Insulation Glazing Research Articles

Condensation risk-based applicability analysis and design of a dynamic thermal insulation window with ventilated airflow in different climates

The exhaust air insulation glazing system (EAIG) integrates exhaust air heat recovery and dynamic insulation to minimize heat loss/gain through the window by allowing the exhaust air to be ventilated through the air gap between two glass panels. However, condensation may form on the internal glazing surface of EAIG during winter. How to prevent the occurrence of condensation and improve technical feasibility of EAIG for various climatic conditions has not been addressed. A numerical model was developed to determine the hourly glazing surface temperatures of EAIG and identify whether condensation will form or not during winter. The condensation probability of EAIG was quantitatively estimated considering various window orientations and climatic conditions. Furthermore, the effectiveness of some potential measures for preventing condensation in EAIG was also investigated. The results indicate that outdoor weather conditions significantly influence the condensation of EAIG. For a climate with a relatively mild winter, slight condensation occurs within the EAIG, while in severe cold climate, long-term condensation with a probability of 45.4 % occurs, which detrimentally affects the practical application of EAIG. Moreover, reducing indoor humidity and adding a low-e coating can effectively reduce condensation probability and expand technical feasibility of EAIG for various climatic conditions. In severe cold climates, the condensation probability decreases from 45.5 % to 6.5 % when employing an additional low-e coating. The findings in this study are beneficial to providing a design guideline for engineers and architectural designers, and enhancing the applicability of EAIG in various climatic conditions.

Laser strengthening of additive manufactured edge seal for vacuum insulated glazing with micro-size glass frit

Sealing of glass edge is a key step in developing cost-effective and durable vacuum insulated glazing for the drive towards net-zero energy buildings. To achieve a high-strength sealing with scalable and low-cost processing, we investigated a novel sealing method based on additive manufacturing and laser process and reported quantitative analysis of the laser assisted method sealing strength and the requirement of vacuum insulation glazing. Micro-size glass frits in printing ink and a continuous-wave laser curing were employed to allow the formation of a hermetic bonding layer with low thermal budget. Controlling various sealing parameters including laser traveling speed, spot diameter, and laser power, the water seepage and mechanical strength of the resulting glass-to-glass bonding were examined. Through the response surface methodology, we identified the optimized sealing condition where the bonding strength reached 5.68 MPa. A comparation of the bonding strength between thermal sealing method and laser-assisted method has been analyzed as well.

Insulation glass units made of thin glass‐polycarbonate composite panels

The combination of brittle thin glass with ductile polycarbonate leads to innovative composite panels. Two outer thin glass panels with one or more inner polycarbonate sheets represent an alternative to conventional laminated safety glass as security safety glazing with a resistance against manual attack. Following development to multi‐pane insulation glazing presents the additional advantages of the composite panel to thermal insulation. This study documents the design of single thin‐glass polycarbonate composite panels as security glazing to multi‐pane insulation glazing with the highest resistance class P8B against manual attack. The paper describes the evolution of the insulation glass unit and the experimental research to reach the defined values of resistance class, heat transfer coefficient and energy transmission. This results in slighter single composite panels and insulation glazing as an innovative alternative to common laminated safety glass as security glazing.

Numerical analyses of the sound transmission at low frequencies of a calibrated Insulating Glazing Unit

The acoustic performances of building elements such as windows are carried out in laboratory according to standards. In addition to the high cost of the experimental tests, the measurements at low frequencies face some difficulties such as the lack of reproducibility, the rooms’ modal behaviour effect and the diffuseness of the acoustic field. To separately study each source of deviation from the ideal experimental situation, four numerical configurations, based on experimental conditions, are proposed to characterize the transmission loss (TL) of an Insulation Glazing Unit (IGU) below 500 Hz. The effect of the emitting and receiving rooms with a comparison to the ideal configuration which has a free field on both sides of the IGU are investigated. The numerical model used for the IGU is calibrated from an Experimental Modal Analysis. As expected, TL results show that there is a significant effect of the modal behavior and the acoustic properties of the rooms at low frequencies. Numerical results are compared to those obtained from experimental tests and a good agreement in the all frequency range of interest is observed. In addition, parametric studies are carried out to investigate the influence of the variation of some properties of the studied structure such as the structural damping and the panel’s thickness.

