Category: Nairobi




poza= cool, to cool (swahili)






Scaling up the method of flowerpot cooling to offer people an independent cooling system for storing food and keeping it fresh. The size of the fridge should provide enough room to store an upstanding waterbottle and at least 1kg of vegetables or fruits…



Making of OCTA POZA


OCTA POZA consists of two clay buckets with a octagonshaped bottum. Unglazed clay in his characteristics has the ability to store moisture and is a natural product. The clay that was picked for OCTA POZA has a high percentage of grog so it can store even more humidity. Once burned, it will maintain it´s bright colour to ensure the best reflection of sunlight.

The material for the required contruction forms had to be solid to keep the clay in shape and preferably waterresistant. Nevertheless the choice was to work with wood to keep the construction convenient. To avoid swelling, the wooden planks of the bottum got coverd with plastic. For the side parts coated mdf planks did the job.


To create a quite even surface of the vessels and to approve a constant thickness of the material, the choice for OCTA POZA´s building method was the “slab technique”.

(Detailed basic instructions for this practice under: )

After making sure that all air was lashed out in the clay, 16 pieces for the walls and 4 more for the baseplate were rolled out into the prepared screen of 2 cm thickness. The parts were carefully cutted out and placed aside for drying until they had reached a leatherlike texture which made the further handling a lot easier. When finally all parts were ready to be attached to each other, a mix of clay and water worked as “glue”  for the joint faces. To ensure more stability to the former cracks,  coils of clay were placed on each of them and firmly connected to the layers aside. The wooden profiles which got more and more closed around the vessel during the process, helped to keep the parts in position. But as soon as the the work was done, they had to be removed quickly to avoid an unbalanced drying process.










How to use OCTA POZA


The two octagon shaped clay buckets get stacked into each other. For the use, the gap between the buckets is filled up with sand that occasionally must be watered to keep the cooling effect running. The inner bucketrim stands out to avoid that sand falls inside the bucket which stores the groceries. To increase the cooling effect, the whole system gets finally covered with a wet cotton cloth that still guarantees enough ventilation to avoid mold formation. OCTA POZA´s efficiency can be elevated if it´s habitat is shady and uncongested. The measurements of the object provide enough room to store an upstanding waterbottle and at least 1kg of vegetables.










Realization in Kenia- a benefit cycle












Visions for OCTA POZA

This natural fridge is designed as a DIY product. The whole process of manufacturing is determined to be copied easily with simple tools that, except for the burning procedure, allows an independent production. OCTA POZA could easily be integrated in any community. The possibility of storing food and keeping it cool is not only interesting for parts in the world which are cut off of electricity and seek for an independent solution. Also the western lifestyle could profit by this sustainable method. All it takes is peolpe who take care of it. An imaginable scenario for OCTA POZA could for example likewise be the installation in an allotment garden. Sited next to a crossing where alot of gardeners pass, this could be a set up, where leftovers from BBQs, gardenparties or plain exessive harvest crops are placed at the disposal for others to use.




Clay Filters for Clean Water ~ Different constructions for using the filter

There are different ways of using the filters.

There are tree factors to proceed from:
1: The material used for the construction should be in a material that can take some amount of water or humidity.
2. The construction should be made of out an inexpensive material, that are accessible in for example the slum areas of Nairobi.
3. It should also preferably be easy to make. 

Here are som alternatives of different forms of constructions that can be interesting within there contexts:


Some of my early examples of different handles: 


WORKSHOP ~ Clay Filters for Clean Water: Learn the ancient method of making water filters


A workshop (get more info here) enables for an open source climate. Since my goal is to learn about the process and the different ways of designing the filters, in order to later teach this knowledge, enabling for people to be able to make their own filters, it is important for me to get all the chances I get to try this format.

An important aspect to gain information is through different ways of input. One of these ways is through having a workshop, and thereby creating a platform for opening up for talking about these issues in general, but also gain knowledge by talking about, and maybe even question, certain aspects of the project, in order to move forward.

Also, sometimes you need to take an detour thru something else in order to be able to cross-fertilize and thereby creating a greater value within the projects. By getting feedback from other people….

By having a workshop and also making a booklet with information on how to make your own water filters, I also enable for more people to get to know about this method and maybe sharing it with others.


Clay Filters for Clean Water ~ What? Why? How?

The method of purifying water in ceramic filters, is one of the first ways of filtering water that we as humans started using. There is written information about water filters dating as long back as we have written records, tracing back to the earliest civilizations of mankind. It has contributed to the public health evolvement, and therefore to the development of the humanity as a whole. When people could go from fulfilling the needs to fulfilling the wants


At least 60 per cent of the adult body is made of water, and every living cell in the body needs it to keep functioning. Water acts as a lubricant for our joints, regulates our body temperature through sweating and respiration, and helps to flush waste. A human can go for more than three weeks without food, but only about a week without water (not considering factors like heat. Put that in the equation and we have a different story).

