scholarly journals Analysis of active system operation optimization in office buildings

2021 ◽  
Author(s):  
Mohammad Reza Ganjali Bonjar ◽  
Bálint Baranyai ◽  
Kristóf Roland Horváth ◽  
István Kistelegdi

AbstractThe aim of this paper is to present a solution for optimizing the operation of the Szentágothai Research Center. This building has several different functions at a high degree, so it can represent most of the difficulties in achieving an ideal level of operation energy consumption while assuring an adequate comfort level.As a first stage of a generic office building optimization research, a monitored reference building of common type was chosen. Various active operation optimization experiments were carried out. The successive reduction of operation intensity and schedules resulted in 63.3% operation energy savings. The results provide considerable potential in generic office design applications.

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Christie D. Lavallée ◽  
Saeedeh Bani Assadi ◽  
Alicia M. Korpach ◽  
James D. Ray ◽  
Jason D. Fischer ◽  
...  

Abstract Background The migration patterns of land birds can generally be divided into those species that migrate principally during the day and those that migrate during the night. Some species may show individual plasticity in the use of day or night flight, particularly when crossing large, open-water or desert barriers. However, individual plasticity in circadian patterns of migratory flights in diurnally migrating songbirds has never been investigated. Methods We used high precision GPS tracking of a diurnal, migratory swallow, the purple martin (Progne subis), to determine whether individuals were flexible in their spring migration strategies to include some night flight, particularly at barrier crossing. Results Most (91%) of individuals made large (sometimes > 1000 km), open-water crossings of the Caribbean Sea and the Gulf of Mexico that included the use of night flight. 32% of all water crossings were initiated at night, demonstrating that night flight is not only used to complete large crossings but may confer other advantages for diurnal birds. Birds were not more likely to initiate crossings with supportive winds, however crossings were more likely when they reduced travel distances. Our results are consistent with diurnal birds using night flight to help achieve time- and energy-savings through ‘short cuts’ at barrier crossings, at times and locations when foraging opportunities are not available. Conclusions Overall, our results demonstrate the use of nocturnal flight and a high degree of individual plasticity in migration strategies on a circadian scale in a species generally considered to be a diurnal migrant. Nocturnal flights at barrier crossing may provide time and energy savings where foraging opportunities are low in an otherwise diurnal strategy. Future research should target how diel foraging and refueling strategies support nocturnal flights and barrier crossing in this and other diurnal species.


2019 ◽  
Vol 2 (S1) ◽  
Author(s):  
Friederike Wenderoth ◽  
Elisabeth Drayer ◽  
Robert Schmoll ◽  
Michael Niedermeier ◽  
Martin Braun

Abstract Historically, the power distribution grid was a passive system with limited control capabilities. Due to its increasing digitalization, this paradigm has shifted: the passive architecture of the power system itself, which includes cables, lines, and transformers, is extended by a communication infrastructure to become an active distribution grid. This transformation to an active system results from control capabilities that combine the communication and the physical components of the grid. It aims at optimizing, securing, enhancing, or facilitating the power system operation. The combination of power system, communication, and control capabilities is also referred to as a “smart grid”. A multitude of different architectures exist to realize such integrated systems. They are often labeled with descriptive terms such as “distributed,” “decentralized,” “local,” or “central." However, the actual meaning of these terms varies considerably within the research community.This paper illustrates the conflicting uses of prominent classification terms for the description of smart grid architectures. One source of this inconsistency is that the development of such interconnected systems is not only in the hands of classic power engineering but requires input from neighboring research disciplines such as control theory and automation, information and telecommunication technology, and electronics. This impedes a clear classification of smart grid solutions. Furthermore, this paper proposes a set of well-defined operation architectures specialized for use in power systems. Based on these architectures, this paper defines clear classifiers for the assessment of smart grid solutions. This allows the structural classification and comparison between different smart grid solutions and promotes a mutual understanding between the research disciplines. This paper presents revised parts of Chapters 4.2 and 5.2 of the dissertation of Drayer (Resilient Operation of Distribution Grids with Distributed-Hierarchical Architecture. Energy Management and Power System Operation, vol. 6, 2018).


