Building Efficiency and Sustainability in the Tropics ( SinBerBEST ) Title Hybrid Simulation for Daylighting of Complex Fenestration Systems for Building Envelopes Permalink (original) (raw)
Related papers
Coupling dynamic energy and daylighting simulations for complex fenestration systems
2015
A new tool for energy and daylighting analysis of complex fenestration systems (CFS) is presented. The tool couples the daylighting simulation engine Radiance with the dynamic building simulation engine TRNSYS and performs integrated simulations using the bidirectional scattering distribution function (BSDF) that characterizes the CFS. The use of the tool allows to implement flexible shading controls based on thermal and daylighting comfort parameters. In order to demonstrate the tool functionality two different control strategies for a shading device, composed of movable venetian blinds, are compared and analyzed.
Experimental validation of daylighting simulation methods for complex fenestration systems
2000
The objective of this paper is to assess the capability of existing lighting simulation methods to predict the performance of complex fenestration systems, which are becoming a commonly used component in buildings construction domain. A specific experimental protocol was conducted to collect reliable reference data based on illuminance measurements inside a black box with (and without) one complex glazing sample
The daylight coefficient method and complex fenestration
The daylight coefficient method has been introduced in computer simulation as an efficient approach to compute indoor daylight illuminances through building static fenestration systems. A set of coefficients are calculated only once prior to simulation start for a given number of elemental patches making up to sky vault and ground. However, for dynamic complex fenestration systems whose optical behavior (transmission, reflection and scattering) may change during simulation (such as windows with shadings), the efficiency of the daylight coefficient method may be compromised as the whole set of coefficients must be re-calculated during simulation.
PLEA …, 2012
During an intensive design-led workshop multidisciplinary design teams examined options for a sustainable multi-residential tower on an inner urban site in Brisbane (Australia). The main aim was to demonstrate the key principles of daylight to every habitable room and cross-ventilation to every apartment in the subtropical climate while responding to acceptable yield and price points. The four conceptual design proposals demonstrated a wide range of outcomes, with buildings ranging from 15 to 30 storeys. Daylight Factor (DF), view to the outside, and the avoidance of direct sunlight were the only quantitative and qualitative performance metrics used to implement daylighting to the proposed buildings during the charrette. This paper further assesses the daylighting performance of the four conceptual designs by utilizing Climate-based daylight modeling (CBDM), specifically Daylight Autonomy (DA) and Useful Daylight Illuminance (UDI). Results show that UDI 100-2000lux calculations provide more useful information on the daylighting design than DF. The percentage of the space with a UDI <100-2000lux larger than 50% ranged from 77% to 86% of the time for active occupant behaviour (occupancy from 6am to 6pm). The paper also highlights the architectural features that mostly affect daylighting design in subtropical climates.
Modelling Complex Fenestration Systems using physical and virtual models
Solar Energy, 2010
Physical or virtual models are commonly used to visualize the conceptual ideas of architects, lighting designers and researchers; they are also employed to assess the daylighting performance of buildings, particularly in cases where Complex Fenestration Systems (CFS) are considered. Recent studies have however revealed a general tendency of physical models to over-estimate this performance, compared to those of real buildings; these discrepancies can be attributed to several reasons. In order to identify the main error sources, a series of comparisons in-between a real building (a single office room within a test module) and the corresponding physical and virtual models was undertaken. The physical model was placed in outdoor conditions, which were strictly identical to those of the real building, as well as underneath a scanning sky simulator. The virtual model simulations were carried out by way of the Radiance program using the GenSky function; an alternative evaluation method, named Partial Daylight Factor method (PDF method), was also employed with the physical model together with sky luminance distributions acquired by a digital sky scanner during the monitoring of the real building. The overall daylighting performance of physical and virtual models were assessed and compared. The causes of discrepancies between the daylighting performance of the real building and the models were analysed. The main identified sources of errors are the reproduction of building details, the CFS modelling and the mocking-up of the geometrical and photometrical properties. To study the impact of these errors on daylighting performance assessment, computer simulation models created using the Radiance program were also used to carry out a sensitivity analysis of modelling errors.
