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Windows typically account for 30% to 50% of heat losses through building envelopes. Monolithic silica aerogel has thermal properties and physical characteristics which make it an attractive material for high performance glazing. Optimizing the thermal performance of individual window components can improve the thermal performance of windows insulated with monolithic silica aerogel. It is important to consider how the thermal properties can be sustained, especially when in contact with other window components such as edge and intermediate spacers and the window frame. The purpose of this research paper is to analyze French style windows insulated with four panes of monolithic silica aerogel and investigate the thermal bridging of edge and intermediate spacers and window frame in order to assess how they collectively affect the centre of glass and edge of glass regions. The research aims to determine the spacer geometry, materials, and window frame that guarantee the best performing window system.

Low-e products have been accepted widely as an energy-efficient solution or energy retrofitting strategy for glazing systems, including single-pane windows, which may reduce the emission of radiant infrared energy and improve the insulating properties of overall windows. However, the addition of a low-e layer may increase the condensation risk, and in turn, significantly diminish the window’s thermal performance. To better understand the condensation effects of low-e windows on overall building energy use, we extended the classic Nusselt filmwise condensation model to establish and validate a simplified double-film-based analytical model, and then characterized the condensation-dependent thermal dynamics of low-e coated single-pane glazing. A series of whole building energy use comparisons between simulations ignoring and considering the condensation effect were conducted. The results indicate that if the condensation effect is taken into account, the low-e single-pane glazing may lead to adverse effects on the energy-saving purpose in certain climates relative to the original single-pane glazing. More careful and comprehensive energy analyses are needed to use low-e products for window energy retrofits.

The window system is generally regarded as the most vulnerable building system for the indoor energy performance of green buildings. Window systems are given significant attention by architects and engineers, especially in areas with long summer and high solar radiation such as the subtropics. This study aims to develop a standard window-to-floor ratio (WFR) system for green residential buildings in the subtropics. Using Autodesk Revit as the interface, a real high-rise residential building was digitalized and imported into Ecotect for energy consumption analysis. Comparative analyses were conducted to determine the optimal WFR for building energy efficiency. Results demonstrated 0.23 as the optimal WFR in Xiamen, one of the typical subtropical cities in Asia. Furthermore, accompanied by a four-sidefins sunshade device and a double glass window (DGW) with clear “glass+air gap+reflective” glass, the building energy consumption was further reduced by 34.47% compared to the initial model, which successfully met the optimization target of 30%, set according to the green building standard. The results of this study are helpful to architects and building engineers when designing or retrofitting green buildings as we provide specific support for design features for energy performance.

This study investigates the influence of glazing characteristics and shading device configuration on energy use and cost, daylighting performance and visual comfort. A typical patient room from a h...

The safety of train stations can be affected by many internal and external threats. Train stations or stations in generally can be classified as soft targets. It can be assumed a potential target for many, especially terrorist attacks. In elevated number of railways stations, large glass surface as facades and stained-glass windows are presented. They present vulnerable part of construction, affected by various type of accidental loads (as blast and impact) in case of terrorist attacks. In this terrorist attack, the biggest cause of injuries and deaths are caused by debris from glass parts of structure. The paper is focused on the glass used in modern construction of train stations. Based on this, several methods of loading condition are described and the resistance of fenestration on such loads is assessed. The practical part of the paper is focused on two types of window systems and the resistance to dynamic loads was evaluated. The experimental testing was performed using a pendulum test. The results showed the resistance of selected types of windows without, as well as, with the use of security protective film. The paper also interprets possible glass failure under dynamic loading.

In recent years, bus fires occur frequently and accidents are often accompanied by serious casualties. Aiming at this situation, in order to improve the shortage of the traditional way of escape for bus and reduce casualties, in this paper, an intelligent escape system for bus through broken Windows was designed. The system adopts modular design, and a large number of experiments and optimization are carried out in dangerous goods early warning, fire detection and broken window effect test. The results show that the system can effectively break windows and quickly open up multiple escape routes in the case of bus fire accident.

