scholarly journals Personalized Evaporative Cooler to Reduce Energy Consumption and Improve Thermal Comfort in Free-Running Spaces

2019 ◽  
Vol 11 (22) ◽  
pp. 6451 ◽  
Author(s):  
Ana Tejero-González ◽  
Paula M. Esquivias

The need to reduce energy consumption in buildings is imperative, but we must maintain individual thermal comfort of the occupants to ensure their well-being and productivity. Personal conditioning systems (PCS) have been suggested as a strategy to achieve both energy efficiency and thermal comfort, as they are considered to be low-energy consumers, allow increasing set-point temperatures, and give occupants the chance to control their own personal environment. While most warm-environment PCS are based on air-movement devices, the potential of using desk direct evaporative coolers (dDEC) has been scarcely explored. This work presents the results of the characterization of a dDEC and its potential for improving the indoor temperature and thermal comfort in a free-running office space. The study proposes adapted corrective power (CPa) and cooling fan efficiency for evaporative systems (CFEe) indexes. Results show that the dDEC achieves thermal comfort with a local effect, and it is recommended to be positioned directly on the desk surface, orientated to the occupant, and at a certain distance. Under these conditions, the CPa reaches −2.8 °C, involving better CFEe than the desk fans studied in the literature. Speed has little effect on the local air conditions, though it does improve the perception of thermal comfort. The relative humidity of the air does not exceed the recommendable limits, but renovation of the indoor air enables better conditions.

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 591
Author(s):  
Lin-Rui Jia ◽  
Jie Han ◽  
Xi Chen ◽  
Qing-Yun Li ◽  
Chi-Chung Lee ◽  
...  

Thermal comfort and indoor air quality (IAQ) of educational buildings can affect students’ academic performance and well-being and are closely related to ventilation energy consumption. Demands of the indoor environmental quality within the classroom generally vary with the education levels and result in ventilation energy consumption accounting for a considerable proportion of the total energy use in bulk educational buildings. Its huge energy-saving potential is attracting worldwide attention from scholars and governments. Therefore, appropriate operation strategies of ventilation systems should be adopted to effectively reduce energy consumption without sacrificing thermal comfort and IAQ. However, the absence of relevant standards and guidelines for designing a quality classroom environment considering the special features of educational buildings remains an important research question. This study conducts a comprehensive review to determine research gaps and identify future directions for the interaction between thermal comfort, IAQ and ventilation energy consumption for educational buildings. The review results show that: (1) The thermal comfort prediction model should consider the influences of genders, ages and socioeconomic backgrounds; (2) The mixed-mode ventilation coupling the natural and mechanical approaches is preferred given its advantage of lower energy consumption and improved thermal comfort, but its control strategies need further exploration; (3) Optimizing passive design parameters of buildings (e.g., window to wall ratios, window orientations and sun shading installations) can significantly reduce the ventilation demands while maintaining indoor thermal comfort; (4) More studies are required for investigating thermal comfort in educational buildings during the heating period; and (5) IAQ of university buildings clearly requires further studies, especially on bacterial and fungal aerosol pollutants, for a more comprehensive assessment of the built environment.


2020 ◽  
pp. 014459872096921
Author(s):  
Yanru Li ◽  
Enshen Long ◽  
Lili Zhang ◽  
Xiangyu Dong ◽  
Suo Wang

In the Yangtze River zone of China, the heating operation in buildings is mainly part-time and part-space, which could affect the indoor thermal comfort while making the thermal process of building envelope different. This paper proposed to integrate phase change material (PCM) to building walls to increase the indoor thermal comfort and attenuate the temperature fluctuations during intermittent heating. The aim of this study is to investigate the influence of this kind of composite phase change wall (composite-PCW) on the indoor thermal environment and energy consumption of intermittent heating, and further develop an optimization strategy of intermittent heating operation by using EnergyPlus simulation. Results show that the indoor air temperature of the building with the composite-PCW was 2–3°C higher than the building with the reference wall (normal foamed concrete wall) during the heating-off process. Moreover, the indoor air temperature was higher than 18°C and the mean radiation temperature was above 20°C in the first 1 h after stopping heating. Under the optimized operation condition of turning off the heating device 1 h in advance, the heat release process of the composite-PCW to the indoor environment could maintain the indoor thermal environment within the comfortable range effectively. The composite-PCW could decrease 4.74% of the yearly heating energy consumption compared with the reference wall. The optimization described can provide useful information and guidance for the energy saving of intermittently heated buildings.


