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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 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.

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.

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.

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 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 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.

Among currently available window systems, aerogel granulate glazing systems are considered promising for achieving good thermal and visual comfort in buildings. In aerogel granulate glazing systems, it is important to evaluate how convection in the granular-filled cavity affects their thermal performance because double glazing systems, which have a similar structure, show variable thermal properties related to the convection effect. In this study, it is shown that the granular-filled cavity hardly influences the air permeance, and therefore, convection can occur in such cavities. Nevertheless, a mock-up of commercially available aerogel granulate window shows practically identical window U-values in hot box measurement with various tilt angles. In other words, convection in the granular cavity does not affect the thermal performance of aerogel granulate glazing systems. The center-of-glass U-values are 0.28 and 0.69 W/(m2 K) for aerogel thickness of 60 and 30 mm, respectively. The total window U-values (using a wood frame) are 0.69 and 0.84 W/(m2 K) for aerogel thickness of 60 and 30 mm, respectively. Furthermore, the granular aerogel in the cavity subsided by ∼3% of its total volume after the hot box measurement. The risks posed by this subsidence under actual conditions should be assessed in later research.

Hospital buildings produce high amounts of emissions and waste. Strategies are needed to reduce their impacts while still providing quality care for patients. As patient rooms occupy the largest space of hospital buildings and windows play a major role in both energy loads and quality of the indoor environment, analysing their role on the environmental performance is seen essential. The goal of our study is to determine window systems which have the highest potential to improve the environmental footprint of hospitals. This paper presents a life cycle assessment (LCA) study of several advanced window systems for patient rooms in Belgium using the MMG+_KULeuven tool. The influence of several components, including glazing, coatings, window frame material and window-to-wall ratio (WWR), on the life cycle environmental impacts are discussed. This study also presents an example of how an integrated energy and environmental analysis can inform architects in the early design stage. ispartof: pages:166-171 ispartof: Procedia CIRP vol:69 pages:166-171 ispartof: CIRP Life Cycle Engineering (LCE) Conference location:Copenhagen, Denmark date:30 Apr - 2 May 2018 status: Published online

This study assessed the applicability of semi-transparent photovoltaics (PVs) that can both produce electricity and transmit light in the window system of a building. The potential of window-integrated semi-transparent photovoltaics (WISPVs) in the current global climate was evaluated by varying the window performance and the conversion efficiency of dye-sensitized solar cells (DSSCs). The feasibility of WISPVs was examined quantitatively based on the standard building envelope properties from the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) and the reported DSSC conversion efficiency. The following seven cities, which are representative of what can typically be found in various climate zones, were selected for the building energy simulation: Miami (Zone 1), Sao Paulo (Zone 2), Sydney (Zone 3), New York (Zone 4), Seoul (Zone 4), Berlin (Zone 5), and Moscow (Zone 6). According to the simulation results from the ESP-r program, the WISPVs were more effective in Zone 4, but less effective in Zones 5 and 6.

This paper explains a method developed to assess environmental performance achieved by rehabilitation of residential buildings in Turkey. Several measures focussing on a reduction in the heating demand were investigated such as replacement of window and insulation of different elements of building skin. The influence of several building characteristics was moreover examined such as window to wall ratio (WWR), orientation and building age. Another important aspect which affects environmental performance is climate. In the context of this method, rehabilitations were proposed for temperate-humid climates like Istanbul. According to the assessment results, an environmental performance is obtained for all proposed rehabilitations. When proposed rehabilitations are analysed separately, the environmental performance ratios resulting from the rehabilitations of exterior walls and projected floors, roof, window system, and floors above unheated spaces reduce respectively. WWR has the highest effect on the environmental performance ratios obtained by rehabilitations. The effects of building age and orientation are in negligible amounts when compared to that of WWR. In the future, these assessments should be carried out for different climatic regions of Turkey as well. This method can be used to assess existing and new buildings in terms of environmental impacts by architects, contractors, building owners or municipal authorities. (C) 2013 Elsevier Ltd. All rights reserved.

