Improved Cooking Stove (ICS) · 2012-01-16 · Cameroon, ICS (January 2010) 1 : 1. ... The climate in Cameroon is in most regions very good for growing plants. Therefore, in the rural

HUYS ADVIES

Improved Cooking Stove (ICS)

Cameroon ~ Clay Soil Wood Cooking Stoves

By: Sjoerd Nienhuys Renewable Energy Advisor Senior Expert Programme (Programma Uitzending Managers, PUM) Hilversum, The Netherlands January 2010

ABSTRACT The Improved Cooking Stove (ICS) can be beneficial for at least half of the two million rural households in Cameroon. The proposed ICS is based on broad experiences and practices from other countries. The village design wood burning ICS has four main components: (1) metal plate and grill; (2) improved shape of the burning chamber; (3) pot support for sunken pot; and (4) smoke control by chimney or hood. A metal top plate is a possible option. The improved “rocket” type burning chamber and “sunken pot” principles increase the firewood burning efficiency by about 35%, or increasing firewood economies up to 75%, as compared with the three-stone open fire. Smoke control by means of a chimney or a hood reduces Inside Air Pollution (IAP), thereby lowering respiratory diseases and eye infections among women and children. In addition, large firewood savings will curtail deforestation and time spent on biomass collection will be cut in half. The outside body of the low-cost ICS is adobe or clay soil, but can be made with baked bricks or even tiled on the outside. The stove is safer around children than the traditional three-stone or half-open wood fires. Manufacturing of the ICS is village based with a small support network by a local NGO. It generates business and income for micro entrepreneurs, while at the same time reduces the country’s dependency on non-renewable fuels. Due to the massive reduction of CO2, it is possible for a well-organised project to obtain Carbon Emission Reduction (CER) credits based on CDM regulations, generating an income of more than €10/tCO2eq reduced. A 10-member household in Cameroun can save per year about 1 ton of firewood (50% carbon content). Points for NGO organisation and development are included. Sjoerd Nienhuys Renewable Energy Advisor [email protected] www.nienhuys.info

TABLE OF CONTENTS 1. INTRODUCTION.....................................................................................................................................................1

2. IDENTIFICATION OF PROBLEMS ....................................................................................................................3

3. DESIGN CRITERIA................................................................................................................................................4

4. ICS TECHNOLOGY................................................................................................................................................6

5. CLAY SOIL-BASED ICS DESIGNS ...................................................................................................................7

6. ICS PROMOTION .................................................................................................................................................11

7. ENTERPRISE DEVELOPMENT........................................................................................................................13

ANNEXE CHULA .................................................................................................................................................................16

ANNEXE ICS WITH PLATE AND GRATE .....................................................................................................................17

ANNEXE ICS WITH SUNKEN POT .................................................................................................................................18

ANNEXE ICS WITH METAL TOP PLATE ......................................................................................................................19

ANNEXE ICS SUNKEN POT WITH METAL TOP PLATE ..........................................................................................20

ANNEXE ICS LARGE SUNKEN POT..............................................................................................................................21

ANNEXE ICS AXONOMETRIC SKETCHES .................................................................................................................22

Cameroon, ICS (January 2010) 1

mailto:[email protected]

http://www.nienhuys.info/

1. INTRODUCTION While visiting a local entrepreneur dealing with environment-related issues, it was observed in his own village that the most primitive way of cooking was being practiced – using three- stone open fires generating massive amounts of smoke in confined kitchens. Although Liquid Petroleum Gas (LPG) stoves and known models of charcoal stoves have been introduced in the larger towns, large amounts of firewood are still being used by low-income people and marketers to provide cooking energy.

SALE OF FIREWOOD, KEROSENE AND LPG BOTTLES IMPROVED CHARCOAL BURNERS WITH CERAMIC LINING

FIREWOOD SALES POINT IN TOWN ROASTED MEAT/FISH SELLER IN THE MARKET About 10 million inhabitants of Cameroon are living in rural areas, many of whom still depend on firewood as a major energy source for cooking. For three-stone open fires, the firewood efficiency is only 10% maximum. Considering the small number of people using an Improved Cooking Stove (ICS), it can be estimated that one million ICSs can be marketed countrywide by local village-based entrepreneurs. Together with manufacturing and marketing of the most advanced types of mobile metal ICSs, a sizeable business can be achieved. The development of any ICS for easy manufacturing by local village women or craftsmen would considerably reduce the time spent on firewood collection and cooking. It would also delay the purchasing of new cooking equipment operating on non-renewable fuels, as well as reduce the country’s foreign currency needs for the importation of cooking fuel.


MOST THREE-STONE OPEN FIRES HAVE AN OVERALL FIREWOOD EFFICIENCY OF ONLY 10%

Carbon Emission Reductions (CERs) A single extended household of 10 members uses about 2 tonnes of dry firewood each year (5.5 kg/day). Each such household will save about 1 ton of firewood/year when using an ICS instead of the traditional three-stone open fire. Half of the firewood is Carbon. Burning the 0.5 ton Carbon produces 1.5/tCO2equivalent. The current CER value of 1 tCO2eq is €10. A family who replaces their traditional three-stone open fire with an ICS can theoretically generate €15/year in CERs. This can be the cost of installing one ICS. Because of the massive reduction of CO2, a well-organised project can obtain CER credits, in accordance with the Clean Development Mechanisms (CDM) regulations, generating an income of €15,000/year for every 10,000 ICSs installed. Such beneficial CER project co-financing, however, will only be feasible when several other conditions are met:

The ICS design has been introduced in several villages and measured for a period of one year to obtain reliable data about firewood saving.

A strong central organisation should be involved in the construction, monitoring and administration of the project because proper records are required.

The project needs to be approved by the CDM Board, a procedure that can take more than a year. Depending on the project format, the costs of registration and obtaining approval are minimal €50,000, while the verification costs €100,000. This means that a hundred thousand ICSs need to be installed to recuperate the investment costs.

