Impact of active façade control parameters and sensor network complexity on comfort and efficiency: A residential Italian case-study

Authors: Joseph Alexander Roberts, Giuseppe De Michele, Giovanni Pernigotto, Andrea Gasparella, Stefano Avesani.

Extensive literature exists on the use of dynamic shading devices for the control of visual and thermal comfort in non-residential buildings, however research in the residential sector is far less widespread. Several control strategies and thresholds are utilised in literature, yet it is unclear how these should be chosen. The aim of this work is to evaluate the impact of several control strategies and parameters on three Key Performance Indicators (KPIs) (adaptive overheating, useful daylight illuminance and heating demand) in a case-study apartment near Bologna, Italy, modelled in TRNSYS 18 and Radiance. Multiple levels of complexity were tested to evaluate the extent of the benefits of each sensor (temperature, irradiance and occupancy). Three commercially available solar control devices were simulated: external and integrated Venetian blinds and electrochromic (EC) glazing.

The study has shown that occupancy-based controls can greatly reduce overheating, while irradiance sensors are only beneficial for certain orientations. The cut-off angle’s limited effectiveness was revealed, as fully closing blinds led to significant additional overheating reductions. Complex controls did not always outperform simpler controls. Heating demand was found to be easy to minimise, while the trade-off tends to be between overheating risk and daylighting availability. Each control parameter’s impact on the KPIs has been evaluated. Optimal solutions are identified which yield near-best performance for all three KPIs, however such ‘optimal’ solutions may not represent the wishes of all users, therefore more studies are required to calibrate the control to the user experience.

Open access paper here.