Performance Of Double-skin Facade Research Articles

Naturally ventilated folded double-skin façade (DSF) for PV integration - Geometry evaluation via thermal performance investigation

Studying the thermal performance of Double Skin Facades (DSFs) with vertical layers has dominated the literature, however, there is still a lack of in-depth research on the performance of DSFs with atypical geometries such as folded cases which can be applied to Building Integrated Photovoltaic (BIPV) systems to improve their performance. To this end, the study evaluates the influence of the fold geometry on heat transfer, flow structure, and airflow rate in the Folded DSF cavities under a hot climate in Iran using an efficient method titled “patching”; the method integrates Soltrace3 with a 2D steady-state CFD model by ANSYS-Fluent. The results show that the fold position and its depth can alter the DSFs performance significantly; the higher the fold depth the more distortion of the flow field inside the cavity; from a practical perspective, the fold position in the upper part of the cavity is suitable for BIPVs application since it can capture 250% higher amount of solar radiation compared to a conventional vertical-layer DSF as the Base Case; the net heat gain through outer layer could improve with increase of fold depth and reach at least 33% higher than the Base Case, meanwhile, the total electricity generation potential of folded cases could be up to 169% higher than the Base Case; thus, the study proved that if the architectural design is of interest, it is highly recommended to consider folded DSFs as a design option.

Saving Energy Through Improving Performance of Double Skin Facades: A Case Study Residential Building in Yazd

The building envelope is one of the most influential factors in energy consumption. Therefore, optimizing the facade of the building with new technologies is one of the most effective passive solutions to provide thermal comfort. The purpose of this research is to design a composite facade, which according to the two main driving forces; the pressure difference caused by the heat flow (air flow and wind force) and the insulation of the air, for a residential building with a typical plan of Yazd in the hot and dry climate of Iran. That can be used to reduce the heating and cooling load of the building. For this purpose, firstly, the effect of two types of two-skin facades - floor-to-floor and all-over two-skin facades - compared to the model without two-skin facades in cooling and heating energy consumption throughout the year was modeled and analyzed with Design Builder version 6.1 software. The results of the constructions show the possibility of reducing about 60% of cooling energy through the creation of air conditioning and 26% of heating energy through the creation of thermal insulation in the residential building simulation model throughout the year by means of two combined shells. The findings of this research lead to the creation of more efficient energy solutions by creating innovation and combining new technologies according to climatic conditions.

The Solar Heat Cutting Performance of Double-Skin Facades

The solar heat cutting performance of double-skin facades was analyzed in this paper. A physical model was built to calculate the thermal characteristics of double-skin facades. The effects of location, floor height, facade facing direction, blind slice angle, and skin style on solar heat cutting were investigated. The results show that double-skin facades can effectively cut the heat flux entering room, especially for west facing facade. Comparing with the single-skin facade, the double-skin facade cuts 1410.2 Wh/m2 more heat to enter room for west facing facade in a clear summer day in Nagano, Japan. Floor height mainly influences the outlet air temperature of the facade intermediate space, but not the heat fluxes. Locations somewhat affect the solar fluxes on outer facade surface.

Investigation of Thermal and Energy Performance of Double Skin Facades in Hot Climate Regions in Turkey

Investigation of Thermal and Energy Performance of Double Skin Facades in Hot Climate Regions in Turkey

Optimisation of the double skin facade in hot and humid climates through altering the design parameter combinations

Architects welcome double skin facade (DSF) due to its aesthetic quality. The first DSF structure was intended to prevent cold weather and strong winds. Nowadays, the application of DSF under different climates has been investigated in many previous studies. However, little work had been done on the behaviour of DSF in hot and humid climates. Therefore, this paper aimed to extend the application into this specific climate and Guangzhou was selected as the sample city. Both the climate and the design influence the performance of DSF. In this paper, rather than explore how each design parameter influences the performance, the design was evaluated from an overall aspect. The Designbuilder software was used to build the single skin facade (SSF) and double skin facade base model. Annual HVAC energy consumption for both the two models was calculated and compared. An optimisation process was conducted to figure out what kinds of parameter combination could make the design more energy-saving and thermally comfortable. The results indicated that it was possible to design an energy-saving DSF system applied in hot and humid climates compared with the SSF model. The efficiency of the DSF could be further enhanced with a better parameter combination. The optimised options had some features in common, which could provide some inspirations for the application of DSF in hot and humid climates.