The overhead expenses of the NGO monitoring the installation should not be exorbitant as to consume all the CER income of the project on its own administration.

Whether or not CERs can be obtained in the future, the introduction of numerous ICSs will vastly improve the quality of life for village women, who now work in smoke-filled houses and spend many hours collecting firewood. This should not wait for CDM or CER approval.


2. IDENTIFICATION OF PROBLEMS The following points are identified:

A. The climate in Cameroon is in most regions very good for growing plants. Therefore, in the rural areas, there is an abundant supply of firewood and other biomass from the forest.

B. Usually people will only start thinking about saving firewood or biomass when everything has been burned and the countryside is turning into a desert.

C. All higher land areas around the towns, in particular land which is not privately-owned garden property of a family, is already devoid of all trees. Stone boulders protruding through the grass indicate an advanced level of soil erosion. Such hilltops would be very difficult to reforest and are already affecting the climate.

D. Charcoal making depends on firewood in the first place. Because all the larger trees are already gone, small trees are now being harvested to provide fuel for inefficient cooking stoves and charcoal making. The price of charcoal is increasing.

E. Because of the deforestation, women have to travel farther or work longer to collect the necessary amount of firewood or biomass; or, alternatively, they need to purchase firewood and charcoal from the traders.

F. Many low-income village people simply do not have the funds to purchase firewood or charcoal. Hence, they will spend ever more time in collecting the biomass and, in doing so, will further increase deforestation and soil erosion.

G. Burning fresh branches, without sufficient drying, will increase the amount of smoke and with that the amount of Internal Air Pollution (IAP) with all its negative health consequences.

H. Most low-income people are not in a position to make the relatively large investment

in a new metal or stainless steel ICS for cooking on firewood or agricultural waste wood. They would rather invest in a modern cooking appliance for a higher grade fuel, such as charcoal, kerosene or gas, even if they cannot afford the recurrent expenditures for the purchase of the high-grade fuel.

I. In most villages, there is no knowledge available on how to make a low-cost ICS with a maximum use of local materials.

J. Villages will only modify their way of cooking when they see the benefits with their own eyes in their own village, preferably in the house of a prominent villager.

K. For the introduction of new technologies, people want a choice of options.


3. DESIGN CRITERIA Although various types of low-cost fixed position and mobile ICSs exist, the models are unknown in many rural areas of Cameroon. People should be given a choice of products depending on their existing cooking habits, along with a comprehensible explanation of the differences in the products and with their current cooking method. Generally, people will easily pay for an upgrade of their cooking equipment when the energy source is of a so-called higher hierarchy. From low to high: dried cattle dung, small biomass, firewood, charcoal, LPG or biogas and finally electricity. Although direct solar energy is not mentioned, it can be rated under the highest level of energy as well. Upgrading an existing firewood stove to an improved firewood stove, therefore, is not seen by many people as an improvement unless it is associated with considerable other benefits, such as time saving, firewood saving, health improvement and safety. The ICS has all of it and therefore introduction should not be very difficult. Because in the village environment people will be unable to invest in relatively expensive metal stoves, this document focuses on clay soil-based ICS. Clay soils and adobe are materials readily available in many villages, especially in those villages where the houses are built from adobe or dried clay soil.

ADOBE OR DRIED CLAY SOIL BLOCKS ARE COMMONLY USED FOR HOUSE CONSTRUCTION IN MANY VILLAGES.

THE SAME MATERIAL CAN BE USED FOR THE CONSTRUCTION OF IMPROVED COOKING STOVES. Because the cooking needs and household sizes differ, various adobe ICS designs are necessary. Stove designs adapted to suit the needs of the household will be better accepted and internally promoted in the village. The following design options have been taken into consideration in this paper for the new ICS construction in rural villages of Cameroon:

• Single pot stove. A single large pot ICS (Ø 50 cm) has been noted in several larger households with multi-generation families. However, in the same multi-generation household, several kitchens were operating, each with a three-stone open fire. The single pot stove is not recommended as it has a relatively low efficiency.


• Double pot stove. A double pot stove has an increased firewood efficiency of 5% as compared to a single pot stove. The two pots can be either similar in size (e.g. Ø 25 cm) or of different sizes (e.g. Ø 30 cm and Ø 25 cm).

• Sunken pot design. In this construction, the hot smoke gasses envelop the cooking pot by which the heat transmission from the hot gasses to the pot is substantially improved than when only the bottom of the pot is heated. Compared with a pot on the stove, an increased firewood efficiency of at least 10% has been achieved.

• Use of long firewood. Chopping of firewood is laborious, difficult and disliked by the cook. Several very high efficiency metal ICS designs exist for which short (5 cm long) chopped firewood is required. The proposed ICS designs in this paper allow for firewood lengths of up to three feet, being gradually shoved into the fire as the wood is consumed.

• A chimney through which smoke is evacuated from the kitchen directly to the outside of the building. Because smoke will be produced when lighting the fire or when the pot is lifted from the stove, it is impossible to evacuate 100% of the smoke from the kitchen. Therefore, additional ventilation is required.

• A hood above the stove with an exhaust directly to the outside. This is complementary or an alternative to a chimney design. The choice between the two designs depends on the kitchen layout and the preference of the cook.

The following design options are also possible, but have not been elaborated upon in this document. Additional information can be obtained from the author.

• Triple pot stoves. The design is basically the same as the double pot stove, but with a third pot position. Stoves of this design will have slightly less heat under the third pot than under the second pot.

• Top heating plate. This ICS design has a thick metal plate on top of the stove with a hole in which the cooking pot is placed. This design is slightly more costly than the other designs presented because of the additional cost of the thick metal plate. The heat transmission to the pot is slightly less than with the sunken pot design, but the pot will become less dirty from soot.

