Energy Needs and Economic Cost of Thermal Comfort in Buildings under a Temperate Climate

2021 ◽  
Author(s):  
António M. Raimundo ◽  
A. Virgílio M. Oliveira
2021 ◽  
Vol 896 (1) ◽  
pp. 012074
Author(s):  
W Budiawan ◽  
K Tsuzuki ◽  
H Sakakibara

Abstract The comfort temperature and sleep quality of Indonesian residing in Japan during summer might be different from Japanese. As an extended previous research, this study aimed to compare the thermal comfort and sleep quality between Japanese and Indonesian students. Male Indonesian and Japanese students aged 20-35 years participated in this study. The participants completed a survey regarding thermal sensation before sleep. During sleep, actigraphy was used to monitor sleep. Additionally, the temperature and relative humidity of the participants’ bedrooms were recorded. The findings of this study indicated that Indonesian students’ bedroom temperature and relative humidity were not significantly different from those of Japanese students during the summer. Most of Indonesian students preferred neutral, like the Japanese students. According to a thermal comfort survey, Indonesians had the same sensation as Japanese (slightly comfortable). However, the Griffiths method revealed that the mean comfort temperature of Indonesian was higher than those of Japanese students. We also discovered that Indonesian students had shorter duration on bed and sleep minute than Japanese students. Furthermore, the sleep rate of Indonesian students was comparable to that of Japanese students. In conclusion, Indonesian students as tropical native became capable of adjusting to the hot and humid conditions in temperate climate, Japan.


Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6192
Author(s):  
Madi Kaboré ◽  
Emmanuel Bozonnet ◽  
Patrick Salagnac

We developed and studied key performance indexes and representations of energy simulation heat fluxes to evaluate the performance of the evaporative cooling process as a passive cooling technique for a commercial building typology. These performance indexes, related to indoor thermal comfort, energy consumption and their interactions with their surrounding environments, contribute to understanding the interactions between the urban climate and building for passive cooling integration. We compare the performance indexes for current and future climates (2080), according to the highest emission scenario A2 of the Special Report on Emission Scenario (SRES). Specific building models were adapted with both green roof and wetted roof techniques. The results show that summer thermal discomfort will increase due to climate change and could become as problematic as winter thermal discomfort in a temperate climate. Thanks to evapotranspiration phenomena, the sensible heat contribution of the building to the urban heat island (UHI) is reduced for both current and future climates with a green roof. The performance of the vegetative roof is related to the water content of the substrate. For wetted roofs, the impacts on heat transferred to the surrounding environment are higher for a Mediterranean climate (Marseille), which is warmer and drier than the Paris climate studied (current and future climates). The impact on indoor thermal comfort depends on building insulation, as demonstrated by parametric studies, with higher effects for wetted roofs.


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%.


2020 ◽  
Author(s):  
Eun Sub Kim ◽  
Dong Kun Lee

<p>This study has formulated artificial neural network models to predict thermal comfort evaluation in outdoor urban areas in Seoul for summer. The artificial neural network models were considerably improved by including preceptions of microclimate, perception of environmental features(e.g urban spatial characteristics and visual stimuli, etc) and personal traits as additional predictor variables. Thermal comfort in outdoor environments has been repeatedly shown to be influenced also by human perceptions and preferences. Despite numerous attempts at refining these thermal comfort, there still have been large discrepancies between the results predicted by the theoretical models and the actual thermal comfort evaluation votes. indeed Thermal comfort model using microclimatic factors including air temperature, air velocity, solar radiation and relative humidity as predictor variables could explain only 7–42% of thermal comfort evaluation votes.</p><p>Accordingly, this study aims to formulate models to predict thermal comfort evaluation in outdoor urban areas for summer in Korea, which is located in temperate climate zone. ANN models were formulated to portray intricate interrelationships among a multitude of personal traits, urban residents’ environmental perception, microclimatic and spatial perception and physiological factors. The prediction performances of the formulated ANN models were compared with those of the commonly used thermal comfort models(PMV, PET). Also, this study aims to identify important factors that influence thermal comfort evaluation in outdoor urban areas. In addition, it is intended to compare whether the important factors and the magnitude of their contributions are different in urban spatial environment. The findings should provide valuable insights for informing urban planning designers on formulating effective strategies to improve the thermal environments in outdoor urban areas in the temperate climate zone.</p>


Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5524
Author(s):  
José Marco Lourenço ◽  
Laura Aelenei ◽  
Jorge Facão ◽  
Helder Gonçalves ◽  
Daniel Aelenei ◽  
...  