Smoothed particle hydrodynamics modeling of the thermal behavior of double skin facades in fires considering the effects of venetian blinds

At present, the fire safety of double skin facades (DSFs) is an important research area due to recent spikes in fires in high rise buildings involving glass DSF systems, and also due to our limited understanding of the thermal behavior of these systems. To overcome this lack of knowledge, a numerical framework is proposed for simulating the thermal performance of DSFs under fire conditions. The framework is based on the smoothed particle hydrodynamics technique and it can be used to compute numerical solutions and simulate the thermal degradation of DSFs under fire conditions. The numerical model was validated by comparing the predicted response parameters in a fire exposed DSF system with those measured in fire experiments. The validated numerical model was then employed to derive empirical equations linking temperature with both the time and location along the interior and exterior glass panes of DSFs. Finally, numerical simulations were conducted for the same DSF configuration but equipped with venetian blinds in order to examine the influence of the blinds on the fire performance of glass DSFs. An in-house MATLAB code was developed and implemented to conduct these numerical simulations. The results obtained from these numerical simulations clearly indicated that the “blind tilt angle” can significantly affect the fire spread characteristics and temperature distribution in DSFs, and thus it should be considered in the design of DSF systems for high rise buildings.

A simulation study on the performance of double skin façade through experimental design methods and analysis of variance

Systematic studies of the thermal fluid dynamic behaviour of building envelope systems through experiment analyses is limited by the relevant amount of time and high costs necessary to carry out a relevant number of tests covering all the possible configurations. Building simulation can be used as a tool to support the design of the experiments, i.e. to test, in a parametric way, different configurations to highlight the main trends, and therefore select the most relevant cases to be tested experimentally. Such a preliminary activity to maximize the effectiveness of the experiments may relates to both parametric analysis of indoor/outdoor boundary conditions, as well as parametric analysis of building envelope configurations. In the framework of a research project on double skin facade (DSF) systems where experiments are planned on a full-scale prototype, a model of a DSF is realized in a whole building energy software tool, and used to carry out a preliminary sensitivity analysis, by means of orthogonal array method and analysis of variance. Simulations were carried out in EnergyPlus, using the Airflow window module, and under steady-state conditions, a series of variables (cavity depth, venetian blinds tilt angle, airflow rate) have been investigated to assess their impact on the heat extract through the ventilation air and the total heat transmission between the outdoor and indoor environment. The results show that the main driver in the performance of DSF considering net heat rate transfer is the irradiation impinging on the façade in terms of boundary conditions, and coherently, the shading device is the feature that most affects the performance of the system among the characteristics of a DSF.

Investigation on Thermal Performance of an Integrated Phase Change Material Blind System for Double Skin Façade Buildings

Double skin facades (DSFs) are widely recognised as sustainable design elements for reducing energy consumption in buildings. However overheating problems in DSFs in warm seasons have been reported in various studies which may cause additional increase in cooling loads in buildings. Although various thermal management strategies and devices are available, they do have some limitations and cannot be readily used for enhancing the performance of DSFs. This paper focuses on both experimental and numerical evaluations on the thermal performance of an integrated phase change material (PCM) blind system for DSF buildings. The numerical models were validated with experimental data in a DSF test facility integrated with the developed prototype. Temperature and heat flux profiles in the DSF integrated with the proposed PCM blind system and aluminium blind were simulated and compared by using computational fluid dynamics (CFD) method. The experimental results indicated that the system was able to stabilise the average temperature in the DSF to about 36 °C in summer days with no significant increase as compared with ambient temperature. Further theoretical evaluations also showed that in comparison with basic aluminium blind, the PCM blind can reduce the air temperature as well as absorbing more heat gain in DSF. Even though the developed system has demonstrated some level of capacity to mitigate the overheating phenomenon in DSF, there is need for further research in optimising the geometry of the system and improving the energy storage efficiency of the PCM.

Modelling of double skin facades in whole-building energy simulation tools: A review of current practices and possibilities for future developments

Advanced building envelope systems can contribute to the reduction of greenhouse gas emissions and improve the energy flexibility of buildings while maintaining high levels of indoor environmental quality. Among different transparent envelope technologies, the so-called double skin facades (DSFs) have been since long time proposed as an effective, responsive building system. The implementation of DSF systems in a real building is highly dependent on the capabilities of the prediction of their performance, which is not a trivial task. The possibility to use whole-building energy simulation (BES) tools to replicate the behaviour of these systems when integrated into a building is, therefore, a crucial step in the effective and conscious spread of these systems. However, the simulation of DSFs with BES tools can be far more complex than that of more conventional facade systems and represents a current barrier. This article is based on evidence from the scientific literature on the use of BES tools to simulate DSF, and provides: (i) an overview of the implementation of DSFs systems in BES tools, with the current capabilities of some selected BES tools; (ii) a comprehensive review of recent, relevant simulation studies, where different approaches to modelling and simulating DSFs are reported; and (iii) the identification of current gaps and limitations in simulation tools which should be overcome to increase the possibilities to correctly predict the performance of DSFs when integrated into a building.

