Top PDF Modeling of Buildings with Electrochromic Windows and Thermochromic Roofs

Modeling of Buildings with Electrochromic Windows and Thermochromic Roofs

Modeling of Buildings with Electrochromic Windows and Thermochromic Roofs

Florida temperature data show that the annual high temperature is about 81.7 °F. In the warmest month, August, the average daytime temperature rises to 90°F [1]. According to the Energy Information Administration (EIA), the average monthly electricity bill in the United States (U.S.) was $118 in 2018. However, in Florida the average electricity bill was $128, which is 9% higher than the average U.S. total electricity bill [2]. In addition, energy consumption has become an important issue because higher energy use leads to higher environmental pollution. A recent survey by the U.S. Green Building Council (USGBC) shows that buildings consume about 73% of the total electricity in the United States, accounting for 41% of all other energy in the world, while emitting 38% of the total carbon dioxide into the atmosphere each year [3]. Modern buildings usually have large facades of windows, known as glazings. Glazings provide good daytime illumination but reduce the energy efficiency of buildings [4]. In particular, cooling has increased significantly in recent years. According to the EIA, energy lost through conventional windows accounts for about 30% of the heating and cooling energy costs [5]. Shadows, blinds, shutters, fins or other mechanized solar control devices are used, but they can cut off connection to the outdoors.
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Electrochromic dynamic windows for office buildings

Electrochromic dynamic windows for office buildings

To determine blind impacts, a control strategy was assumed in energy modeling runs that there were an equal percentage of down and closed blinds, raised blinds, and those that are down but with the vanes open at various angles. Using this control assumption, energy simulation results indicated a 50% reduction in daylighting energy sav- ings (lighting and cooling energy savings associated with reduced artificial light use) and a slight increase in heating energy savings, for a total of 5–6% more annual energy consumption in comparison to a case with static glass, dim- mable lights and no manual blinds. There will be little to no change in the cooling energy use in the space due to manual
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Energy Performance Modeling of Buildings with Directional Reflective Roofs

Energy Performance Modeling of Buildings with Directional Reflective Roofs

DOE-2.1E also uses simple but accurate assumptions to reduce the running time of simulations. This program also known as one of the accurate building energy simulation tools which is being used by researchers and building industry. Sullivan & Winkelmann (1998) validate the accuracy of DOE-2.1E in predicting heating energy, room air temperature and incident solar angle on the windows with measured data. Carriere et al. (1999) compared the estimated amounts of energy consumption of HVAC system by DOE-2.1E and experimental data. It is concluded that this software can estimate the total HVAC energy consumption (i.e. electrical heat pump) within 5.8%. Finally DOE-2.1E is free for public and its complete guide books (such as DOE- 2.1 Basics (1991), DOE-2 Engineers Manual (1982) and DOE-2 Reference Manual (1980)) provide a lot of information for users.
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A comparative energy analysis of three electrochromic glazing technologies in commercial and residential buildings

A comparative energy analysis of three electrochromic glazing technologies in commercial and residential buildings

importance while the building codes don’t require interior shading virtually every building with windows has them to address visual and thermal comfort. Observation suggests that manually operated shades are rarely used optimally [66]. The classic use pattern is to lower them to address immediate glare conditions but often they are not raised after the glare source is gone. This real world operation is therefore unlikely to capture some of the winter solar gain assumed in our modeling and thus relative DBEC performance will look better than presented here. For southern regions where cooling dominates overall building energy use, the DBEC savings are most apparent. In regions with less predominant cooling loads, the savings are lower but remain positive. The largest observed savings intensity is $0.12 per ft 2 of glass area annually in region 1A and 2A.
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Green Roofs and Biodiversity

Green Roofs and Biodiversity

list of the 15 most dominant plants present on all 10 sub-roofs. Poa compressa, Festuca ovina, and Bromus tectorum were present on nearly all sub- roofs on all dates. Some typical plant species in the first years were Lolium perenne, Festuca rubra, and Poa pratensis; these declined after some years. Cerastium semidecandrum and Setaria viridis were typically associated with the green roof plants over all the years of the survey. Other species, such as Apera spica-venti, were found during dry summer climate situations, but their presence became more apparent with increasing rainfall. Poa annua and Senecio vulgaris, typical garden weeds, were common on the green roofs but only had a low cover value. The final column in Table 4 indicates the dominance of the plant species according to the sum of cover values for all observation dates on all sub-roofs. Allium schoenoprasum didn't start growing on the roofs until some years after they were built, but its cover value increased rapidly. This plant was the most dominant species in terms of cover. The 110 plant species had a sum cover value of 35,142 over all the years, while A. schoenoprasum alone had 19,512—or 56% of the total. The 10 next most common species after A. schoenoprasum had a combined sum cover value of 9,143. The remaining 99 plant species had a combined sum cover value of 6,487. The cover values for these three groups of plants are shown in Figure 3.
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A Naphthalene-Based Multi-Electrochromic Material and Its Neutral Green Electrochromic Device

