Silva, Pedro Paulo Fernandes, Alberto Hernandez Neto, and Ildo Luis Sauer. "Evaluation of Model Calibration Method for Simulation Performance of a Public Hospital in Brazil." Energies 14, no. 13 (June 24, 2021): 3791. http://dx.doi.org/10.3390/en14133791.
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This work presents an extensive study on methodologies to calibrate electric energy consumption in buildings. A comparison between several calibration methodologies shows different approaches addressing the same issue, suggesting a lack of a unique methodology that is reproducible for every building. Additionally, no methodology fits the Brazilian public context, such as the predominance of Unitary Air Conditioning Systems (UACS) and buildings which have operated for more than 30 years. A new calibration methodology for performance simulation is proposed to deal with such features. The methodology is separated into two evidence-based steps according to the size of the Heating, Ventilation and Air Conditioning (HVAC) systems used to control buildings’ indoor environments: the first step is dedicated to calibrating medium- and large-sized HVAC systems, and the second step is dedicated to calibrating small-sized HVAC systems. University Hospital of University of São Paulo (UH-USP) is used as a test bed to implement the proposed methodology. Accuracy indicators show the efficiency of the methodology in terms of calibrating a simulation of the whole UH-USP building and Chilled Water Plant on a monthly basis in terms of accuracy and the time needed to perform the calibration. However, regarding simulation of UACS, the application of the methodology was inconclusive. This study leaves open the question of the trade-off between increasing model outcome accuracy and the strictness of accuracy indicators applied to UACS and poorly automated large-sized air conditioners.
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Lv, Liugen, Yiying Luo, Yi Xiang, Xiangjiang Zhou, and Chen Huang. "Research on the dynamic heat transfer of stratified air conditioning zone building surfaces in large space scale rig based on low supply-middle return." Science Progress 103, no. 3 (July 2020): 003685042095092. http://dx.doi.org/10.1177/0036850420950926.
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Radiation heat and convection heat exist on stratified air conditioning zone building surfaces in large space, and they have significant impact on cooling load calculation and thermal comfort analysis. Actually, heat transfer in large space is usually under non-steady condition. Based on an actual large space, a 1:4 scale model experiment rig is built as research object, which has: typical sloping ceiling structure, columnar low supply air, middle return air, inner surfaces periodic heat flow simulation system, heat measurement, and control system. For stratified air conditioning zone building surfaces in large space, radiation heat transfer calculation model is presented based on Gebhart radiation model and radiation heat is calculated by matrix calculation. Convection heat transfer calculation formula is presented based on inner surfaces temperatures and indoor air temperatures. Taking two periodic heat flow experiment conditions, building surfaces temperatures and indoor air temperatures of stratified air conditioning zone in large space were collected, taking model calculation program to compute dynamic radiation heat and convection heat. The result indicated the dynamic characteristics of radiation heat and convection heat of stratified air conditioning zone building surfaces in large space. It provided some important information for dynamic heat transfer research in stratified air conditioning zone building surfaces in large space.
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Abu, Rahaman, K. A. Oladejo, A. O. Popoola, K. T. Oriolowo, and K. M. Odunfa. "Design and Simulation of Air Conditioning System in a Large Auditorium Based on Computational Fluid Dynamics." European Journal of Engineering Research and Science 5, no. 9 (September 29, 2020): 1117–23. http://dx.doi.org/10.24018/ejers.2020.5.9.2062.
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Air conditioning system is an indispensable part of buildings today. The cost of this system increases with the rise in energy consumption which poses a challenge as well as air distribution in large auditoria. Analysis of results can also be daunting when designing this system. The study focuses on designing an air conditioning system in a large auditorium, applying Computational Fluid Dynamics (CFD) and visualizing the result in a Virtual Reality (VR) environment. The 3-dimensional model of the 520-capacity Technology Lecture Theatre, University of Ibadan, Nigeria was drawn with Autodesk Revit and modified into the geometry applicable for Displacement Ventilation (DV) and Mixed Ventilation (MV) for ease of numerical analysis with ANSYS Fluent. The building model and simulation results were then imported into Unity software for visualization in VR. The DV achieved better thermal comfort and air distribution in the computer simulation. At a supply temperature of 292.15 K, the DV system was able to keep the auditorium temperature at about 296.50 K, while the MV system at a supply temperature of 289.15 K was only able to maintain the temperature at 295.40 K. The temperature profile showed that the lower region where the students were seated was colder in DV compared to MV by at least 3 K. The results were also observed from a convenient position in VR. This study, with the aid of CFD and VR, was able to establish that displacement ventilation design has better air flow, lower energy consumption and is efficient for an air conditioning system in a large auditorium.