Windows are one of the most important components of the building envelope from which several high level performance requirements are expected. Some of these performances are contradictory with each other which increase the importance of the design and material selection of windows. Natural lighting and thermal performance are examples for the contradictions in window design. Usually when transparency is increased in windows the thermal conductivity of the system is also increasing which decrease the overall thermal performance of the window. Shutters are the components of a window which is mainly used to control the natural lighting through a window system. Another important benefit from the shutters may be its contribution to overall thermal performance of the window systems. As a Mediterranean country several types of traditional window shutters have evolved in Turkey. Istanbul is the historical and economical capital city of Turkey and wooden vertical pivoted shutters are the most common type of shutters in the traditional wooden Istanbul houses. There is also a growing trend in the usage of vertical PU filled aluminium roller shutters in these kinds of houses. Two houses using each other type of shutters are examined in 2012 for determining the most efficient type of shutters in terms of energy usage. An inventory analysis is introduced, a comparative assessment of embodied and operational CO 2 emissions on the two case houses’ windows is realized and the results are presented in this paper.

Many Korean apartment units use balconies as semi-indoor spaces by installing external windows. These balconies form environmental buffer spaces to improve comfort and reduce cooling and heating costs. However, the balcony spaces of some units have been removed and have been placed in living rooms. The removal of these environmental buffer spaces has caused problems. Significant heat loss through windows is one of the most serious problems; window surface condensation caused by low surface temperatures in the winter makes residents uncomfortable and damages construction materials. Therefore, it is evident that window design requires improvements. This study introduces a double window system with improved thermal performance and ventilation slits to solve the window surface condensation problem in apartment units without balconies. To verify the thermal performance of the proposed system, temperature factors were analyzed by field measurements. The condensation frequencies were also evaluated by temperature factors at an indoor temperature of 25 °C and 55% humidity. Ultimately, the double window system was able to reduce condensation frequency greatly. An examination of the air volume by ventilation slit operational mode found that the case with an open outer window bottom vent and an inner window top ventilation slit, discharged the indoor vapor effectively and increased the dew point of the window's surface.

The indoor thermal quality is one of the main study topics in the sustainable building field. The HCRI-BIPV smart window was developed to be used in the indoor environmental control on building living quality. This paper describes the 0.75 kWp capacity of grid-connected system by photovoltaic energy, which was controlled by indoor thermal environment. The monitoring research scale is the office time, whose data is recorded between 08:00 am to 17:00 pm. When the indoor temperature was arrived 26 °C or higher, the windows would be opened to cool down by the fresh air, which made the indoor temperature less than 10 °C and more. The accumulative power performance of the smart window system has 130.01 wKh of the in six months research. For consideration of each evaluated factors, the HCRI-BIPV smart window not only offer the passive energy situation for its power loading but also improve the indoor thermal environment by natural ventilation. The research presented an intensely interesting data for Taiwan BIPV smart window development between the BIPV application and building energy design.

This paper aims to characterize the thermal performance of a window system that consists in doubling an existing window, converting it into a ventilated double window. The air coming from the outside circulates upwards through the channel between windows and enters the building through a vent on the top of the window's case. A series of experimental measurements was conducted in a test cell exposed to real outdoor weather conditions located in a mountain region at Centre of Portugal, during heating season in order to determine how this window system can act as a heat exchanger. It was found that such window system act as an efficient heat exchanger using transmission heat losses and solar radiation to preheat ventilation air, thus reducing the building's operational energy costs. An average of about 19 m 3 /h of air flow rate was found with an air temperature increment within the air gap of about 6 °C, during night-time, for an indoor/outdoor temperature difference of about 16 °C. Air temperature increment reached up to 12 °C using a plastic shutter. With solar radiation, the average of that increment was about 10 °C. This is a simple and cheap building technology which can be implemented both in new and existing buildings.