• Ceramic burning chambers. Some designs made from baked clay are available from the Internet. One design has been presented by the author in the document: Terracotta One Pot ICS. See: www.bioenergylists.org/nienhuystop www.nienhuys.info/mediapool/49/493498/data/TOP-ICS_Nov_2006_.pdf

• A chimney back boiler or smoke water

heater to the stove. Details can be provided.

• Concentric metal pot rings for two different pot sizes; can be complemented with a lid.

• Elevated stoves. Raised stoves for cooks preferring to stand.

A TABLETOP HEIGHT, TWO-POT CLAY SOIL STOVE

WITH CONCENTRIC METAL POT RINGS, A SMOKE WATER HEATER,

NICELY WHITE WASHED, IN A VERY CLEAN KITCHEN

IN THE HIMALAYAS


http://www.bioenergylists.org/nienhuystop

http://www.nienhuys.info/mediapool/49/493498/data/TOP-ICS_Nov_2006_.pdf

4. ICS TECHNOLOGY The technology of the ICS is directly based on the existing “Rocket Stove” developed by Aprovecho, along with Dr. Larry Winairsky (see sketch below). All elbow-shaped ICSs have the following aspects and components: (a) Thin, long wood pieces allow a better

combustion. (b) Air enters from under a metal plate, below the

fire position, and improves combustion. (c) The metal plate and grill are essential

features for minimal air entry above the fire and enhanced air entrance from below.

(d) The small, elongated burning chamber increases the temperature and allows complete burning of the wood gasses. The size depends on the overall size.1

(e) Insulation of the burning chamber increases the burning temperature and thereby completes the burning of gasses.

(f) The complete burning of the firewood produces little amounts of ash residue and unburned gasses, resulting in less smoke and soot.

(g) The hottest point is just above the flame, about 10-12 cm above the burning firewood.

(h) The narrow space between the pot and shield increases heat transmission to the pot.

(i) The heat of the fire can be regulated by adding or removing sticks. (j) Removal of all the sticks quickly extinguishes the fire and stops further firewood

consumption. Main advantages are:

About half the amount of firewood is needed as compared to the traditional stove. Time saved in firewood collection or money spent on the purchase of firewood is reduced by half.

Cooking time is reduced due to the hotter fire. The stove is built against the wall in the room to allow support for the chimney. Cooking pots blacken less with soot, requiring less time in cleaning. The fire is enclosed and the outside of the stove is cold, providing safety.

Disadvantages of this type of stove are:

• The person tending to the fire needs to feed the burner regularly to maintain an adequately high cooking temperature.

• Long sticks require a support frame which is attached to the metal plate and grill under the burning chamber.

• The fire does not emit light because it is totally enclosed (no yellow flames). • There will be no charcoal remains and little amount of ashes. • To remove the ashes during the cooking, a metal bar with a hook is required. • The design without a chimney needs a hood to collect the smoke and flue gasses. • When made from clay soil, it takes a few days before the stove is dry for maximum

cooking efficiency.

1 In one village, the height of the burning chamber was reduced by the maker because the villager wanted the flames to touch the pot as with the traditional fire. However, by doing so, the efficiency of the ICS is reduced.


5. CLAY SOIL-BASED ICS DESIGNS Considering the various design criteria and technical features of the ICS, the villager will need to make an informed decision as to which design is best for him/her. The efficiency comparisons are made in relation to the traditional three-stone open fire, having an average firewood efficiency of only 10%. The percentage figures given below are approximate because they depend on the material used for the walls, the precision of the design in relation to the pot and the height of the pot. Frying is possible over the first cooking hole on all stoves, but not easily over the second cooking hole as it has a lower temperature. The third cooking point is mainly used for heating water. Advantages of the clay soil stoves: low cost because of use of local materials; the stove can be made by locally trained villagers; many different designs are possible; owner maintenance is possible; smoke evacuation from the kitchen area by chimney or hood; improved firewood efficiency. Disadvantages: must be constructed on-site, inside the kitchen; not movable; must dry a few days before it can be used; chimney goes through wall or roof. Important: determine the need for one, two or three cooking pots and their sizes. A two cooking pot stove is advised by which the second point is commonly used for heating water or simmering. Cooking with three pots will be about 5% more efficient, but the last cooking point will not be as hot as the first or second cooking points. The various options are listed below (A to H): A. The Chula. Simple clay soil ICS design without metal firewood plate and grate. The pot

stands partly in the stovetop surface. Shallow, wide, rounded bottom pots and frying pans are used with this design. For two-pot stoves, the firewood efficiency increases to 15% when both positions are used. A detailed description of the various design options is provided on pages 10-18 of: www.practicalaction.org/smoke/docs/region_nepal/smoke-technololgy-inventory-nepal.pdf For the body of the Chula stove, the following mix is used: 3 volume parts clay soil (over 50% clay content), 2 volume parts of finely chopped straw and 1 volume part of cow dung.

FIREWOOD ENTRANCE IN FRONT OR ON THE SIDE CHIMNEY EXTENDS TO CEILING AND THEN OUTSIDE

Advantages: very low-cost design; can be extended to three pot holes. Firewood efficiency for two pot holes about 15% as compared to the three-stone open fire with a 10% efficiency. Disadvantages: firewood saving as compared with the following stoves is the smallest; therefore, this model is not fully recommended. The following designs are better.


http://www.practicalaction.org/smoke/docs/region_nepal/smoke-technololgy-inventory-nepal.pdf

Orientation: The firewood entrance is in the long side of the stove (on the cooking side) or in the length of the stove. Placing the firewood opening in the length of the stove allows longer pieces of firewood and hence does not obstruct access to the pots (photo chapter 3). With the firewood opening on the cooking side, it is easier for the cook to observe the quality of the fire. The location of the opening can be changed if the cook is unsatisfied.

