The next generation of advanced fenestration products includes dynamicelectrochromic (EC) windows which can modulate the solar energy entering a building by application of an applied voltage. The windows can be switched from 62% visible transmittance (Tvis), 0.47 solar heat gain coeﬃcient (SHGC) to a fully tinted state with 62% Tvis, 0.09 SHGC. EC windows save energy in buildings – the total energy use for an eight story ASHRAE 90.1 2007 commercial oﬃce building with EC windows was modeled using the eQuest building simulation program and compared with the energy use of the same building with a variety of static glazings. The simulations were carried out in three US climate zones, encompassing a broad range of environmental exposure conditions from hot and dry (Arizona) to very cold (Minnesota). For all climate zones, building energy savings with EC glass were P45% when compared to single pane static glazings common in existing building stock. When EC glass was compared to ASHRAE 90.1 2007 code compliant glazings, energy savings greater than 20% were calculated for the same building conﬁguration. Optimum EC window control and performance strategies were derived from the modeling results. The EC glass and dimmable electric lights were synergistically controlled to maximize the use of natural day- lighting and minimize electricity for lighting. Since EC glass can tint to 62%, shades and/or blinds are not required for glare reduction, and building occupants always have a comfortable working environment and an unobstructed view and connection to the outdoors. All static glazing systems were assumed to have manual shading devices that are pulled by building occupants when glare becomes uncom- fortable. For integrated building control systems, the peak load is signiﬁcantly reduced when dynamic glazings are part of the building envelope. Consequently, chiller costs are lower, and the upfront capital costs for new building construction are reduced. Another key beneﬁt of EC glass, elucidated by the simulations is reduction of CO 2 emissions. EC glass reduces peak load carbon emissions by as much as 35% in new construction and 50% in renovation projects.
In our research we use the technology of electrochromic (EC) glazing to maximize the use of daylight and minimize the energy consumption in buildings while preserving visual and thermal comfort of the users. We propose an advanced automatic control of EC windows coupled with an anidolic daylighting system (ADS), blinds and dimmable fluorescent lights. EC windows with a visible transmittance range (Tv) of 0.15 – 0.50 were installed on the southern façade of an office room of the LESO experimental building (EPFL campus in Lausanne, Switzerland). The system is divided in two independent zones: The lower zone is equipped with EC windows and blinds while the upper zone features in addition the ADS, which facilitates the even distribution of daylight across the room. Electric lighting is used only complementary when daylight is not sufficient. Data regarding instantaneous weather conditions, room conditions, as well as user wishes is collected and recorded in the database of the building's central management system (KNX/EIB).
Most building’s occupants favor daylight as their primary light source. Although most developers understand the higher premium value that normally comes with a space with more windows, the effects of “extensive daylighting on organizational efficiency” is not as well considered . In the building sector, an increase in demand for sustainable energy and strategies for management of nat- ural light indoors and its relationship with artificial lighting requirements has led to exploration of alternative façade designs. One of the most active areas in building design is advancements of technologies related to win- dows and specifically the glass. The driving forces be- hind such breakthroughs are issues related to interior day-lighting enhancement, maximizing occupants view and comfort, and reducing operational costs. Conse- quently these also have an environmental impact which makes the focus on glass worthwhile. In addition, other factors such as cultural mentality, health regulation, and occupant expectations have added to the momentum to- wards “healthy buildings” through use of unconventional façade designs .
often appearing as an afterthought rather than an integral feature of the building design. A variable shading device is likely to perform better than a fixed brise soleil, but these are rarely considered due to increased cost and maintenance issues compared to static devices. Electrochromic (EC) glass changes transmittance in response to a small applied voltage (less than 5 volts DC). An EC window can be operated automatically or manually to control light penetration, without compromising the view out. By providing unobtrusive dynamic shading in this way, EC glazing has significant potential to improve daylighting and energy use in new and existing buildings. Unsurprisingly, EC glazing has attracted significant research since its inception in the 1980s [Lampert, 1984; Svensson & Granqvist, 1984]. However, most of these studies have been simulation-based [Sullivan et al, 1994; Moeck et al, 1998] or lab-based using scale models or full-scale rooms [Piccolo et al, 2009; Lee et al, 2006; Clear et al, 2006; Zinzi, 2006; Lee at al, 2012 and others]. Only a few of these have included a systematic assessment of the experience of human users of the technology [Clear et al, 2006; Zinzi, 2006; Weinold, 2003]. However, those that did include human participants were lab-based, so that participants only experienced the technology for short periods of time (i.e. hours), and not in their normal work setting.
Feedback from participants suggested that they value the ability to see through the windows continously. Theirs is an urban view, comprising a parking area, a road and nearby buildings. During interviews, they commented positively about the ability to see people and vehicles coming and going. Before the installation of the EC windows, participants indicated that with the blinds drawn, the room had a tendency to feel “closed in”. Several participants observed that when the windows are tinted, the sky looks darker than it is in reality, giving the false impression that it might rain, for example. However, the windows should not normally be tinted under cloudy conditions, and if so, only briefly, so this may not be a significant issue for other installations.