The development of a green and environmentally friendly window system is always the upmost target among other requirements for modern buildings. Here, a smart window with a dynamic regulation mode ...

Glazing and window systems in New Zealand have been shown to be susceptible to significant damage as evidenced by the past decade of earthquakes. The seismic performance of glazing and window systems has resulted in considerable financial loss, disruption in business and physical injuries following earthquakes. In order to investigate the vulnerability of residential windows in typical light timber framed buildings racking testing was conducted on six wall configurations. Numerous observations of window performance were made during the testing and from these results fragility functions were developed for timber and aluminium framed windows. These fragility functions suggest that even at low displacement levels damage can occur to windows that can potentially affect weather-tightness and require repairs following an earthquake. These functions can inform decisions around designing for resiliency in residential structures in New Zealand.

While the primary role of window attachments is often to moderate glare and solar heat gains, they are also able to provide additional daylight to interior spaces. For this purpose, a variety of daylight-redirecting window systems have been developed over the past 150 years. Fixed reflective systems (slats/light shelves) or prismatic systems that rely on total internal reflection work well under specific solar conditions, but generally sacrifice performance over a much wider range of incident solar angles and sky conditions. Dynamic systems - typically reflective slats - are more responsive to sun angles but have not been able to achieve optimal performance for glare and daylight redirection efficiency. A previous investigation into an adjustable, reflective blind concept first conceived of in the late 1970s showed promise but was not reduced to practice due to lack of adequate simulation and analysis tools. In this paper, this concept is further developed and its energy and visual comfort performance evaluated for four mid-latitude, temperate climates using ray-tracing simulation techniques. Results indicate significant potential lighting energy savings when compared with conventional automated reflective blinds (2.1–4.9 kWh/(m2·a), or 14%–42%, depending on climate and orientation) or, especially, manually-operated matte white venetian blinds (1.4–7.9 kWh/(m2·a), or 9%–54%, depending on climate and orientation), while maintaining acceptable or better visual comfort conditions throughout the interior space.

To warm the window system, high-quality thermal insulation of the window profile is required, which is measured by the reduced coefficient of heat transfer resistance.The article sets the task of developing the design of the window profile from various materials in which the change in heat transfer resistance occurs without equipment readjustment.The author analyzes the main disadvantages of existing designs of metal-plastic profiles, which have a sufficiently high coefficient of heat transfer resistance, as well as profiles that allow you to change the coefficient of heat transfer resistance of the window profile.It was found that most window profile designs do not allow changing the coefficient of heat transfer resistance of the profile without changing its thickness. The consumer is not able to choose a profile design of a certain thickness, but with a large heat transfer coefficient. Such an opportunity exists only if you change the profile material. It has been established that window profile constructions that allow changing the heat transfer resistance coefficient without changing the profile thickness are designed only for window systems made of metal-plastic. The use of existing window profile designs in which it is possible to change the heat transfer coefficient of resistance for a window profile made of various materials is possible, but requires a certain readjustment of equipment, which leads to a rise in the cost of the window system and negatively affects the ability of customers to buy this type of product.The technological possibility of changing the heat transfer resistance coefficient of window profiles made of various materials in various ways without changing the thickness of the profile and without changing equipment is shown. The proposed design of a window profile made of various materials provides a higher coefficient of heat transfer resistance of the window profile, improves the soundproofing properties of the window system, eliminates the need for certain equipment readjustment, maintains the simplicity of window profile production, and almost does not increase the cost of the window system. The social value of the proposed design is that it retains aesthetic qualities

In the era of digitalization and automation, individuals endlessly need to switch previous manual operating systems. During this paper, Authors tend to describe the Window automation system framework, and that they demonstrate here however it works and additionally describes all functions. This window is one type of distinctive good window that may gather its nearest condition info and end its activity like open, close, and send knowledge to the man of affairs, using IoT. It tends to be controlled by physical and autonomous (automated and internet applications). It will quantify the thickness of residue, dampness, temperature, and it additionally will determine gas, water (rain or snow), smoke, light, fire, dust, once distinguishing it took immediate actions supported matters. Here, the actions are; open and close the window receive commands from the user, and send collected knowledge to the user. At long last, authors have directed some real tests of assorted kinds of the sensing element for the shrewd window framework.