B. The improved clay soil ICS with a metal firewood plate and grate. The firewood

efficiency of the single pot stove is about 20%. This means saving half the amount of firewood as compared to the open three-stone cooking fire. The pot stands on top of the stove. Shallow, wide pots and frying pans are used in combination with this design. For two- pot stoves, the efficiency increases to 25% when both positions are used.

This design is higher than the above Chula. The metal plate and grate allows the air to enter from below and with that improves the combustion. The same frame supports the long firewood sticks. Advantages: low-cost design; can be extended to three pot holes; good firewood saving; higher fire temperature; faster cooking and frying. Disadvantages: The metal plate and grate adds to the cost. When leaving out the plate/grate, the firewood efficiency reduces to below the level of the Chula indicated above.

Important Measurements: (1) The firewood opening above the plate/grate has the same cross section as the burning chamber and the chimney; (2) The diameter of the burning chamber is about half the pot diameter; (3) The height of the burning chamber is 1½ times the width of the burning chamber. The pot is minimal 10 cm above the top of the flames; (4) Size and shape of the cooking pot(s) most frequently used have to be known. The pots have to stand above the hole. Round bottom pots may sink slightly into the hole and are most suited for this type of stove.

C. A sunken pot design, combined with metal firewood plate/grate. The efficiency of the

one-pot sunken pot stove is about 30%. For a two-pot stove, the overall firewood efficiency increases to 35% when both positions are used.

This design is higher than the above plate/grate design B. The pot stands inside the stove on a double Ø 10 mm steel reinforcement bar. Advantages: can be extended to three pot holes; stove model with the best firewood saving as compared with above models. Disadvantages: The metal plate/grate and additional pot support bar adds to the cost. The top side of the hole needs to be maximum 1 cm wider than the pot, being only 0.5 cm all around. Some flue/smoke gasses will escape through this 0.5 mm gap between the pot and the stove body. Pot handles will become hot.

Important Measurements: (1) The pot is placed eccentric over the burning chamber (see drawing annexe); (2) The firewood opening above the plate/grate has the same cross section as the burning chamber and the chimney; (3) The diameter of the burning


chamber is about half the pot diameter; (4) The height of the burning chamber is 1½ times the width of the burning chamber; (5) The pot is minimal 10 cm above the top of the flames; (6) The depth of the upper surface to the support bars depends on the height of the pot handles; (7) For sunken pots, precise measurement of the outside diameter of the pots is important; (8) Both flat and round bottom pots will stand on the lower support bars; (9) For pots larger than Ø 40 cm, 12 mm support bars should be used; (10) The height of the pot under the handle(s); see the sketches H1. The cooking efficiency of the sunken pot stove design improves with higher pots because more heat is transferred to the sides of the pot. Recommendations: There should be good cross ventilation or an additional hood to evacuate smoke from the kitchen. Fire is controlled by closing the air intake and removing the firewood. General: The above stove sketches A, B and C show the design option of a clay soil top surface of the stove. These are good, low-cost options. The surface can be kept clean and firm by regularly applying a clay wash, clay lime wash or cement lime surfacing. It is possible to apply a metal top later or use metal closure rings.

D. A flat mild steel top plate, pot on top. For low-cost stoves, a flat mild steel of 1.2 mm

(gauge 18) is recommended for the metal plate. This thickness can still be worked by hand and folded around the sides. For a stove with the pot on the top of the plate, the plate needs an additional one or two Ø 12 mm support bars.

The metal top plate covers most of the stove. Two Ø 12 mm support bars need to be placed between the two holes because the pots stand on the metal top plate. Advantages: The metal top protects the surface of the stove and it can easily be kept clean. Compared with the clay soil top stove B, the whole body of this stove is lower. An additional ring can be fitted for use of smaller pots. Disadvantages: The metal top plate makes this option more expensive than the clay soil top.

Important: The metal plate should be folded around all the edges to avoid sharp areas. The entire metal plate will become very hot and will warm the cooking area.

E. A flat mild steel top plate, sunken pot. For low-cost stoves, a flat mild steel of 1.2 mm

(gauge 18) is recommended for the metal plate. This thickness can still be worked by hand and folded around the sides. If heavy pots are not placed on the top sheet, no

additional support bars are needed. Advantages: The metal top protects the surface of the stove and it can easily be kept clean. The whole body of this stove has the same height as stove C. Disadvantages: The metal top plate makes this option more expensive than the clay soil top.

Important: The metal plate should be folded around all the edges to avoid sharp areas. The entire metal plate will become very hot and will warm the cooking area.


F. A chimney for the evacuation of smoke. The chimney can either go vertically through the roof or pass to the outside of the building near the ceiling/roof. The external exhaust from the chimney must avoid sparks from a hot fire escaping and setting fire to thatched roofs. The most economic solution is to make the chimney from dried clay soil blocks in the corner of the room. Making chimney pipes from baked clay is also an option.

CHIMNEY OUTLET THROUGH THE WALL VERTICAL CHIMNEY AND WITH EXTRA HOOD G. A hood over the stove area for the evacuation of smoke. Depending on the materials

used and the size of the construction, this may be more expensive than a chimney. A hood can be made from sheet metal or from plastered bamboo mats. Above the hood, a chimney or wall outlet evacuates the smoke to the outside.

H. Large sunken pot design for large households, community kitchens and commercial

kitchens. The actual size depends on the cooking pots (pots in photo are Ø 50 cm).

Details: Inner lining is made with baked bricks for durability. The outside is finished with ceramic tiles. In combination with a metal top plate. One pot can be kept warm on the plate in front of the chimney. Additionally, a smoke water heater for the supply of hot water can be installed in the first part of the chimney. A smoke hood is required or good kitchen ventilation. When the pot is very large and high, a step can be made to better reach inside the pot.


