H0W TO OPERATE AN EFFICIENT WOOD BURNING STOVEpumicestove.com/.../10/How-to-Operate-an-Efficient-Wood-Burning-St… · H0W TO OPERATE AN EFFICIENT WOOD BURNING STOVE ED KEANE 08/09/2013

H0W TO OPERATE AN EFFICIENT WOOD BURNING STOVE

ED KEANE 08/09/2013

HOW TO OPERATE AN EFFICIENT WOOD BURNING STOVE

( SUPPLEMENT 3 )

STOVE BUILT IN USA USING REFERENCE DOCUMENT

REFERENCE:

HOW TO BUILD AN EFFICIENT WOOD BURNING STOVE

REVISION (A) 07/16/2013


ED KEANE 08/09/2013 Page 1

Introduction

This supplement (3) is educational information for the stove installers to pass on to the

women who will be the primary user of the efficient wood burning stove. It requires a new

method of cooking which will be a negative because it requires more work preparing wood

and feeding the stove as you cook, however the benefits are many. The benefits are a

healthy environment for the family, less burns and less time foraging for wood. The work

and time added will be offset by the stove efficiency requiring less wood. I can understand

that the woman who cooks wants to do what she is doing and her mother did before her. If

I could design a stove that would fit her life style that would be the best scenario but

studies show that is not possible. To burn wood efficiently there is a need for a rocket

elbow. To remove the toxic smoke from the home I need a smoke path and a chimney. The

stove needs to be raised to protect the children from serious burns. To obtain these benefits

the woman who cooks needs to understand the importance of efficient wood burning

stoves and how they work. The installer needs to understand these instructions so he could

educate the new stove owner on how to use the stove. The main objective using an

efficient wood burning stove is to use the minimum amount of wood to cook a meal. The

women who cook everyday will be the ones who make it work but they need the basics

first and then they can form groups and be the educators.

Preparing Wood

First we need to cut the wood to the proper length about 40 cm long. In the USA we use a

bow saw and a sawbuck see Figure 1. Whatever method you use, make it ease so it will

become a normal routine.

Splitting Wood

If the wood pieces are larger than about 5cm diameter they should be split. When you split

wood you create more exposed area and it burns better. To split wood you will need to

place the log on a hard surface. You will need a steel wedge and a sledgehammer or an axe

see Figure 2. Figure 3 shows wood that has been cut and split and is ready to be stacked

for drying prior to use.



Drying Wood

The moisture content of fresh cut wood is high. This wood will result in a smoky fire that

will not burn efficiently, the wood needs to be dry. To dry the cut and split wood, stack it

in a sunny spot for at least three months before using. In the rainy season the wood needs

to store in in the home.

Feeding the Stove

Figure 4 is a view at the centerline of the stove that shows how to feed the wood into the

combustion chamber. Only the tips of the wood burn and as tips burn off the wood pieces

need to be pushed gradually into the combustion chamber (CC). Therefore the cook needs

to attend the stove while the food is cooking. If the food is cooking to fast wait before

adding more wood.

If and the wood has been pushed into the combustion chamber a brick can be used to cover

the CC opening while the food shimmers see Figure 5. If the cooking slows down remove

the brick and add more wood and repeat the process. See Figures 6 and 7 for pictures that

demonstrate the process.

Note; If there is excess oxygen wood will burn too quickly and the food will cook too fast.

Wood burning too fast can be the result of too much draft and there is no damper in the

chimney to regulate the draft. A brick covering the CC inlet will help slow down the air

intake to the combustion chamber which will act as a damper.

Cleaning the Chimney

There is little information in the reference document on how to fabricate and build a

chimney that removes the smoke from the home. The chimney needs to be fabricated in

sections so it can be disassembled. Figure 9 shows a young girl cleaning a stove pipe

section with a broom made with stiff straws fastened to a long handle. This is necessary to

prevent buildup of creosote in the stove pipe that can cause a fire. This is a real

maintenance item and may be alien to the user of the new efficient wood burning stove.

Here again education will be important to the operation and maintenance of an efficient

wood burning stoves. This item is important and more attention needs to be given to the



details for disassembly of the stove pipe. There may be a need for a special group who will

be responsible for fabricating the stove pipe and will perform maintenance and cleaning of

the stove pipe where the new stoves are installed.

Problems

Figure 8 shows some problems with some of the early stoves installed in Sumbawanga.

This is not to be critical, they are important lesson learned and they can be rectified. They

demonstrate the need for education and it is not easily solved. The women who cook have

been using three stone fires their hold life and now they need to change and change is

never easy. The women are an import part of any stove project and they need to be

involved and understand what we are trying to accomplish.

Instructions for Safe Cooking

Herein page 11, are instructions for safe operation of the new efficient wood burning

stove. However a lot more information and education is required for the women who cook

and operate the new stoves. The more they know about the stove and its benefits they can

accept the new life style associated with cooking on a new efficient wood burning stove.



FIGURE 1 CUTTING FIRE WOOD TO LENGTH IN THE USA

This is just an example, to use this method you would need a bow saw and a sawbuck

(wood support that can easily be built). However you accomplish this task make it ease so

it will become a normal routine.