High variation in building operations as a function of occupancy type and climate, and consequently energy performance, mean that some U.S. market segments are much more suitable to DBEC deployment than others. To illustrate the geographic scope of these market segments, and the magnitude of their potential benefit from DBEC deployment, several maps have been generated. Figure 15Figure 17 show the cost savings per unit area of glazing for large office, medium office, and midrise residential models, respectively. These savings are given relative to the high performance static glazing, rather than ASHRAE windows, as was done in early sections. The high performance static glazing is used here because it is a better basis for comparison for deployment in an energy efficient building. In such a building, the high performance static represents a more realistic competitor to the DBEC or other advanced window technologies, rather than windows that are simply code-compliant.
Selkowitz, S.E., E.S. Lee, O. Aschehoug. 2003. Perspectives on Advanced Facades with Dynamic Glazings and Integrated Lighting Controls. CISBAT 2003, Innovation in Building Envelopes and Environmental Systems, International Conferences on Solar Energy in Buildings, October 8, 2003, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
This study aims to assess the impact EC and TC technologies can have on buildings. eQUEST software is used to simulate and evaluate the energy performance of a commercial office building and a residential house. The simulations include modeling of low-E glass, low-E EC glass and TC roof for two climatic zones in the US, zones 2 and 5. The simulation results show the use of EC glass in an office building can produce 12% to 18% energy savings, while in residential buildings 3.8% to 5.3%. The influence of EC glass on a commercial office building is much greater than that in a residential unit because of the number of glass windows used in a commercial building. A cool roof calculator was used to estimate the energy savings resulting from the use of a white reflecting roof. When both a TC roof and EC glass windows are used, the results show that the energy savings for an office building are 27.8% to 35%, while for
Thus the design and operation of real estate can play an important role in energy conservation in advanced societies. Awareness of this fact is growing. The increasing emphasis on “green rating” sys- tems for buildings—initiated by both government and industry—gives witness to this development. In general, these ratings assess the energy footprint of buildings, and they may provide owners and occupants with a solid yardstick for measuring the energy efficiency and sustainability of properties. However, the use of these ratings has so far been limited, and the global diffusion of rating systems is relatively slow. Moreover, both real estate developers and institutional investors are understand- ably uncertain about how far to go in implementing environmental investments, since the economic rationale for the development of sustainable buildings is based almost entirely on anecdotal evidence.
With increasing awareness of sustainable development in the construction industry, there are other voluntary building environmental schemes to measure the performance of buildings at national and international levels. The most widely used schemes are: Leadership in Energy and Environmental Design (LEED) which was developed by the U.S. Green Building Council; the Building Research Establishment Environmental Assessment Method (BREEAM), which was launched by the U.K; and Green Star which was launched by the Green Building Council of Australia. These schemes are based on a rating system that apply to a wide range of building types, both new buildings and existing buildings (Roderick et al. 2009). A range of environmental issues such as materials, energy, water, pollution, indoor environmental quality and building site are covered by these rating schemes but, most importantly, energy demand reduction is essential to gain higher ratings. Retrofit of existing buildings provides an opportunity to gain higher ratings in these schemes which can increase a building’s value, aesthetic appearance, energy performance and indoor comfort (Ebbert 2010).
Computational analysis is the most effective tool at these initial design stages, ‘..., the remaining viable options are explored in more detail, requiring more rigorous analysis of the key design elements. Some very detailed modelling might be required to prove particular strategic concepts in order to avoid time and money being wasted later if the design has to be revised fundamentally (CIBSE, 1998).’ Dynamic thermal simulations are particularly effective where current market software such as IES VE, EDSL, Design Builder. Dynamic thermal simulation engines produce documents that include SBEM output, EPC and BRUKL compliance. For CFD analysis, PHOENICS software (CHAM, 2016) provides more detailed air flow analysis for air change rates air, air flows and direction in steady state analysis. In many cases budget is the primary driver to decide if passive strategies are included within construction schemes, as complex geometries and thermal mass is unfortunate side effect. Although budget can be contributing factor to decision made, design team members are required to provide significantly more time for passive strategies, in order to design acceptable solutions with assistance from computational models. The primary aim of any system design is to maintain internal environmental room conditions in accordance with legislation and guidelines.
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 . 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
You will be directed to the “Add to Cart” page. Here you will see a description of the applications within the Microsoft Office Professional Plus 2010. You are given an option to either Download or Mail Order this software. (This part of the document will be directed to your choosing the Mail Order disc. ) Before proceeding with your selection read the facts below.
