The Factors of Ventilation

Factors contributing to the construction of Homes in Senegal

Documentation

1. Auberge

This location shows how the environment is taken into consideration where wind and natural light is used from the outside. This is a relaxing area where no extra energy such as light or air conditioning is usually needed due to the use of the space.

The way this location in the Auberge uses the courtyard is a really great way where it takes into consideration all the natural light provided by the sun and has shade through the use of vegetation.

This is an example of the type of windows currently used where the slant in the windows allows for natural light and wind circulation to occur. This type of design however does not allow for them to be closed and let mosquitos and other bugs in.

This is showing another view of the upstairs lounge area in the hotel where the space is clearly meant to resemble the same purpose as courtyards do, a place to socialize and relax during the day.

2. Sacree Coeur

This is an example of a recent neighborhood development in Sacree Coeur where middle class homes are being developed and are taken environmental aspects into consideration. This includes better air circulation through the different designs for the windows, doors, and outside elevations. The second story shows a incorporated porch design which helps with ventilation.

This picture shows one of the temporary homes being built all around Dakar so that land can claimed. These homes provide many jobs but are not efficient material-wise as these homes get destroyed after they are approved and are usually replaced with the homes in the previous page.

3. Thiaroye Sur Mer

Location: Thiaroye Sur Mer.

It is one of the poorest neighborhoods of Dakar. The houses are built right next to each other and a small alley separates block of houses. The doors and windows have small openings to let the air in.

4. Keur Momar Sarr

This shows an upclose view of a window style where air circulation is being taken into consideration and is a cheap and affordable alternative to a window with glass.

This temperature reading was taken from one of the bedrooms in Keur Momar Sarr and shows how hot it can get and the current temperature at that moment. It reached a peak of 84 degrees Fahrenheit and was currently that temperature when this picture was taken in the afternoon around 3 pm.

This is showing the temperature inside of a school room in Keur Momar Sarr where as can be seen, can get really hot but with low humidity.

Analysis

1. Doors

As can be observed through the pictures above, some people would rather have air circulation than safety from mosquitos and malaria as temperatures can get really high, especially within a confined space. Doors would best be made from wood since it has a lower heat coefficient than most materials used for doors. Metal doors have a heat coefficient of 1.2 Btu/hr ft^2 degrees Fahrenheit while wood can either be .45 or .65 Btu/hr ft^2 degrees Fahrenheit.

2. Roof

The roof is a very important aspect within the construction of homes and buildings and does not seem to be as high in priority. Roofs can have a major impact on the temperature within a home. A high solar reflectance is the most important characteristic of a cool roof as it helps to reflect sunlight and heat away from a building, reducing roof temperatures. A high thermal emittance also plays a role, particularly in climates, like in Senegal, that are warm and sunny. Reduced energy use makes a cool roof transfers less heat to the building below, so the building stays cooler and uses less energy for air conditioning. Roofs can also Improve human health and comfort as cool roofs can help to prevent heat-related illnesses and deaths. Together, these properties help roofs to absorb less heat where this can have an impact on the lifestyle of its inhabitants.

Chimney (stairs)

Although chimneys are not too common, chimneys can affect air circulation quite well in favor of the homeowner. Roofs create the stack effect which will cause air circulation. During the hot season, the warmer indoor air rises up through the building and escapes at the top either through open windows and ventilation openings. Since warm air is rising, it reduces the pressure in the base of the building where cooler air can come in through windows. One way that can create this stack effect is through staircases as was the case where we spent our nights in Keur Momar Sarr. This style allows for air circulation without interfering much with the homeowner’s lifestyle.

image from:

http://greendesigncollective.com/green/_strategies/30-roof-monitor.jpg

3. Sun directions

After several interviews with masons and homeowners, the findings about the sun direction was the same, it was not taken into consideration in the design and construction of buildings. However, knowing the direction of the sun is critical while building a house, especially when it comes to the openings and ventilation. Knowing the positions of the sun at each time of the day enables the architect to design accordingly. For example, facades on a house to provide shades for the building and help with overheating.

image from: http://www.architecture.com/RIBA/Aboutus/SustainabilityHub/Designstrategies/Earth/1-1-3-2-Buildingorientation.aspx

4. Wind Directions

Another important aspect to consider when designing a building is the wind directions, especially in countries that are affected by high wind currents. Surprisingly, there were little to none consideration to wind directions in building designs and constructions in the places visited in Senegal. Even though people knew the wind direction, this critical information was ignored.

In the school in Keur Momar Sarr where we visited, the buildings were built against the wind directions. Therefore, the rooms temperature were very high  and the air did not circulate easily.

