CONGRESO
Optimization of building facade solar protection design in an urban context Energy and interior comfort through BIM and evolutionary algorithmic modelling a case study in two cities Porto, Portugal and Valencia, Spain.
Abstract
Since half of the world's population lives in cities that collectively consume three quarters of global resources, with predictions of their increase to three quarters by 2050 [1], it is imperative to understand and create strategies to minimize energy consumption in this particular environment. Current energy efficiency directives in EU buildings (Directives 2002/91 / EC, 2010/31 / EU, Nearly Zero Energy Building) impose new requirements on the construction and renovation of buildings with the aim of creating a NZEB built-up landscape. Solar protection design in Mediterranean countries represents a both functional and cultural architectural element used for centuries to ensure the comfort of its occupants and nowadays to minimize energy consumption.
Solar gains can contribute positively to the thermal energy performance of the building, in the form of passive gains, or negatively, in case of need due to lack of exposure or formal and material lack of control. The urban landscape, with the surrounding built environment presents a great challenge to achieve this goal. The approach of maximizing the use of solar energy - whether for the active conversion using solar thermal and / or photovoltaic collectors, or by bioclimatic passive strategies, allows the reduction of heating and lighting energy. The design team is presented with a challenging task that can be overwhelming. To work towards this goal, computational modeling directed to the availability of solar radiation can be a tool to support design decisions for architecture and urbanism. However, the probability of finding an ideal solution by manual trial and error method is extremely time consuming and does not guarantee the optimal result. Manual calculations can be made for determining the best solar envelope using the solar azimuth and elevation data alongside the projected shadows of neighboring constructions or context. However, manual calculations are a long and inaccurate process for urban environments.
Nonetheless, today with the aid of digital calculation designers can create workflows that may overcome these obstacles. Some computer-aided and parametric design programs integrate environmental simulation tools that include the ability to evaluate solar envelope performance. A procedure that requires some external information, such as location, surrounding volumes, plans that define the area to be evaluated and periods of analysis. However, this system only allows to evaluate the potential of the solar envelope, being the process of manual optimization, often based on the experience knowledge acquired from the designer, limiting the range of solutions to these factors and the time available for the design. Given the geometric and volumetric complexity of the urban environment along with the objectives of the study, an alternative and more efficient method is proposed.
