Solar shading

This paper presents the first results of a research work aimed at the optimisation of a shading system through parameters of visual comfort – Useful Daylight Illuminance (UDI), Daylight autonomy (DA) and Daylight Glare Probability (DGP) – and Total
Energy (TE) consumption (cooling, heating and lighting per year). The goal is to define a shading system for office buildings that delivers visual comfort for users whilst reducing energy consumption for indoor climate control and artificial lighting.
As the design of the shading system considers the use of shape memory alloys (SMA) as micro-actuators to accomplish solar
adaptation, Origami pattern has been adopted to guarantee a relatively large displacement of the shading system with a small
deformation of the SMA wires actuators. Thanks to this shape change, generating overlapped pleats and angle variation and using different materials, it has been possible to provide alterations of the direct light transmission inside the building while maintaining a certain degree of diffuse light component.

This paper provides an overview of available innovative shape morphing building skins and their design
principles. In particular, the proposed review deals with comfort-related issues associated with dynamic
solar shading devices, building integration of smart materials, and morphological analyses related to the
most recent shape morphing solar skins.
In the first part of the paper, an introduction to the typologies of movement in architecture, its
concept and application are presented. An explanation of biomimetic principles together with an overview
of user’s response to dynamic shading devices is also provided. This is followed by the description
of the design principles for shape morphing solar shadings with particular focus on energy and comfort
aspects, smart materials and biomimetic principles for efficient movements.
A review of most recent developments on the topics of comfort, users’ response and control of
dynamic shading devices, is presented and summarized in a comparison table. The main technical and
mechanical properties of the most diffused smart materials (Shape Memory Alloys, Shape Memory
Polymers and Shape Memory Hybrids) that can be used for innovative shape morphing solar skins are
illustrated in detail and compared. Biomimetic principles for efficient movements complete this part of
the work.
The principles illustrated in the previous part of this paper are then used to critically analyse the most
recent examples of building integrated shape morphing shadings.

Integrating daylight and energy performance with optimization into the design process has always been a challenge for designers. Most of the building environmental performance simulation tools require a considerable amount of time and iterations for achieving accurate results. Moreover the combination of daylight and energy performances has always been an issue, as different software packages are needed to perform detailed calculations. A simplified method to overcome both issues using recent advances in software integration is explored here. As a case study; the optimization of external shadings in a typical office space in Australia is presented. Results are compared against common solutions adopted as industry standard practices. Visual comfort and energy efficiency are analysed in an integrated approach. The DIVA (Design, Iterate, Validate and Adapt) plug-in for Rhinoceros/Grasshopper software is used as the main tool, given its ability to effectively calculate daylight metrics (using the Radiance/Daysim engine) and energy consumption (using the EnergyPlus engine). The optimization process is carried out
parametrically controlling the shadings’ geometries. Genetic Algorithms (GA) embedded in the evolutionary solver  Galapagos are adopted in order to achieve close to optimum
results by controlling iteration parameters. The optimized result, in comparison with conventional design techniques, reveals significant enhancement of comfort levels and energy efficiency. Benefits and drawbacks of the proposed strategy are then discussed.

An integrated design approach has been applied to the case study of a new zero energy building in Milan. The case study is a four-story university building mainly dedicated to offices for teachers and researchers. The design approach combines facade orientations, internal space design, high envelope insulation, solar control devices, daylight integration, efficient lighting, and natural and mechanical ventilation with hygrometric and thermal recovery system. A parametric analysis was carried out, by means of dynamic simulation, in order to optimize and assess efficacy and synergies of such strategies in the moderately hot and humid climate of Milan. The influence of the choice of the comfort set point, according to standard EN 15251, has also been investigated. The results show that natural night ventilation and solar control optimized with daylight integration might have a significant impact in reducing cooling and lighting energy demand and system loads without increasing heating demand.

Contemporary records that indicate immense energy consumption, especially in large-scale buildings, along with the dynamic parameters of climate conditions and diverse occupancy needs have necessitated an extensive research into climate responsive envelopes. With the ever-growing variety of innovative façade components and intelligent kinetic systems, finding ways to simplify the design approach is becoming more and more important. The integration of smart materials into established technologies can lead to simpler, cost-effective and user-friendly kinetic solutions.

This paper focuses on climate-responsive shading, providing an evaluation of existing kinetic shading system examples and proposing their optimization with the implementation of shape memory alloys (SMAs). These materials exhibit the unique ability to have pre-programmed form settings that are connected to specific temperature values. Due to this fact, shape memory alloys can be a lightweight, solid-state alternative to conventional smart assemblies with the additional ability of acting both as an actuator, controller and sensor. Architectural components could thus be independent of intermediaries, integrating adaptability through the material use itself. An advantage of using SMAs within the context of responsive systems is that the sensor/actuator cycle could be completely internalized, significantly reducing the complexity of the system and leading to a constitutive model.

In this paper we specifically try to identify the components in existing kinetic shading systems that could be improved with shape memory alloy actuators. Furthermore, we explore the potential for novel aesthetics and specifically the augmented ability given from SMAs for the design and application of more intriguing morphological changes of the façades. In this way, the shading elements will provide the ability to adjust the interior conditions inside the building and also change the way people perceive it.

The method for approaching the research question is based on computer simulations and lab scale models implementing nickel-titanium (Nitinol) alloy wires. We aim to demonstrate the possibilities as well as the restrictions of such an implementation. The techniques for the SMAs-based, climate-responsive shading systems that we explore are aimed toward new constructions as well as existing building stock, with the goal to avoid complex control systems. We believe that incorporating these no-mech dynamic systems into façades could lead architects to more seamless, biophilic designs with positive impact on ecological imprint and the potential to be more efficient and affordable to a broader audience. We hope that the results presented in this paper will stimulate a further interest in the integration of shape memory alloys within architectural components.

A transition to a solar-based carbon neutral economy is crucial to reduce the overall ecological footprint and greenhouse gas (GHG) emissions while providing new housing for the growing urban population worldwide. One of the key measures to achieve such reductions as a way to mitigate and adapt to climate change is to increase food and energy self-sufficiency in residential areas. The objective of this study is to explore the potential self-sufficiency in terms of food and energy in generic residential districts in Singapore and Southeast Asia. Computational tools are employed to obtain quantifiable indicators based on sunlight availability. A series of building typologies and urban forms was created as abstractions from actual residential developments in Singapore (1.3°N). In total, 57 cases were assessed in terms of sunlight availability and the impact of three density and geometry parameters: plot ratio, site coverage and building height were considered. Results from selected cases were compared to Hanoi's conditions (21°N). The results show that the indicators having the higher impact on the food and energy self-sufficiency are plot ratio and building height. The cases with the lowest plot ratio (PR < 1.9) achieved food self-sufficiency when a hybrid higher-yield farming method was applied. Regarding energy harvesting, the cases with the lowest building height (<42 m) achieve energy self-sufficiency due to the maximum exposed area with PV per number of residents. In low-latitude regions, solar access is more evenly distributed among all facade orientations than in higher latitudes, therefore providing all facade orientations with food and energy harvesting potential. Food and energy self-sufficiency in equatorial regions is more heavily influenced by the available farming and PV area in relation to the total population than by the reduction of sunlight availability due to building typology and morphology.

The architectural integration of photovoltaic technologies is
one of the most interesting issues today among those related
to the disciplines of architectural design and architecture
technology. This paper delas with some case studies that are considered to be of particular interest for the architectural integration of PV awnings and fabrics.