Photo Credit: Amanda Mustard
The relentless growth of cities urges for solutions that relate to the improvement of levels of comfort in confined spaces. Slums, being directly affected by the lack of space, are an intriguing object of study. With constraints on cost and feasibility, we believe the population will greatly benefit from a passively powered space-conditioning system.
How? Software “Sake”
We have developed software that provides strategies that most affect natural ventilation by changing the following parameters:
A* (Openings): The value refers to the amount, geometry and distribution of openings that a building has to the exterior and interior network. These openings usually are windows, doors, chimneys, etc. The variation of this value will help to define the amount of fresh air coming into the building.
H (Height): This parameter refers to the height of a building. Hot air is driven to the upper part of a building due to its decrease in density, and vice versa when cold. This phenomenon creates differences in pressure, generating the opportunity to drive passive ventilation with the control of this parameter.
S (Interior surface): The interior surface area mostly affects to the amount of energy that a material can absorb and release. Changing this parameter will allow us to control the temperature of an interior according to current adaptive comfort models.
These values depend on a climate analysis that our software “SAKE” performs. With the climate data extracted from a specific location, we can provide a desired ventilation rate (Fn) to determine the amount of fresh air that a building has. If this rate is high, the ventilation will be high, if this rate is low, the ventilation will be low.
All these parameters are part of relationships that our program “SAKE” uses. Thanks to vector data collected from GIS like “Open Street Maps” or “Google maps 3D viewer”, we can analyze existing buildings and provide retrofit or new design strategies.
Our efforts will be focused toward the following goals:
Definition of comfort zones (ASHRAE): This will set goals in terms of finding ideal living conditions according to the location of study. If climate conditions are too extreme for the implementation of Athermal resonator strategy, we will suggest ways to improve living quality during other seasons.
Extrapolate the analysis: Our ultimate goal is to design a simple tool that will allow the accurate analysis of an urban condition so as to provide intervention methods to improve the thermal performance of the built and unbuilt environment.
Case study: Cairo Slums
We are using Cairo (Egypt) as the location of our project. Cairo is located in a hot arid climate where cooling is needed most of the year to achieve thermal comfort.
Although Cairo haS historically witnessed a large range of passive architecture innovations to address the hot dry climate, today, modern architects ignore these techniques. Instead of using wind catcher, roof lanterns and Mashrabiyas, nowadays everything is substituted by the HVAC systems. The residential building industry is responsible for the 43% of the total energy consumption of Egypt, which increased in the last five years. This caused the government to cut the electricity in all districts of Cairo in an average of 2 hours a day in summer and half an hour a day in winter in the last two years.
We are choosing slums in Cairo in particular for a context for our study, mainly for the alarming growth rate or these settlements, which is clearly out of the government’s control. The Egyptian Housing Ministry estimates that 40% of Cairo’s population is living in slums.
It became a fact that it is not only impossible to remove the existing informal areas, but also to very hard to control reduce the growth rate of these areas: this is the ugly truth.
Therefore, it became an urgent matter to study and research these slum areas and try to fix the problems on a larger scale with the available resources: the bare minimum. The slums areas have a lot of problems; we are aiming to passively solve the lack of ventilation/thermal comfort for people to have a ‘humane’ life.
Focusing on the morphology of the slums themselves, they are in a stagnant bath of unmoving air. Buildings are so close together and streets are so narrow that the air is literally forced into motionlessness. These conditions are unbearable for locals living without fresh air at the urban scale. In Cairo, the need is dire and with “Allometric Sake” we are providing solutions based on simple and economical architectures.