Ecobuilding with shutters in Africa
Green buildings are emerging all over the world and all have a priority
objective: to minimizing, and if possible reducing to zero the amount of
consumed energy… most of the time by heating buildings in winter. The big
challenge is therefore insulation to minimize heat loss during the cold
season. Designers then hunt for air holes, try to incorporate
heat-insensitive materials, optimize room lighting during the cold season,
etc.
But what about green buildings in Africa, which consume less energy
for heating than European buildings. Would not there be ecological issues in
Africa? Que nenni! But the stakes are different: for most African countries,
the energy spent on heat must be saved. Air conditioning is the energy abyss
of many African, Asian and American buildings.
Paradoxically, there are
few examples of buildings with true ecological characteristics. We must look
for them, find them, we will say it ourselves. And yet, when we find them,
we find real nuggets.
Among these nuggets, here is the project "9
degrees" Hassan Hachem designed the BAD architectural firm.
This is a tower project for
Equatorial Guinea.
The project initially set strong constraints and
objectives.
1. Minimizing the absorption of solar heat from outside 2. Reducing
the demand for primary energy for cooling and ventilation by means of
passive systems 3. Optimally using sunlight during the day 4. Saving
water 5. Improving landscape and biodiversity 6. Closing the life
cycle and future adaptability 7. Reducing / Reuse / Recycle 8. LEED
and environmental management The result is surprisingly elegant and
advanced from a technical point of view. Currently, the project is being
finalized and three options have been explored.
1. Minimizing vertical solar heat absorption through fixed blades.
In warm climates such as Equatorial Guinea, to minimize the absorption of
solar heat through the outer skin, avoid direct sunlight on the exterior
facade. While the shadow of the outer walls is paramount, it can have a
negative impact on natural lighting levels indoors especially in offices.
Option A uses vertical blades of the same type at different distances to
filter the direct sunlight before it crossed windows and walls, in all solar
directions. Whereas deep blades are a traditional African solution
(protecting during the dry season, but allowing the sun, in the rainy
season, to heat the building in the mornings), sunscreens covering the
entire facade allow a more uniform intensity and a more compact built
volume.
2. Minimizing vertical solar heat absorption through fixed blades.
In warm climates such as Equatorial Guinea, to minimizing the absorption
of solar heat through the outer skin, direct sunlight should be avoided the
outer walls. While the shadow of the outer walls is paramount, it can have a
negative impact on natural lighting levels indoors especially in offices.
Option A uses vertical blades of the same type at different distances to
filter the direct sunlight before it crosses windows and walls in all solar
directions. Whereas deep blades are a traditional African solution
(protecting in the summer, but allowing the winter sun to warm up the
building in the mornings), sunscreens covering the entire facade allow a
more uniform intensity and a mor compact built volume.
3. Minimize solar heat absorption through a cantilever slab.
Again, in warm climates like Equatorial Guinea, to minimize absorption of
solar heat through the outer skin, it is necessary to prevent the light from
sun falls directly on the outer walls. While the shadow of the outer walls
is essential, it may have a negative impact on the indoor levels of natural
lighting, especially in offices. According to Hassan Hachem, the
project's promoter, the three design options aim to set a new benchmark for
sustainable design in the Central African region. It's also about getting a
high LEED level or some other instrument of sustainable design. The future will tell if this project is keeping its promises, but
in any case, the initiative deserves to be welcomed.
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