scholarly journals Efficiency of ventilated facades in terms of airflow in the air gap

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Krzysztof Schabowicz ◽  
Łukasz Zawiślak ◽  
Paweł Staniów
Keyword(s):  
Energy Savings ◽  
Heat Removal ◽  
Developed Countries ◽  
Sustainable Construction ◽  
Heat Transmission ◽  
Wind Speeds ◽  
Heat Transfer Efficiency ◽  
Open Joint ◽  
Heat Removal Efficiency ◽  
Ventilated Facade

Abstract The gradual exploitation of the natural environment has forced most developed countries to promote ecological solutions and the development of sustainable construction. Ventilated facades perfectly match into this trend, and with their appropriate design, they bring real energy savings. This paper analyzes numerically the influence of the inflowing air, mimicking the wind, on the efficiency of heat removal from the ventilated space and heat transmission by thermal radiation and conduction through the consecutive layers of the external wall. For the purpose of comparison, two variants of ventilated facade were adopted: open and closed joints, at different wind speeds prevailing outside. The results obtained show that in windless weather, the ventilated facade with open joints shows higher heat removal efficiency and thus lower heat transmission to the building interior. At higher wind speeds of 5 m/s, the open-joint and closed-joint ventilated facades achieve similar heat transfer efficiency, and the prevailing temperature inside the building for the two technologies is almost identical. Subsequent increments of incoming wind on the building result in minimal differences in the heat transmission to the building interior, representing changes of about 0.1°C at increments of another 5 m/s of incoming wind. Conscious use of this facade technology, along with appropriate urban design of cities, can help reduce the energy needed to cool buildings during the summer period.

FC 135A STEP TOWARD GREEN NEPHROLOGY: APPLYING THE PASSIVE HOUSE CONCEPT TO THE CONSTRUCTION OF DIALYSIS FACILITIES

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Christophe Mariat ◽  
Jocelyne Rey ◽  
Annie Olivier ◽  
Perrine Jullien
Keyword(s):  
Health Care ◽  
Environmental Impact ◽  
Energy Savings ◽  
The Body ◽  
Sustainable Construction ◽  
Passive House ◽  
Pump System ◽  
Dialysis Facility ◽  
Dialysis Facilities ◽  
House Standard

Abstract Background and Aims The environmental impact of dialysis is now being largely recognized. It requires from the nephrology community to actively explore novel environmentally responsible health-care practices. Among them, conception of energy-efficient facilities may be an important prerequisite for improving the environmental impact of dialysis. The Passive House concept is an internationally recognised, performance-based energy standard in construction which so far has been rarely applied to medical facilities and never to dialysis centres. We report our experience with the first passive-house certified dialysis facility in Europe. Method The Passive House concept is a sustainable construction standard for nearly zero energy buildings (the Resolution of the European Parliament of 31/01/2008 has called for its implementation by all member states by 2021). Principles and design tools of the Passive House concept are freely available for all architects. The concept combines a particularly high level of insulation with a specific system of ventilation. Geothermal energy and energy from inside the building such as the body heat from the residents or solar heat entering the building are the main energy sources. Passive House buildings allow for heating and cooling related energy savings of up to 90% compared with typical building stock and over 75% compared with average new buildings. Results The François Berthoux Center (www.artic42.fr) is a 4 400 m2 dialysis facility operated by 40 health care agents and providing care to 135 patients. It was designed following the Passive-House standard, applied for the first time to such a medical building. Several adjustments specific to the dialysis activity were necessary. The most unexpected aspect was the importance of hemodialysis machines as an energy source. Thorough thermal evaluation showed that the heat provided by different type of hemodialysis machines was systematically superior to the energy mandatory during the coldest day of the year (>10 W/m2). In practice, the center turned out to be fully operational with no external source of heating. The downside was that the geothermal pump system was not sufficient to fully regulate temperatures during the warmest period of the year. Optimal cooling was achieved by the addition of conventional AC systems in the hemodialysis rooms. Overall, as compared to a similar center, energy savings provided by the The François Berthoux Center were substantially less than what is expected from a conventional Passive House building but were over 50%. The extra-cost of the construction was estimated to 3 to 5%. Conclusion In conclusion, the concept of eco-friendly building should extend to dialysis facilities. Application of the Passive House Standard in the context of hemodialysis requires to take into account some specificities that can impact the global environmental performance of the building. However, the net result is clearly in favor of such a construction, which is both affordable and sustainable.