Today, 1 out of 10 people in the world lack access to clean water.

1 out of 5 deaths of children under 5 worldwide, is due to a water-related disease.

It should be a human right to have access to clean water. And it we know a way of solving the issue, why don’t learn people how to make their own and spread the knowledge?  Buy using accessible cheap materials, these filters are a ideal low cost way to cleaning water for a big group of people that are otherwise at risk of getting sick or even die from drinking unclean and contaminated water.


Ceramic water filters are an inexpensive and effective type of water filter, that rely on the small pore size of ceramic material to filter dirt, debris, and bacteria out of water.

By mixing dry clay and sawdust (see more information under Clay Filters for Clean Water ~ How to mix the clay) you get fine pors in the material, where the pathogens gets stuck. If done correctly, and when also dipped into the antibacterial mixture of colloidal silver, it creates a filter that will filter the water from dangers with a 99.9% security.

As this project is adressed mainly towards rural areas where there is a huge shortage of clean water (in this case we have a collaboration with organisations in Kenya) it is important to take notice of the accessibility and costs of these filters.

They are low cost. Pricing for ready-to-use filters, is usually between $15 to $25. Replacement clay filters will cost $4 to $6. If you take care of the filter, you could use it up to 5 years. So that could equal an amount of 40 cents/year.

Materials that are easy to access. And there are already factories in Kenya, close to Nairobi, that are working with doing these filters.

KENYA: There are already factories making a standardised ceramic water filter. But those are not always the most sufficient ones, since the point of use looks different at different locations. My goal is to learn how to make the filters, to then be able to teach out the knowledge by having workshop-like lessons with the people who are in need of these, so that they then can make their own, according to their needs.

BERLIN: By starting this process in Berlin, I hope to get insights on different ways of using this method. Because, there are areas of use in the western world also. Some examples are: In boats (where the water in the tank might get contaminated), when one wants to collect rainwater or water from a lake, or for people living on the countryside that has an own well that might get contaminated. In all of these cases, the filters would have different sizes and shapes, and the ideal solution to this would be to be able to make a personalised one.

For more information and research on ceramic water filters, please klick here.

Clay Filters for Clean Water ~ How to mix the clay

Since sawdust is mixed in the clay, it needs to do from dry to wet.
These are the ingredients that you need for making the clay are the following:

  • Sawdust
  • Dry Clay
  • Water
  • (Colodial silver)
  • A mold
  • A kiln


Mix the sawdust with the ball clay. (Warning! Dry clay is very harmful for the lungs, you should always use a mask and do it under ventilation or outside.) Parts should be 50/50, but you could also use more sawdust and still get a good functional filter. The size on the sawdust should be quite small, a #30 (600 Micon) size sieve works best, although other sizes can work. Smaller is not advised, as it will be a slow process to sieve and will slow the filtration rate. Larger can be used, up to the size of a window screen, although the filtration quality will suffer some, since it will reduce both plasticity and strength.

Sawdust to the left and dry clay to the right


Close up sawdust
Close up dry clay
Mixing the two

Add water. Just add a bit of water at a time and mix it well.

Put a bit at a time
Until it gets to a good consistency – not too dry and not too sticky

Once the clay is workable, wedge it to further mix the clay and remove bubbles from the inside of the clay. Then shape into the form you want. Either just like a small bowl or by carefully smudging it in a mold. But make sure that there is no air inside, otherwise the bowl risk exploding in the oven due to air pressure. Ideal wall width should be around 0.5 – 1 cm.

You could make a shape with your hands
Or, the best way, simply put it in a mold and let it dry.
You see when the clay begin separating from the mold
And then you just flip it over and let it dry until you can put it in the kiln

Fire it. A temperature around 890 degrees C is the optimal firing temperature because it creates a balance between porosity and strength. The organic material (the sawdust) will burn off, leaving behind pores for the filtration to take place.


Beware of cracks. If the firing was done correctly, it should not have resulted in any significant cracks, although there may be some cracks leftover from the forming of the clay. Cracks will make any filtering done by the ceramic useless.

The clay will need to be soaked in water before it can actually filter anything, otherwise your first attempts at filtering water through will just be soaked into the body of the ceramic. Once it has been soaked, pour the water to be filtered in and place the pot over something such that it can drip out of the bottom. If you do this soaking in colloidal silver, the filter gets an even better protection.

If this process is done correctly, this filter should have the ability to filter out 95% (or up to 99% with colloidal silver) of the pathogens in the water.

Classification of the different existing pathogens

You have probably done this at one point of your life. Throwing a silver coin in a well for good luck? That’s probably is a part of old folklore, since silver has been long known for having effective antibacterial properties. That it’s colloidal means it is a mixture in which one substance of microscopical particles is suspended throughout another substance (in this case silver particles in water).