6. ICS PROMOTION Experience shows that neighbour-to-neighbour promotion is the most effective method to ensure success of a new product in rural areas. Villagers tend to value and respect the opinions of their peers when this is based on personal experience and testimony. In Cameroon, the possible influence from local kings and their households can play an important role. Mobilizing a wife of the local king in ICS promotion should be considered. Demonstration of Models To make women aware of the features and possibilities of the ICS, local demonstration in a real household situation by a family who has been using the ICS for an extended period is required. The user can then explain how it changed her life and cooking behaviour; giving the pros and cons. This is the best method to convince others. ICS models need to be used in selected households under the following conditions:

(a) The household spends substantial time on firewood collection or pays for firewood. When firewood is readily available or very cheap, the economical benefit is little.

(b) The household uses firewood and biomass as their principal cooking fuel. (c) The household needs to measure (weigh) the total amount of firewood used on a

weekly basis. Each new supply of firewood added to the stock must also be weighed. At the end of the week, the remaining firewood is weighed and the net firewood consumption of that week calculated.

(d) The household must record the number of meals cooked on a chart (see below). (e) The household must be willing to receive visitors in the kitchen and explain the

functioning, savings, advantages and disadvantages of the ICS. (f) The household needs to provide feedback information to the animator who will visit

the same villager after a few weeks to collect the information.

Registration Form - Firewood Consumption for Cooking per Household

Name of ICS Owner: Measure 0.1 kg Precision

Number of Adults: Village: House: Children under 6:

Number of Meals/Day (child < 6 yrs = 1/2 meal)

Mon

day

Tues

day

Wed

nesd

ay

Thur

sday

Frid

ay

Satu

rday

Sund

ay

Tota

l Num

ber

of M

eals

A. T

otal

kg

of fi

rew

ood

at th

e st

art o

f the

wee

k

B. T

otal

kg

of fi

rew

ood

ad

ded

durin

g th

e w

eek

C. R

emai

ning

am

ount

of

firew

ood

at e

nd o

f wee

k

D. T

otal

fire

woo

d us

ed

durin

g w

eek.

D=A

+B-C

WEEK 1 Breakfast

WEEK 1 Lunch

WEEK 1 Dinner

WEEK 1 Tea

Total

Average use of firewood per meal = Total D divided by total number of meals Name of Record Collector: Date:

A simple spring-scale is required for the firewood measurements.


Promotion Team (Animators) The programme promotion team should select rather intelligent recipients in each village who can understand the principles of the ICS and can explain the same to their neighbours. It also means that the household having the demonstration ICS should have an adequate status in the society to allow receiving neighbours and other people in their kitchen.2 An animator needs to be able to explain the advantages and disadvantages of the model ICS to the potential buyer. The animator is also responsible for assembling the data into a table/chart and reporting on the experiences of the villager.

An ICS is not specially designed for the poor, but rather to save time, money, health and the environment.

Efficiency Testing In order to provide clear data on the efficiency of the ICS, the standard water boiling test should be realised by the promotion team for both the traditional stove and the ICS. The standard water boiling test can be copied from the TOP-ICS paper or from the Internet. Marketing Strategy NEVER promote an ICS (or any other article) “for the poor” as this will work EXTREMELY counterproductive in the general acceptance by the public. It is the wealthier and intelligent people who should use the ICS for economic and efficiency reasons. The newly introduced article will then sell itself. Other people will follow or copy the behaviour of the more advanced people from their society, not from the poorest. Limit Subsidy to Entrepreneurs The NGO or development agency should not subsidise consumer products, but only support the demonstration process. From the very onset, collaboration needs to be sought with local entrepreneurs and distribution channels to be involved in the manufacturing and marketing. The manufacturer, entrepreneur or sales outlet can be supported with the supply of free user or installation manuals, advertisement, credit in the form of supplies, training, etc. Community-Based Promotion Community-based promotion and dissemination allows maximum communication with the target groups and influence in the decision-making process of individuals. This is important for replication and sustainability reasons. It is always the most advanced citizens in each village who are copied by others in the application of new technologies. It is essential for villagers to pay a real price for the equipment so they make a financial investment and take better care of the equipment. Their household economy will indicate whether or not the financial investment is worthwhile and if the return on that investment is cost effective. Clear data on firewood and other fuel costs must be available in combination with the possible savings the new ICS will provide.

2 In one case, the household was from a very low social status; hence, the higher (wealthier) people did not want to visit their house. Because this higher caste did not apply the technology, others also ignored the innovative design.


7. ENTERPRISE DEVELOPMENT The clay soil ICS design needs to be marketed through village women associated with existing local networks, such as village organisations and women’s clubs. The executing NGO would make contracts with metalworkers for the mass manufacturing of the ICS metal components. Orders and delivery of the components to the village promoter can be organised through a district or regional project trainer. Local village women who promote the clay soil-based ICS must be able to assist the house owner or the cook desiring such a stove. That house owner needs to participate in the construction, especially in collecting the source material such as clay soil or adobe blocks. By involving the house owner or cook in the construction of the ICS, they will learn how to maintain the stove. After the new clay soil-based ICS has been manufactured, it needs to dry out for one week. The first cooking cycle will also assist in further drying the fresh ICS. Until the ICS is completely dried out, no optimum firewood efficiency will be obtained. Contracting and Subcontracting The initial series of metal components for the ICSs can be contracted to metalworkers on the basis of the drawings. Good quality control on design, measurements and functioning is required. A simple order form should be developed to keep track of orders. Jigs for Series Production For series manufacturing of the metal components, jigs and patterns should be made, especially for cutting, folding and welding. The jigs will assist in ensuring all components are cut to the same length and welded correctly. Although some initial time and material investment will be necessary for making the jigs, the cost will be quickly recovered owing to the improved and faster working method. NGO Development The following steps in the ICS development process can be realised by an NGO: a) Construction of two or more clay soil ICSs in the extended household of the NGO

manager, along with (1) him/herself, (2) the family/cook and (3) a trainer. This is to obtain experience, understand the drawings, select the best set of working tools, take step-by-step pictures of the process and monitor precisely the firewood savings.3 Manufacturing costs in time and money should be calculated on the basis of this experience.