Assessing Daylight Performance of Single vs. Double Skin Façade in Educational Buildings: A Comparative Analysis of Two Case Studies

The bulk of research on the performance of double skin facade is carried out in moderate climate with concern to ventilation and thermal performance. This research concerns day-light performance of double skin facades in hot arid zones, in Educational Buildings. This investigation adopts an inductive method using comparative analytical approach to convert general intuitions on the daylight performance of a double skin facade, in hot arid areas, into the grounds of understanding its performance based on research.Based on two case studies of lecture halls; the first with Single Skin Façade (SSF) and the second with Double Skin Façade (DSF); the impact of double skin façade on lighting performance is examined. The Protocol was applied to south facing models under overcast sky conditions to test significant effects of double skin façade on illumance values inside the lecture halls. Simulation results indicate that a double skin facade can achieve high lighting performance with better energy savings than a single skin façade; also the basic characteristics of width and distance of two walls are examined. It was expected that DSF fail to meet the acceptable standard indoor illuminance requirement of 200 to 300 lux. Comparing the single and double skin facade, the area percentage of the lecture hall, which covered with acceptable illumination level of 200 to 300 lux, are found in range of 10%, 50% respectively. In addition, the area percentage of the lecture hall, which covered with acceptable illumination level of 100 to 300 lux, is found in range of 30%, 80% respectively.

Parametric study of double-skin facades performance in mild climate countries

The application of double-skin facades is an interesting technical solution but, at the same time, highly affected by the climatic conditions of the building location. Southern European countries are characterized by relevant solar gains that play a major role in the performance of double-skin facades. In this work, a parametric study is carried out to systematically assess the impact, in the building performance, of geometry, airflow path, cavity depth, openings area and type of glazing. The study is based in numerical simulations using DesignBuilder/EnergyPlus, taking advantage of the available CFD module for a better insight on the relevant energy transfer phenomena. It was found that the most important aspect for the efficiency of a double-skin facade is the airflow path and the most efficient geometry was the multi-storey double-skin facade, presenting, in average, 30% less HVAC related energy demands. Internal gains proved to be one of the key factors for the building's energy performance and facade orientation can represent a difference of up to 40% in energy demand between north and southern oriented facades.

The Impact of Opening Sizing on the Airflow Distribution of Double-skin Facade

Double-skin facade (DSF) has been widely used in different kinds of architecture as new building envelopes. The position of the shading louver and opening size of the air layer is the key point to thermal performance of DSF. A temperature test, which is in a DSF building in Wuhan, has been conducted in this paper. The ANSYS software has also been used to simulate the velocity and temperature field in the DSF with different opening size. The results show that the test data keeps well accordance with the simulation. Significant differences exist in the velocity and temperature field in DSF with different shading louver position and opening size. The computing results in summer day indicate that as the opening size varies from 0.1m to 0.6m, temperature and velocity of the air in the layer decrease first, then remain the same. Temperature and velocity distribution becomes more regularly with the louver shading in the middle of the layer or near the outside glass than the region close to the inside glass. The testing data in sunny day keeps well accordance with the simulation result, which means the simulation results have certain reliability.

Energy Performance and Thermal Comfort of Double-Skin and Single-Skin Facades in Warm-Climate Offices

The energy performance and thermal comfort of an office building with single and double skin facades, in a warm climate was studied using TAS software. A double-skin facade is an envelope construction that consists of two transparent surfaces separated by a cavity. The extra skin can reduce cooling demand in summer and heating demand in winter. It is concluded that in a warm climate office, a double skin facade can perform better than a single skin facade. In a warm climate a double skin facade fully provides heating and thermal comfort in winter. In a warm climate however its benefit in summer is limited. Further studies are needed to increase the performance of double skin facades in summer.