This paper reports an experimental and simulation study on application of automated Venetian blind for daylighting in tropical climate. A horizontal blind system operating automatically under programmed control was constructed and integrated onto the glazed windows to form a window system with an automated blind in a room of a laboratory building. A dimming controller was also integrated to the lighting system of the room. Different operation schemes of the window system were devised and tested in the attempt to maximize energy savings while maintaining the quality of the visual environment in the room. Intensive measurement of illuminance of the interior space was undertaken during the experiments. A methodology for calculation of interior daylight illuminance and associated glare corresponding to the configurations of the experiments was adopted. The method was coded into a computer program. Results of calculation from the program agree well with those from experiments for all the schemes of operation conducted. The program was used to simulate the situation when each scheme of operation was implemented for a whole year. It was found that such window system with automated blind enabled energy savings of 80%, but a more sophisticated scheme also helped maintain the interior visual quality at high level.

The development of vacuum glazing is a significant advance in the area of low heat loss glazing systems with great potential to reduce building heating and when combined with solar control glazing, cooling loads. The basic concept of vacuum glazing is reviewed and the procedures and research undertaken in the development of both high-temperature and low-temperature sealing of vacuum glazing are outlined. The achieved thermal performance of current laboratory systems and those that are now commercially available are presented. The potential levels of performance that may be achieved using high-performance low-emittance (low-e) coatings and tempered glass are reported. Research into window systems that incorporate vacuum glazing to achieve improved thermal performance is also outlined.

Aluminum spacer used to keep the glass panes apart acts as a thermal bridge that increases the risk of inside surface condensation due to its high thermal conductivity. In this study, the inside surface condensation in double glazing window systems with conventional aluminum spacer and insulation spacers made of thermally broken aluminum and thick-walled plastic, respectively, is evaluated. Evaluation method and judgment criteria for preventing inside surface condensation are suggested. Thermal characteristics of window system in residential unit are analyzed and two-dimensional steady state heat transfer simulation is carried out in order to obtain the lowest inside surface temperature. The results show that the application of insulation spacer can substantially increase the lowest inside surface temperature, temperature difference ratio and inside air humidity for preventing inside surface condensation and satisfy the required minimum temperature difference ratio.

The paper examines the feasibility of using transparent micro-perforated absorbers (MPA) in a window system to allow noise attenuation whilst at the same time maintaining high levels of comfort ventilation and daylighting. The underlying theory for micro-perforated panels and membranes and the application in silencers is presented. Experiments have been performed between a semi-anechoic and a reverberant chamber using a standard window mock-up, and the effectiveness of MPA has been demonstrated. With a constant air backing, MPA are more effective with a wider ventilation path. With an air flow of up to 2 m/s the performance of the MPA remains unchanged. Current results are based on readily available materials and relatively simple configurations, but the theoretical analysis suggests possibilities for increasing the noise reduction and widening the frequency range by using more strategically designed materials and configurations.

This paper is concerned with minimizing thermal bridging through typical window systems in buildings of hot regions. The present approach is based on an integrated 3D dynamic simulation. The theoretical background of the adopted approach is presented. The reliability of this approach in evaluating thermal bridges as well as its applicability to different geometric shapes is proved. It is found that the thermal bridging through typical window systems is significant and should be taken into account in buildings design. Applicable construction for window systems are proposed to minimize thermal bridging in the buildings of hot regions.

Heating and cooling energy calculations and building energy simulations need the overall heat-transfer coefficient (U-factor) of windows. This study focuses on the U-factor of a window with a cloth curtain indoors. Two side-by-side hot boxes are built in a laboratory for testing the window U-factors. The tested window systems are 100% glass area without frames which are equivalent to the center of glass of practical windows. The two types of tested window systems are the single glazing and the double glazing with a cloth curtain, respectively. The effect of curtain edge sealing conditions on U-factors is also studied. The empirical equations of the center-of-glass U-factors are derived from the experimental data. The corrections for the effects of window frames and outdoor wind velocity are made thereafter. The corrected empirical equations can be easily used to estimate the U-factor of a practical window with a cloth curtain.