Colloidal silver is deactivating the bacteria. The quantity of colloidal silver applied per filter was more important to bacteria removal than the method of application. The best method of application is to dip it in colloidal silver for a few minutes when it’s fired. Lining the filter with colloidal silver also prevents the growth of microorganisms within the filter itself.



Fridges without electricity


Fridges are items that most people of the western hemisphere take for granted  and wouldn´t want to miss in their daily lifes. Understandable since this invention is a big help when it comes to keep groceries fresh and durable. However most people of the world need to spare them due to electricity reasons, missing structures or simply because they are not affordable. In order to that, a lot of food gets wasted and thrown away before it has the chance to feed the hungry.


But there are exsisting methods to keep edibles stored fresh and cool that work completely independent and without electricity!


Earth Cellar


Wet fabric technique


Flower Pot Cooling



In the case of Kibera the first solution wouldn´t be possible. The earth in the ground is for wide parts contaminated and the soil too hard and dry for digging without the help of machines…also there is a serious lack of space…The second example involves a serious danger to attract the mosquito which is responible for spreading the dengue fever… so it´s the Flower Pot Cooling that deserves a closer examination…


An issue: DENGUE FEVER!!!

Since the Flower Pot cooling system is still operating with water, even if it´s not lentic and just causes more or less the same situation that comes with moist soil and watering plants, it can´t hurt to give it a second thought…

Luckely nature provides us with a lot of herbs and plants that are not so attractive amongst mosquitos.

Next to Lavender, Lemon Balm, Lemon Thym, Lemongrass, Catnip, Basil, Garlic, Rosemary and Marigoldit´s the indish Neem tree that is really helpful to keep all kinds of bugs in check. His scent is pleasant for humans and unbearable for most types of mosquitos. Why not minimizing the risks and planting these natural repellants next to the cooling system to make it as uncomfortable as possible for the dengue mosquito to get close ?



Cooltiles – a detour into a tempting Modular System that sadly proofed to be completely pointless for that matter…



easy and quick production:





tiles that would allow modular sizes:




To make the cooling effect work, the natural fridge demands an concentric shape that is also limited in the size. The bigger the size , the thicker the walls of the vessel must be! To keep the temperature low, the distance between the center and the wall can´t be indefinitely wide! Plain physics…

The cracks between the tiles represent an attractive spot for bugs to hide and place their eggs. Not something what most people would want next to their food.





Tequipanoa – Community Network

Our idea is to found a organization selling, nice and compact mostly self running “growing boxes” which everybody can buy to explore our system for themselves at home, with the money paid for them, a fund will be established, from which our organization is supporting social groups in development countries etc. to build the IBC growing system.

Through this we hope to build up a social network providing the needed parts (3D-printed, worms, etc.) to each destination. We will start this project in Nairobi, Kenya where we will try to work together with local resellers, fablabs and farms providing everything so communities are able to grow there own vegetables, regardless off the ground pollution to create some kind of self sufficiancy for people dependend on the market prices and big companies.

Ugali time!

A Swiss, an Italian, an American, and a Kenyan cooking ugali in a Berliner kitchen.

Shabu told us that at the beginning he was not able to prepare food in our kitchen. It’s hard to get used to other cultures food habits/ systems when your culture is so different. For Cristina it was difficult to eat with her hands 😛

Some notable observations:

  • The ugali is shaped into a spoon to eat the vegetables so that no utensils are required.
  • A lot of water is needed to clean the pan.
  • Cleaning needs to be done quickly so that the ugali doesn’t stick to the pan.
  • The preparation was surprisingly quick and simple. We only needed a spoon, a pan, and a pot.
  • The ugali is shared from one big dish in the center of the table.


Kibera markets – clean food storage

Current situation in the streets of Kibera: vegetables & fruits which are supposed to be sold on markets are displayed on bare ground.Not only during rain season this is a serious hygiene issue…

What can be done? Is there a way to solve it quick and easily, preferably with upcycled materials that leave the traders with no extra costs?



used materials:

  • buckets, cans, containers…whatever comes in hand and is suitable for carrying goods to the market..preferably stable enough to be used as a seat, when flipped over…
  • fabric scraps, firm plastic bags, any other material that can be torn in stripes and resist humidity…



bucket or container which are used for transporting the goods, gets tucked inside a costumized woven backpack. Once at the market, the content of the bucket gets spilled on an also woven hammock which was stored on the backside of the backpack to guarantee more comfort while transporting and serves now as a display for the goods.