In terms of COVID-19 pandemic, the mechatronic system, essentially a smart window, supplemented with devices for interception and disinfection of drops and capsules with viruses and bacteria, both outside and inside. This allows preventing the ingress of infected aerosols into the room along with streams of air rising along the buildings and spreading inside it in the presence of infected people along with turbulent jets of air. With widespread use, the system helps to reduce the spread of infection, transmitted mainly by airborne droplets. The hardware for controlling the window system is performed on a board from the Arduino MEGA 2560 R3 ATMEGA16U2 family, two control boards with ten relays and ten sensor modules. Control program for the window system control circuit is written in the LabVIEW graphical programming environment (National Instrument USA).

The Solar Heat Gain Coefficient (SHGC) is one of the energy loss factors in buildings, which affects a cooling load significantly. A variety of shading devices and high-performance windows have already been developed and applied to a large number of buildings to reduce a cooling load. However, performance evaluation on these shading devices and high-performance windows has depended on calculation via mathematical models and simulations. These evaluation methods have limits when reflecting heat characteristics of the ever-increasing complexity and development of window systems accurately in a realistic way. Thus, it is critically necessary to verify performance evaluation results through actual measure. The purpose of this paper is to measure the SHGC of various types of windows and shading devices and to analyze the difference between the calculated value and the measured value. The experimental result is as follows. SHGC of venetian blind is lower than SHGC of roll screen and Triple shade. The higher the glass SHGC was, the higher the SHGC reduction rate was under the same condition. The larger the slot angle was, the greater the SHGC performance improved. The analysis result on measured and calculated values showed that a mean different ratio was 4.86 %, which was matched within 5 % of the deviation rate. However, the different ratio tended to increase as the complexity of structures and types of windows increased.

After a brief outline of the historical past, the study focuses on the three main elements of public administration: the organisation, the tasks and competences and the characteristics of the staff.Different but complementary research methods (historical, comparative, dogmatic) show the changes in the management and operation of official administration over historical periods. The formalised, subordinated and superordinate public administration is increasingly replaced by a customer friendly, service-like administration. The corresponding organisational framework is the government window system, while the institutions of general administration order provide the opportunity to implement fast, cheap and efficient services. The commitment, skills and professionalism of the public administration staff remain the most important factor for the realisation of a modern, service oriented state.Changes in the nature of official administration is not straight-line, but the tendency is the strengthening of the help and service image.

Development of electronic customs is currently a relevant area of work for both the Eurasian Economic Commission and the Federal Customs Service (FCS) of Russia. It relates to the introduction of a “single window” mechanism, one of the blocks of which is electronic customs. The need of customs audit implementation in the work of customs services in the EAEU countries emphasizes its development being part of the block of electronic customs. However, the introduction of customs audit is restrained by uncertainty in its understanding. The article analyses the existing customs audit application practice for customs control of goods abroad. It is determined that in all researched countries customs audit is understood as a form of customs control. In the study, the authors develop possible approaches to implementation of customs audit in the activities of the Russian Federal Customs Service, namely a form of customs control (based on the experience of foreign countries), a subject type of business activity, and a special type of state control. Possible negative consequences of customs audit introduction in each case are analyzed. In addition, the authors prove that introducing a new form of customs control (customs audit) would be inexpedient. The results of the experiment on customs audit application conducted by the FCS of Russia are also analyzed in the article. The analysis reveals a lack of considerable positive results confirming the validity of introduction of customs audit as a business activity. The authors establish that the best decision at the moment would be the creation of a separate public authority engaged in customs audit. This would allow the workload of customs authorities in goods post-clearance control to be redistributed, and would ensure a wide use of authentic audit reports made by officials in categorizing the participants of foreign trade activities and granting them various simplifications and preferences. It would also expand the necessary cooperation between authorities and participants of foreign trade activities, realizing the principles of the single window system, and could eventually help replace the desk customs inspection.