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Abu, Rahaman, K. A. Oladejo, A. O. Popoola, K. T. Oriolowo, and K. M. Odunfa. "Design and Simulation of Air Conditioning System in a Large Auditorium Based on Computational Fluid Dynamics." European Journal of Engineering and Technology Research 5, no. 9 (September 29, 2020): 1117–23. http://dx.doi.org/10.24018/ejeng.2020.5.9.2062.
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Air conditioning system is an indispensable part of buildings today. The cost of this system increases with the rise in energy consumption which poses a challenge as well as air distribution in large auditoria. Analysis of results can also be daunting when designing this system. The study focuses on designing an air conditioning system in a large auditorium, applying Computational Fluid Dynamics (CFD) and visualizing the result in a Virtual Reality (VR) environment. The 3-dimensional model of the 520-capacity Technology Lecture Theatre, University of Ibadan, Nigeria was drawn with Autodesk Revit and modified into the geometry applicable for Displacement Ventilation (DV) and Mixed Ventilation (MV) for ease of numerical analysis with ANSYS Fluent. The building model and simulation results were then imported into Unity software for visualization in VR. The DV achieved better thermal comfort and air distribution in the computer simulation. At a supply temperature of 292.15 K, the DV system was able to keep the auditorium temperature at about 296.50 K, while the MV system at a supply temperature of 289.15 K was only able to maintain the temperature at 295.40 K. The temperature profile showed that the lower region where the students were seated was colder in DV compared to MV by at least 3 K. The results were also observed from a convenient position in VR. This study, with the aid of CFD and VR, was able to establish that displacement ventilation design has better air flow, lower energy consumption and is efficient for an air conditioning system in a large auditorium.
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Ma, Longkai, and Zhili Zeng. "A Survey of the Influence of Air Distribution on Indoor Environment and Building Energy Efficiency." Journal of Physics: Conference Series 2287, no. 1 (June 1, 2022): 012041. http://dx.doi.org/10.1088/1742-6596/2287/1/012041.
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Abstract With society paying more and more attention to energy conservation, building energy conservation has become a problem that must be considered in the design phase. In addition, modern life makes people spend more time indoors every day. Reasonable indoor air distribution positively impacts a comfortable indoor thermal environment and reduces building energy consumption. This paper discusses the influence of air distribution on indoor thermal comfort and building energy saving. Reasonable air distribution in the air-conditioned room will create a comfortable indoor thermal environment, which is helpful for the physical and mental health of personnel and efficient work. Meanwhile, it can also effectively reduce the equipment's initial investment and operating energy consumption and realize building energy savings. The design of indoor air distribution cannot be a single, isolated project. A comprehensive analysis based on each station's environmental thermal comfort requirements in the work area must be carried out to reduce air-conditioning operation energy consumption and achieve building energy-saving goals. For existing buildings and large space buildings, the corresponding air distribution design scheme should be designed reasonably. This paper also suggests future research directions on indoor air distribution.
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Horn, Valéria V., and Annamaria Dudas. "Acoustical aspects of the reconstruction of a historical building with closed courtyard." Pollack Periodica 15, no. 1 (April 2020): 197–208. http://dx.doi.org/10.1556/606.2020.15.1.19.
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Abstract The Szentgyörgyi-Horváth-house is one of the major historical buildings of Balatonfüred. The design of the reconstruction was preceded by detailed architectural historical study. The reconstruction of the building was realized by retaining the original structures. For the new function the building was equipped with an air-conditioning engine-room. The air conditioner is a significant source of noise for the apartments facing the courtyard of the building, due to its continuous operation. The acoustic examination of the enclosed yard was calculated with two different approaches. The distance-dependent approximation, which is usual for large halls, was approved. Building construction structures were determined based on the results to meet the acoustic requirements.
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Li, Dongmei. "Analysis on the monitoring system of energy conservation and comfort in office buildings based on internet of things." International Journal of Low-Carbon Technologies 15, no. 3 (February 17, 2020): 351–55. http://dx.doi.org/10.1093/ijlct/ctz083.
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Abstract In order to reduce the cost of central air conditioning, we need to reduce its energy consumption. This paper briefly introduced Internet of Things and the energy-saving and comfort monitoring system of central air conditioning based on the Internet of Things. The system took comfort degree as constraint and energy efficiency as objective to control energy saving of central air conditioning. Company X in Guanghan, Sichuan, China, was taken as an example for analysis. The system was compared with the energy-saving control system which took temperature and power as constraints. Compared with before the energy-saving control, the proportion of air conditioning downtime in the working hours of employees increased after the implementation of the two kinds of energy-saving control systems, and the proportion of downtime under the energy-saving control system designed in this study was larger; in addition, after the control of the two kinds of energy-saving systems, the energy efficiency of the air conditioning significantly improved, and the air conditioning under the control of the energy-saving system proposed in this study had more improvement in energy efficiency and higher energy-saving efficiency. The energy-saving control method proposed in this study can effectively reduce the power consumption of the central air conditioning in the office.