A Naphthalene-Based Multi-Electrochromic Material and Its Neutral Green Electrochromic Device

organic small molecules such as viologens, metallophthalocyanines [3], and finally conducting polymers [4]. As a kind of important electrochromic material, conducting polymers have several advantages, such as structurally controllable HOMO–LUMO band gap, easy tuning of colors, fast switching times, high contrast ability and processibility [5]. They have been widely used in electrochromic displays [6], smart windows [7], electroluminescent organic light emitting diodes (OLEDs) [8], camouflage materials [9] and electrochromic devices [10–12]. For conjugated polymers, the electrochromism is related to the doping-dedoping process, the doping process modifies the polymer electronic structure, producing new electronic states in the band gap, causing color changes [13]. Thus, the electrochromic properties of conducting polymers can be varied over a wide range via proper choice of heteroaromatic ring and substituents [14].
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Electrochromic Iridium Oxides56-61

Electrochromic Iridium Oxides56-61

Other important properties of these films which may be affected by the open, solvent-separated structure of the hydrous polymer layer include the fact that the reduced [r]

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Retrofitting of ETFE roofs

Retrofitting of ETFE roofs

The ETFE roof designed and fabricated in 2011 fort the Winter Garden of the Crown Plaza Hotel in Verona is an examples of projects based on ETFE foils that required the retrofitting of t[r]

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Productive Green Roofs

Productive Green Roofs

Although interest in productive gardening, as part of a healthy, high density city lifestyle, is growing rapidly, severe spatial constraints limit opportunities for ground- level community gardens and urban farms. Over the last ten years, community groups in cities around the world have begun to activate under-utilized building roof spaces for use as community-based urban rooftop farms (URF). These spontaneous projects offer valuable opportunities to address this situation by creating city-based venues for food production, social interaction, and active recreation, and have generated a sense of stewardship for the built environment. Additionally, URFs can have environmental and sustainable building benefits, such as improved building thermal performance, reduced urban heat island effect, increased sound insulation, and urban greening, similar to those of traditional green roofs systems.
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Introduction to Green Roofs

Introduction to Green Roofs

http://hugeasscity.com/2008/05/15/seeking-nominations-for-least-used-park-in-seattle/ http://archinect.com/forum/thread/75451/seattle-vancouver-trip-suggestions http://www.igreenspot.c[r]

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The Effect of Transition Hysteresis Width in Thermochromic Glazing Systems

The Effect of Transition Hysteresis Width in Thermochromic Glazing Systems

the effect of different hysteresis properties of the ther- mochromic transition. The results demonstrate that such thermochromic glazing could have an additional energy benefit in excess of those approaches currently used in warmer climates. This arises from a combination of ab- sorbing and heat mirror behaviour. The best energy per- formance occurred in the warm climate examined and where the thermochromic transition temperature was lowest and the hysteresis width at it’s thinnest. In this instance the energy demand of the model could be re- duced by 54% compared to a standard double glazed system. The results also indicate that transition tempera- ture has a much larger effect on the energy demand re- duction properties of the glazing than the hysteresis width—an improvement of 1% per degree T c reduction
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Designing and Fabrication of Electrochromic Windows Using Tungsten Oxide Films Prepared Through Sol-gel Coating on a Glass

Designing and Fabrication of Electrochromic Windows Using Tungsten Oxide Films Prepared Through Sol-gel Coating on a Glass

electrolytes and electrodes, can savers energy and/or convert it [1-3]. Since 1953, when Balzers presented a very clear description of electrochromism in tungsten oxide films or, since 1969, when Deb changed the situation of EC knowledge by his publications, more and more scientists have engaged in the research field of EC materials, and, as a result, more EC materials have been discovered and reported [3,4]. Electrochromic (EC) materials are able to reversibly and persistently change their optical properties at an external voltage. They are considered as one of the most promising candidates for energy-saving smart (ESS) windows [1]. The primary function of glass, particularly in architectural applications, is to transmit light. A smart-window glass would be one whose light transmission properties can be changed in response to an external stimulus such as light, heat, or electrical impulse [3,5]. Well-known examples are photochromic, thermochromic, and electrochromic glasses. Electrochromism is broadly defined as a reversible optical change in a material induced by an external voltage. Many inorganic and organic species show electrochromic properties throughout the electromagnetic spectrum [6-8]. Among them, smart windows have an important application because they can effectively save energy by regulating the solar heat gain and providing indoor comfort through reversible color changes. Many applications have been developed based on these unique properties. The properties have been applied in such things as electrochromic
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Thermochromic Biopolymer Based on Natural Anthocyanidin Dyes