AN EXPERIMENTAL AND SIMULATION STUDY OF DAYLIGHTING IN ATRIUM BUILDING IN THE TROPICS
This study investigates an application of the daylight in an adjoining space of an atrium building in a tropical climate. Physical experimentation using a scale model was performed under real skies to measure the daylight illuminance and its distribution in the adjoining space and to validate the daylight calculation from a simulation software namely "BESIM". BESIM uses the ray-tracing method to deal with the beam light calculation and the fluxtransfer method for determining the interior light from the diffuse skylight. Using BESIM, the interior daylight in the adjoining space was evaluated as functions of well index and interior surface reflectance. The simulation results show that with the strong sunlight and the high luminosity of the tropical sky, daylighting in the atrium building is applicable. The daylight is generally sufficient for circulation in the adjoining space throughout the day and all year round. For Thailand where is located 5-20 degrees north of the earth equator, the influence of the sunlight to the northern area of the space is larger than other areas. The sunlight also causes a high variance of the daylight in the area. The more uniformity of the daylight distribution is observed for the southern area of the space. The use of interior shading helps improve the daylight distribution and increase the daylight level for the lower floors of the atrium.
Computational Modeling of Translucent Concrete Panels
Journal of Architectural Engineering, 2015
The last decade has witnessed a heightened interest in making buildings more sustainable, which has been fueled largely by the increase in energy costs and advancements in manufacturing technology. Lighting consumes a substantial amount of this energy, making it necessary to look for alternative technology that depends more on natural lighting. This study investigated a novel building envelope material that consists of optical fibers embedded in concrete. The fibers are used to channel solar radiation into the building to reduce the dependence on artificial lighting especially during peak time. This paper presents a geometrical ray-tracing algorithm to simulate light transmission properties of the proposed translucent concrete panel. It was concluded that a tilt angle of 30°for the panel transmits the maximum amount of light among all the tilt angles considered. Using this tilt angle, the rate at which sunlight radiation is absorbed by the panel was calculated, and a preliminary study was conducted to estimate the solar heat gain coefficient of the panel for possible use in place of a glazing material by the construction industry.
Energy and Buildings, 2015
A new Radiance-based modelling approach called Fener is presented. The motivation is to be able to perform detailed analyses of complex fenestration systems (CFS) from the energetic and daylighting points of view in a computationally efficient manner, so the benefits of innovative products can be easily quantified. The model couples daylighting and thermal simulations in a time-step basis, so that shading control strategies that depend on thermal variables, such as indoor air temperature and energy load, can be simulated without iterating between full-year simulations of a thermal model and a daylighting model. Fener is a single-zone energy model that uses the three-phase method and bi-directional scattering distribution functions (BSDF) to predict the transmitted solar irradiance and indoor illuminance of office spaces with CFS. An evaluation of the model is presented. Fener is tested against EnergyPlus and classic Radiance for different fenestration systems and sky conditions. Cooling and heating energy demand, transmitted solar irradiance and indoor illuminance are compared. As an exemplary application, Fener is used to assess the performance of an innovative perforated lamella system together with a control strategy that depends on indoor air temperature.
Sustainability, 2014
Overheating, glare, and high-energy demand are recurrent problems in office buildings in Santiago, Chile (33°27'S; 70°42'W) during cooling periods. Santiago climate is warm and dry, with high solar radiation and temperature during most of the year. The objective of this paper is to evaluate the thermal and daylighting performance of office buildings transparent faç ades composed of three different complex fenestration systems (CFS). Each CFS contains a different external shading device (ESD): (1) external roller, (2) vertical undulated and perforated screens, and (3) tilted undulated and perforated screens. The study was carried out by in situ monitoring in three office buildings in Santiago, Chile. Buildings were selected from a database of 103 buildings, representing those constructed between 2005 and 2011 in the city. The monitoring consisted of measuring the short wave solar and daylighting transmission through fenestration systemsby means of pyranometers and luxometers, respectively. This paper shows measurements that were carried out during summer period. A good performance is observed in a building with the external roller system. This system-applied to a northwest faç ade-shows a regular and high solar and daylighting control of incoming solar radiation.
Daylight simulation in buildings
PLEA 2008, 2008
Emphasis on daylight is given to non-domestic buildings because in such buildings the specificity of the activities or the high levels of illumination demand a more careful control on daylighting examined for design purposes. Clearly energy saving in that situation is one of the reasons for that emphasis. This paper deals with light coming into the rooms through the window providing natural light once the window is considered the only system that provides and controls light flux and distribution. Rooms can be classified according to their occupancy and use, and then many different activities requiring different illumination levels can be developed in the same space. Room's classification is the first step to establish the ratio window to the floor area for daylight purposes. Therefore the aim of the present work is to investigate window’s characteristics as a mean to assess daylighting. Windows’ parameters were taken up to calculate daylighting for 12.00m² rooms. The simulated cases were accessed varying windows position, shape, size and geometry, maintaining in all cases 3.60m² area. This methodology can be applied in architectural education aiming students’ comprehension about users’ comfort and energy savings. ECOTECT and Radiance softwares were used to simulate the proposed windows’ parameters.