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Simpson, James, and E. Gregory McPherson. "Potential of Tree Shade for Reducing Residential Energy Use in California." Arboriculture & Urban Forestry 22, no. 1 (January 1, 1996): 10–18. http://dx.doi.org/10.48044/jauf.1996.002.
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Electric utilities in California currently sponsor planting of approximately 75,000 yard trees annually as an energy conservation measure. In this study we evaluated the potential effects of tree shade on residential air conditioning and heating energy use for a range of tree orientations, building insulation levels and climate zones in California using computer simulation. Trees shading a home's west exposure produced the largest savings, both annual (kWh) and peak (kW), for all climate zones and insulation levels considered. Next largest savings were for southwest (annual and peak) and east (annual only) locations. Three trees (two on the west, one on the east side) reduced annual energy use for cooling 10 to 50 percent (200 to 600 kWh, $30 to $110) and peak electrical use up to 23 percent (0.7 kW). Except in climates with little air-conditioning demand, cooling load reductions were always greater than increased heating loads associated with shade from south side trees in winter. Air-conditioning savings, both peak and annual, were larger in warmer climates and uninsulated buildings; percentage savings were larger in cooler climates and for more energy efficient buildings. Recommendations are made regarding locating yard trees to maximize energy savings.
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Ragab, Karim Mohamed, Mehmet Fatih Orhan, Kenan Saka, and Yousef Zurigat. "A Study and Assessment of the Status of Energy Efficiency and Conservation at School Buildings." Sustainability 14, no. 17 (August 26, 2022): 10625. http://dx.doi.org/10.3390/su141710625.
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The building sector consumes a significant portion of global energy use. In this regard, this work was undertaken to study the status of energy efficiency and conservation at a large school building in the northern part of United Arab Emirates (UAE). The annual electrical consumption at the school was analyzed and an awareness survey among the students and teachers was conducted to measure the level of awareness as well as to assess the current energy consumption practices. In order to identify energy saving opportunities, an energy audit was carried out wherein the school energy consuming systems, particularly the lighting and air-conditioning systems, were assessed. Furthermore, thermography scanning of the school building envelope was conducted to examine the building insulation and identify air leakage locations. The building electricity supply and distribution systems were assessed using power analyzer and thermography devices. The energy conservation measures identified include removing the extra lighting, installing motion sensors in classrooms and labs, as well as integrating a Networked Optimization Software with the current HVAC (heating, ventilating and air conditioning) system. The methodology consists of seven fundamental steps: (1) case study data collection (analysis of buildings and utility data); (2) survey of real operation conditions; (3) understanding of building behavior; (4) analysis of energy conservation measures; (5) estimation of energy-saving potential; (6) economic assessment; and (7) proposing Energy Conservation Measures (ECMs). In this regard, the school energy consuming systems (lighting, building envelope, and air conditioning (AC)) were examined to identify possible ways to reduce the school energy consumption. The results indicate that the cost of installing motion sensors in classrooms, and labs is approximately AED 20,000 (United Arab Emirates Dirham), which yields an annual energy saving of AED 93,691. Furthermore, with all energy saving measures, a total annual saving of AED 364,000 is anticipated, which is approximately 16% of the annual electricity bill.
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Wang, Xin, Dekang Li, Jinchi Zhao, Fei Wang, and Qianru Zhang. "A Study of Energy Utilization and Carbon Emission Audit of a Commercial Mall in Hot Summer/Warm Winter Region in China." E3S Web of Conferences 356 (2022): 01036. http://dx.doi.org/10.1051/e3sconf/202235601036.
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Evaluation on the carbon emissions of large public buildings and carbon reduction measures are very important to help reach carbon peak demand and carbon neutral. The purpose of this study is to conduct energy audits and energy-saving assessments on large public and commercial buildings to find out the impact of various behavioural activities related to buildings on carbon emissions and energy consumption, and to explore the carbon reduction potential of buildings. In China, the energy structure based on fossil fuels will not change in a short term, and energy consumption will inevitably increase with economic development; however, the energy efficiency is the main factor that affects the building carbon emissions. And changing energy efficiency will reduce emissions by 9.29%, while improving the energy structure will reduce emissions by only 0.46%; it is the key work to slow down greenhouse gas emissions in buildings that is reducing power consumption of electrical equipment, especially the air-conditioning system, which can result in 49.72% energy saving after reforming.
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Olama, Mohammed, Teja Kuruganti, James Nutaro, and Jin Dong. "Coordination and Control of Building HVAC Systems to Provide Frequency Regulation to the Electric Grid." Energies 11, no. 7 (July 16, 2018): 1852. http://dx.doi.org/10.3390/en11071852.