ENERGY SAVINGS IN FORMATION FLIGHT OF PINK-FOOTED GEESE

1994 ◽  
Vol 189 (1) ◽  
pp. 251-261 ◽  
Author(s):  
C Cutts ◽  
J Speakman
Keyword(s):  
Energy Savings ◽  
Flight Path ◽  
Total Power ◽  
Maximum Information ◽  
Optimal Position ◽  
Wind Speeds ◽  
Anser Brachyrhynchus ◽  
Spacing Variation ◽  
Wing Tips ◽  
Wing Tip

Fifty-four skeins of pink-footed geese (Anser brachyrhynchus) were photographed from directly underneath to eliminate the effects of perspective distortion, and the wing-tip spacings (the distance between adjacent birds' wing tips perpendicular to the flight path at maximum wingspan) and depths (the distance between adjacent birds' body centres parallel to the flight path) were measured at the same time as local wind speeds. The photographs were used to test for savings in induced power from wing positioning relative to the predicted positions of vortices generated by other wings, using a theoretical model. The mean wing-tip spacing corresponded to a saving in induced power of 14 %, less than one-third of the maximum possible. The saving in total power might be as low as 2.4 %. The high variation in wing-tip spacing suggests that pink-footed geese found difficulty maintaining position and thus adopted a strategy of flying outboard of the optimal position that maximises savings. This may minimise the risk of straying into a zone where savings are negative. There was a significant correlation between depth and wing-tip spacing, supporting an alternative communication hypothesis, whereby the birds position themselves to obtain maximum information on their neighbour's position. In high winds, there was little change in wing-tip spacing variation but a decrease in depth variation, suggesting a shift towards more regularly spaced skeins.

scholarly journals Sustainable Construction by Means of Improved Material Selection Process

2019 ◽  
Vol 3 (1) ◽  
pp. 85 ◽  
Author(s):  
Koorosh Gharehbaghi ◽  
Maged Georgy
Keyword(s):  
Energy Savings ◽  
Material Selection ◽  
Selection Process ◽  
Sustainable Construction ◽  
Construction Operation ◽  
Selection Factors ◽  
Strength And Durability ◽  
Operation Cost ◽  
Selection Of

Whilst sustainable construction relates to both a building’s structure and the use of proper life cycle processes, the selection of the most appropriate material/s is deemed a considerable undertaking. Throughout a building’s lifecycle that extends from design, construction, operation, maintenance, renovation, until demolition, the selection of sustainable material/s is a particularly crucial task for the development and establishment of such structures. Traditionally, there are three main materials for general construction: (1) Steel, (2) Concrete and (3) Timber. These materials not only influence the function within the structure, but also affect the operation cost and energy usage. Operation cost reduction and energy savings are typically elements of the sustainable construction sphere. However, in developing countries, there is a variety of highly critical factors, which can impact material selection as well as the long-term sustainability of the structure, including: Fire Performance, Environmental Impact, Structural Performance (strength and durability), and Functioning Capabilities. Accordingly, this paper will first compare the sustainability of these three key materials and then converse with appropriate processes for material selection. Attention will be given to the sustainable construction recompense associated with the different material selection factors. Doing so ensures a more sustainable built environment by means of an improved material selection process.

Characteristic Heat Removal Efficiency for Thermosyphon Solar Water Heaters During the System Application Phase

2004 ◽  
Vol 126 (3) ◽  
pp. 950-956 ◽  
Author(s):  
J. M. Chang
Keyword(s):  
Removal Efficiency ◽  
Empirical Model ◽  
System Application ◽  
Heat Removal ◽  
Solar Water Heater ◽  
Water Heater ◽  
Solar Water ◽  
Water Heaters ◽  
Heat Removal Efficiency ◽  
Solar Water Heaters

The overall performance rating of a thermosyphon solar water heater should take into consideration its heat removal efficiency during the system application phase. This study employs a precise on-line operation to first identify physical heat removal patterns of a thermosyphon solar water heater, and then develops an empirical model for deriving its characteristic heat removal efficiency. This empirical model is in the form of a logarithmic curve, and has a high data correlation coefficient of 0.889 to 0.967. Based upon the empirical model, this study defines a characteristic heat removal efficiency parameter for thermosyphon solar water heaters. Finally, this study establishes a storage tank design method which enables the characteristic heat removal efficiency of the complete system to be optimized.