MOEMS micromirror arrays in smart windows for daylight steering

Micro-opto-electro-mechanical systems (MOEMS) micromirror and shutter arrays have gained huge interest in research and applications. Our study starts with an overview on the technological achievements and experimental results of groups that have been working on this field. The main part of our study is revealing the MOEMS micromirror array technology for light steering via smart glazing for buildings. The mirror array is actuated electrostatically and integrated between the panes of insulation glazing. Depending on user activity as well as daytime and season requirements, the MOEMS micromirror arrays shall enable personalized light steering, energy saving, and reduction of CO2 emission. Technological fabrication of subfield addressing up to 64 fields inside the arrays is presented. Experimental characterization results such as actuation voltages, maximum and minimum transmission, contrast, and energy saving potential are reported. Using an industrial window module fabrication process, a laboratory demonstrator and a function demonstrator have been implemented. Rapid aging tests including vibrations, extreme temperatures, multiple temperature cycles, and long-term electrostatic actuation of micromirror structure were performed to evaluate reliability and lifetime. These results validate extrapolated lifetimes—in future applications as active windows—far beyond 40 years, as well as their robustness during transportation, installation, and against all vibration influences in buildings.

Spatial Delight and Environmental Performance of Modernist Architecture in London – Golden Lane Estate

This paper investigated the spatial delight and environmental performance of the open spaces and two selected apartments in the modernist buildings at Golden Lane Estate built after the 2nd World War, between 1952 and 1961. This estate is a Grade II listed, high density, low cost housing complex designed by three young architects: Peter Chamberlin, Geoffrey Powell and Christof Bon. It was built over a bombed site and well embraced the post-war modern architecture ethos, environmental considerations and inclusion of social facilities and landscaped communal spaces. Selected communal open spaces and two apartments in different building blocks with similar attributes were chosen for this study. However, one apartment has been refurbished with internal insulation and secondary glazing for improving the comfort conditions. Through fieldwork, which included subjective observation of the spatial quality of both outdoor and indoor spaces, on-site monitoring and interview of the building occupants, first-hand information on the environmental and comfort conditions inside the apartments were obtained. Through performance based theoretical analysis, archival research and observations, the spatial quality and comfort conditions in the apartments and their energy demand were critically assessed. The research findings indicate that the design of the communal outdoor spaces in the Golden Lane Estate were well thought through and the spacing between the building blocks responded well to the requirements of spatial delight, solar and daylight access and outdoor environmental comfort. Through selective enhancement of the thermal property of the building envelope, the original naturally ventilated and well day-lit living environments were maintained while energy demand was reduced by 30%, and the overall comfort level was significantly improved. This paper presents the feasible strategies to tackle the environmental challenges in the post-war Grade II listed residential buildings in the UK.

The Influence of Building Envelop Materials on its Life Cycle Performance: A Case Study of Educational Building in Thailand

The analysis of life cycle energy (LCE) and life cycle carbon (LCC) of building were performed in this study in order to identify the solutions for reducing energy-related carbon emission throughout building life time. The influence factors associated with building envelop materials (wall, insulation, window, window-to-wall ratio) were evaluated. The result showed that operation phase contributed a vast majority (>90%) of LCE and LCC. Only 4% emissions saving could be achieved if autoclaved aerated concrete block, cellulose insulation and triple glazing were implemented with WWR of 0.17. The finding suggested that reducing carbon emission should not only be prioritized through use of high energy efficient materials/technologies but should also integrate energy saving measures since energy demand in tropical country is quite high for cooling building. In addition, increasing a possibility and feasibility for supplying renewable energy should be further investigated importunately.

A New Structure of Vacuum Insulation Glazing for Edge Effect Reduction: A Parametric Study

In this study, a new method was introduced to reduce the edge effects of vacuum insulation glazing. To this end, the use of a metal structure for sealing was proposed to replace the existing sealant method. The results of a numerical simulation were verified using theoretical values, and the same numerical method was applied to new structures. It was checked that the sealing by new method showed about 50% thermal efficiency compared with the conventional method. We found that some guidance on design factors can be provided by simultaneously examining the thermal and structural performance when designing vacuum insulation glazing.