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Buildings consume 73% of electricity produced in the United States and, currently, they are largely passive participants in the electric grid. However, the flexibility in building loads can be exploited to provide ancillary services to enhance the grid reliability. In this paper, we investigate two control strategies that allow Heating, Ventilation and Air-Conditioning (HVAC) systems in commercial and residential buildings to provide frequency regulation services to the grid while maintaining occupants comfort. The first optimal control strategy is based on model predictive control acting on a variable air volume HVAC system (continuously variable HVAC load), which is available in large commercial buildings. The second strategy is rule-based control acting on an aggregate of on/off HVAC systems, which are available in residential buildings in addition to many small to medium size commercial buildings. Hardware constraints that include limiting the switching between the different states for on/off HVAC units to maintain their lifetimes are considered. Simulations illustrate that the proposed control strategies provide frequency regulation to the grid, without affecting the indoor climate significantly.
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Ezema, I. C., and S. A. Maha. "Energy Efficiency in High-rise Office Buildings: An Appraisal of its Adoption in Lagos, Nigeria." IOP Conference Series: Earth and Environmental Science 1054, no. 1 (September 1, 2022): 012037. http://dx.doi.org/10.1088/1755-1315/1054/1/012037.
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Abstract High-rise office buildings are naturally energy-intensive as energy is required in large quantities to run modern building services and to power equipment needed for a hitch-free operation of the buildings. It was found in studied literature that maintaining good indoor environmental quality through air-conditioning, lighting and powering of office equipment contribute the most to an office building’s total energy consumption. Hence, over time, various strategies have been employed to reduce the intense energy demand in high-rise office buildings. This paper adopted the use of both literature review and case study methods. The paper identifies the key energy efficiency strategies that have been successfully deployed in high-rise office buildings using the literature review approach. Also, case studies were conducted on three relatively new high-rise office buildings in Lagos, Nigeria by evaluating them against the background of the best practices in energy efficiency. The study found that deployment of energy efficiency strategies in high-rise office buildings in the study area is still very low especially in the areas of building orientation, building envelope design and the use of renewable energy. However, the use of day-lighting techniques and sustainable lighting systems are quite prominent in the office buildings studied. The study underscores the need to make high-rise office buildings more sustainable through energy efficiency strategies across the whole building life cycle of design, construction, use and end of life.
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Feng, Yayuan, Youxian Huang, Haifeng Shang, Junwei Lou, Ala deen Knefaty, Jian Yao, and Rongyue Zheng. "Prediction of Hourly Air-Conditioning Energy Consumption in Office Buildings Based on Gaussian Process Regression." Energies 15, no. 13 (June 24, 2022): 4626. http://dx.doi.org/10.3390/en15134626.
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Accurate prediction of air-conditioning energy consumption in buildings is of great help in reducing building energy consumption. Nowadays, most research efforts on predictive models are based on large samples, while short-term prediction with one-month or less-than-one-month training sets receives less attention due to data uncertainty and unavailability for application in practice. This paper takes a government office building in Ningbo as a case study. The hourly HVAC system energy consumption is obtained through the Ningbo Building Energy Consumption Monitoring Platform, and the meteorological data are obtained from the meteorological station of Ningbo city. This study utilizes a Gaussian process regression with the help of a 12 × 12 grid search and prediction processing to predict short-term hourly building HVAC system energy consumption by using meteorological variables and short-term building HVAC energy consumption data. The accuracy R2 of the optimal Gaussian process regression model obtained is 0.9917 and 0.9863, and the CV-RMSE is 0.1035 and 0.1278, respectively, for model testing and short-term HVAC system energy consumption prediction. For short-term HVAC system energy consumption, the NMBE is 0.0575, which is more accurate than the standard of ASHRAE, indicating that it can be applied in practical energy predictions.
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Yuan, Jihui, Toshio Yamanaka, Tomohiro Kobayashi, Haruto Kitakaze, and Kazuo Emura. "Effect of highly reflective building envelopes on outdoor environment temperature and indoor thermal loads using CFD and numerical analysis." E3S Web of Conferences 111 (2019): 06031. http://dx.doi.org/10.1051/e3sconf/201911106031.
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In recent years, the climate change (CC) and urban heat island (UHI) effects are becoming serious problems, affecting people’s life and health, especially in hot summer. For large cities such as Tokyo and Osaka in Japan, the UHI effect is particularly intense. It is known that about 40% of urban anthropogenic heat comes from buildings in large cities. To reduce the anthropogenic heat of buildings is an important countermeasure to this problem. Strategies for UHI mitigation include urban ventilation, urban greening, green roof, highly reflective (HR) roads, and HR building envelopes, etc. Among these mitigation strategies, the research on HR building envelopes has been carried out globally. However, it is not clear that how the HR building envelopes affect the urban outdoor environment temperature and indoor thermal loads of urban buildings which is directly related to the selection of heating, ventilation and air conditioning (HVAC) system. Thus, this study aims to evaluate the effect of solar reflectivity of building envelopes varied from 0.1 to 0.9, on the outdoor environment temperature and indoor thermal loads of buildings located on Osaka University Suita Campus, Japan, using Computational Fluid Dynamics (CFD) and numerical analysis.