This study investigates solutions for facade renovation of general officebuildings built between 1960 and 1980 in the Copenhagen Municipality. 44 buildings are used for the study. They share common structural and construction principles like the use of beams and columns and prefabricated elements. The problems that face these buildings are a high number of overheating hours and high heating consumption. Four strategies are tested for the renovation: external re-insulation, double-skin facade (existing inner facade), double-skin facade (new inner facade) and curtain wall. External re-insulation and curtain wall provide the best results for reducing the energy consumption for heating.
Tackling the challenge of climate change is about confronting the critical question of how we should value sustainability. The built environment is a reflection of our understanding through growing awareness of the solutions to issues that confront us. Public Works Department Malaysia (PWD) has taken steps progressively to create, adapt and apply a sustainable building project management throughout building lifecycle; planning, design, construction, monitoring and maintenance as to achieve a green nation by 2020. This approach focus on energy efficiency and energy saving in building sector thus in line with Malaysia’s target to reduce carbon emission of 40% from 2005 level by 2020 as mentioned by Prime Minister of Malaysia at COP15 in Denmark, December 2009. Indeed, PWD has taken serious action significantly to lead this mission by implementing and achieving sustainable projects towards healthy and quality environment by using Green Building criteria to achieve sustainable building design. This aim is a collective approach from government agencies such as Ministry of Green, Technology and Water, Standard & Industrial Research Institute of Malaysia (SIRIM), Ministry of Natural Resources & Environment and Ministry of Housing & Local Authority with cooperation from the professional bodies namely Malaysian Institute of Architects and Association of Consultant Engineer Malaysia. The government has built several energy efficiency and green demonstration projects such as Low Energy Office (LEO), Green Energy Office (GEO) and Energy Commission Building. This paper outlines some of PWD experiences in implementing sustainable practices for government
Distance from windows. Median votes of satisfaction provided by occupants whose workstation was within 4.6 m from a window were invariably higher than those expressed by users sitting far from the perimeter across the two groups of buildings. Users sitting further than 4.6 m from a window expressed higher satisfaction with building, workspace, and almost all IEQ parameters in non-BREEAM buildings. All differences detected were significant and with an effect size of relevant magnitude. Spatial layout. Median votes of satisfaction from occupants of enclosed offices (private and shared) were positive in both BREEAM and non-BREEAM buildings. For these layouts, inferential tests did not detect statistically significant differences, even if effect sizes of practical relevance suggested higher satisfaction in non-BREEAM buildings. For users of cubicles, votes varied depending on IEQ parameter, but differences were consistently not significant. Conversely, significant and substantive higher satisfaction with building (ΔMdn= -1.50***, r= -0.50), workspace (ΔMdn= - 2.00***, r= -0.49), amount of light (ΔMdn= -2.00*, r= - 0.31), visual comfort (ΔMdn= -2.00*, r= -0.33), amount of space (ΔMdn= -1.00**, r= -0.40), air quality (ΔMdn= -2.50***, r= -0.53), noise (ΔMdn= -2.00***, r= -0.53), temperature (ΔMdn= -2.00**, r= -0.39), visual privacy (ΔMdn= -1.00*, r= -0.37), and sound privacy (ΔMdn= - 2.50***, r= -0.60) was expressed by occupants of open spaces in non-BREEAM certified buildings.
Airflow rates are invariably controlled by dampers at the inlets and outlets by using a building management system (BMS). This makes the strategy eminently suitable for buildings with large, possibly open plan, spaces when no single occupant is exercising control over the internal environment, e.g. libraries, theatres and conference halls. However, the strategy does not entirely preclude operable windows, should this be deemed desirable, although some caution is required to avoid unwelcome draughts and the preferential supply of air from the windows rather than from the air delivery shaft when in mechanical cooling mode. Most importantly, it is possible for a NV building to have a sealed façade, thus opening up this low energy strategy as a real design possibility on noisy and polluted sites, in areas where security is of particular concern, to buildings which house valuable or easily stolen objects or where the façade must offer maximum design flexibility, for example, to adopt the vernacular of the surrounding buildings in areas of historic importance .
The study reviewed the concept of life cycle assessment. Also, this work reviewed previous studies in life cycle assessment of officebuildings. Methodology of the research applied to an eight-story office building case study to demonstrate the application of system. Two structural components and one envelope component were compared basis of the six environmental indicators. The result of the case study was found the optimum alternatives of pre-cast and tilt-up officebuildings which have the lower environmental impacts. Stakeholders of a project must not only find the quickest way to complete their work but also considering a way which has the least impacts on environment. Although the result of case study was shown pre-cast and tilt-up office building have lower impacts on environment, there are several other factors to consider when selecting the best method applicable to the project. This study had only one objective, mitigating impacts of office building on environment throughout its life cycle. To consider multi objective in the methodology such as minimizing life cycle costing can open a new research title for future works.