scholarly journals Analysis of Energy Consumption in Different European Cities: The Adaptive Comfort Control Implemented Model (ACCIM) Considering Representative Concentration Pathways (RCP) Scenarios

2020 ◽  
Vol 10 (4) ◽  
pp. 1513 ◽  
Author(s):  
Daniel Sánchez-García ◽  
David Bienvenido-Huertas ◽  
Jesús A. Pulido-Arcas ◽  
Carlos Rubio-Bellido

Reports of Intergovernmental Panel on Climate Change have set various greenhouse gas emissions scenarios, through which the evolution of the temperature of the planet can be estimated throughout the 21st century. The reduction of the emissions from the different activities carried out by mankind is crucial to mitigate greenhouse gas emissions. One of the most significant activities is users’ behaviour within buildings, particularly the use of Heating, Ventilation and Air-Conditioning systems. Modifying users’ behaviour patterns to guarantee acceptable thermal conditions inside buildings could lead to considerable energy saving percentages, and adaptive thermal comfort models could be an opportunity to achieve important savings. For this reason, this study analyzes the potential to apply adaptive thermal comfort models to use artificial air-conditioning systems by modifying setpoint temperatures. The analysis was conducted in five major European cities (Barcelona, Berlin, Bern, Rome, and Vienna) and in five climate change scenarios in the year 2050. The results showed that, in general, the energy saving achieved by adaptive strategies was larger in the cities with a greater cooling demand. Also, in both Representative Concentration Pathways (RCP) of the Fifth Assessment Report (AR5) considered, the energy saving were decreased in the cities of Barcelona and Rome, with values lower than those of the Fourth Assessment Report (AR4) scenarios considered, whereas in the cities of Berlin, Bern, and Vienna, the saving in the RCP scenarios is greater than those in the other scenarios.

2019 ◽  
Vol 11 (2) ◽  
pp. 328 ◽  
Author(s):  
Aiman Albatayneh ◽  
Dariusz Alterman ◽  
Adrian Page ◽  
Behdad Moghtaderi

The building industry is regarded a major contributor to climate change as energy consumption from buildings accounts for 40% of the total energy. The types of thermal comfort models used to predict the heating and cooling loads are critical to save energy in operative buildings and reduce greenhouse gas emissions (GHG). In this research, the internal air temperatures were recorded for over one year under the free floating mode with no heating or cooling, then the number of hours required for heating or cooling were calculated based on fixed sets of operative temperatures (18 °C–24 °C) and the adaptive thermal comfort model to estimate the number of hours per year required for cooling and heating to sustain the occupants’ thermal comfort for four full-scale housing test modules at the campus of the University of Newcastle, Australia. The adaptive thermal comfort model significantly reduced the time necessary for mechanical cooling and heating by more than half when compared with the constant thermostat setting used by the air-conditioning systems installed on the site. It was found that the air-conditioning system with operational temperature setups using the adaptive thermal comfort model at 80% acceptability limits required almost half the operating energy when compared with fixed sets of operating temperatures. This can be achieved by applying a broader range of acceptable temperature limits and using techniques that require minimal energy to sustain the occupants’ thermal comfort.


2018 ◽  
Vol 10 (9) ◽  
pp. 3091 ◽  
Author(s):  
Raúl Castaño-Rosa ◽  
Carlos Rodríguez-Jiménez ◽  
Carlos Rubio-Bellido

The design and construction of buildings is currently subject to a growing set of requirements concerning sustainability and energy efficiency. This paper shows a case study of the Torre Sevilla skyscraper, located in the city of Seville (in the south of Spain), which has high-tech energy-efficient features and which uses air-conditioning systems during most of its operating hours. The analysis carried out starts from a simulation in which occupants’ thermal comfort are obtained, based on the adaptive comfort model defined in the standard EN 15251:2007. With this approach, it is possible to determine the number of hours during operation in which the building has adequate comfort conditions only with the help of the envelope and natural ventilation. Consequently, the remaining useful hours require the use of air-conditioning systems. The results show that it is possible to improve the thermal performance of the building due to its location in the Mediterranean climate. To do this, advanced mixed mode (through manual-opening or mechanically-controlled opening windows) and active air-conditioning are suggested. This experimental proposal provides a reduction of the occupation hours which require the use of air-conditioning equipment by 28.57%, reducing the air-conditioning demand and, consequently, the energy consumption of the building.


2020 ◽  
Vol 12 (11) ◽  
pp. 4636
Author(s):  
Lucía Pereira-Ruchansky ◽  
Alexis Pérez-Fargallo

Energy improvement studies normally use energy demand reduction as an indicator, disregarding dwellings that do not use air-conditioning systems or do so only under extreme weather conditions. They also do not quantify the impact of climate change on results. This research seeks to evaluate and prioritize energy improvements for existing Uruguayan dwellings, assessing energy demand and thermal comfort in both the current and future climate. A social dwelling was monitored and calibrated to assess energy efficiency measures simulating the current climate and for 2050 (IPCC Scenario A2). The results show that improvements must be linked to the use of air-conditioning in dwellings. When air-conditioning use is unknown, for example, in public policy, thermal transmittance in walls should be between 0.50–0.61 W/m2 K, in roofs between 0.32–0.47 W/m2 K, in openings 2.7 W/m2 K, airtightness under 5 ACH n50 and with solar protections. However, when the use under free running is certain, thermal transmittance in walls and roofs should be 0.85 W/m2 K with an airtightness of 9.2 ACH n50 and solar protection used to avoid overheating. The operational ventilation and solar protection parameters were helpful to guarantee comfort, underlining the need for their inclusion and to train those who use them.


Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 81
Author(s):  
Rongjiang Ma ◽  
Shen Yang ◽  
Xianlin Wang ◽  
Xi-Cheng Wang ◽  
Ming Shan ◽  
...  

Air-conditioning systems contribute the most to energy consumption among building equipment. Hence, energy saving for air-conditioning systems would be the essence of reducing building energy consumption. The conventional energy-saving diagnosis method through observation, test, and identification (OTI) has several drawbacks such as time consumption and narrow focus. To overcome these problems, this study proposed a systematic method for energy-saving diagnosis in air-conditioning systems based on data mining. The method mainly includes seven steps: (1) data collection, (2) data preprocessing, (3) recognition of variable-speed equipment, (4) recognition of system operation mode, (5) regression analysis of energy consumption data, (6) constraints analysis of system running, and (7) energy-saving potential analysis. A case study with a complicated air-conditioning system coupled with an ice storage system demonstrated the effectiveness of the proposed method. Compared with the traditional OTI method, the data-mining-based method can provide a more comprehensive analysis of energy-saving potential with less time cost, although it strongly relies on data quality in all steps and lacks flexibility for diagnosing specific equipment for energy-saving potential analysis. The results can deepen the understanding of the operating data characteristics of air-conditioning systems.


2021 ◽  
Vol 13 (7) ◽  
pp. 3614
Author(s):  
Zeyad Amin Al-Absi ◽  
Mohd Isa Mohd Hafizal ◽  
Mazran Ismail ◽  
Azhar Ghazali

Building sector is associated with high energy consumption and greenhouse gas emissions, which contribute to climate change. Sustainable development emphasizes any actions to reduce climate change and its effect. In Malaysia, half of the energy utilized in buildings goes towards building cooling. Thermal comfort studies and adaptive thermal comfort models reflect the high comfort temperatures for Malaysians in naturally conditioned buildings, which make it possible to tackle the difference between buildings’ indoor temperature and the required comfort temperature by using proper passive measures. This study investigates the effectiveness of building’s retrofitting with phase change materials (PCMs) as a passive cooling technology to improve the indoor thermal environment for more comfortable conditions. PCM sheets were numerically investigated below the internal finishing of the walls. The investigation involved an optimization study for the PCMs transition temperatures and quantities. The results showed significant improvement in the indoor thermal environment, especially when using lower transition temperatures and higher quantities of PCMs. Therefore, the monthly thermal discomfort time has decreased completely, while the thermal comfort time has increased to as high as 98%. The PCM was effective year-round and the optimum performance for the investigated conditions was achieved when using 18mm layer of PCM27-26.


2014 ◽  
Vol 493 ◽  
pp. 74-79
Author(s):  
Y.A. Sabtalistia ◽  
S.N.N. Ekasiwi ◽  
B. Iskandriawan

Energy consumption for air conditioning systems (air conditioning system) increased along with the increasing need for fresh air and comfortable in the room especially apartments. FAC system (Floor Air Conditioning) is growing because it is more energy efficient than CAC (Ceiling Air Conditioning) system. However, the position of the AC supply is on the lower level at the FAC system causes draft discomfort becomes greater as air supply closer to the occupants so that thermal comfort can be reduced. Heat mixture of windows, exterior walls, kitchen, and occupants in the studio apartment affect thermal comfort in the room too.This study aims to determine the position of the AC supply which has the best thermal comfort of FAC system in the studio apartment. It can be done by analyzing ADPI (Air Diffusion Performance Index), the distribution of air temperature, wind speed, RH (Relative Humidity), and DR (Draft Risk) to change the position of the AC supply supported by CFD (Computational Fluid Dynamics) simulation.This result prove that AC position 2 (on wall near the kitchen) is more comfortable than AC position 1 (on the bathroom wall) because AC position 2 away from occupied areas, thereby reducing the occurrence of draught discomfort.


2021 ◽  
pp. 108432
Author(s):  
Peiping Zheng ◽  
Chunxiao Wang ◽  
Yanchen Liu ◽  
Borong Lin ◽  
Huijun Wu ◽  
...  

Author(s):  
Somaye A. Mohamadi ◽  
Abdulraheem J. Ahmed

<span>Despite their complexity and uncertainty, air conditioning systems should provide the optimal thermal conditions in a building. These controller systems should be adaptable to changes in environmental parameters. In most air conditioning systems, today, there are On/Off controllers or PID in more advanced types, which, due to different environmental conditions, are not optimal and cannot provide the optimal environmental conditions. Controlling thermal comfort of an air conditioning system requires estimation of thermal comfort index. In this study, fuzzy controller was used to provide thermal comfort in an air conditioning system, and neural network was used to estimate thermal comfort in the feedback path of the controller. Fuzzy controller has a good response given the non-linear features of air conditioning systems. In addition, the neural network makes it possible to use thermal comfort feedback in a real-time control.</span>


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