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Yan, Chengchu, Shengwei Wang, Cheng Fan, and Fu Xiao. "Retrofitting building fire service water tanks as chilled water storage for power demand limiting." Building Services Engineering Research and Technology 38, no. 1 (September 24, 2016): 47–63. http://dx.doi.org/10.1177/0143624416669553.
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Peak demand cost usually contributes a large proportion of the total electricity bills in buildings. Using existing building facilities for power demand limiting has been verified as effective measures to reduce monthly peak demands and associated costs. Fire service water tanks exist in most commercial buildings. This paper presents a comprehensive study on how to effectively retrofit existing building fire service water tanks as chilled water storage for power demand limiting. Important technical and economic factors that may affect the implementation of the proposed retrofitting are addressed. Two retrofitting schemes, i.e. a small ΔT (storage temperature difference) scheme and a large ΔT scheme are proposed for integrating the chilled water storage system into an existing all-air system and an existing air-water air conditioning system, respectively. Two optimal demand limiting control strategies, i.e. time-based control and demand-based control, are proposed for maximizing the monthly peak demand reduction of buildings with regular and variable peak occurring time, respectively. The cost-effectiveness of different retrofitting schemes in three real buildings in Hong Kong is analysed. Results show that substantial cost savings can be achieved with short payback periods (0.7–2.6 years) for the retrofits in these three buildings. Practical application: This paper presents a techno-economic analysis on retrofitting existing building fire service water tanks as chilled water storage for power demand limiting and operational cost saving. The proposed retrofitting schemes and demand limiting control strategies enable chilled water storage systems to be readily applied to most existing buildings. Building owners can benefit from the peak demand cost saving as the monthly peak demand can be significantly reduced by using chilled water storage. The extra costs involved in tank retrofits and system integrations can be paid back within three years.
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Cai, Ning, and Chen Huang. "A Study of Cooling Load Calculation of Stratified Air Conditioning System for Large Space Based on the Simultaneously Solving Model." Applied Mechanics and Materials 672-674 (October 2014): 1755–61. http://dx.doi.org/10.4028/www.scientific.net/amm.672-674.1755.
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A calculation method for cooling load of stratified air conditioning system based on the simultaneously solving model is presented. Thermal environment experiment under summer condition is carried out in a large space building, indoor air temperature, inner wall surface temperature and cooling capacity were obtained; the stratified air conditioning cooling load calculated by the simultaneously solving model is compared with air conditioning cooling capacity in experiment, the relative error is 14%, taking the loss of cooling capacity and leakage loss, it can be thought that the simultaneously solving model can be used to calculate cooling load of stratified air conditioning system.
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Osipov, S. N., S. L. Danilevskiy, and A. V. Zacharenko. "THE USE OF AIR LAYERS IN BUILDING ENVELOPES FOR ENERGY SAVING DURING AIR CONDITIONING." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 60, no. 5 (September 28, 2017): 470–83. http://dx.doi.org/10.21122/1029-7448-2017-60-5-470-483.
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Since there are no large natural energy resources in Belarus, energy savings ought to be a point of the special attention. With this regard it is important to develop modern ways of savings during the process of air conditioning inside new buildings with an air layer in the enclosure, especially in translucent ones. The system of ventilation of air layers in the enclosure of a building has been introduced in which air movement is caused by the gravitational and aerodynamic forces. It makes it possible to arrange further ventilation – a natural, forced or a hybrid one. With the purpose of increasing and streamlining natural draught the partitions are used separating the different parts of air layers. For natural ventilation with the use of gravitational forces the holes in the upper and lower parts of the partitions between adjacent air layers are applied. Natural ventilation in the holes of the partitions is regulated by movable shutters, blinds or other adjusting devices. For combined or forced air exchange between adjacent zones of air layers fans are used pumping air from the air layer zones with a higher temperature to zones of air layers with lower temperature and vice versa. When air exchange is forced, in order to intensify the infiltration of air into zones of air layers jets are laid on a hard surface. In order to cool a multi-layered enclosure of a building, where the movement of air between the air layers (that have been formed by internal partitions) is being fulfilled by a natural, forced or combined mode, a part of the air or the total air processed inside the building (i.e. conditioned or non-conditioned air cooler as compared with the outside one) is being sent to these strata. Combined or forced flow of the air processed inside the building into the air layers is done through the ducts associated with the output channels of the air conditioners. The internal partitions are equipped with the air valve hole.
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Craig (INVITED), A. B. "A Review of Radon Mitigation in Large Buildings in the US." Radiation Protection Dosimetry 56, no. 1-4 (December 1, 1994): 29–32. http://dx.doi.org/10.1093/oxfordjournals.rpd.a082417.
