My research focuses on how to use the wavelengths of light, the phenomenon of ectotherms and how to translate it into architecture.
I decided to concentrate on the phenomenon of ectotherms; animals who have specialised cells that enable colour change within their skin. Variable reasons exist for lizards and chameleons to change their appearances: age, gender, colour of the environment, season of the year, temperature, mood, physical state of health or the intensity of light.
I am mostly interested in the cause of different seasons, temperature and intensity of light. For this I chose the Agama Agama, the rainbow lizard, a lizard belonging to the Agamidea family, found in most Sub-Saharan Africa.
They change the colour of their skin to maintain a favourable body temperature. During night males are dark and keep a low body temperature. In the morning, when the sun comes out, they seek a sunny spot, where they can absorb the wavelengths of the sun to raise their body temperature. During this process their skin turns pale and transforms into different colours. This use this feature to protect themselves whenever they have reached their perfect body temperature. Turning light, their skin reflects the wavelengths and prevents them from overheating.
This chemical reaction is called ‘thermoregulation’. So what does trigger the light-sensitive receptors in their skin?
During night when the skin isn’t exposed to sun radiation, the melanosomes are dispersed throughout the cells. This gives their skin a darker colour, which enables them to faster absorb the sun in the morning. When they have gathered enough heat from the sun, the melanosomes are aggregated in the centre of the cell. This gives their skin a lighter colour, in this case different colours, which enables them to reflect the light to not overheat during the day.
My question is how can we use this natural process and translate it into architecture? Maybe we could use the colour-shifting-phenomenon as a facade element to control the heat on the inside of our buildings?
We know that light smooth materials reflect the wavelengths of the sun thus less heat is transported into the building. On the other hand by using dark rough materials the sun radiations are absorbed and thus warms up the building.
Buildings reacting to their climatical environment do already exist.They are often surrounded by a skin with responsive components. These buildings are mainly focused on the inlet and protection of sunlight.
- Al Bahr Tower in Abu Dhabi : The different screens covering the facade operates as a curtain wall. At night the screens will fold and the glass facade will be visible.As the sun rises the curtain wall will close and the screens will unfold again creating a sun barrier for the facade.
- RMIT Design Hub in Melbourne : The outer skin incorporates automated sunshading that includes photovoltaic cells, evaporative cooling and fresh air intakes that improve the internal air quality and reduce running costs. The cells have been designed so that they can be easily replaced as research into solar energy results in improved technology and part of the northern façade is actually dedicated to ongoing research into solar cells.
- Esplanade in Singapore : A glazed steel space frame with triangular aluminium sun shields protects the building from the sun and from overheating the glass facade. The shields are set to be more open or closed, depending on the angle the sun hits them, so the glass facades are protected from direct sunlight without limiting the views.
My main focus consist in finding a material / creating an adaptive facade with which one I can regulate the temperature inside of my building. For this I am concentrating on the outside temperatures and the daylight hours.
To study the different temperature drop during the seasons in Morocco, I chose Ouarzazate as a case study. Ouarzazate, also called the door to the desert, is situated in the south of Morocco at the edge of the desert.
It has a subtropical-desert-climate with high temperatures during summer, quite chilly temperatures during winter and a quite steady daylight-curve.
How can I use this information to develop a prototype?
Would it make sense to shift the colouring during night and day? Or would it be smarter to shift it over the different seasons?
Thinking about different materials, which would shift colouring, I stumbled upon two-sided sequins used in clothing. It’s one material with two different sides behaving and catching the light differently. Thinking about the shape of the elements I stumbled over the 8 pointed star, which is very often used in the moroccan tiling and referred to as ‘sibnyyah’. The symbol stands for interconnectedness, faith and ultimate harmony.
The idea is to create a kinetic facade with two different sides. One side being in a light reflecting material, which wouldn’t absorb too much heat, useful during the warm seasons or during day. The other side being in a dark absorbent material, collecting all the heat from the sun and transferring it to the inside during the cold seasons or during morning.
The octagon shapes are fixed on rods and would pivot depending on the temperature on the inside. Is the maximum comfort level of room temperature reached, the facade would rotate and the light-tinted side would reflect the sun radiation avoiding any overheating on the inside. The idea is to create a facade, which is responsive to its environment and to its climate.
- Lizards – David P. Badger – Voyageur Press – 2006
- The conversation – Devi Stuart-Fox – http://phys.org – 03/05/2013 http://phys.org/news/2013-05-chameleons-creatures-colour.html (Retrieved 7/09/2016)
- http://www.ouarzazate.climatemps.com (Retrieved 12/09/2016)
- http://www.archdaily.com/270592/al-bahar-towers-responsive-facade-aedas (Retrieved 10/09/2016)
- http://www.archdaily.com/335620/rmit-design-hub-sean-godsell (Retrieved 10/09/2016)
- https://www.esplanade.com/about-us/architecture-and-building-design (Retrieved 10/09/2016)