Experimental and zonal modeling for wind pressures on double-skin facades of a tall building

This paper investigates wind pressure characteristics on a corridor double-skin facade (DSF) of a tall rectangular building through experimental and numerical modeling. Firstly, wind-tunnel experiments have been carried out to study the wind pressures acting on three surfaces of the corridor DSF of the building: the outside and inside surfaces of the external skin and the outside surface of the internal skin. The characteristics of the wind pressure distribution on the DSF are investigated for different DSF layouts, air corridor width and incident wind angles. The mean and standard deviation of the pressure coefficients are presented for twelve wind angles over 360°. The experimental data show complex wind pressure distributions inside and outside the air cavity. Then, the zonal approach is applied to model the inner-gap pressures on the DSF. The results from the zonal modeling compare relatively well with the wind-tunnel measurements. Thus, the zonal approach is an effective tool for evaluating the performance of DSF on tall buildings and may be an efficient alternative to the traditional wind-tunnel test and computational fluid dynamic (CFD) method.

Operation and control strategies for multi-storey double skin facades during the heating season

The implementation of the double skin facade (DSF) has been the object of broad study in recent years. However the performance of DSF is often questionable because of the lack of experiment and monitoring data, especially regarding multi-storey DSFs.In this study, the actual behavior of a multi-storey double skin facade was measured during the heating season in an office building located in South Korea. The validation of the simulation model was made against measured data with the three statistical indices of the mean bias error (MBE), the root mean squared error (RMSE), and the coefficient of determination (R2). The wind pressure coefficient for the airflow network simulation was calculated using computational fluid dynamics. Based on the control scheme and operation strategies, three types of models were proposed and analyzed with the validated simulation model. These models include a model using DSF as a thermal buffer space (Case 1), a model applying a control scheme on the operable windows (Case 2), and a model using a cavity space as a preheating space for an HVAC system (Case 3). It was found that significant energy saving is possible if multi-storey DSF is integrated with an HVAC system as a preheating space.

Thermal behaviour of a ventilated double skin facade in hot arid climate

Modern Movement in architecture has resulted in a large number of high-rise buildings with glazed facades which increase the energy load of the buildings. To combat this phenomenon in colder climates, architects have turned to using double skin facades. These facades comprise of: a completely transparent external facade; an internal skin; and an air layer between the two. Research on the performance of double skin facades mostly considers cold and moderate climates. In addition, data collection is normally based on simulations, rather than actual field measurements. In this paper a building with double skin facade was monitored for 2 weeks in summer and 2 weeks in winter in the hot arid climate of Iran, in order to observe the behaviour of the facade both in hot and cold conditions. Additionally, simulations were performed on the case study building with and without double skin facade, to assess the effectiveness of the facade. The results revealed that the temperature difference between the outer skin, the inner skin and the cavity can significantly save heating energy in winter. To reduce the cooling loads in summer it is essential to introduce additional techniques such as night ventilation and installation of shading devices for the cavity.

Natural ventilation in the double skin facade with venetian blind

As a new-style building, the thermal performance of double skin facade with the venetian blind cannot be predicted for the absence of suitable tool. In the paper, a detailed analysis of the thermal process in glass double facade with venetian blind was made. The governing equations were solved by comprising CFD, optical and heat balance model for multi-layer transparent system. It is shown that the more complex natural ventilation exists in the two air gaps divided by venetian blind, which cannot be reflected with the simplified model. Comparing the simulation results with the experiment data in the literature, a good agreement was achieved. Hence, it can be used as a reliable tool to analyze the ventilation in the double skin facade with a venetian blind.

On the performance of double skin facades in different environmental conditions

This paper compares the heating and cooling loads between a double skin façade and a single skin façade in different and contrasting climates. The thermal and lighting properties of both types of facades are calculated, based on the hypothesis of a virtual south facing office room. The results of the above calculations show that in climates with high sunshine duration, the difference in heating and cooling loads is less for a double skin façade in comparison to a single skin facade. This difference ranges from about 30% in the Mediterranean to about 40% in the Arabian peninsula in the case that the single skin building is not equipped with automatic shading devices, whereas in the case that both buildings have automatic shading devices the above percentages range from about 5.5% to 7.5%, respectively. The same difference in heating and cooling loads between the two types of facades is significantly reduced in colder Continental climates such as Moscow, as well as temperate climates such as London.

The design, installation and maintenance of the modern office building

The use of double skin facades (DSF) in the building sector and its thermal benefits have been widely studied numerically over the last 30 years. These modelling and simulations are based on different typologies, which have evolved altogether with the available computational resources. The models that have been used to study the thermal performance of DSF can be grouped as analytical and lumped models, non-dimensional analysis, network models, control volume, zonal approach, and computational fluid dynamics (CFD). This paper describes these different typologies of numerical modelling highlighting their benefits and limitations, and overviews the research produced using each typology.