The study focuses on the heat transfer coefficient (U-factor) of a window with a long-wave high-reflectivity venetian blind (LWHRVB). Two side-by-side hot boxes are built in a room for testing the window U-factors. The tested window systems are 100% glass area without frames, which are equivalent to the center-of-glass of common windows. The slat of venetian blinds is made of plastic with aluminum film glued on each side, and the long-wave reflectivity is 0.93. The two types of window systems tested are the single glazing and the double glazing with the LWHRVB, respectively. The effect of slat slope-angles of venetian blinds on U-factors is also studied. The empirical equations of the center-of-glass U-factors are derived from the experimental data. The corrections for effects of window frames and outdoor wind velocity are made thereafter. The corrected empirical equations can be easily used to estimate the U-factor of the practical window with the LWHRVB.

In the present article an interactive simulation program illustrating grain boundary and fracture phenomena in solids is described. The dynamical behaviour of a two-dimensional Lennard-Jones model system under stress, with either a grain boundary or an initial crack, is simulated through a molecular dynamics algorithm. All parameters defining the system and the dynamical load are set through a graphical user interface. A run-time representation of the system is displayed on a graphics window, which has been endowed with magnification and other visualization aid tools. The program runs on a UNIX-X11 Window System platform. The graphical part relies on the MOTIF library. The program has been devised for illustrative purposes. It displays the main elements of an interactive simulation and may be regarded as giving an illustration of the concept of interactivity. Due to the power of run-time animations in conveying ideas and concepts, it may prove to be useful, as well, as an instructional tool.

Electrochromic (EC) glazings for architectural window systems must have desirable solar control properties, be designed for high-volume manufacture, and exhibit outstanding durability. This paper discusses performance and both real time and accelerated testing of prototype monolithic lithium-ion EC glazings in insulating glass units (IGUs). Outdoor exposure at New Jersey and Arizona (desert) test sites shows good switching performance under the different solar irradiance conditions. Accelerated test results include room temperature and elevated temperature electrochemical cycling, electrochemical cycling in combination with photo/thermal cycling, and temperature/humidity testing of IGUs.

Application sharing enables users to share a program running on one computer with other people in a group work such as desktop conferencing. In this paper we propose an application sharing method using window capturing to share applications under MS-Windows with Win 3.1/95/NT and X window system and evaluate the performance of the prototype system. To overcome the system performance degradation as a function of the number of participants, we propose an efficient retransmission strategy to minimize end-to-end delay. With the use of the window capturing method, the prototype system allows any MS-Windows application to be shared regardless of not only the window systems but also the version-up of window systems.

A numerical calculation procedure for an air flow window (AFW) system integrated with a roll screen is presented. Both heat and air flows within the window elements such as the outside pane of glass, the outside air space, a venetian blind, the inside air space and a roll screen, are taken into account by considering the thermal and air flow networks. Agreements between measured and calculated results of temperatures and pressure differences through a series of experiments carried out in an environmental test chamber were observed. To identify the quantitative characteristics of an AFW integrated with a roll screen, a series of numerical simulations were performed with the results from using a large resistance to the air flow from the upper half area of the roll screen. These show that this was effective in terms of thermal characteristics and suggest that a tightly-meshed roll screen, situtated in the upper half area, is suitable for both environmental and design reasons. If the heated air flow generated from the inside air space to the room were dispersed properly, the thermal efficiency of the AFW integrated with a roll screen would be equal to a conventional AFW system. The effect of a cold draft passing though the roll screen is also discussed.

The effect of slat angle and absorptance on the heating and cooling loads of buildings in Seoul (South Korea) has been studied. An analytical model of a window system with venetian blinds is developed and validated with published experimental data. The validated model has been successfully incorporated into the TRNSYS computer program. Hour-by-hour heating/cooling loads of a typical building, with and without venetian blinds, are compared. Results show that the use of windows with venetian blinds can reduce the building heating load by about 5% and cooling loads by as much as 30%.