Thermochromic Biopolymer Based on Natural Anthocyanidin Dyes

Recently a novel thermochromic poly(lactic acid) (PLA)-composite material was presented. Depending on temperature the incorporated anthocyanidin dye was found to be present either in its neutral or anionic anhydrobase form. A reversi- ble formation of PLA-dye complexes triggered by conformational changes of the polymer backbone was proposed to explain this thermochromic effect. In order to study the influence of the dye structure on the PLA-dye complex forma- tion and on the thermochromic properties of the PLA-composite material a variation of the anthocyanidin dye structure was investigated. The results indicate that a hydroxyl group in 3’-position of the anthocyanidin dye resulting in the presence of adjacent hydroxyl groups is mandatory for the PLA-anthocyanidin dye complex formation and thus for the occurrence of thermochromism.
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Numerical Investigation of Three dimensional Turbulent Wind Flow around Two Square Buildings with Hip Roofs

Numerical Investigation of Three dimensional Turbulent Wind Flow around Two Square Buildings with Hip Roofs

In Ref. [16] a valuable CFD simulation of cross-ventilation for a generic isolated building took place. In Ref. [17], a considerable analysis of airflow over building arrays for assessment of urban wind environment was carried out. The current investigation, aims to study the three – dimensional turbulent wind flow around two square buildings with pyramid roofs of trivial architectural forms for an arbitrary geographical location. The novelty of this work is that the independency of the numerical solution for any possible distribution of mesh points was demonstrated in a theoretical manner without the necessity of changing the original mesh with simultaneous repetition of the computational process.
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Multi-electrochromic 2,7-linked Polycarbazole Derivative and Its Application in Electrochromic Devices

Multi-electrochromic 2,7-linked Polycarbazole Derivative and Its Application in Electrochromic Devices

The optical memory in electrochromic devices is an important parameter since it is directly related to its application and energy consumption during the use of ECDs [17]. The optical spectra for PBTC/PEDOT device was monitored at 600 nm as a function of time at –0.8 and 1.8 V by applying the potential for 1 s for each 200 s time interval (Fig. 8). As depicted in Fig. 8, at the reduced state, the device shows a true permanent memory effect since there is almost no transmittance change under applied potential or open circuit conditions. In blue colored state device is rather less stable in terms of color persistence, however this matter can be overcome by application of current pulses to freshen the fully colored states. The same phenomena were aloso found for procedure PBEC/PEDOT device (data was not shown), which exhibited a good optical memory.
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Dynamic ornament: An investigation of responsive thermochromic surfaces in architecture

Dynamic ornament: An investigation of responsive thermochromic surfaces in architecture

Following these experiments we produced a series of prototypes exploring the use of pixels as a means of producing patterns. Pixels offer the advantage of flexibility in what is displayed – although increasing the resolution of the pixel grid greatly increases the complexity of the hardware involved in controlling a large number of individually- addressable circuits. The solution commonly employed to deal with this complexity is multiplexing, a method which allows the microcontroller to select a single pixel based on its column and row address.We chose to make pixels using tightly-packed copper traces (figure 13), placed so close together that when heated the circuits would blend together to form a solid shape. The largest pixel prototype (figure 12) consisted of 256 pixels in a 16x16 array. Each pixel was a square, 1 cm on each side, containing a 50 cm copper circuit. This surface was then painted with a coat of white paint, followed by two coats of thermochromic pigment, leaving the pads of the circuits exposed. We also produced several prototypes that used resistors as pixels – the smallest SMD resistors are about 1mm 2 , and can be used to heat the overlying ink with a small
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Problems in Practice:Critiquing on Thermochromic based Displays for Representing Skin Conductance

Problems in Practice:Critiquing on Thermochromic based Displays for Representing Skin Conductance