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Abstract The Environmental Protection Agency of the US carried out its initial research on radon mitigation in houses, both existing and new. A review of this work is presented in another paper at this workshop. Four years ago, this work was expanded to include the study of radon in schools, both new and existing, and now includes studies in other large buildings, as well. Factors affecting ease of mitigation of existing schools using active soil depressurisation (ASD) have been identified and quantified. Examination of the building and architectural plans makes it possible to predict the ease of mitigation of a specific building. Many schools can be easily and inexpensively mitigated using ASD. However, examination of a fairly large number of schools has shown that a significant percentage of existing schools will be hard to mitigate with ASD. In some cases, the heating, ventilating, and air conditioning (HVAC) system can be used to pressurise the building and retard radon entry. However, in some cases no central HVAC system exists and the school is difficult and/or expensive to mitigate by any technique. Prevention of radon entry is relatively easy and inexpensive to accomplish during construction of schools and other large buildings. It is also possible to control radon to near ambient levels in new construction, a goal which is much more difficult to approach in existing large buildings. The preferred method of radon prevention in the construction of large buildings is to design the HVAC system for building pressurisation, install a simple ASD system, and seal all entry routes between the sub-slab and the building interior.
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Fisher, G., B. Ligman, T. Brennan, R. Shaughnessy, B. H. Turk, and B. Snead. "Radon Mitigation in Schools Utilising Heating, Ventilating and Air Conditioning Systems." Radiation Protection Dosimetry 56, no. 1-4 (December 1, 1994): 51–54. http://dx.doi.org/10.1093/oxfordjournals.rpd.a082421.
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Abstract As part of a continuing radon in schools technology development effort, EPA's School Evaluation Team has performed radon mitigation in schools by the method of ventilation/pressurisation control technology. Ventilation rates were increased, at a minimum, to meet the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) standard Ventilation for Acceptable Indoor Air Quality (ASHRAE 62-1989). This paper presents the results and the preliminary evaluations which led to the team's decision to implement this technology. Factors considered include energy penalties, comfort, indoor air quality (IAQ), building shell tightness, and equipment costs. Cost benefit of heat recovery ventilation was also considered. Earlier results of the SEP team's efforts have indicated a severe ventilation problem within the schools of the United States. An integrated approach to radon mitigation in schools and other large buildings which control radon as well as improve overall IAQ should be the goal of radon remediation where practical. Two case studies are presented where HVAC technology was implemented for controlling radon concentrations. One involved the installation of a heat recovery ventilator to depressurise a crawl space and provide ventilation to the classrooms which previously had no mechanical ventilation. The other involved the restoration of a variable air volume system in a two-storey building. The HVAC system's controls were restored and modified to provide a constant building pressure differential to control the entry of radon. Pre-mitigation and post-mitigation indoor air pollutant measurements were taken, including radon, carbon dioxide (CO2), particulates, and bio-aerosols. Long-term monitoring of radon, CO2 building pressure differentials, and indoor/outdoor temperature and relative humidity is presented.
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Mota, Lia, Alexandre Mota, Cláudia Pezzuto, Marcius Carvalho, Marina Lavorato, Lorenzo Coiado, and Everton Oliveira. "Development of a Surface Temperature Sensor to Enhance Energy Efficiency Actions in Buildings." Sensors 18, no. 9 (September 12, 2018): 3046. http://dx.doi.org/10.3390/s18093046.
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The air temperature increase in urban centers can lead to problems such as increased energy consumption associated to air conditioning, the intensification of pollution, human discomfort and health problems. In this context, the building envelope plays an important role in urban thermal equilibrium. Energy efficiency rating systems for buildings (LEED—Leadership in Energy and Environmental Design, AQUA—High Environmental Quality, PROCEL Edifica, etc.) stimulate energy efficiency actions in the built environment, considering, for example, the envelope and energy efficiency initiatives in buildings. Research carried out recently has shown that monitoring of buildings can provide important information about building performance, supporting building control strategies and enabling actions aimed at improving energy efficiency and thermal comfort. More specifically, wireless sensors are also being used to monitor buildings. This work proposes and presents the development of a surface temperature sensor that can support actions to enhance energy efficiency in the built environment, meeting the requirements proposed by the energy efficiency rating systems of buildings. This sensor must have characteristics such as low cost, the storage capacity of a large amount of data and the possibility of remote monitoring of the collected temperatures. Computer simulations and validation tests were carried out showing that the proposed sensor allows the remote monitoring (using a wireless transmission system) of the surface temperature in buildings, respecting the requirements of high storage capability and low cost.
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Mai, Ronny, Ralph Krause, and Christian Friebe. "Enhancement of ventilation efficiency in residential buildings by pulsating air-flow." E3S Web of Conferences 111 (2019): 06067. http://dx.doi.org/10.1051/e3sconf/201911106067.