Village or house of NGO manager. NGO manager =1 Wife/cook = 2 Trainer = 3

b) Meeting with the headman or local king (influential people) in the village to explain the

operation and benefits of the ICS installed in the house of the NGO manager. This implies a cooking demonstration. On the basis of this explanation and given the manufacturing cost of the different designs, several model ICSs should be contracted with the local headman or king (not donated). Existing firewood consumption is first

3 During an entire month before the installation of the ICS, it is necessary to take an accurate weight measurement of the existing firewood consumption of the same household. The real savings based on practical use can only be calculated by comparing the old situation with the new situation.


monitored by the NGO manager or trainer. Preferably, the wife of headman or king should show interest in becoming the village promoter (5) of ICSs in the entire village. The trainer (3), together with the village promoter (5), will construct the new ICSs in the household of the village headman or king (4). The NGO manager (1) monitors this process. The trainer will continue to monitor future firewood consumption. The village promoter will thereafter give explanations and demonstrations to other villagers.

Village or house of headman, king or chief in village. NGO manager =1 Trainer = 3 Wife of headman = 5 Village promoter = 5 Headman = 4

c) The village promoter (5) will have to possess a set of tools and construction manuals of

all the different stove designs. She makes contracts with other villagers (6) to install an ICS in their houses. The villager needs to pay for the metal components with the order and prepare the materials required for the new ICS; this includes roof passage for the chimney. The village promoter orders the metal components from the trainer (3). When these elements arrive, the villager promoter realises the ICS together with the villager or cook. She receives another payment for her labour and assistance in the ICS construction. New ICS designs for the promoter will be built together with the trainer (5, 6 and 3)

New house in the village. Trainer = 3 Village promoter = 5 Contracted person = 6 House owner/cook = 6 Motorbike = 7

d) The trainer and village promoter can have communication by telephone. The village promoter needs to pay for the metal and brick components and other items ordered (e.g. pots) in full at delivery. At this point no credit should be extended. If the village promoter extends credit to the other villager, it is an internal matter and may not affect the project. Internal village credit may be supplied by a village-based saving and loan scheme (S&LS). The trainer needs to pay the NGO in cash for the metal or baked brick components. The NGO can make mass orders with its suppliers.

e) The trainer will follow the same procedure in the next village; selecting a key family in

the village; install a few demonstration ICSs and make contract agreements with the selected village promoter. For every new design of ICS, the trainer should make that ICS together with the village promoter (5, 6 and 3). The trainer must ensure that the village promoter has a set of tools, manuals and order forms. The trainer should have a motorcycle (7) with some carrying capacity for the metal components.

The following sketch depicts the development of one trainer in one sub-district. A village promoter can realise two ICSs per day if all materials are available on site.


(1) Manager NGO (2) Wife manager (3) Trainer (4) House owner (5) Promoter (6) House owner (7) Motorcycle A = phase one B = phase two C = phase three D = phase four

f) Following the ICS introduction in one district, other trainers can be set up in new districts. Training of these trainers is in coordination with the trainers in the first district. All trainers communicate with the NGO for supplies, manuals and new developments. The NGO realises quality control for the products.

Central organisation of various trainers on motorbikes, each systematically working a district. Possible products: Pressure cooker Solar box cooker Metal top plate ICS Metal grate/plate ICS Solar Home System Thermos bottles Pots and pans

g) New developments can include additions to the stoves, such as the smoke water heater.

New energy-related equipment, such as solar cookers, solar water heaters (SWH) and thermal insulation boxes, can be introduced through the same network. Cooking books, pressure cookers for higher altitudes, stacking pots and mobile metal ICSs can also be marketed. By adding the additional equipments, which can be bought from a catalogue, the income for the trainers and village promoters can increase if based on sale commissions.

Other activities when the operation is well managed: h) Invite colleagues from other NGOs to partake in the promotion activity and provide them

with the promotional material and marketing network. i) Invite colleagues from other districts in the country for an explanation of the technology,

production and dissemination process, advantages, bottlenecks and solutions. Provide them with the technical and financial details for local replication.

j) Organise entrepreneur exchange visits between different regions so a new entrepreneur can learn from an experienced one.

k) Organise networking between entrepreneurs so they can benefit from central supply and transport facilities against reduced prices.

l) CDM regulation with CER when 100,000 ICSs are installed. For more information on cooking stoves, see: www.stoves.bioenergylists.org www.crest.org and www.hedon.info/goto.php/ImprovedCookstove For more information on indoor air pollution: www.who.in/indoorair/presentations and www.who.in/indoorair/publications


http://www.hedon.info/goto.php/ImprovedCookstove

http://www.who.in/indoorair/presentations

http://www.who.in/indoorair/publications

ANNEXE Chula The design of the Chula (Nepal, India) is mentioned here in order to better understand the development of the ICS. The two-pot Chula can have a firewood efficiency of 15% as compared to 10% for a three-stone open fire. By confining the fire, this design will save (15-10)/15 = 30% of the firewood as compared to the three-stone open fire.

The chimney extends to at least one meter above the stove and can go through the roof or wall to the outside.

An ICS has low space-heating properties because the fire is confined. It also does not emit light. When space heating is required, the chimney should be made of metal (0.4 mm = gauge 28 sheet metal) and be at least four meters long before it goes to the outside.

The firewood entrance can be made in the front or at the side. A smoke water heater can be realised when a hot water tank is installed as the bottom part of the chimney. For drinking water, stainless steel is recommended. The tank tap should be above the ground in order to avoid damage to the stove if it leaks. The firewood efficiency for a two-pot Chula with the smoke water heater can be as much as 20%.