Plasma heating in nuclear fusion reactors by feed of millimeter waves from gyrotrons calls for effective and reliable high-vacuum-tight window systems with preferably 1 MW power transmission as a major prerequisite. Experiments were performed in which the functionality of the chosen concept was proved and the design calculations were verified.

The new class of transparent insulation materials is classified and characterisation methods are summarised. An overview on available materials and a comparison of these new materials with conventional glazing systems is given. The high potential of these materials in collector systems is briefly discussed. In the final section an overview on new optical switching materials is given, which may help to achieve economically interesting system costs.

This article presents an operational and thermal performance study on automated venetian blind window systems. They are systems with pivoted louvers installed horizontally, sealed hermetically between two glass panes and controlled automatically following the thermal needs. The experimental studies were carried out in two identical test cells (2.43 m high, 1.48 m wide, and 1.92 m deep) used as variable temperature calorimeters. One was equipped with an automated window system and the other double glass window without louvers. Various parameters were measured and recorded: louver angle, inside and outside air temperatures, cloud cover. The operational and thermal performances of the automated louver system have been demonstrated and compared with that of the ordinary system.

This paper deals with the problem of allowing a participant to dynamically join and leave a computer-based conference that is already in progress. A conference is a synchronous collaboration session where participants at remote locations are cooperating through identical copies of windows generated by applications shared by all conference participants. In this paper, an efficient solution to the problem of accommodating a latecomer is found by recording the modifications to the window system's state implied in the series of commands generated by the applications, and later imposing these state modifications on a latecomer's window system.

This paper is concerned with development of a user-friendly design-independent CAD window system using object-oriented paradigm and the recently introduced HP X widget environment. The HP X widget system provides a number of useful object-oriented data structures, called widgetclasses, which are created by X toolkit intrinsics. The data structure of the CAD window system is described by a hierarchical tree of widgetclasses and creating three groups of functions: C void functions, callback functions, and widget functions. The system can be easily linked to any CAD package.

Glazing materials with variable optical properties (switchable glazings) offer the ultimate in control over the light and energy entering a building. Products of this kind are in their initial stages of development, and guidelines that relate window energy performance to glazing material properties are needed. Though the use of computer program for calculating window thermal and optical performance parameters, we evaluated (1) the relative performances of three switchable glazings prototypes with differing solar transmittance spectra; (2) the differences between glazings that switch from transmitting to reflecting and those that switch from transmitting to absorbing; and (3) the effects of positioning the switchable glazing in a window. We focused on design conditions for cooling-dominated buildings, since switchable glazings are expected to reduce cooling and lighting loads. We conclude that the differences in thermal performance between absorbing and reflecting switchable glazinhgs can be eliminated through proper placement of the glazing in a window system and through the use of other spectrally selective glazings.

In view of the potential of aerogels for use in double-glazed window systems, sound transmission loss (STL) of aerogel-based glazing systems has been theoretically computed using the wave impedance approach and the results compared with corresponding values for conventional glazing. The results show a significant change in the double-leaf resonance frequencies caused by the aerogel layers and suggest that by selecting suitable material properties, aerogel glazing systems can be made acoustically superior to equivalent conventional glazing in a chosen frequency rage. The STL values for the glazing systems with aerogel of the highest density studied (285 kg/m3) were found to be significantly better than those of air-based glazing systems.

An environment for prototyping distributed applications is described that supports different communication primitives with specified delays, and provides primitives to aid debugging and evaluation. The environment also supports heterogeneous computation in which processes can execute on different hardware. Different source languages can be used for coding different modules of the processes. The system has a centralized control and monitoring facility which is based on the Suntools window system. This approach allows users to develop distributed applications using existing languages and packages, as opposed to restricting users to using only specialized specification languages, and extends the type of work done by R. Hayes et al. (1988) by providing primitives to assist in profiling and instrumenting the applications. >

This study presents an experimental study on full-size automated venetian blind window systems consisting of horizontal pivoted louvers installed and hermetically sealed between two glass panes. The experimental study was carried out using a test cell of 2.43 m high, 1.48 m wide, and 1.92 m deep. Various parameters were measured instantaneously and recorded using a data acquisition system: interior and exterior air temperatures; various surface temperatures; and total and direct solar radiations. A linearized numerical model was used to verify the experimental results.