By knowing the wind direction, architects can provide openings to ease the ventilation inside the buildings. In a classroom in Louga, the windows were built to facilitate the ventilation inside, making the room very comfortable.

image from http://sustainabilityworkshop.autodesk.com/buildings/wind-ventilation

           

5. Property of Materials

For roofs, one of the most commonly used materials is corrugated metal. Corrugated metal is available in sheets with wavy ridges and is used in construction projects for roofing or siding. It is lightweight and economical to install and is highly durable and is able to support a large amount of weight without buckling. Homes in coastal regions are more likely to use corrugated metal, since it is a moisture-resistant material. It is a low-maintenance choice, and may be less expensive to install than other building materials, such as brick or concrete. This product can also be recycled, and this fact makes it attractive to homeowners who want to go "green." Corrugated metal siding can be made from aluminum or steel. Aluminum is the material of choice in areas near the ocean, since the aluminum will react with the moist, salty air to form aluminum oxide.

When looking at heat transfer coefficients, corrugated metal as a roofing material is 1.5 Btu/hr ft^2 degrees Fahrenheit while 2 inches of concrete slab has a coefficient of 0.3 Btu/hr ft^2 degrees Fahrenheit. As can be seen, concrete would be preferable as it has a lower heat coefficient.

Tile roofing, which lasts a long time and will not burn under a scorching summer sun, is a great choice for warm climates. Clay tile, which was used in one of the schoolhouses, usually last longer than any other kind of roofing material. Tiles are also fireproof and resist rot and insects. These tiles are however very heavy that the roof needs reinforcement to support its weight. Concrete tiles will last just about forever but the the material they lie on will go bad every eight to twenty years. Tile roofing is also expensive which explains why it is not used as often.

6. Challenges with Ventilation

Even though ventilation is an important aspect to consider in building construction, there are some challenges associated with ventilation, especially in the country of senegal.

1. Insects and Diseases

By letting too much air in, there is a risk of letting insects inside the house, especially mosquitoes. Most houses are build with a central open courtyard. The courtyard helps with the ventilation, however, it allows mosquitoes to get in and spread malaria. In the raining season, malaria cases may increase due the the high number of mosquitoes. In the dry season, there are a lot of flies that spread diseases such as typhoid fever, cholera and dysentery.  

image from http://www.who.int/malaria/publications/country-profiles/profile_sen_en.pdf?ua=1

2. Energy costs

The lack of proper ventilation causes many Senegalese families to invest in fans or air conditioners, which drive their electricity cost very high. In an interview with Aminata, a jewelry seller on the Island of Goree, she revealed that she spent about 20,000 F CFA, an equivalent of $40 on electricity each month. Her energy bills represent a big portion of her volatile income. The reason why her energy cost is so high is the fact that her one room house does not have the proper ventilation to provide a comfortable and cool environment.

3. Dust

Because of the dry and arid climate, dust is a threat to many households. Therefore, without proper ventilation techniques, the wind can spread large amount of dust inside buildings, making inhabitants lives very difficult. In the recent years, the numbers of dust storms has increased because of climate change.

image from http://newscenter.berkeley.edu/2011/12/12/climate-change-kills-trees-in-africa/

Malaria, Bugs & the Outside World

Malaria, Bugs & the Outside World

by Talia Dunyak & Jennifer Chen

1. Data

1. Clinics: The clinics in Senegal are generally run by doctors. They are often in charge of distributing bed nets and giving vaccinations and other medical tests and treatments. Sometimes clinics are too far away for people to easily access. They’re are not enough doctors within Senegal because of the “brain drain.”
2. Bed nets are usually hung from the ceiling or wall and should cover the entire bed. There should be one net for each bed, but due to the lack of nets this is not always the case. Nets come in several varieties and can be changed from circle to square nets and vice versa.
3. Nets should be washed with regular soap and water and not with detergent. They should be air dried in the shade, not in the sun. This helps to make the impregnation last longer.
4. Bed nets are shipped to Senegal from other countries. Some labs are dedicated to testing the efficiency of the nets (making sure they last as long as the company says they do).
5. Bed nets are freely distributed through the Senegalese governmental organization PNLP every five years. This allows many people to receive nets and because of this the malaria rate has gone down.
6. Mosquitos are attracted to standing pools of water and breed in stagnant water. Because people often wash their clothing in the courtyards of their homes, standing water can be a problem within homes.
7. One way to prevent mosquitos coming into the home is by using screens. The problems with screens is that they often allow for dust to blow into the home, which is undesirable.
8. After malaria, typhoid is the most common disease. Typhoid is spread by dirty water and food and can spread quickly throughout a community.
9. A new lab will be opening soon in Thies. It was funded by Tulane University and will be used for  laboratory research. This Lab is connected to the existing lab that does work with testing the effectiveness of nets.
10. Although nets are not always free, free nets should be given to pregnant women by clinics. Pregnant women should also take several pills as a precautionary effort against malaria.
11. Many people are in health associations, which work sort of like insurance groups. By paying a nominal fee, members are granted access to free or subsidized healthcare and transportation to clinics.
12. The best protection against malaria is sleeping under bed nets.
13. Bed nets are also the cheapest form of protection against malaria, and nets when not free only cost about 500 CFA ($1).
14. Educational campaigns, such as the ones held by Speak Up Africa, have helped to lower the prevalence of malaria in Senegal.
15. “Set setal”, the cleaning of the village streets to prevent trash buildup, which may attract mosquitos, flies, other bugs, etc.