High-Tech Solutions for Building Retrofit: Investigation of Window Systems with Vacuum Glazing

The retrofit of the historical building stock has gained significance due to energy efficiency requirements in the building sector. Major attention is drawn to windows as they are typically the building components with the highest heat transfer coefficient of the building envelope. Therefore, vacuum glazing is a potential option for improving the thermal performance of casement windows. In this context, specific considerations regarding building physics and heritage protection regulations are required.The present contribution describes the current progress of the research project VIG-SYS-RENO. New double glazing products with durable vacuum layer are emerging on the market. Such developments can be regarded as a major step toward energy-efficient windows with U-values close to conventional opaque building elements. Small thickness and excellent thermal resistance of vacuum insulation glazing renders it an attractive option in thermal retrofit of historical buildings. Vacuum glazing systems could potentially offer a feasible balance between conservation and thermal performance of windows. However, prior to any application, a set of aspects and potential issues have to be assessed and explored. These include: (i) thermal bridging effects in different joint positions, for instance the glass edge seal and the frame & wall joint; (ii) the positioning of tight layers in composite or casement windows; (iii) aspects of structural integrity of windows equipped with vacuum glazing. The present contribution structures the different aspects that need to be considered in utilization of vacuum glazing in thermal retrofit, describes applied evaluation methods, first results of the ongoing research project, and illustrates the influence of various rebate depth and length of the edge seal on thermal transmission of the window.

A Case Study on the Verification of Passive Office Energy Performance Comparing Actual Energy Consumption to Simulation Result

The objective of this study is to verify energy performance of passive office building compared to existing building using computer simulation tool, EnergyPlus. S building was selected as a passive office building, which is the first passive office building in KOREA, and the building satisfy the passive house standard. The annual energy consumption data were compared to the heating and cooling load result of EnergyPlus, to verify simulation accuracy. The conditions of existing building were selected from Korean envelope standard and the categories of the conditions are the insulation thickness and glazing composition. As a result, the passive office showed 28% reduced energy consumption, compared to the existing building, with ordinary envelope under Korean building envelope standard.

Overview of natural cross-ventilation studies and the latest simulation design tools used in building ventilation-related research

High-performance insulation, draught stripping and double glazing have effectively sealed off the fresh air routes and have made adequate natural ventilation impossible inside the modern energy-efficient home nowadays. Cross ventilation, a passive cooling method for buildings, is a major type of natural ventilation. Various study approaches have been reported; however, there is still no appropriate simulation tool that can predict the indoor thermal environment of natural ventilation. The typical building energy simulation for investigating a naturally ventilated building adopts thermal simulation and an airflow network. However, the airflow network approach for airflow estimation in building energy simulation cannot accurately predict indoor airflow by solving the pressure-flow algebraic equation, the mass balance equation and hydrostatic pressure variations. Recent advances in computer performance and computational fluid dynamics (CFD) software integrated with building energy simulation have made it possible to improve the accuracy to assess the performance of natural ventilation and also to give more realistic predictions of airflow in buildings. This chapter overviews and discusses various network airflow models integrated with CFD in the natural ventilation of buildings. Examples of results obtained with this approach are given to demonstrate the significant effects of such a coupling programme on natural ventilation prediction accuracy.

Edificio administrativo André & Cíe., S. A., en Lausana

This building has a triangular planform It has two basements, ground floor, six storeys, an attic and terrace. The offices, which are air conditioned, occupy the external part of the building, and the inner zone of it is taken up with the service facilities, lifts (also a goods lift, for documents and suchlike), dressing rooms, posting room and a service staircase. Office rooms are mutually separated by mobile partition walls. These are fixed according to a standard module, which allows for the formation of «cells» of unitary or larger number of units of size. The management rooms have fixed partitions and occupy the south wing of the fifth floor. In the attic there is a small dining room, and a smoking room for foreign clients. A very fine view is enjoyed from these rooms. The building structure is made of reinforced concrete, and the external enclosures are curtain walls, made with light weight metal, which enclose large sized fixed windows and smaller ones, which can be opened. All of them have insulation glazing and Venetian blinds. To the external observer, this building gives a powerful impression of lightness, transparency and modern design.