An innovative control strategy for Breathing Walls aimed at both heating and cooling energy savings
Year: 2025
Type: article
Abstract: Breathing Wall technology, which is based on the thermal interaction between porous envelope layers and ventilation airflow, is a prominent Dynamic Insulation system for buildings due to its energy-saving potential and adaptability. Previous studies identify two working regimes: pro-flux and contra-flux, depending on heat flux and airflow directions. The efficacy of Breathing Wall technology during winter, using the contra-flux regime with inward flow, has been demonstrated. However, the effectiveness in dissipating heat during summer of the pro-flux regime, traditionally associated with outward airflow, has been tested only by few studies affected by some limitations. This work presents a numerical investigation of the effectiveness of Breathing Wall technology in reducing air conditioning energy needs throughout the year, focusing on defining a control strategy for highly variable outdoor summer conditions. A virtual case study of an office building in Milan (Italy) is analysed using TRNsys 18 in combination with a Matlab script, to compare the combination of Breathing Wall components and dedicated ventilation units to a reference building with a non-permeable envelope and a traditional ventilation system. Results show savings of up to 22% in winter and, due to the innovative control strategy, 14% ÷ 16% in summer. Over the entire year, the total electricity consumption for thermal use and ventilation is reduced by up to 18% compared to the reference case. This work also provides a deeper understanding of the underlying physics and a framework for adapting the control strategy to different contexts, increasing the flexibility of this technology and its adaptability to future climate conditions. • Winter and summer performance analysis of a building with Breathing Walls envelope. • Optimization of a control strategy to operate the Breathing Wall envelope in summer. • HVAC yearly electricity use 18% lower than in a reference building. • The airflow direction affects the pro and contra flux working regime effectiveness. • Improved understanding of dynamic interaction between Breathing Wall and buildings.
Source: Energy Conversion and Management
Authors: A. Alongi, A. Angelotti, L. Mazzarella
Institution: Politecnico di Milano
Language: English
Subfield: Building and Construction
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,600
OpenAlex ID: W4416754869