Abstract
With the global target to promote energy saving in buildings, various studies draw attention to the role of environmentally benign building envelopes. In this regard, double-skin façades (DSFs) have been proposed as a promising passive building technology to enhance the energy efficiency and improve the indoor thermal comfort at the same time. A comprehensive analysis of the current design of DSFs, and their technical aspects is presented in this paper. Construction characteristics of DSFs are also reported. The impacts of DSFs on the energy efficiency and thermal performance are discussed by looking at measured and simulated performances. Findings confirm that significant benefits result from using DSFs. Finally, research opportunities are outlined for further investigation.
1. Introduction
Sustainable development principles in the built environment have encouraged researchers to focus on more efficient building envelopes. Façades, as a principal constituent of building envelopes, have a vital role in protecting indoor environments and controlling the interactions between outdoor and indoor spaces. Nevertheless, conventional façades can lead to poor natural ventilation, low level of daylighting, thermal discomfort, and increased energy consumption. These disadvantages are often intensified in modern façades having substantial amounts of glazing [2]. As the result of high solar thermal gains or significant thermal loss at night or in cold climate, extensive glass curtain walls cause significant energy consumption [3]. In recent years, new façade technologies have been designed and proposed for better thermal insulation, shading the solar radiation, improved thermal comfort and visual quality [4,98]. Among the emergent advanced façades, double-skin façades (DSFs) have been proposed as an efficient solution to control the interactions of indoor and outdoor environments [5–18]. As a basic definition, "Double-skin façade is a special type of envelope, where a second “skin”, usually a transparent glazing, is placed in front of a regular building façade" [8].
6. Conclusions
Buildings account for approximately 40% of global final energy use and this clearly indicates the necessity to adopt effective sustainable techniques for optimizing the performance of green buildings. One of the most critical aspects of designing energy efficient systems for integration in green buildings is to draw sufficient attention to the façades during the early stage of design. This is due to their direct impacts on the overall energy budget, user’s comfort and cost of the building services. In this line, the study developed a holistic overview of available literature on DSFs with viewpoint to their analytical procedures, ultimate benefits and challenges. This research aimed to oversee the current implications and implementations plus the future prospects of DSF systems. Findings confirmed that DSFs are globally widespread as a generally acceptable energy saving technique, an attractive option for improving the sustainable energy performance and an architecturally sleek option of building envelopes. Various attempts have been done to quantitatively measure and analyze their effectiveness. On the contrary, some studies criticized that only well-designed/ventilated DSFs can perform efficiently and their overall performance is highly dependent on the climatic conditions.