The exhaust air glass unit (EAGU) can be treated as an integration of multilayer glazing unit and heat recovery device to utilize the exhaust air from conditioned space with a fresh air ventilation system to improve the thermal performance of window system. However, compared with the conventionally used mechanical ventilation with a heat recovery (MVHR) system, whether the use of EAGU is energy-efficient or not has not been estimated. In this paper, a numerical model, validated by experimental measurement, was used to calculate the hourly cooling and heating loads and annual energy demand of EAGU. This study compared the annual energy performance of EAGU and MVHR under various conditions, and further discusses the applicability of EAGU for different climates. The results indicate that the energy saving potential of EAGU ranges from 26.8% to 38.2% for different climate conditions. In the cooling season, the energy saving potential of EAGU performed much better than that of the commonly used MVHR. However, the EAGU was inferior to the MVHR in the heating season. Moreover, the EAGU is more suitable for application in warm climates, rather than cold climates. This study can provide some application guidelines about the selection of exhaust air heat recovery devices for maximizing the energy saving potential.

This study investigates the application of the evaporatively-cooled window system in hot and humid climates and assesses its seasonal performance and benefits in terms of energy savings. The validated system is a hybrid combination of solar chimney, window and evaporative cooler that induces a natural buoyant flow originated by direct solar radiation application. As proper solar radiation data is critical in applying solar-driven technologies, an on-site weather station was established in Qatar for the measurement of several meteorological parameters for the entire year of 2016. The measurements represent actual validated data recordings in the city of Doha, mimicking harshly hot and humid weather conditions. The simple application of the evaporatively-cooled window on a typical office space subjected to such driving weather conditions was found to save 8.8% of the space total annual energy demand. During the summer, the performance of the system was enhanced by saving 11.3% of the space total daily heat gain. However, the benefits of the system diminished and were sometimes unfavorable during the winter due to its limited cooling performance caused by high humidity. ? 2018 Elsevier Ltd The authors would like to thank consultant engineer Mr. Armin Baeumler and his team from SAPA company for their efforts during the installation and commissioning of the meteorological site at Qatar University. Also, the financial and in-kind support of Qatar University is greatly acknowledged. Scopus

The purpose of this study is to measure airtightness of building components in newly constructed apartment buildings in South Korea. For the measurements, electrical, architectural and two mechanical components regarding water and air systems were categorized and air leakage rates of these parts were measured by the blower door test. In addition to these building components, air leakage rates on the entrance door and three different building heights were analyzed. Moreover, the results obtained by the blower door test were compared with the tracer gas measurements. As a result, the air leakage rates (ACH50) were between 0.7 and 1.0 h−1, when all parts were sealed. When unsealing all parts, the ACH50 values ranged from 1.6 to 2.7 h−1. In addition, the ACH50 values were highly influenced by the entrance door and window systems. By improving the windows and the entrance door, the air leakages can be significantly reduced in residential buildings. Furthermore, the comparison results obtained by the tracer gas and blower door showed that artificially produced pressure difference condition can cause the overestimated ACH value.