2. Analysis

1. The only time you are under the bed net is when you’re in bed, so during the day, there are still many opportunities to contract malaria. Ways to work around this problem include finding alternative ways to preventing malaria.
2. One problem is that in rural areas, clinics can be few and far between and there may not be any available doctors. This is because of the brain drain currently occurring with Senegal’s professional class, who are using their Senegalese education to go elsewhere. Even if doctors are available, transportation to the doctor is an issue as well.
3. Bug spray is also good protection (used by foreigners) but it is not readily available for local communities - too expensive. Regarding the environment it might not be environmentally safe to use sprays, but it could help.
4. In outdoor courtyards, if it was possible to either put some sort of net or screen over the “roof” of the courtyard, this could greatly reduce the amount of mosquitoes present in the outdoor living space. For cooking, some sort of chimney structure could be created to let smoke out.
5. The development of an insect-repellent brick or paint could be developed to help ward off mosquitos from the home.
6. Because mosquitoes are attracted to standing water, there has to be a way to reduce (or reuse?) standing water. Ways of doing this could involve planting gardens in the courtyard that use the drain water from bathing/cooking or finding some sort of way to drain and reuse water so it is not standing in the outdoor living space.
7. Regarding the standing water, on a national infrastructure based way, a movement to create drainage systems could help with the removal of breeding grounds of mosquitoes. (see article)
8. It could be possible to make some sort of nets or screens out of recycled plastic. This would both reduce trash and work to increase screen usage in homes.
9. Why are window screens not a main method to keep mosquitoes out of homes? Window screens are fairly cheap and sturdy, and they can be nailed to the window or wall. Yes, dust will still get into the house, but dust will get in through any open window or door. Drapes and other coverings could also be used to decrease dust, if it’s a concern.
10. Children are the main targets of educational campaigns. Schools are a good target to reach the major audience. To get children engaged, many campaigns use sport platforms, such as soccer. Educational campaigns are proven to be effective in the fight against malaria.
11. One major thing that could be done is figuring out a type of screen that could be made or incorporated into buildings. If we are considering making bricks with slits (weep holes) in them, maybe it would be possible to build a brick that has a built in screen. It could work as both an aggregate and a way to eliminate mosquitoes entering the home.
12. When some people notice the symptoms of a disease, they may automatically assume it’s malaria because it’s so prevalent (malaria and typhoid also have very similar symptoms) Doctors will give them medication without doing any lab tests to confirm that the person has malaria. If they don’t actually have malaria, it is a waste of resources to distribute the wrong medication, and could also be a cause of death.

Keur Massar and Sacre Coeur

Keur Massar is a developing suburb just a few miles outside of Dakar which, much like many other places in and around Dakar, was nothing but a small desert settlement just five years ago, but is now a sprawling forest of concrete houses. It was exciting to see the rapid development taking place in the town, especially as we had more of a personal connection to it as it is the site of Nafi's future home. Her home will be one of many that are rapidly being erected around the town, and will cater to her and her family's needs, giving them a more secure place to live than Goree as they are free from eviction at the whim of the government.

Sacre Coeur is a district in Dakar a veritable stone's throw away from the airport in which we landed and first set foot in the country (for many of us, the continent). This district is home to Fallou, a former adviser to the former Prime Minister of Senegal and current professor. His home, on the contrary to Nafi's, is already fully built and developed and the district in which it was built is already built up and inhabited, though still developing. Sacre Coeur is similar though to Keur Massar in its swiftness of development, having once been a thinly-populated desert region (Fallou's home being one of the only developments on the land) and now a sprawling mass of wall-sharing houses.