Considerations about the construction:

The stove needs to be made according to the existing pot sizes. A strong spoon and short knife are used for shaping the adobe material. The stove needs to be maintained or repaired with fresh mud plaster if the pot openings or the baffle (elevation under the second hole) get damaged. The pot should fit precisely to avoid smoke into the kitchen.

The chimney should be cleaned every three months (four times per year). A bottom side outlet can be made on the chimney, which is closed after each cleaning.

The stove can be raised or placed on a low table if the cook wants to stand. Firewood can be stored under the table.

The ceiling of the flue gas duct inside the stove can be reinforced with six 40 cm long Ø 8 mm bars. If the clay soil structure is very strong, these reinforcements are not required.

The chimney can be masoned with burned clay bricks in soft clay or with adobe blocks. For small cooking pots, the fire entrance, the flue gas duct (5 cm x 20 cm) and the chimney will have a section of 100 cm2 or Ø 10 cm.

The new stove needs to dry out completely before it is fired in full. The following stove designs have similar considerations.


ANNEXE ICS with Plate and Grate The ICS with metal plate/grate is higher than the above Chula design because of the modified air intake. Improved burning of the firewood gives a higher temperature and shorter cooking times. The two-pot model will have a firewood efficiency of 25% as compared to the three-stone open fire with 10%. Because of improved burning, this design will save (25-10)/25 = 60% of the firewood as compared to the three-stone open fire. This ICS has a removable block under the chimney to allow cleaning. A thin metal slide (0.4 mm, gauge 18) can be inserted before the chimney to control the draft in case of strong winds.

This stove design is for a pot size of Ø 20 cm only. When the pot size increases, the dimensions of the stove will change. The table below gives the most efficient dimensions of the construction. For all the stoves, the height of the grate/plate is only 5 cm.

Pot Size in Ø

Litres of Pot

Volume H<Ø

Opening Height

including Metal Grate-Plate

Height

Firewood Opening Width x Height

Burning Chamber Ø or Square

Height from Below to

Pot Bottom

Section of Flue Duct

Section of Chimney

Duct

Ø 20 cm 4 14 cm 10 x 14 cm Ø 10 cm 9 x 9 cm 27 cm 90 cm2 90 cm2







The grate has the same size as the burning chamber. The maximum width of the extended support end is the same as the pot size. The length of the plate depends on the wall thickness of the stove.


ANNEXE ICS with Sunken Pot The ICS with sunken pot is higher than the above stove design because of the additional height for the sunken pot. Improved heat transmission to the pot also gives shorter cooking times. The two-pot model will have a firewood efficiency of 35% as compared to the three-stone open fire with 10%. Because of improved burning, this design will save (35-10)/35 = 70% of the firewood as compared to the three-stone open fire. This ICS has a removable block under the chimney to allow cleaning. A thin metal slide (0.4 mm, gauge 18) can be inserted before the chimney to control the draft in case of strong winds (see model above).

This stove design is for a pot size of Ø 25 cm only. When the pot size increases, the dimensions of the stove will change. The table on page 17 gives the most efficient dimensions of the construction. For all the stoves, the height of the grate/plate frame is only 5 cm.

This ICS design is the most energy efficient, especially with deep pots, because the sides of the pot are also heated by the fire flue gasses. For shallow frying pans, the model from the former page can be used as it will make less difference. Similar to the drawing on page 17, a metal thin plate can be inserted before the chimney for areas where strong chimney drafts may occur. The longer the chimney, the more draft will exist. The amount of fire is controlled by closing the air intake and removing the firewood from the opening. The firewood opening is the front side of the stove. The front side of the cooking pot in this ICS is lined up with the front side of the burning chamber. This causes the flue gasses to adequately envelop the pot and after that flow to the second cooking point and chimney. The cook needs to stir the contents of the pot or turn the pot regularly. A limited amount of flue gasses will escape alongside the pots. For this reason, either very good ventilation must be present in the kitchen or an additional hood should be constructed over the stove with an outlet to evacuate the smoke out of the kitchen.


ANNEXE ICS with Metal Top Plate The ICS with metal top plate is lower than the ICS with metal grate/plate because the thickness of the clay soil top surface has been reduced. Improved burning of the firewood gives a higher temperature and shorter cooking times. The two-pot model will have a firewood efficiency of 25% as compared to the three-stone open fire with 10%. Because of improved burning, this design will save (25-10)/25 = 60% of the firewood as compared to the three-stone open fire. The top plate will become hot and can be used to keep other dishes warm next to the cooking holes. The ICS has a removable block under the chimney to allow cleaning. With a round sheet metal ring, smaller pots can also be placed over the first cooking hole.

This stove design is for a pot size of Ø 20 cm. When the pot size increases, the dimensions of the hole and the stove will change. The table on page 17 gives the most efficient dimensions of the construction. For all the stoves, the height of the grate/plate frame is only 5 cm.

This ICS design is more versatile in use because several types of larger pots can be placed over the hole, but the metal top plate makes it more costly. To keep the cost low, 1.2 mm sheet metal (gauge 18) is used, but this sheet needs to be supported by two Ø 12 mm bars. For shallow frying pans, this model is the most energy efficient and comfortable. Regular maintenance of the baffle under the second cooking hole should be assured. A baked brick can be used in this location to minimise the amount of maintenance. The baffle causes the flue gasses to be pushed upward under the second pot opening. The amount of fire is controlled by closing the air intake and removing the firewood from the opening. Because the top plate will become hot, the stove will warm up the kitchen. In the event more heat is required in the kitchen during the winter period, a long metal chimney can be used. For the summer period, adequate ventilation should be present to remove the heat.