In view of global warming and following fossil energy consumption caused by the using of heavy-loaded air conditioners, smart windows, which can intelligently regulate solar radiation, became a highly anticipated strategy to slow down the pressure. As most of the traditional hydrogel-based smart windows abruptly switch between transparent and opaque making a sudden change in temperature and light, we established a poly-N-isopropylacrylamide (PNIPAM) thermo-responsive hydrogel system with additional cross-linking of chitosan and Al3+, which exhibited a smooth thermo-response during heating and a novel recovery hysteresis during cooling. By enabling additional gentle transition in translucency, we are able to retain a comfortable indoor temperature/lightness balance during an increase in outdoor temperature, in avoidance of sudden indoor darkness at elevated temperature. By enabling additional control in the thermo-response hysteresis, this methodology provides a solution to continuously shield the dazzling afternoon sunshine until a comfortable outdoor temperature is reached. And the response degree and response temperature can be adjusted by the contents of chitosan and Al3+, respectively, so that the material can be customized personally. Moreover, we discovered that the hydrogel-based smart window system constructed by this methodology bears notably enhanced strength, toughness and conductivity, making it a comprehensively promising candidate for customizable smart windows.

We describe the development of an interactive car window system designed to support passengers in engaging with the external environment during a journey. Through advances in embedded digital technologies, cars increasingly have a potential to become interactive spaces, in which passengers will find it possible to interact with the external environment through in-car interfaces. However the utility and benefit of such interactive systems for passengers has not been well studied. There is a need therefore, to study the design and use of these technologies, as they are emerging. We thus investigated how digital technology might support passengers' interactions with the external environment. Through a focus group (n=6) and interviews (n=5) we investigated passengers' attitudes towards, and practices during, ordinary car journeys. From this scoping study we formulated five design considerations for designing/implementing a prototype interactive car-window system. This system was then evaluated through an in-lab user study (n=8). Qualitative thematic analysis of interviews during the user study suggested a variety of orientations towards ‘passengering’, the act of being a passenger, on a journey. Herein we critically examine the role of our interactive technology in supporting desired experiences of ‘active passengering’.

Oversized window systems with extreme heights are becoming increasingly popular at European and global market. Such sizes can cause problems of bending of wooden elements which results in the decrease of main window properties and structural integrity. Double casement wooden windows of the 2 m height, with and without reinforcement, were tested at the pressure load of 2000 Pa in order to define its behaviour and develop numerical simulation. Numerical models were defined as an assembly of individual wooden elements with mutual contact, orthotropic behaviour, simulated dowels constrain and insulated triple glass unit. Simulations have provided insight in to mutual behaviour of all individual elements and have proven that contact between window and the wall represents weak point rather than the integrity of the wooden frame elements as initially assumed. During the next phase special reinforcements used to restrain moments at the contact points were tested both numerically and psychically.

Fenestrations allow for natural daylight and outdoor views, but also represent the least thermally efficient portion of the building envelope, and thus can be a source of unwanted direct sunlight and associated discomfort glare. A well-designed fenestration system operated with proper control strategies is capable of reducing building energy usage significantly while maintaining a both thermally and visually comfortable environment for occupants. This paper reviews and analyzes window design studies for high-performance buildings, which could be interpreted as decision-making processes to achieve the window performance goals by controlling a series of design variables (e.g., location and dimensions of windows, glazing type, etc.). An overview of available design options for window systems to date is introduced first, and then the decision-making methodologies of window systems are categorized and analyzed to present a comprehensive review, where we present a detailed analysis of sequential knowledge-based design methods and simulation-based optimization methods. Last, potential challenges and future research trends are identified and analyzed to help promote all automatic simulation-based optimization design methods for high performance fenestration systems.

Purpose: According to the 4th industrial revolution, interest in artificial intelligence is increasing in the field of architecture. However, there are few studies that applied artificial intelligence in the field of architecture. Therefore, this study compares and analyzes the artificial intelligence researches in domestic and overseas architectural and window areas in depth and grasps the technology applicable to window ventilation systems based on artificial intelligence. Method: A total of 456 papers were searched by using domestic and foreign scholarly search engines with kewords;`Artificial Intelligence`, `Artificial Neural Network`,`Machine Learning`, `Support Vector Machine`, `Genetic Algorithm`, `Building`, `Architecture`, `Window Ventilation System`, `Smart Window`, `Smart Ventilation`. Result: Research using artificial intelligence in the field of architecture has been steadily increasing. Among them, there are 266 studies(58.3%) in the field of building environmental facilities. In addition, 312 cases of window system research were investigated, and 115 cases of ventilation related research were 36.9%. The results of this study will be used as basic data for the development of window ventilation system based on artificial intelligence.