From our own observations and from what we've gathered from the information we received from Nafi and Fallou, we gained some valuable insight into the development of Dakar and Senegal at large. A cursory glance at both Keur Massar and Sacre Coeur, along with a knowledge of the differential trends in the development of the two areas, would show that the areas in and around Dakar are developing very rapidly, where the geography, society, and economy of certain areas come about one-hundred-eighty degrees in degrees in about a decade; entire neighborhoods exist, families make livings, and cultures develop in areas where not but a few years ago, there was only a few homes, some isolated families, and miles of desert land. However, this development seems to be moving much too rapidly and unsustainably. It seems that the goal for many of these areas is mainly to throw as many houses up as possible in as short of a time as possible. In Keur Massar, one can see this by the sheer number of houses that seemingly span miles of open land. In Sacre Coeur, this is evidenced by the loopholes that are exploited in HLM and SECAP policies, where the government loans a house to low income people, who then pay off the loan quickly in order to knock down the loaned house and build their own. People seem to just want to build houses and don't have much regard for the long-term consequences. In Keur Massar, standards and regulations are very loose, as the houses don't have any zoning regulations in place, and don't even have plans for waste water management. In Sacre Coeur, the government buildings are essentially being wasted as people never actually live in them and only knock them down to build new ones.

These problems can be stemmed to the government, which needs tighter standards and regulations and enforcement thereof. We'll talk about it in class because I'm being kicked out of the wifi room right now.

Going to Gorée Island

Today was our group’s trip to Gorée Island. It was a really beautiful island with much history behind it. This island is now a national landmark that is governed by the Senegalese government. The government redistributed the land to the natives of this land and is now a place for tourism and a home for artists.

Throughout Goree Island, we were able to explore the different ways people use their homes. This place is unique in that it shows what happens when society adapts to buildings rather than the other way around. This happened because the Senegalese government does not allow new permanent buildings to be built but in exchange everyone there has a 100 year lease for free homes. The inhabitants are usually artists that make their living through their creations and I learned first hand how persuasive people can be and ended up buying many souvenirs.

The inside structure of homes is straight to the point with few renovations. Since the inhabitants have adapted to their surroundings, although not the most practical way to make use of space, the necessities can be found within their homes. There is not much walking space inside the homes and many spots within the homes are multi-functional. The couches for example are also used as beds while bedrooms and living rooms can be in the same room. Window use for air circulation is scarcely found but on the day we visited, I did not find the room's air to be stale due to the windy environment. The exterior view of homes is the transition point between the outside world and inside atmosphere where shoes are taken off and doors are left open at times. I thought mosquitos would be a big problem because of this but I was actually surprised there were not as many bugs out. I did see the dust to be a problem though because it was around the middle of the day and one women already had a pile of sand in her home. The exterior of homes can also have additions to the side that are temporary because of the rules on the island. These additions are really needed but unfortunately are unstable shacks that take away from the overall beauty of the island. Improvements I see that can be made would be to continue with the use of multifunctional furniture as it works well in China and in situations of limited space. There is a big difference between some of the buildings on the island as different ethnicities have their own style of architecture. One of the buildings we visited was The House of Slaves. This is one of the oldest houses on the island with the objective to show the terrors of the slave trade. This building had two main sets of stairs with the right side being the way to go up and the left set of stairs from the point of view when you come in was used to go down. From this point, the slave owners picked out the slaves they wanted. Afterwards, the slaves were led through the “Door of no return.”

The problem of connecting to the city of Dakar is a major problem that needs to be addressed because transportation is not too cheap and when the children have to go to school, their only option is to head on to Dakar as the Island does not have the schools that they need. The island has much more potential as a place of tourism due to the history on the island although it has been improving over the years according to Professor Kart. As of now, the island’s inhabitants could be kicked off at any moment but for the time being, is a way of free housing for the residents and a way to let culture thrive. 

Talia's views on the Goree:

Some of the ways that we saw people trying to keep mosquitoes out of their houses today included large curtains that covered all the openings, such as doors and windows, and big screen doors. As Zeke pointed out to us, you have to open and shut the doors quickly to make sure that no mosquitos follow you into a home. This is clearly a modification to the buildings that is to make them more comfortable (and safe) for the residents.

It was really interesting to see how the people on the island adjusted to the existing structures. Seeing the wooden lofts and the windows in the repurposed homes was really interesting. Also, I think it is inefficient that the residents of the island are not allowed to build permanent structures on the island. If they were able to build permanent structures, there would be a lot less wooden buildings falling apart around the island and it would be better to support the family compound living social structure if they could build. That’s just my opinion though.

Article on African City Development featuring Dakar

Why Africa's Cities Need More Autonomy

Na nga def? Salaam alaikum! Bonjour!

Welcome to Senegal and to our research log. We will be posting photos, data, and research notes here for our Spring Break research trip in Dakar and Keur Momar Sarr, Senegal.

For more information, you can link to our group facebook page: 
https://www.facebook.com/LehighinSenegal2015/timeline?ref=page_internal