Task 56
Task 56
SHC Task 56

Building Integrated Solar Envelope Systems

Solar Gains Control Systems

Commercial Systems

Architectural Shutters

By Carolin Hubschneider, Fraunhofer IBP, Germany

Product Description

Brief Concept Description

Architectural shutters are elements which dynamically solve fundamental functions of the façade: solar shading, daylight control, dynamic façade U-value, natural ventilation, and noise reduction. Shutters can be moved horizontally or vertically in front of the window and cannot be used on fully glazed façades. In their most sophisticated versions, shutters can increase the façade insulation and control utilization of solar heat gain and daylight, thus reducing the energy needs for heating, electric lighting, cooling and ventilation.

Architectural and Technological Integration into the Envelope

An aluminium framework-based façade system is mounted directly on the outside of the window frames using an integrated, exterior placed drive system. Shutters are suitable for plane façades and can be used for both new and existing buildings and for all façade orientations. However, since shutters need ‘parking spaces’ when they are open, the energy saving potentials can normally only by realized on façades with maximum 50% glazing.

Integration into the Building: System and Comfort

Shutters should be operated automatically (with manual override) to realize the potential energy savings and improvement of thermal and visual indoor climate. For this reason, they have to be connected to the power supply of the building. For the control algorithm, input data from several sensors of the building automatization (photo sensor, temperature sensor and presence sensor) has to be used.


Figure 56. Examples for shutters (Reference: left - Photo by HardyS from Pixabay; right - Photo by Pierre Ch√ĘtelInnocenti on Unsplash).

SWOT Analysis

Strengths

  • U-value and g-value of the façade are adjustable and depending on the climate condition solar heat gains can be used or rejected
  • The application of transparent material with high insulation is possible
  • High privacy is possible
  • Street noise is attenuated
  • Burglary risk is reduced

Weaknesses

  • Regular service and maintenance are needed
  • The possibility of installation depends on the façade design (can normally only by realized on façades with maximum 50 % glazing because of the “parking space” for the shutters)
  • An additional system is necessary to cope with glare when shutters are not activated
  • When shutters are activated, the view is reduced
  • The appearance of the façade is changed by the installation of shutters

 
Opportunity

  • Dynamic u- /g-value is getting more important because of climate change
  • In rooms with several workplaces and windows, shutters can be set to individual positions

 
Threats

  • The system cannot be applied to currently popular all-glass facades
  • Next to the windows, space for storing the shutters is needed; the corresponding space is unavailable for other technical devices

Lessons Learned

  • As a retractable system, shutters can help to dynamically optimize the energy flow through the facade depending on daytime, time of year and occupancy demands. Nevertheless, their flexibility regarding daylight supply, glare control, view out and solar protection is generally not as high as it is for venetian blinds.
  • Shutters need regular service and maintenance.
  • As the system does not operate like for instance venetian or textile blinds only in the facade pane, the applicability depends on facade design. I.e. enough space, «parking space» is required beside the window itself. They have therefore a larger architectural signature.
  • Shutters are generally more wind resistant compared to venetian or textile blinds and therefore are also suited for buildings of medium height.