Simplified metrics (U-value, g-value) are often used to energy use for space heating and cooling when conventional windows are adopted, but they are not fully capable of describing the thermophysical behaviour of more advanced windows. In this paper the impact of these metrics on the estimation of the energy use for space heating and cooling in case of a double skin façade is evaluate. The results of the investigation for one climate show that, even if the inaccuracy for a double skin façade is higher than for a conventional window, the inaccuracy is still acceptable in the preliminary design phase. © 2017 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

The article considers issues of the prospective development of the «single window system» in the foreign arena of the Kyrgyz Republic. The main directions and methods to improve the system and tentative implementation results are considered. The successful implementation of this system will expand the scope of foreign trade of the Kyrgyz Republic, which is the current task of an adaptation in the Eurasian Economic Union, as well as interaction with the «Silk Road Economic Belt» project.

This paper aims to derive the operational modes of a parallel double-window system that reduces cooling energy consumption and satisfies indoor comfort through natural ventilation. The parallel double-window system examined in this paper is a window system that could control indoor draft distribution and adjust the size of the opening depending on indoor and outdoor conditions. The system can be used in five ways (all close, out-open + in close, out-open+in open (tilt), out-open+in open (turn) and all open). This work verified the energy savings and indoor comfort of the existing mode experimentally, which were originally derived based on simple calculations at the time when the parallel double-window system was developed. A new operation mode, Alt 1, was derived, which addressed problems of the existing mode. In addition, in this work, the operation mode Alt 2 was derived, which simplified Alt 1 so that the actual occupant can use the system easily. By measuring these three operation modes and comparing the results with those of energy plus simulations, the work derived the amount of cooling energy savings and the level of indoor comfort through the use of an appropriate operation mode during inter-seasonal periods. Compared to when the natural ventilation operation mode was not used, cooling energy consumption was reduced by 60% when the operation mode was in use. The cooling temperature set point could have a significant impact on cooling energy consumption.

Directing against the energy consumption analysis and energy saving reconstruction of new wall of prefabricated single building in heating season, proposing a new type of assembled building structure system, with emphasis on new wall and concrete wall, taking the engineering construction of prefabricated single building in Chongqing as an example, the difference of energy consumption between the new wall of prefabricated single building and concrete wall have been compared and analyzed based on the simulation software DeST developed by Tsinghua University. The experiment result shows that the annual energy consumption of new wall in prefabricated single building model is lower than that of the concrete model compared with ordinary aluminum alloy single glass windows and energy-saving Windows. What’s more, the energy-saving rate of new wall can reach 29%, which equals 7500kwh of power or 923kg of standard coal. The average room temperature of prefabricated single building can reach 13.51°C compared with concrete model which average room temperature is 11.96°C. The difference of dynamic temperature between the two models can reach 2°C–4°C. Furthermore, the thermal load of the new wall model of the prefabricated single building is about 33.18 W/m2, the concrete model is about 63.1 W/m2. After the energy-saving reconstruction, the energy consumption of ordinary window system is 1200kwh/m2, the inert gas-plated low-e membrane hollow window system of that is 900kwh/m2 and the saving energy rate is about 25%.

В статье дается обзор системы оказания государственных и муниципальных услуг в многофункциональных центрах, основной целью которой является упрощение получения справок и разрешительных документов населением по типу «единого окна».