FIGURE 2 SPLITTING FIRE WOOD

FIGURE 3 SPLIT WOOD READY TO STORE



FIGURE 4 SECTION AT CENTERLINE OF STOVE

Section view shows method of feeding fire wood into combustion chamber. A longer piece

of wood is used for pushing. The object is to burn the tips of the wood until it is consumed

and push in the remaining section of wood.

BY HAND

PUSH

WOOD TO

SMOKE

WOOD

COOKING

PLATE

FIR

E

FEED WOOD INTO THE COMBUSTION

CHAMBER



FIGURE 5 -SECTION AT CENTERLINE OF STOVE WITH BRICK

INSTALLED TO REDUCE AIR INPUT

Once the fire wood has been pushed into the combustion chamber the input air can be

reduced to slow down the cooking and save wood and prevent fast burn that can damage

the stove (combustion chamber, cooking plate and chimney). If the cooking slows down

remove brick and add more wood and repeat process.

LOOSE BRICK

TO REDUCE AIR

INPUT INTO

FIRE

SMOKE

FIRE

STEEL WOOD

RACK

COOKING PLATE



FIGURE 6 PICTURE AT FACE AT CC INLET SHOWING WOOD

BEING PUSHED INTO THE CC

FIGURE 7 -STOVE PICTURE SHOWING A METHOD OF REDUCING

AIR INPUT USING A BRICK TO ACT AS A DAMPER

A LONG PIECE OF

WOOD TO PUSH

SHORTER PIECES

INTO CC

LOOSE BRICK TO

REDUCE AIR INPUT

INTO COMBUSTION



Problem

FIGURE 8 EXAMPLE OF A PROBLEM

First the wood needs to be cut in smaller pieces and feed into the stove during cooking.

The black soot on the face of the stove housing indicates the wood was burning outside the

combustion chamber (CC). The stove housing at the CC inlet is eroded from fast burns due

to a high draft from the chimney. This stove with fast burn will eventually damage the

stove housing, which is already happening it can warp the cooking plate and reduce the

life of the chimney. Therefore the instructions herein need to be followed.

It’s good we built prototype stoves and learned that these things can happen.



(This should be done outside the home because it is a dirty job)

FIGURE 9 A YOUNG GIRL CLEANING A STOVE PIPE



INSTRUCTIONS FOR SAFE COOKING

1. DO NOT BURN PAPER, LEAVES, TRASH, PLASTICS OR GARBAGE –USE

ONLY WOOD.-

2. BURN ONLY SEASONED WOOD THAT IS DRIED FOR A LONG TIME.-THIS

IS NECESSARY TO PREVENT CREOSOTE AND TAR BUILDUP IN STOVE

PIPE THAT CAN CAUSE FIRES.-

3. USE THE FOLLOWING MAXIMUM WOOD SIZE, LENGTH- ABOUT 50 CM

WITH CROSS SECTIONAL SIZE –WIDTH 5CM- HEIGHT 5 CM- PREPARE

WOOD FOR COOKING BY SPLITTING AND CUTTING TO LENGTH-

4. FEED WOOD ON STEEL RACK INTO COMBUSTION CHAMBER USING A

PIECE OF WOOD- IDEALLY ONLY THE TIPS OF WOOD SHOULD BE

BURNING AND THE FIRE SHOULD BE DIRECTLY UNDER THE POT.

THERE SHOULD BE NO FIRE, EXCEPT IN THE COMBUSTION CHAMBER-

5. REMOVE ALL ASHES FROM THE COMBUSTION CHAMBER BEFORE

STARTING A NEW FIRE AND WHILE OPERATING THE STOVE, IF THE

ASHES FILL UP ABOVE THE TOP OF THE WOOD TRAY.-

6. START FIRES WITH A BUNCH OF VERY THIN STICKS OF WOOD WITH A

FIRE AT ONE END, PLACE THE LIT END INTO THE COMBUSTION

CHAMBER ABOVE WOOD TRY, THEN ADD LARGER PIECES AND SLIDE

THEM ALL THE WAY INTO THE COMBUSTION CHAMBER-THIS IS AN

IMPORTANT TECHNIQUE TO DEVELOP THAT WILL MINIMIZE SMOKE

DURING STARTUP.-

7. WRAP A SCREEN AROUND STOVE PIPE IN AREAS THAT CAN BE

REACHED BY CHILDREN TO PREVENT THEM FROM TOUCHING THE

STOVE PIPE AN RECEIVING BAD BURNS, -THE STOVE PIPE AND THE

STEEL COOKING PLATE TEMPERATURE DURING OPERATION IS ABOUT

230 DEGREES CENTER GRADE. THAT IS OVER TWICE THE

TEMPERATURE OF BOILING WATER

Documents

H0W TO OPERATE AN EFFICIENT WOOD BURNING STOVEpumicestove.com/.../10/How-to-Operate-an-Efficient-Wood-Burning-St… · H0W TO OPERATE AN EFFICIENT WOOD BURNING STOVE ED KEANE 08/09/2013