ANNEXE ICS Sunken Pot with Metal Top Plate The ICS sunken pot with metal top plate has the same height as the clay soil design. Improved burning of the firewood gives a higher temperature and shorter cooking times. The two-pot model will have a firewood efficiency of 35% as compared to the three-stone open fire with 10%. Because of improved burning, this design will save (35-10)/35 = 70% of the firewood as compared to the three-stone open fire.

This drawing is for a pot size of Ø 30 cm. For all the stoves, the height of the grate/plate is only 5 cm.

Regular maintenance of the baffle under the second cooking hole should be assured. A baked brick can be used in this location to minimise the amount of maintenance. The baffle causes the flue gasses to be pushed upward under the second pot opening. The amount of fire is controlled by closing the air intake and removing the firewood from the opening. The dimensions for the firewood opening, the burning chamber and the distance under the pot are the same as in the table on page 17. The firewood opening is the front side of the stove. The front side of the cooking pot in this ICS is lined up with the front side of the burning chamber. This causes the flue gasses to adequately envelop the pot and after that flow to the second cooking point and chimney. A limited amount of flue gasses will escape alongside the pots. For this reason, either very good ventilation must be present in the kitchen or an additional hood should be constructed over the stove with an outlet to evacuate the smoke out of the kitchen. The top plate is supported by the clay soil tunnel, which is supported by the short bars. In this design, no pots stand on the top plate. If the exit flue channel is extended for placing pots, additional support bars are advised (see annexe with axonometric construction details). The upper side of the flue channel can also be made with baked clay tiles; these avoid the need for steel reinforcement bars. If baked clay tiles are available, this is a more durable and cheaper solution. Overlapping clay tiles can also form the finishing of the top surface of the stove.


ANNEXE ICS Large Sunken Pot The ICS large sunken pot is used for communal kitchens, such as for very large families, clinics, small industries and restaurants. Because of the larger and longer duration of the fires, it is recommended to line this type of ICS with baked bricks; thereby reducing maintenance. The burned bricks are masoned with soft clay, which will also bake with the continued fires. This larger ICS can be finished off with ceramic tiles for better appearance and hygiene. The two-pot model will have a firewood efficiency of 35% as compared to the three-stone open fire with 10%. The two-pot design will save (35-10)/35 = 70% of the firewood as compared to the three-stone open fire. With the smoke water heater, the firewood saving will be as great as 75%.

In this design, the flue channel continues under a metal plate with a second cooking hole and an area for simmering food. The installation has an additional smoke water heater. Water supply comes into the top of the tank. A tap at the low side allows hot water to be drawn for cooking, washing up or other kitchen use. This is beneficial in kitchens with long-burning fires.

The cross section below illustrates the interior being made of baked bricks, requiring less maintenance than the clay soil ICS designs. An air intake in the middle of the construction, under the channel, allows secondary air to mix with the flue gasses. This will cause additional burning power under the second cooking point.

General: For the realisation of the ICSs, it is recommended to make detailed manuals with axonometric drawings for each layer. This way the village promoter will be better guided in the construction of the stove. With five ICS stove designs and five pot diameters, this means 25 construction manuals. A first project phase will determine which ICS designs are most liked by the villagers.


ANNEXE ICS Axonometric Sketches The sketches below are an example for the ICS sunken pot with metal top plate manual. The sketches indicate the principle, but they are not drawn to scale. These types of sketches can be complemented with the respective plans of each layer. Designs for a hood construction can be added.

Sketch I A flat basis against one wall of the kitchen. The design can be left or right. The place will depend on the best location for the chimney, so it would not leak during rains. Sketch II After selecting the pot sizes, use adobe blocks or clay soil with 50% clay content to build the base for the burning chamber. The burning chamber can be lined with baked bricks for durability. Sketch III The second layer is 13 cm high. The shelf is made from planks, corrugated sheet metal or concrete. The baffle is made of a baked brick, after which the flue channel is also placed higher.


Sketch IV The two pot supports are placed at the correct height, the front one slightly lower than the second one and dependent on the height under the pot handles. The widening of the front burning chamber and the front flue channel are shaped. Sketch V Another layer is built. Both pot spaces are developed and the rear flue channel is added. In this case, the flue channel is extended to provide a third point for heating a pot on the plate. Between the two pot spaces, a bar support is made for the roof of the first flue duct. As an alternative, a baked brick or tile can be used when it has the correct shape.

Because this ICS design is slightly complicated, it is recommended to make plan type drawings as well. It is worthwhile to invest time in making detailed, clearly understandable drawings and manuals with precise material lists rather than repeatedly training field staff. A large-scale ICS production project should be organised so material packages (except the clay soil) are readily available according to the chosen stove design. These can be packages with or without the baked clay bricks. In some countries, only the burning chamber is a prefabricated clay pot, whereas in other countries, the flue ducts are prefabricated in baked clay units as well. These designs have implications for ease of transportation and added costs.


Sketch VI The top layer of the ICS without the metal plate. With the addition of a smoke water heater, the flue duct should end under the chimney pipe of the boiler. The metal plate has a cut-out section wider than the chimney hole to allow masoning the chimney on the basement. The chimney plug can be made of two baked bricks, standing on a support. When high winds may cause extra draft, a chimney slide is advised.

When the new ICS is made of moist adobe blocks or clay soil, it will need to dry completely before the burning efficiency is optimal. With this design, some smoke will enter the kitchen alongside the pots. Good ventilation in the kitchen is important, but it is better to construct a ventilated hood over the stove area. The chimney should be cleaned every three months. When pinewood or other wood with a high tar content is burned, cleaning should be more regular. The outside and inside surface of the clay soil stove can be maintained with a clay soil wash. The outside of the stove can be maintained with a clay soil and lime wash for neat presentation.

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Documents

Improved Cooking Stove (ICS) · 2012-01-16 · Cameroon, ICS (January 2010) 1 : 1. ... The climate in Cameroon is in most regions very good for growing plants. Therefore, in the rural