2014 ◽  
Vol 18 (3) ◽  
pp. 925-934 ◽  
Author(s):  
Meghana Charde ◽  
Sourabh Bhati ◽  
Ayushman Kheterpal ◽  
Rajiv Gupta

Energy efficient building technologies can reduce energy consumption in buildings. In present paper effect of designed static sunshade, brick cavity wall with brick projections and their combined effect on indoor air temperature has been analyzed by constructing three test rooms each of habitable dimensions (3.0 m ? 4.0 m ? 3.0 m) and studying hourly temperatures on typical days for one month in summer and winter each. The three rooms have also been simulated using a software and the results have been compared with the experimental results. Designed static sunshade increased indoor air temperature in winter while proposed brick cavity wall with brick projections lowered it in summer. Combined effect of building elements lowered indoor air temperature in summer and increased it in winter as compared to outdoor air temperature. It is thus useful for energy conservation in buildings in composite climate.


Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3348 ◽  
Author(s):  
Jaesung Park ◽  
Taeyeon Kim ◽  
Chul-sung Lee

In Kuwait, where the government subsidizes approximately 95% of residential electricity bills, most of the country’s energy consumption is for residential use. In particular, air-conditioning (AC) systems for cooling, which are used throughout the year, are responsible for residential electric energy consumption. This study aimed to reduce the amount of energy consumed for cooling purposes by developing a thermal comfort-based controller. Our study commenced by using a simulation model to investigate the possibility of energy reduction when using the predicted mean vote (PMV) for optimal control. The result showed that control optimization would enable the cooling energy consumption to be reduced by 33.5%. The influence of six variables on cooling energy consumption was then analyzed to develop a thermal comfort-based controller. The analysis results showed that the indoor air temperature was the most influential factor, followed by the mean radiant temperature, the metabolic rate, and indoor air velocity. The thermal comfort-based controller-version 1 (TCC-V1) was developed based on the analysis results and experimentally evaluated to determine the extent to which the use of the controller would affect the energy consumed for cooling. The experiments showed that the implementation of TCC-V1 control made it possible to reduce the electric energy consumption by 39.5% on a summer representative day. The results of this study indicate that it is possible to improve indoor thermal comfort while saving energy by using the thermal comfort-based controller in residential buildings in Kuwait.


2020 ◽  
pp. 102013
Author(s):  
Ahmet Yüksel ◽  
Müslüm Arıcı ◽  
Michal Krajčík ◽  
Mihriban Civan ◽  
Hasan Karabay

2017 ◽  
Vol 12 (1) ◽  
pp. 123-141 ◽  
Author(s):  
Ahmed Radwan ◽  
Mohamed H. Issa

This exploratory research aims to evaluate indoor environmental quality in the classrooms of three school buildings in Southern Manitoba, Canada, and to evaluate the well-being of these schools' teachers as it pertains to their perception of their classrooms' indoor environment. The schools include a middle-aged, conventional school; a new, non-green school; and a new, green school certified using the Leadership in Energy and Environmental Design rating system. The methodology involved using a mobile instrument cart to conduct snapshot measurements of thermal comfort, indoor air quality, lighting and acoustics in classrooms and an occupant survey to evaluate teachers' long-term satisfaction with their classrooms' indoor environmental quality. The results showed that the new, green and new, non-green schools' classrooms performed better than the conventional, middle-aged school's classrooms with respect to some aspects of thermal comfort and indoor air quality only. Teachers in the new, green school and in the new, non-green school were more satisfied than teachers in the conventional, middle-aged school with their classrooms' overall indoor environmental quality, lighting quality and indoor air quality. Surprisingly, the new, green and new-non green school classrooms' performance were very comparable with the new, green school's classrooms performing statistically significantly better with respect to relative humidity. Similarly, none of the differences in teachers' satisfaction ratings between the new, green and new, non-green school were statistically significant.


2017 ◽  
Vol 65 (9) ◽  
Author(s):  
Joern Ploennigs ◽  
Amadou Ba ◽  
Paulito Palmes

AbstractModern buildings are data-rich environments that can contain thousands of IoT devices. However, most of this data is not analyzed in order to reduce energy consumption and improve occupants' comforts. This is often due to the required large manual effort for integrating the data into analytic systems. Semantic models allow to model the required meta-data and to arrive at an automated integration process. This is demonstrated for the new Brick ontology, that comprehensively models meta-data in buildings. It is extended by model concepts enabling to address challenges pertaining to physics and thermal comfort. Moreover, this Brick ontology is further extended by reasoning approaches in order to better exploit knowledge. As an example, the proposed approach is used to compute and diagnose virtual sensors so as to assess thermal comfort in a real building.


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