scholarly journals Estimation of energy consumption efficiency in office rooms cooling systems to create thermal comfort for the user

2021 ◽  
Vol 738 (1) ◽  
pp. 012016
Author(s):  
N P Lisa ◽  
Z Zuraihan ◽  
R Fernand ◽  
D Siska
Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 81 ◽  
Author(s):  
Małgorzata Fedorczak-Cisak ◽  
Katarzyna Nowak ◽  
Marcin Furtak

Improving the energy efficiency of buildings is among the most urgent social development tasks due to the scale of energy consumption in this industry. At the same time, it is essential to meet high requirements for indoor environmental quality and thermal comfort. The issue of overheating is most often analysed in summer but it also occurs in transition seasons, when the cooling systems do not operate. The paper attempts to evaluate the effectiveness of external mobile shading elements on the microclimate of rooms with large glazed areas in the transition season. Passive solutions, such as shading elements, which limit the increase of indoor temperature, do not always allow the acquisition and maintenance of comfortable solutions for the duration of the season, as demonstrated by the authors. Temporary cooling of the rooms may be necessary to maintain comfortable conditions for the users, or other solutions should be devised to improve comfort (e.g., reduction of clothing insulation characteristics). The novelty of the study consists in the analysis of comfort in a “nearly zero energy consumption” building (NZEB) during a period not analyzed by other scientists. This is a transition period during which heating/cooling systems do not operate. The research task set by the authors involved the assessment of the possibility to reduce office space overheating in the transition season (spring) by using external shading equipment in rooms with large glazed areas. An additional research task aimed at checking the extent to which user behaviour, such as reduction in clothing insulation characteristics, can improve comfort in overheated rooms. The results of the tests reveal that the difference in the ambient air temperature between a room with external venetian blinds and an identical room with no venetian blinds in the transition season, i.e., from 27 March to 6 April 2017, ranged from 12.3 to 2.1 °C. The use of a shading system (external venetian blinds positioned at an angle of 45°) reduced the number of discomfort hours by 92% (during working hours) compared to the room without external venetian blinds. A reduction in the thermal insulation of the clothes worn by people working in the room with no venetian blinds helped to reduce the number of discomfort hours by 31%.


2021 ◽  
Vol 9 (1) ◽  
pp. 14
Author(s):  
María Jesús Romero-Lara ◽  
Francisco Comino ◽  
Manuel Ruiz de Adana

Efficient air cooling systems for hot climatic conditions, such as southern Europe, are required. Regenerative indirect evaporative cooler (RIEC) and desiccant regenerative indirect evaporative cooler (DRIEC) could be interesting alternatives to direct expansion conventional systems (DX). The main objective of this work was to evaluate the seasonal performance of three air cooling systems in terms of thermal comfort, ventilation and energy consumption. DRIEC was the recommended system to serve a standard classroom in terms of thermal comfort and RIEC in terms of ventilation and energy consumption.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4436
Author(s):  
María Jesús Romero-Lara ◽  
Francisco Comino ◽  
Manuel Ruiz de Adana

Efficient air-cooling systems for hot climatic conditions, such as Southern Europe, are required in the context of nearly Zero Energy Buildings, nZEB. Innovative air-cooling systems such as regenerative indirect evaporative coolers, RIEC and desiccant regenerative indirect evaporative coolers, DRIEC, can be considered an interesting alternative to direct expansion air-cooling systems, DX. The main aim of the present work was to evaluate the seasonal performance of three air-cooling systems in terms of air quality, thermal comfort and energy consumption in a standard classroom. Several annual energy simulations were carried out to evaluate these indexes for four different climate zones in the Mediterranean area. The simulations were carried out with empirically validated models. The results showed that DRIEC and DX improved by 29.8% and 14.6% over RIEC regarding thermal comfort, for the warmest climatic conditions, Lampedusa and Seville. However, DX showed an energy consumption three and four times higher than DRIEC for these climatic conditions, respectively. RIEC provided the highest percentage of hours with favorable indoor air quality for all climate zones, between 46.3% and 67.5%. Therefore, the air-cooling systems DRIEC and RIEC have a significant potential to reduce energy consumption, achieving the user’s thermal comfort and improving indoor air quality.