Design of the Controller Cooling System of an Electric Vehicle

2014 ◽  
Vol 663 ◽  
pp. 213-217 ◽  
Author(s):  
M.M. Rahman ◽  
T.J. Hua ◽  
H.Y. Rahman
Keyword(s):  
Heat Transfer ◽  
Electric Vehicle ◽  
Cooling System ◽  
Removal Rate ◽  
Heat Removal ◽  
Developed Countries ◽  
Internal Resistance ◽  
Heat Transfer Fluids ◽  
Computational Fluid Dynamics Cfd ◽  
Forced Air

As an effort in reducing the dependency on fossil fuel, efforts have been gathered to develop electric vehicle (EV) for the past decades. Technology of electric vehicles (EV) has been initialized in developed countries. However, the latter have different geographical and environmental conditions. Therefore, the system of EV cannot be utilized directly in this country. The controller of an EV functions by utilizing a potentiometer; supplying a certain amount of voltage from the batteries to the motor by driver’s force applied to the acceleration pedal. This action generates a huge amount of heat due to the internal resistance of the controller (e.g. potentiometer). In order for an EV to operate at optimum condition, temperature of the controller has to be maintained at a certain limit. Hence an effective cooling system is required to be designed to fulfill the above condition. The objective of this paper is to present the design of the cooling system for the controller of an electric vehicle (EV). Two types of cooling system namely liquid cooled plate heat exchanger and forced air cooled finned structure are designed and evaluated to assess the behavior of heat transfer as well as effects of heat transfer fluids and cooling system material towards the heat removal rate. Simulation using Computational Fluid Dynamics (CFD) for both cooling systems has been carried out to have better understanding. CFD results are compared with some of the analytical results. The findings revealed that both systems are suitable to be implemented as EV controller cooling system in Malaysian Environment.

Energy evaluation of an horizontal open joint ventilated façade

2012 ◽  
Vol 37 ◽  
pp. 302-313 ◽  
Author(s):  
María José Suárez ◽  
Cristina Sanjuan ◽  
Antonio José Gutiérrez ◽  
Jorge Pistono ◽  
Eduardo Blanco
Keyword(s):  
Energy Evaluation ◽  
Open Joint ◽  
Ventilated Facade

Elimination of Thermal Bridge by Thermal Insulation Composite Material

2012 ◽  
Vol 482-484 ◽  
pp. 1654-1659 ◽  
Author(s):  
Tomáš Pospíšil ◽  
Jan Pěnčík ◽  
Libor Matějka ◽  
Libor Matějka ◽  
Alena Kalužová ◽  
...  
Keyword(s):  
Composite Material ◽  
Life Cycle ◽  
Natural Resources ◽  
Thermal Insulation ◽  
Energy Savings ◽  
Sustainable Construction ◽  
Thermal Bridge ◽  
Reduce Heat Loss ◽  
New Material ◽  
Inorganic Fillers

With the sustainable construction the emphasis is placed on energy savings, reducing of consumption of natural resources, extending of the life cycle of recycling, etc. The research has brought about a new material - thermal insulation composite material - which is formed by a combination of recycled polymers and inorganic fillers satisfying the condition of recyclability. Using this material in the solution to eliminate thermal bridge at the wall foot can reduce heat loss of the building.

scholarly journals Environmental and Social Sustainability in UK Construction Industry: a Systematic Literature Review

2019 ◽  
Vol 5 (1) ◽  
pp. 100
Author(s):  
Fotios Misopoulos ◽  
Vicky Manthou ◽  
Zenon Michaelides
Keyword(s):  
Literature Review ◽  
Construction Industry ◽  
Systematic Literature Review ◽  
Environmental Sustainability ◽  
Social Sustainability ◽  
Developed Countries ◽  
Three Dimensions ◽  
Sustainable Construction ◽  
Community Sustainability ◽  
Bottom Line