The embodied impacts of window materials can be considered as hidden impacts. However, as buildings have become more energy efficient, the impacts of the windows are recognized as being increasingly significant and have not been thoroughly analyzed. Thus, comprehensive analysis should be performed to inform the wise selection of energy-efficient windows with lower embodied impacts. This article proposes an approach based on embodied impact assessment and Pareto optimal frontier to support environmentally friendly design of windows. A comprehensive assessment of the embodied environmental impacts of a standard size window was implemented for 32 alternative systems, considering four framing materials (aluminum, fiberglass, polyvinyl chloride, wood) and eight glazing solutions (for single-, double, tripled-glazed). Environmental impacts were calculated for non-renewable primary energy, global warming, acidification, eutrophication, and ozone layer depletion. Pareto optimal frontiers were identified, showing the trade-offs between environmental impacts and thermal transmittance (U-value). The components of the two main parts of a window (frame and glass) have been characterized to identify those that contribute most to the total embodied impacts. The results show that tempered or laminated glass and the glass coating (low-E film) increase the embodied impacts of glazing solutions. Of the framing materials, wood has the lowest embodied impacts in all categories, while aluminum has the highest impacts for the double and triple-glazed solutions. The breakdown of the embodied impacts of aluminum-framed window systems shows that the frame has higher impacts than the glazing, as it accounts for 60–80% of total embodied impacts. In the windows with polyvinyl chloride (PVC) and fiberglass frames, the frame is responsible for most of the embodied impacts for single-glazed windows (58–86%) and almost the same proportion for double-glazed windows (46–54%), but lower for triple-glazed (22–40%). The contribution of a wood frame (

This paper presents results of a study investigating ventilation mode, solar heat gain and daylight performance via vertical fenestration of a common school building in Portugal. In recent years, there has been a growing awareness in energy-efficient building design and operation of the building stock. The windows are usually the first component to be replaced by new and more efficient ones. Dynamic envelope/window systems may optimize the performance of the building when taking into account airing, solar heat gain rejection/acceptance and daylight admission. Higher thermal resistance glazing implies a reduction of solar transmittance. A typical school building located in Covilha, Portugal was used for the study. Three different conventional windows were used for comparison: a single pane as found in the building, a double-pane to increase the thermal resistance and a double-pane with daylighting controls. Different simulation tools were used during this study. To be comparable with other studies,...

This paper presents an approach proposed for assessing economic performance of retrofit applications performed at functional building element level in residential buildings and exemplifies it for the city of Istanbul, which has a temperate-humid climate. This approach covers three steps. In the first step, typical buildings and their properties are determined by analysing the residential buildings in Istanbul, and then the retrofit alternatives are generated. In the second step, an economic impact analysis is performed for typical buildings by considering the costs during their life cycle phases. In the third step, a life cycle cost assessment is done according to the variables, which are defined as window-to-wall ratio (WWR), window system, thermal insulation material, orientation and building age. The most beneficial retrofits are lastly determined depending on their economic performance ratios (EPRs). In conclusion, insulating exterior wall, projected floors, floors above unheated space and roof floors separately provide the highest benefits at the age of 30, and the lowest benefits occur at the age of 15 for all WWRs. The highest EPRs are obtained for the WWR of 10% at all ages. The renewal with PVC frame provides benefit while the renewal with wooden frame causes losses. Orientation slightly affects the EPRs. The use of stone wool in the retrofit causes a reduction in the EPRs due to high investment cost of stone wool. When the 20-year-old building which has the WWR of 10% is insulated with extruded polystyrene and renewed with PVC, it provides the highest benefit of about 45%.

This study evaluated the energy performance of an a-Si semi-transparent PV insulating glass unit (IGU) via numerical simulation and experimental tests. Combined with the measured optical and electrical characteristics of the PV laminate, an integrated model was developed to simulate the overall energy performance of the PV IGU in EnergyPlus. Outdoor experiments were conducted to validate the accuracy of the simulation model. The proper consistency between the simulation results and the experimental data indicated that the simulation model was reliable for predicting the overall energy performance of PV IGU. With the validated model, a sensitivity analysis was conducted to investigate the influences of air gap depth and rear side glass, and an optimal design scheme was proposed to maximize the energy efficiency of PV IGU in Hong Kong. Finally, the energy saving potential of the optimized PV IGU compared to the other commonly used window systems was evaluated. It was found that the energy saving potential of the optimized PV IGU was 25.3% and 10.7%, respectively, compared to the single clear glass window and the Low-E glass window. The methodology developed in this study is expected to provide a useful reference for simulating the energy performance of PV IGU.