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Contrary to conventional air-conditioning systems in non-residential buildings, the air-flow conditions are almost never considered in ventilation systems for residential buildings. Both the air inlets and the outlets are usually located at unfavourable places. This situation culminates in large buildings with many flats, where simplest supply-air apertures are installed with respect to cost restrictions. With small air flow rates, the ventilation efficiency is very poor due to a lack of air mixture. In order to improve the situation, a new supply air aperture has been developed recently. The air flow rate is designed to vary with time, with a low auxiliary energy requirement, with clear maxima and otherwise reduced flow rate. Hence, the corresponding momentum was expected to improve the air mixture in the room. First measurements confirm that the transient flow conditions allow high intrusion depths and a good mixing of the air. The pulsating airflow reduces the risk of draughts and increases both ventilation efficiency and thermal comfort in the living area. Moreover, the energy efficiency is improved as the average air-flow rate can be reduced.
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Hicks, Bruce B., William R. Pendergrass, Christoph A. Vogel, and Richard S. Artz. "On the Drag and Heat of Washington, D.C., and New York City." Journal of Applied Meteorology and Climatology 53, no. 6 (June 2014): 1454–70. http://dx.doi.org/10.1175/jamc-d-13-0154.1.
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AbstractData from a network of micrometeorological instruments, mostly mounted 10 m above the roofs of 12 buildings in Washington, D.C., are used to derive average values and spatial differences of the normalized local friction velocity u*/u ≡ ()1/2/u (with u being the wind speed reported at the same height as the covariance is measured, w being the vertical wind component, primes indicating deviations, and the overbar indicating averaging). The analysis is extended through consideration of two additional sites in New York City, New York. The ratio u*/u is found to depend on wind direction for all locations. Averaged values of u*/u appear to be best associated with the standard deviation of local building heights, with little evidence of a dependence on any other of the modern building-morphology indices. Temperature covariance data show a large effect of nearby activities, with the consequences of air-conditioning systems being obvious (especially at night) in some situations. The Washington data show that older buildings, built largely of native limestone, show the greatest effects of air-conditioning systems. The assumption that the nighttime surface boundary layer is stable is likely to be most often incorrect for both Washington and New York City—the sensible heat flux resulting from heating and cooling of building work spaces most often appears to dominate.
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Franco, Alessandro, Lorenzo Miserocchi, and Daniele Testi. "Energy Intensity Reduction in Large-Scale Non-Residential Buildings by Dynamic Control of HVAC with Heat Pumps." Energies 14, no. 13 (June 28, 2021): 3878. http://dx.doi.org/10.3390/en14133878.
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One of the main elements for increasing energy efficiency in large-scale buildings is identified in the correct management and control of the Heating Ventilation and Air Conditioning (HVAC) systems, particularly those with Heat Pumps (HPs). The present study aimed to evaluate the perspective of energy savings achievable with the implementation of an optimal control of the HVAC with HPs. The proposed measures involve the use of a variable air volume system, demand-controlled ventilation, an energy-aware control of the heat recovery equipment, and an improved control of the heat pump and chiller supply water temperature. The analysis has been applied to an academic building located in Pisa and is carried out by means of dynamic simulation. The achieved energy saving can approach values of more than 80% if compared with actual plants based on fossil fuel technologies. A major part of this energy saving is linked to the use of heat pumps as thermal generators as well as to the implementation of an energy efficient ventilation, emphasizing the importance of such straightforward measures in reducing the energy intensity of large-scale buildings.
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Xiong, Ai Min, Fei Yu Li, and Xuan Xie. "Intelligent Shading Control System Based on the Lonworks Bus." Applied Mechanics and Materials 273 (January 2013): 665–68. http://dx.doi.org/10.4028/www.scientific.net/amm.273.665.
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In order to improve the lighting and temperature control in large public buildings, intelligent shading technology has been growing attention. This intelligent shading control system is based on the Lonworks bus. It uses various sensors to detect indoor and outdoor light intensity and temperature changes automatically, the system provides reasonable the curtain control program to change the height of the curtains and the blade angle, to regulate indoor lighting and air-conditioning, reducing building energy consumption in all aspects. Common TCP / IP protocol is used to achieve a seamless connection with the building automation system. It concerns with energy saving, low carbon, environmental protection, intelligence concept of modern building.
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Jiao, Lichao, and Xian Rong. "Analysis of Principal Factors on Energy Consumption of Expressway Service Buildings." Energies 15, no. 12 (June 16, 2022): 4392. http://dx.doi.org/10.3390/en15124392.