To be used as a seat (what people already do) ,empty bucket or container gets flipped around and placed back inside the woven backpack.Slipknots on the backpack allow the attachment and uplifting of hammock between the bucket and  the bin of the next marketneighbour who has the same backpack-hammock system…and so on and so on…unless you have a whole chain of backpack-hammock-systems on the markets…

Backpacks and hammocks could be constructed in workshops or even by the traders during markettimes while they are waiting for the costumers. Community activity is included, since another person is always needed to make it work. Supposably this system could also work for bbq events in the western life, where food is placed and easily spilled on blanckets…






First weaving experiments:

KENYA ~ New design on Ceramic water filters

  • There are 48 million people living in Kenya
  • 7 million of those live in Nairobi
  • 17 million people in Kenya don’t have access to safe water
  • Over 32 million people don’t have access to adequate sanitation in Kenya.
  • Every year 1.7 million people, mainly children under the age of five, die from diarrhea which is caused by unsafe water.

  • Potters for Peace work with setting up a workshops in areas where clean water is a problem.
  • Low-tech and low-cost
  • Eliminate 99.88% of water-born disease agents

A ceramic water filter is a simple, bucket-shaped (11” wide by 10” deep) clay vessel that is made from a mix (by weight) of local terra-cotta clay and sawdust or other combustibles, such as rice husks.

When the filters are fired  the milled, screened combustible material burns out, leaving porous clay walls. The filters are tested to make sure they meet a standard rate of filtration and then they are coated with colloidal silver. The combination of fine pore size and the bactericidal properties of colloidal silver produce an effective filter.

When in use, the fired and treated filter is placed in a five-gallon plastic or ceramic receptacle with a lid and faucet. Water passes through the clay filter element at the rate of 1.5 to 2.5 liters per hour.

Pricing for ready-to-use filter units, including the receptacle, is determined by local production costs and is usually between $15 to $25. Replacement clay filters will cost $4 to $6. A basic production facility with three or four workers can produce about fifty filters a day.

Potters for Peace does not operate filter-making facilities or sell filters, they train others to do so, and the filter factories that they assist are run as independent businesses owned by organizations or individuals. Potters for Peace receives no financial benefit from the filter producers but filter technicians have their expenses paid and may receive a stipend while working on a new facility.

There is a local producer called Chujio Ceramics, in Limuru, 1 hour outside Nairobi.

Potters for Peace recommendations to me: 
“There is always a need for sexy container designs. The filter is usually sold with a plastic bucket which has less than positive associations (trash can). I’m sure you could benefit from talking to them and getting some insight with their experience in marketing the filter.”

“We generally suggest using multiple filters for schools and other communal settings, but one of the biggest advantages of the filter is that it treats the water at the Point of Use (household or school), reducing the chance of recontamination after filtration.  So there are actually advantages to keeping the filter small, portable, and in the home.”


Cooking in Kenya

The Kenya Ceramic Jiko, is a stove which uses charcoal as fuel. It has an hourglass shape, and it is made from a metal exterior, with a ceramic internal liner. The ceramic liner has holes in its base, which allows ash to fall through and be collected in the box located at thme bottom of the stove.

– Wikipedia

We had a closer look at the traditional way of cooking in Kenya and we learned a lot about the jiko. To get to know how people in Kenya are using it, we had a talk with Shabu.

Our questions:

  • Where do they cook? Why do they cook inside?
  • Is it known that the smoke is unhealthy?
  • Do people have or build chimneys?
  • What kind of fuel is used? Cooking at home/ cooking at the kiosk.
  • Is slow cooking an alternative option to cook?

What we learnd:

  • Either people cook with an open fire, a jiko, a kerosin stove, or a saw dust stove.
  • People are cooking inside for privacy. They light up the stove outside and continue cooking inside.
  • People are aware of the unhealthy emissions from cooking but they don’t have many other options to choose from.
  • The jiko is one of the best options when cosidering money and health.
  • Because the houses in the slums are not owned by the people that are living there, they don’t build chimneys.
  • When cooking at home, mostly the jiko is used with charcoal or gas. In the kiosks, mainly the kerosin stove and the saw dust stove is used.
  • Slow cooking is not successful because there is not enough time in their daily schedule.
  • Fire outbreaks are caused by cooking accidents.

Clean Cooking – initial research

After talking with Shabu, a Kenyan artist from Nairobi currently living in Berlin, we were interested in the many problems concerning food in the slums. We began by exploring a broad range of issues about food from cultivation to consumption. Going further into this topic, we narrowed our research to focus on clean cooking.

The goal of clean cooking is to:

  • Reduce household air pollution
  • Use less fuel to save money
  • Cut CO2 emissions
  • Improve hygienic conditions

Our research also included looking at existing solutions that either improve the traditional way of cooking or are focused on using sustainable resources.

Solari- Portable Solar Cooker
Wonderbag_non-electric portable slow cooker








Baker Stove-Energy Efficient Cookstove
Elsa Stove- pyrolysis stove that uses biomass