Windows are thermally weak compared with external walls and roofs, and have a large effect on the indoor thermal and light environments, and the energy used for lighting and for heating, ventilation, and air-conditioning. Furthermore, it is important that the window system and blinds could be controlled appropriately according to the wishes of the occupants to ensure satisfactory thermal and light environment, and acceptable views from the windows. This paper reports the basic concepts and the advanced technologies and mechanisms of the windows for controlling heat and light, and their effects based on specific examples.

Korea has set a goal of reducing greenhouse gas emissions (GHGEs) to levels 37% below the “business as usual (BAU)” level by 2030, and the building sector, in particular, aims to reduce GHGEs by 45,000,000-ton CO2-eq by 2020. In order to reach this goal, it is crucial to reduce GHGEs that result from energy consumption in apartment buildings, which account for approximately 65% of all buildings in the capital region where the population is concentrated. Moreover, as apartment buildings not only have high window-to wall area ratios, but also use insulating glazing (IG) with low thermal performance, an advanced window system with low heat transmittance (U-value), such as a concrete structure, is necessary for effective GHGE reduction. Therefore, this study aims to evaluate the GHGE reduction effects from replacing existing IG vacuum insulating glazing (VIG) with low U-values in the apartment housing located in the capital region. The analysis revealed the possibility of a GHGE reduction by 45%–79% with the application of commercial VIG with U-values of 0.7 W/m2·K in lieu of the existing IG with U-values ranging from 1.2 to 3.3 W/m2·K for all apartment buildings located in the capital region. Furthermore, GHGEs could be reduced by 82%–93% by replacing the existing IG with VIG with U-values of 0.2 W/m2·K.

The air-bubble sheet has been widely used to wrap fragile products for long-distance transportation. The further usage of the air-bubble sheet as a thermal-insulation material for the reduction of the thermal conductivities of windowsystems has occurred because of its low price, in addition to its thermal-conductivity properties. In this study, the thermalperformances of a variety of commercial air-bubble sheets according to various applications were evaluated. The experimentswere performed with single-glazed and double-glazed windows and three types of air-bubble sheets of different air volumes.U-values are used and were calculated for the determination of the thermal performances that are based on the KS F 2278.The maximum decrease of the U-value was measured as 1.092 when a sheet was attached onto the frame of single-glazed window. The square-like air-bubble sheet that contains the largest air volume shows the highest thermal-resistance value.Double layers of the air-bubble sheets show better performances than those of the single layers on both sides of the windows.

In this study, the effects of lock operations on the infiltration rates for the two window types sliding and lift sliding(LS) are investigated through experiment and simulation. The airtightness levels of the two window types-with locks bothon and off-were measured according to the KS F 2292 Test method of airtightness that is used for windows and doors.The air-flow rates of both window types with the locks on for a pressure differential of 10 Pa are 1.98 ㎥ /( ㎡ h) and 1.68 ㎥ /( ㎡ h), respectively; with the locks off, the air-flow rates of the sliding and LS windows are 2.64 ㎥ /( ㎡ h) and 5.83 ㎥ /( ㎡ h), respectively, whereby the air-flow rates are 33% higher for sliding and 247% higher for LS. The air change per hour (ACH) was calculated using the ventilation-simulation software CONTAM. For the sliding window, the ACH changedfrom 0.45 to 0.57 when the lock was operated from on to off, representing an increase of 27%. For the LS window, theACH changed from 0.29 to 0.81, showing an increase of 179%.

Through a mock-up test the surface temperature distribution and condensation characteristics were analyzed for a vacuum insulated glass (VIG) window, manufactured through an in-vacuum method, and c...