Over the last decade, we have seen a growing HCI interest in emotional wellbeing and affective health [17] particularly focused on emotional memories [14,15,21,22,23], particularly in old age [18] and end of life care [19], affective representations through smart materials [24], and support for mindfulness [2,20]. With the growing interest in biosensing a growing number of technologies focus on capturing biosensory data such as skin conductance, heart rate variability, breathing rate, movement data, brain activity information [29,30,31,32]. Often such information is displayed through biosensory representations in numerical and graph-based form. However, there are other systems which aim to empower users by employing ambiguous biosensing representations [5,7,11,12,16,24,28] to provoke multiple interpretations of biosensory data. These systems often employ mobile and desktop screens which are not always on sight. However, a growing number of research is trying to use alternative kind of displays using thermochromic materials to represent biosensory information [3,7,24]. Such displays are often integrated into wearables and clothing. A growing interest in materials research within HCI and interaction design has helped us understand how the qualities of materials unfold when designing and using interactive systems [8,10,27]. They highlight the importance of understanding the aesthetic and experiential qualities of materials. According to Giaccardi and Karana, different individuals experience materials in different ways as: “properties of a material, the artifact in which a material is embodied, one’s previous experience and expectations, and social and cultural values inevitably affect how we experience” [6]. The framework proposes that materials are experienced at four different levels i.e. sensorial, interpretive, affective and performative level.
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Energy consumption and CO2 emission reductions trough refurbishment of residential buildings’ roofs by applying the green roof system: Case study

Energy consumption and CO2 emission reductions trough refurbishment of residential buildings’ roofs by applying the green roof system: Case study

isting flat roof by using green roof. The energy needed for heating the buildings on an annual level has been taken into account since this parameter is the only one recognized by the cur- rent legislation as the relevant one for determining thermal properties of the building’s enve- lope. New Belgrade, as a part of the city which is characteristic for its large number of same or similar buildings, was chosen for this research. Blocks 45 and 70 are the best example of the post war ideology which promoted fast building process trough multiplying same build- ings over a vast free space. For this reason it is possible to examine influence of a new roof solution on one building but to multiply the results on other, same or similar, buildings since they share unified characteristics. Two types of buildings can be found in examined blocks and a representative building for each type was examined trough two possible scenarios. An additional scenario was introduced – control roof, which was used for comparing benefits of the proposed green roof systems to a traditional solution most commonly used in Serbia. As a result of this process, following conclusions were made:
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Crystal structure of the thermochromic bis­­(di­ethyl­ammonium) tetra­chlorido­cuprate(II) complex

Crystal structure of the thermochromic bis­­(di­ethyl­ammonium) tetra­chlorido­cuprate(II) complex

Thermochromic compounds exhibit a reversible change in color corresponding to a change in temperature. This change can occur in the solid state or in solution and is typically due to geometry rearrangement at the molecular level. Several mechanisms have been proposed for this rearrangement, including phase transitions, changes in solvation, changes in ligand geometry, coordination number, and finally crystal packing (White & LeBlanc, 1999). There are two generally accepted classes of thermochromism: (i) continuous; used to describe a gradual change in color, most likely due to breaking or rearrangement of the crystal structure (Roberts et al. , 1981), and (ii) discontinuous; used to describe a dramatic change in color over a specific or small temperature range (Van Oort, 1988). Two classes of thermochromic compounds that have practical applications today include liquid crystals and leuco dyes. Liquid crystals exist on the boundary between the liquid and solid states. They are classified as discontinuous due to the chemistry of their transitions (Amberger & Savji, 2008). As a result, thermochromic liquid crystals have been used to make ‘mood rings’, thermometers, and game pieces (Chandler, 2012). Although color changes in liquid crystals are more sensitive to external stimuli such as temperature changes, they have a highly specialized manufacturing process and are difficult to make. For this reason, new thermochromic compounds such as leuco dyes are highly sought after. Leuco dyes are easier to work with and less sensitive to temperature changes. They have been used in advertising labels, textiles, and packaging for microwaveable syrup bottles and beverage cans that indicate content temperature changes (Muthyala,
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Synthesis and Electropolymerization of 9H-Carbazol-9-Ylpyrene and Its Electrochromic Properties and Electrochromic Device Application

Synthesis and Electropolymerization of 9H-Carbazol-9-Ylpyrene and Its Electrochromic Properties and Electrochromic Device Application

electrochromic materials have been developed, such as inorganic metal oxide, mixed-valence metal complexes, organic small molecules and finally conjugated polymers [7]. Recently, electrochromic conjugated polymers have received much attention due to their fine-tunability of the band gap (and the color) [8], outstanding coloration efficiency [9], fast switching times, excellent processability and low cost [10]. For conjugated polymers, the electrochromism is related to the doping–dedoping process, the doping process modifies the polymer electronic structure, producing new electronic states in the band gap, causing color changes [11].
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