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As commercial transportation complexes, expressway service buildings have large passenger flow and a poor energy-saving effect, and have become the focus of energy conservation and emissions reduction efforts in the transportation field. At the same time, the particularity of the function determines that it is within the scope of no municipal supporting facilities, which renders them typical energy island-type buildings. This paper takes the expressway service buildings in a cold area as the research object, and carries out the correlation and partial correlation analysis of the factors influencing the operating energy consumption of the air-conditioning system. For the analysis of factors affecting the energy consumption of expressway service buildings during the operation period, considering that most of the service buildings are in the form of heating and cooling air conditioners, this paper chooses to represent the “refrigeration period” with a more obvious degree of influence. At the same time, during the operation period, because the ontological characteristics have been determined according to the analysis results, the outdoor meteorological characteristics are the main factors affecting the energy consumption of expressway service buildings. These include the dry bulb temperature and horizontal plane solar irradiance index, as well as the indoor comprehensive environment parameters: temperature, CO2 concentration index, indoor personnel density index. Based on the above analysis, a low energy consumption operation strategy for the air-conditioning system is proposed. The results of this article are of great significance for the construction of energy consumption models for expressway service buildings and the adoption of low energy consumption strategies.
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Jankovic, Ljubomir. "Experiments with Self-Organised Simulation of Movement of Infectious Aerosols in Buildings." Sustainability 12, no. 12 (June 25, 2020): 5204. http://dx.doi.org/10.3390/su12125204.
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The ultimate aim of sustainability in buildings gained an additional new dimension as the start of the year 2020 saw a rapid worldwide spread of the infectious disease caused by a coronavirus named COVID-19. There is evidence that, in addition to person to person contact, the disease transmission occurs through airborne droplets/aerosols generated by breathing, speaking, coughing or sneezing. For that reason, building heating, ventilating and air conditioning systems can play an important role, as they may both contribute as well as reduce the transmission risk. However, there is insufficient understanding of the movement of infectious aerosols in buildings. This article introduces a method of bottom-up emergent modelling of the movement of infectious aerosols in internal space using a physics engine, and reports on simple simulation experiments. The results show that the smallest droplets that are large enough to contain the virus can be suspended in the air for an extended period of time; that turbulent air flow can contribute to the infectious aerosols remaining in the room; and that unidirectional air flow can contribute to purging the room of the infectious aerosols. The model introduced in this article is a starting point for further development and for increasing our understanding of the movement of infectious aerosols in buildings, and thus for increased sustainability of building design.
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Ni, Jia Jia, Li Tao, Yi Jun Wang, and Jin Lei Wu. "The Energy Consumption Investigation of the Hotel Central Air-Conditioning System and the Research of Energy Saving Measures." Advanced Materials Research 712-715 (June 2013): 1614–18. http://dx.doi.org/10.4028/www.scientific.net/amr.712-715.1614.
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Through to investigation on present situation of the Changzhou Changrui Hotel air conditioning system energy consumption, by analysis the energy consumption, the power consumption of hotel central air-conditioning system charge 58% of the total electric, accounted for a large proportion. So we should take the necessary measures to reduce the expenses of air conditioning system energy consumption. According to the analysis of data on the survey, we put forward some particular energy-saving measures of central air-conditioning system of the hotel, including strengthening the building envelope insulation, energy saving technology of doors and windows, measures of roof energy saving, setting reasonable indoor temperature, adopting frequency control air-conditioning, reuse waste heat of the central air-conditioning, using the condensation water of central air conditioning to make-up water and reducing temperature of cooling tower , and drying the fresh air independently.
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Zamhuri, Muhammad Ikhwan, Haslenda Hashim, and Ho Wai Shin. "Optimal Design of Integrated Chiller Capacity with Ice Thermal Storage for Commercial Buildings through Cooling System Cascade Analysis." International Journal of Innovative Technology and Exploring Engineering 10, no. 2 (December 10, 2020): 165–75. http://dx.doi.org/10.35940/ijitee.b8301.1210220.
Full textAbstract:
Chilled water air conditioning system is used to supply cooling systems in large capacity for industrial processes and commercial buildings. Air conditioners contribute more than 60 percent of electricity consumption in buildings. District Cooling System (DCS) technology comprises a central chiller plant which provides advantage compared to local air conditioning system. It has higher efficiency, uses less power in system operation, allows more usable space in buildings, and can be operated with minimum manpower while handling same amount of cooling load. The integration of a chiller with ice thermal storage (ITS) offers more operational flexibility while reducing space cooling expenses. This paper presents a systematic framework for design and operation of District Cooling Plant (DCP) comprising an integrated chiller and ice thermal storage system. The Cooling System Cascade Analysis (COSCA) based on pinch analysis is constructed to determine the chiller optimal size and ice thermal storage capacity. The District Cooling System configuration for this study comprises a cooling tower, chiller (centrifugal, variable centrifugal, glycol) and ice thermal storage system. The application of this technique to fulfil 66,284 refrigerant tonne hour (RTH) cooling load demand from commercial buildings reveals the optimal capacity of the chiller is 3068.91 refrigerant tonne (RT), ice tank rating at 989 refrigerant tonne (RT) and ice tank capacity is 9892.75 refrigerant tonne hour (RTH).