Research on sustainability in the construction industry is common in construction journals addressing the potential adverse effects conventional practices have in the construction community. Sustainability is addressed through the environmental, social and economic impacts in literature and researchers and practitioners always drive the need for an equal attention on these three dimensions, but not so successfully at present. Sustainability covers a broad content with various suggested approaches arising from different countries all over the world. Previous studies have investigated sustainable construction issues as a global concept and in individual developed countries such as the US, Australia, and China. The aim of this research is to investigate the extent of coverage, by academia, of the sustainability concept in UK construction industry, with a focus on the environmental and social aspects of sustainability, based on the Triple Bottom Line framework. The researchers conducted a systematic literature review, searching relevant articles with predefined criteria in two major bibliographical databases, which offer great coverage of the existing academic journals in social sciences. The study utilised the PRISMA reporting approach and the search resulted in thirty-one suitable articles. The findings revealed that environmental sustainability receives much more attention than social sustainability. Added emphasis is given to green buildings and materials used. Government regulations seem to be the leading driver for adopting sustainable practices, while lack of knowledge/awareness of sustainable best practices is the leading challenge.

scholarly journals Perfection of cooling systems of overhead tuyeres heads of 250-t BOFs

2019 ◽  
Vol 75 (3) ◽  
pp. 327-336
Author(s):  
S. P. Panteikov ◽  
L. M. Uchitel’ ◽  
V. V. Ivko ◽  
Yu. I. Kharchenko ◽  
Yu. P. Makhlai ◽  
...  
Keyword(s):  
Cooling System ◽  
Heat Removal ◽  
Internal Surface ◽  
Side Surface ◽  
Operating Characteristics ◽  
Blow Down ◽  
Cooling Systems ◽  
Nozzle Block ◽  
Heat Removal Efficiency ◽  
Positive Effect

Deterioration of tips cooling as a result of number of nuzzles increase in tuyere heads does not allow to use multinozzle (six and more) overhead tuyeres for increasing of steel melting technical and economical indices and operating characteristics of technological equipment. The main reason of it is as follows: deterioration ofcooling results in over-heating and burnt-outof tips material in the farthest nozzle zone following the overhead tuyeres breakage. To avoid the water stagnant areas in the farthestnozzle zones of the heads cooling route and therefore to increase the overheads oxygen tuyeres of 250-t BOF operation life, a new design of the six-nozzle tuyere head with asymmetric cooling of tips farthest zones elaborated, manufactures and tested. The perfection of the six-nozzle heads cooling system included asymmetric (relating the side surface of the nozzle block) installation behind every nozzle (in the water direction) a guidingblade of special design. It enabled to increase to a maximum degree the heat removal efficiency from the internal surface in the tip farthest zones and had a positive effect on the overhead tuyeres heads resistance. The workability of the proposed design of the six-nozzle tuyere head with asymmetric cooling of farthest zones was confirmed during test-industrial heats at 250-t BOFs of OJSC “Dneprovskysteel-works”. The heats were carried out with oxygen consumption of 800–1200 m 3/min and regime of partial afterburning ofexit gases. The water consumption for tuyeres cooling decrease from 320–340 m 3 /h, at that the  water temperature difference at the tuyere entry and exit varied in the range of 11–16 °C depending on blow-down duration. Application of the new design of the six-nozzle tuyere head with asymmetric farthest zones cooling enabled to increase the sixnozzle heads resistance by a factor 1.287 comparing with six-nozzle heads without farthest zones cooling and by a factor of 3.327 comparing with regular five-nozzle tuyere heads. The effect reached thanks to more rational cooler distribution and increase ofits velocity. The metal pick up of shafts of the six-nozzle tuyere head with asymmetric farthest zones cooling: while the five-nozzle tuyeres were taken off for salamander cutting off after 1–5 heats, the six-nozzle tuyeres were taken off for the salamander cutting off after 79–81 heats. It indicated a higher efficiency of heat running blow-down and slag regimes with application of proposed design of the six-nozzle tuyere head with asymmetric farthest zones cooling.

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