Task 56
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IEA-SHC Solar Heating & Cooling Programme International Energy Agency
Task 56
SHC Task 56

Building Integrated Solar Envelope Systems

Solar Energy Harvesting Systems

Prototype Systems

SunRise façade – Modular Building-Integrated Solar Thermal System

By Matteo D'Antoni and Paolo Bonato, Eurac Research, Italy

Product Description

Brief Concept Description

The SunRise facade is an innovative multifunctional metal and glass curtain wall façade module developed for the tertiary building sector. It integrates a solar-thermal system composed of a thermal collector, a small-size water storage and a radiant panel. Moreover, an “hydraulic unit” integrated in the parapet hosts the required hydronic components (pump, valves etc.), a dedicated control box and sensors integrated for metering purposes. The system can harvest solar radiation to cover space heating and hot water preparation loads but can also be used as terminal for the distribution of space heating and cooling energy with the use of the radiant panel. The hydronic circuit of the SunRise façade is connected with the building’s central heating/cooling loop.

Architectural and Technological Integration into the Envelope

Solar thermal collector, thermal storage and radiant panel are installed in the lower opaque section of the façade module, as shown in Figure 28. All the hydronic components in the parapet are hosted in a metal shell designed to guarantee airtightness and a robust structure to support the solar collector. Thanks to the modular structure of the solution, the hydraulic unit in one façade module can be shared with multiple inter-connected façade modules. Maintenance of solar active façades is an issue, especially in the case of high-rise buildings. In this solution, the radiant panel is removable to access the integrated components, minimizing the effort in case of failures. Concerning aesthetics, the radiant panel gives a pleasant homogeneous appearance from inside, whereas the presence of the solar-thermal collector defines the exterior visual appearance of the façade modules.


Figure 28. Internal (left) and external (right) views of the SunRise façade module installed in a test chamber at Eurac Research.

Integration into the Building: System and Comfort

The SunRise façade integrates all safety and operational components required to work autonomously, such as safety valves, expansion vessel, deaerator, solar pump etc. The SunRise façade is coupled with the building’s central energy generation and distribution system with a 2-pipe or 4-pipe connection, to cover all thermal loads including DHW preparation and space cooling delivery. The radiant panel integrated in the façade can deliver heating/cooling, but very deep rooms and the core of the building might require additional emission terminals for a proper climatization. In order to maximize exploiting solar irradiation and improve the local thermal comfort, the management of the heat fluxes from the collector to the integrated thermal storage and to the building’s central system is key: an on-board control and monitoring unit manages the system.

SWOT Analysis

Strengths

  • Heating and cooling distribution is integrated in the façade, hence living area is not affected
  • A hydraulic module functioning as hydronic, control and monitoring unit is used to manage the heat supply and to meter the heat fluxes
  • The façade is modular and can be adapted to fulfil different width and height requirements
  • The unit can be prefabricated using standardized components

Weaknesses

  • solar-thermal collectors define the exterior visual appearance of the façade modules
  • The investment cost is higher compared to conventional passive façade solutions
  • The integration of components in the façade results in additional thickness and weight, which affects the installation burden in turn
  • Space cooling, ventilation and space heating of the core of the building must be fulfilled by traditional systems 

 
Opportunity

  • Solar thermal collectors with highly valued visual characteristics are entering the market
  • Façades of high-rise buildings are rarely exploited for RES generation
  • The solution can be adapted to multifamily buildings

 
Threats

  • Architects’ awareness and acceptance is a major barrier to overcome
  • Certification of safety and energy performance of the façade module is timeconsuming and expensive due to the wide range of national or international standards
  • The cost of fossil fuel energy is comparatively low and incentive schemes often ignore innovation and CO2 emission savings, owing to technological advances

Lessons Learned

  • Architects’ awareness and acceptance is a major barrier to overcome
  • Certification of safety and energy performance of the façade module is timeconsuming and expensive due to the wide range of national or international standards
  • The cost of fossil fuel energy is comparatively low and incentive schemes often ignore innovation and CO2 emission savings, owing to technological advances 

Further Reading

D’Antoni M., Bonato P., Fedrizzi R. “On the development of a façade-integrated solar water storage”. Journal of Façade Design and Engineering, Vol. 6 Nr. 2, pp. 9-20, April 2018. DOI: https://doi.org/10.7480/jfde.2018.2.2048.