The 2018 revision of the European Performance Building Directive (EPBD) requires that from the year 2020 onwards, all new buildings will have to be “nearly zero energy buildings”. It also further promotes smart building technologies, raising awareness amongst building owners and occupants of the value behind building automation. The European Commission also identified, in 2011, Key Enabling Technologies (KETs), which provide the basis for innovation in the EU. In the frame of the SUDOKET project, the Solar XXI building was used as a pilot case, as innovative integrated solutions and technologies are monitored and controlled. The objective of this paper is to validate a simulation of the laboratorial test room in EnergyPlus with data obtained experimentally and determine the impact of the control systems on energy needs and on thermal comfort. Two systems, in particular, were studied: the Building-Integrated Photovoltaic (BIPV) and the earth tubes. Once validated, the simulation of the test room without the systems was created, allowing their impact to be determined. The results show that, for the analysed periods, BIPVs reduced the heating consumption by 22% while also increasing thermal comfort, and the earth tube system would reduce the cooling needs by 97%.


Biomimetics ◽  
2022 ◽  
Vol 7 (1) ◽  
pp. 14
Author(s):  
Miguel Chen Austin ◽  
Kevin Araque ◽  
Paola Palacios ◽  
Katherine Rodríguez Maure ◽  
Dafni Mora

Urban growth has increased the risk of over-heating both in the microclimate and inside buildings, affecting thermal comfort and energy efficiency. That is why this research aims to evaluate the energy performance of buildings in terms of thermal comfort (operative temperature (OP) levels, satisfied hours of natural ventilation SHNV, thermal lag), and energy efficiency (roof heat gains and surface temperatures) in an urban area in Panama City, using superficial-heat-dissipation biomimetic strategies. Two case studies, a base case and a proposed case, were evaluated using the Designbuilder software through dynamic simulation. The proposed case is based on a combined biomimetic strategy; the reflective characteristics of the Saharan ant applied as a coating on the roofs through a segmented pattern such as the Zebra’s stripes (one section with coating, and another without). Results showed that the OP decreased from 8 to 10 °C for the entire urban zone throughout the year. A reduction of 3.13% corresponding to 8790 kWh per year was achieved for cooling energy consumption. A difference of 5 °C in external surface temperature was obtained, having a lower temperature in which the biomimetic strategy was applied. Besides, it was evidenced that a contrasted-reflectivity-stripes pitched roof performed better than a fully reflective roof. Thus, the functionality of Zebra stripes, together with the reflective characteristics of the Saharan ant, provide better performance for buildings’ thermal regulation and energy needs for cooling.


2016 ◽  
Vol 22 (4) ◽  
pp. 271 ◽  
Author(s):  
Jaroslav Jerz ◽  
František Simančík ◽  
Jaroslav Kováčik ◽  
Peter Oslanec Sr.

The high energy efficiency of buildings can be achieved if energy needs are almost entirely covered by the supply of renewable energy sources obtained directly on the building or in its immediate vicinity. The technology providing efficient storage of the heat at a time of excessive sunlight is necessary if a returns of investment for the construction of small houses with zero energy balance should be less than 10 years. The regular alternation of day and night cycle resulting in continuously changing amount of sunshine falling on the building roof causes even though a small but very well usable potential. The concept presented in this contribution is based on the storage of energy obtained through the aluminium foam roof and facade cladding, which are capable of absorbing the desired, or even take away the excess energy to the surroundings if necessary. The energy effectively generated by this way is by means of piping system distributed by heating liquid medium/coolant to interior ceiling heat exchangers made of aluminium foam enabling due to filling by <span style="text-decoration: underline;">P</span>hase <span style="text-decoration: underline;">C</span>hange <span style="text-decoration: underline;">M</span>aterial<span style="text-decoration: underline;">s</span> (PCMs) to store the energy required for heating/cooling for a period of at least several hours. This progressive technology, therefore, contributes significantly to reducing of energy demand and thus also the prices of future not only large buildings but also small family houses that are able to achieve the optimal thermal comfort by extremely low costs. Possibility to manufacture facade, as well as the interior panels of aluminium foam, is a good prerequisite for ensuring that these structural components could be in the nearest future made from fully recyclable aluminium alloys. This fact indicates large potential chance for long-term sustainable further development of above-mentioned advanced technologies.


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.


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