Multi-domain model-based control of an adaptive façade based on a flexible double skin system

Abstract

Adaptive envelopes have the potential to significantly reduce energy use in buildings while ensuring high performance. These envelopes interact with multiple interconnected domains, such as daylight, indoor air quality, thermal comfort, and energy use, which can often conflict with one another. Identifying and developing suitable control strategies that can optimally manage the envelope’s impact on many domains and avoid sub-optimal operations is an open challenge. Conventional approaches commonly adopted in buildings and building envelope control based on schedules or relatively simple decision trees may be unable to tackle the dynamic behaviour of adaptive envelopes. Due to their complexity, more advanced control approaches based on simulation-informed decision-making are scarce in both research and practice. In this work, we propose a multi-domain model-based control (MBC) algorithm for an adaptive façade concept based on a flexible Double Skin Façade (DSF). The proposed method, which aims for a balanced performance over different comfort domains and energy use, employs a co-simulation approach where the DSF is modelled in a Building Energy Simulation (BES) tool and the control algorithm to manage the simulation and optimize the control of the façade is developed in a generic programming language. To the best of our knowledge, this is one of the first attempts to design and demonstrate the effectiveness of a simulation-informed control strategy that can handle and optimise the behaviour of a complex façade by considering multiple performance objectives. The innovation of this approach lies in the MBC algorithm that selects the optimal façade state among over seventy possible states at each timestep, the practical demonstration of the feasibility in a BES tool, and the complexity of the controlled façade system. To verify the effectiveness of the proposed control approach, we compared the innovative MBC to more traditional control strategies, such as schedule and rule-based controls, revealing how it enabled the façade to achieve a better performance in all the analysed domains. By applying the MBC to three different year periods, we showed that the energy and environmental performance was within the selected comfort criteria for all the domains for>80% of the occupied hours, and an energy reduction of up to 70% was simultaneously obtained if compared to more traditional approaches. The control approach presented in this study and the simulation method employed can be used not only to improve the performance of advanced adaptive façades by providing an effective solution to the challenge of balancing multiple conflicting performance domains but also for more conventional building envelope systems that exhibit a certain degree of dynamic behaviour.