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ABSTRACT
Façade technology has been undergoing continuous evolution with various systems suited for enhancing energy performance and occupancy comfort in new and retrofit buildings. In cold climates, Double Skin Façades (DSF) can provide a solution to low ambient temperatures and a potential for façade-integrated energy production, thus responding with a great extent to such measures. This study presents a new workflow to optimize DSF through balancing the façade's geometric form with relevant thermal loads, daylighting availability, and energy efficiency potentials in buildings. Brute-force parametric simulation was applied with a combination of visual scripting and sensitivity analysis to understand the behaviour of the outer and inner skin layers of DSF in cold climates. Thermal transmittance was calculated and modeled for radiative and conductive heat flow. The optimization was performed for five geometric parameters: Tilt angle within the façade (г), Window to Wall Ratio (WWR), Vision-Spandrel Ratio (VSR), Floor Height (h), and Cavity Depth (d). Results indicate that, among the effect of a multitude of variables, a DSF system with an integrated renewable energy source can achieve nearly 38.7% to 45.2% energy improvement. In terms of daylighting availability and visual comfort, a г of 50o was the most adequate in balancing Annual Daylight Exposure (ASE) and Spatial Daylight Autonomy (sDA) ranges with an h of 3 m to 3.5 m. Higher values of h yielded moderate energy improvement with best visual comfort conditions. If d is held constant at 1.2 m, energy performance was found to be optimum with reduced floor heights.
INTRODUCTION
Achieving energy efficiency in buildings is highly emerging as a main concern in the world. Today's buildings are responsible for around 40% of the energy use and around 38% of CO2 emissions, which influences the necessity of adopting effective solutions to contribute to carbon-neutral goals and tackle net-zero energy aspects (Chang & Shen-Guan 2015; Amasyali & ElGohary 2018). The urgent need to adapt to such approach has had researchers and building professionals focus on optimizing the role of façades in energy efficiency, thermal and visual comfort, and the possible integration of energy harnessing systems in buildings.
Façades have the primary role in controlling the indoor spaces and maintaining the relationship between the internal and external environments (Gelesz & Reith 2015; Ghaffarianhoseini et al....