A method of optimizing fenestration design for daylighting to reduce heating and cooling loads in offices

Modern office building designs tend to increase the window share per facade to make the building more impressive with extensive visibility and well daylit rooms. In general, an increased window share results in higher energy usage and higher costs of heating and cooling, but these disadvantages can be reduced with a more careful design. The aim of this paper is to show the influence of window design and room layout on heating and cooling demand and daylight availability in office buildings in northern Europe. The results in the paper are based on design calculations for two different room types and daylight measurements on two room scale models in a daylight laboratory. The calculations show the influence of window design parameters on the cooling and heating demand. The daylight measurements show the influence of window design parameters on the availability of daylight. The results have then been combined to show a feasible window design regarding daylight availability and the resulting cooling and heating demands for different window orientations. The results show that in most cases it is possible to find a combination of window share and window solar factor that is feasible with regard to daylight as well as cooling and heating. The main finding is that there is a smaller or wider range of feasible designs for different window orientations

Cooling Demand and Daylight in the New Tallinn Town Hall Buildings the Influence of Facade Design

AbstractThe site of the new Tallinn Town Hall designed by the BIG architects is situated to the north of the medieval city center on the edge of the green ring close to the waterfront. The goal is to create a new urban typology that combines the human scale and intimate experience of the medieval townscape, with the public space and municipal symbolism of the modern extension. The New Town Hall will be an open and permeable public institution, extending both town center and the green ring all the way to the water's edge. The building will be created of a village of ten individual departments and two for common space and meeting rooms. Each department is accommodated in its own dedicated office building. A thirteenth building, the tower hosts the City Government, the City Council and the Council Hall on the top floor. The departments are grouped together to meet the programmatic requirements of adjacencies. The departments are consolidated in a village-like cluster, allowing them to perform as a single open office structure as well as ten independent departments. The departments are hinged on the corners and rotated to leave courtyards for daylight and views between them. The many generous openings also provide views to the public ground floor below as well as the sky above. The current paper gives an overview of the daylight modeling and facade design, describes passive architectural cooling strategies considered. Estonia is situated in latitude 59° which means that the solar angle of incidence is rather low from late autumn to early spring. The maximum solar angle of incident is just 7° in December 21st. Then at the other side the summer temperatures are of average 27°C which makes the shading strategies essential. The building is currently in detail design phase and the construction work will presumably start in early 2014. The building has been already shortlisted for a World Architecture Festival Award in the Future Projects and Competition entries category

Application of Sensitivity Analysis in Design of Sustainable Buildings

ABSTRACT: Building performance can be expressed by different indicators as primary energy use, environmental load and/or the indoor environmental quality and a building performance simulation can provide the decision maker with a quantitative measure of the extent to which an integrated design solution satisfies the design requirements and objectives. In the design of sustainable Buildings it is beneficial to identify the most important design parameters in order to develop more efficiently alternative design solutions or reach optimized design solutions. A sensitivity analysis makes it possible to identify the most important parameters in relation to building performance and to focus design and optimization of sustainable buildings on these fewer, but most important parameters. The sensitivity analyses will typically be performed at a reasonably early stage of the building design process, where it is still possible to influence the important parameters. The methodology is presented and an application example is given for design of an office building in Denmark