2017 ◽  
Vol 25 (2) ◽  
pp. 33-38
Author(s):  
Ema Nemethova ◽  
Werner Stutterecker ◽  
Thomas Schoberer

Abstract The aim of the study is to evaluate the potential of enhancing thermal comfort and energy consumption created by three different radiant systems in the newly-built Energetikum office building. A representative office, Simulation room 1/1, was selected from 6 areas equipped with portable sensor groups for the indoor environment monitoring. The presented data obtained from 3 reference weeks; the heating, transition and cooling periods indicate overheating, particularly during the heating and transition period. The values of the indoor air temperature during the heating and transition period could not meet the normative criteria according to standard EN 15251:2007 (cat. II.) for 15-30% of the time intervals evaluated. Consequently, a simulation model of the selected office was created and points to the possibilities of improving the control system, which can lead to an elimination of the problem with overheating. Three different radiant systems - floor heating/ cooling, a thermally active ceiling, and a near-surface thermally active ceiling were implemented in the model. A comparison of their effects on thermal comfort and energy consumption is presented in the paper.


2019 ◽  
pp. 01-15
Author(s):  
Jani DB

The continuous progressive demand of building construction raises many issues regarding supply of high grade electricity. It creates many environmental issues for its production like as global warming. So, the passive cooling buildings were welcomed to respond variable climate in order to reduce energy supply for thermal comfort as well as health of building users. The aim of designing a passive building is to take best advantage of the regional outdoor ambient conditions. Passive cooling refers to a building architectural approach that mainly goal on heat gain control and heat dissipation in a architectural structure in order to ameliorate the indoor thermal comfort with low or nil energy consumption. Passive cooling systems use non-mechanical methods to sustain a comfortable indoor temperature and are a main aim in extenuating the impact of buildings on the regional environment. The energy consumption in buildings is very much with the anticipation to further increase because of improving standards of leaving and the increase of industrialization. The use of HVAC in building has exponentially rises over the past few decades and quite enough to contribute in the enormous use of high grade electrical energy consumption. This paper reviews various passive cooling techniques used in the green building and their role in providing thermal comfort and its significance in energy conservation with the help of architectural interventions.


2019 ◽  
pp. 53-65
Author(s):  
Renata Domingos ◽  
Emeli Guarda ◽  
Elaise Gabriel ◽  
João Sanches

In the last decades, many studies have shown ample evidence that the existence of trees and vegetation around buildings can contribute to reduce the demand for energy by cooling and heating. The use of green areas in the urban environment as an effective strategy in reducing the cooling load of buildings has attracted much attention, though there is a lack of quantitative actions to apply the general idea to a specific building or location. Due to the large-scale construction of high buildings, large amounts of solar radiation are reflected and stored in the canyons of the streets. This causes higher air temperature and surface temperature in city areas compared to the rural environment and, consequently, deteriorates the urban heat island effect. The constant high temperatures lead to more air conditioning demand time, which results in a significant increase in building energy consumption. In general, the shade of the trees reduces the building energy demand for air conditioning, reducing solar radiation on the walls and roofs. The increase of urban green spaces has been extensively accepted as effective in mitigating the effects of heat island and reducing energy use in buildings. However, by influencing temperatures, especially extreme, it is likely that trees also affect human health, an important economic variable of interest. Since human behavior has a major influence on maintaining environmental quality, today's urban problems such as air and water pollution, floods, excessive noise, cause serious damage to the physical and mental health of the population. By minimizing these problems, vegetation (especially trees) is generally known to provide a range of ecosystem services such as rainwater reduction, air pollution mitigation, noise reduction, etc. This study focuses on the functions of temperature regulation, improvement of external thermal comfort and cooling energy reduction, so it aims to evaluate the influence of trees on the energy consumption of a house in the mid-western Brazil, located at latitude 15 ° S, in the center of South America. The methodology adopted was computer simulation, analyzing two scenarios that deal with issues such as the influence of vegetation and tree shade on the energy consumption of a building. In this way, the methodological procedures were divided into three stages: climatic contextualization of the study region; definition of a basic dwelling, of the thermophysical properties; computational simulation for quantification of energy consumption for the four facade orientations. The results show that the façades orientated to north, east and south, without the insertion of arboreal shading, obtained higher values of annual energy consumption. With the adoption of shading, the facades obtained a consumption reduction of around 7,4%. It is concluded that shading vegetation can bring significant climatic contribution to the interior of built environments and, consequently, reduction in energy consumption, promoting improvements in the thermal comfort conditions of users.


2020 ◽  
Vol 51 (10) ◽  
pp. 909-923
Author(s):  
Ibrahim Yasin Terzioglu ◽  
Oguz Turgut
Keyword(s):  

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