Business TRON specifications define a workstation environment supporting interchange of high-level data, a graphical interface and a window system. This paper describes a prototype OS based on the BTRON specifications. An Integrated data model, the real object/virtual object model, is central to the design.

A low cost, highly insulated window system, which can be fabricated with easily available materials, is described. The system can be installed by adding an i.r. transmitting sheet and a reflecting layer to an existing window. The reflecting layer may be in the form of a shade, Venetian blinds, or a curtain. The thermal resistance ( R ) values of several variations of the system are computed and tests are described which verify that the system works as predicted by theory.

The optical properties of metal coated glass substrates have been investigated. Thin films of various thicknessesof the noble metals: Cu, Ag, Au, the transition metals: Cr, Fe, Co, Ni and the free electron-like metal Al were thermally evaporated onto glass substrates. The front and backside reflectance and the transmittance between 0.35 and 15 μ m were measured. The obtained data were used to calculate the integrated values of solar reflection and transmission as a function of metal film thickness. The application of metal films on domestic windows as sun-screens and heat-mirrors are discussed. It is concluded that Cu is the best coating in a window system if good heat insulating properties are desired. This is due to its ability to remain continuous at very thin film thicknesses. An infra-red reflectance of 86 per cent combined with a solar transmittance of 55 per cent was obtained for a 70film. For solar heat-protection Au-films are found to be superior owing to their transmittance peak in the middle of the visible wavelength region. The transition metals are less selective than the noble metals, but due to their flat response-curves in the visible range they cause a smaller change in colour of the transmitted and reflected light.

The performance of a single family residential solar house with three different window systems is presented. Of these three systems, two are window sunspace systems that operate as a heating component in winter and as a solar chimney for summer ventilation. The first window sunspace system is a small, local one and operates like a Trombe wall. However, contrary to a Trombe wall, the system presented here allows the penetration of daylight like any window. This window system can easily be used in small apartment buildings, where extra area for full-scale sunspace is not available. The second window sunspace system is a large central one and is designed between two tilted roofs. The heat collected by this sunspace is driven down into the living area by forced convection. The central window sunspace system collects sufficient amount of energy to heat the floor, which is shaded by the neighbouring building to its south. Such a situation is frequently encountered in low-rise high density areas. The realized solution can generally be applied to such areas. Evaluation of the expected performance of the building was carried out during the design process by means of a detailed simulation model. Comparisons between actual measurements during the first year occupancy and the simulation model are presented.

This paper presents an experimental study on automated venetian blind window systems which consist of horizontal pivoted louvers installed and hermetically sealed between two glass panes. The experimental studies were carried out using a variable temperature calorimeter (0.64 m high, 0.67 m wide and 0.61 m deep) and a test cell (2.43 m high, 1.48 m wide and 1.92 m deep). Various parameters were measured instantaneously and recorded using a data acquisition system: inside and outside air temperatures, various surface temperatures and total and direct solar radiation. A linearized numerical model was used to evaluate the thermal resistance, the solar heat gain, and the shading coefficients of the window systems.

Strontium-90 in seawater samples was analyzed aboard the USS Knorr by direct extraction of the 90 Y daughter. The extraction was made in two 17-gallon heavy-walled glass bottles. Yttrium carrier was added and the 90 Y was extracted with HDEHP in toluene, back-extracted with HCl, and purified with a second HDEHP extraction. The Y was mounted as the oxalate and counted in a methane end window system. Check analyses were performed in a shorebased laboratory equipped with low background beta counters. The results of the sea and shore analyses were consistent within the limits of error. The test demonstrates that 90 Sr analyses can be performed satisfactorily at sea, and that a better equipped laboratory and counting facility would improve the performance considerably.