2021 ◽  
Author(s):  
Omar Siddiqui

The applicability of utilizing a variety of thermal mass including phase change materials with commonly used building materials is investigated through the use of simulations and physical testing. The thermal performance and occupant comfort potential of a novel solid-solid phase change material, known as Dal HSM, is compared and contrasted to commonly available forms of thermal mass. Detailed experimentation is conducted to successfully integrate Dal HSM with gypsum and concrete. The measurement of physical characteristics such as compressive strength and modulus of rupture is conducted to ensure that the PCM-composite compound retains the structural integrity to be utilized in a typical building. The use of thermal mass in the Toronto Net Zero house was found to contribute to energy savings of 10-15% when different types of thermal mass were used. The comfort level of the indoor occupants was also found to increase. The performance of Dal HSM was found to be comparable to a commercially available PCM known as Micronal in the heating mode. The cooling mode revealed that Dal HSM provided slightly lower energy savings when compared to Micronal due to a lower phase transition temperature and latent heat. The performance of physical test revealed a decrease in the compressive strength as the concentration of Dal HSM was increased in the PCM-gypsum specimens. Tests were also performed to analyze the impact of increasing the PCM concentration on the flexural strength of PCM-gypsum composite.


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6597
Author(s):  
Ahmet Bircan Atmaca ◽  
Gülay Zorer Gedik ◽  
Andreas Wagner

Mosques are quite different from other building types in terms of occupant type and usage schedule. For this reason, they should be evaluated differently from other building types in terms of thermal comfort and energy consumption. It is difficult and probably not even necessary to create homogeneous thermal comfort in mosques’ entire usage area, which has large volumes and various areas for different activities. Nevertheless, energy consumption should be at a minimum level. In order to ensure that mosques are minimally affected by outdoor climatic changes, the improvement of the properties of the building envelope should have the highest priority. These optimal properties of the building envelope have to be in line with thermal comfort in mosques. The proposed method will be a guide for designers and occupants in the design process of new mosques or the use of existing mosques. The effect of the thermal properties of the building envelope on energy consumption was investigated to ensure optimum energy consumption together with an acceptable thermal comfort level. For this purpose, a parametric simulation study of the mosques was conducted by varying optical and thermal properties of the building envelope for a temperature humid climate zone. The simulation results were analyzed and evaluated according to current standards, and an appropriate envelope was determined. The results show that thermal insulation improvements in the roof dome of buildings with a large volume contributed more to energy savings than in walls and foundations. The use of double or triple glazing in transparent areas is an issue that should be considered together with the solar energy gain factor. Additionally, an increasing thickness of thermal insulation in the building envelope contributed positively to energy savings. However, the energy savings rate decreased after a certain thickness. The proposed building envelope achieved a 33% energy savings compared to the base scenario.


Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 895 ◽  
Author(s):  
Ilaria Ballarini ◽  
Giovanna De Luca ◽  
Argun Paragamyan ◽  
Anna Pellegrino ◽  
Vincenzo Corrado

Directive 2010/31/EU promotes the refurbishment of existing buildings to change them into nearly zero-energy buildings (nZEBs). Within this framework, it is of crucial importance to guarantee the best trade-off between energy performance and indoor environmental quality (IEQ). The implications of a global refurbishment scenario on thermal and visual comfort are assessed in this paper pertaining to an existing office building. The retrofit actions applied to achieve the nZEB target consist of a combination of envelope and technical building systems refurbishment measures, involving both HVAC and lighting. Energy and comfort calculations were carried out through dynamic simulation using Energy Plus and DIVA, for the thermal and visual performance assessments, respectively. The results point out that energy retrofit actions on the building envelope would lead to significant improvements in the thermal performance, regarding both energy savings (−37% of the annual primary energy for heating) and thermal comfort. However, a daylighting reduction would occur with a consequent higher electricity demand for lighting (36%). The research presents a detailed approach applicable to further analyses aimed at optimizing the energy efficiency measures in order to reduce the imbalance between visual and thermal comfort and to ensure the best performance in both domains.


Religions ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 671
Author(s):  
Tove Giske ◽  
Pamela Cone

This paper presents and compares similarities and differences between nurses’ and patients’ reports on comfort levels with spiritual assessment. Spiritual care is a part of nurses’ professional responsibilities; however, nurses continue to report that they are poorly prepared for this. There is limited research on patients’ expectations or perspectives on spiritual care. For the original mixed-method, two-phased study, a 21-item survey with 10 demographic variables, and some open-ended questions related to the comfort level of assessing/being assessed in the spiritual domain were distributed to 172 nurses and 157 hospitalised patients. SPSS was used to analyse and compare the results from nurses and patients; thematic analysis was used to examine the open-ended questions. Nurses reported a higher high degree of comfort with spiritual assessment than patients reported towards being assessed spiritually. Both nurses and patients saw respect and trust as key to building a relationship where open questions related to spirituality can be used as a helpful way to assess patients spiritually. Increased understanding of the best approach toward a patient must be based on the beliefs, values, and practices of that patient so that spiritual care can be individually tailored, and nurses can help patients move along the path to healing.


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