Geoliv.dk November 2014 Dolleris is licensed under a...

1 | D i p l o m a i n A p p l i e d P e r m a c u l t u r e D e s i g n - C a t h r i n e D o l l e r i s - 2 0 1 4

Cathrine Dolleris

Geoliv.dk

November 2014

Diploma in Applied Permaculture Design by Cathrine

Dolleris is licensed under a Creative Commons Attribution-NonCommercial-

NoDerivatives 4.0 International License.

Based on a work at www.geoliv.dk.

http://creativecommons.org/choose/www.geoliv.dk


http://creativecommons.org/licenses/by-nc-nd/4.0/





Content The problem ....................................................................................................................................................................... 3

Resources available ........................................................................................................................................................ 3 Schedule ..................................................................................................................................................................... 3

Research ............................................................................................................................................................................. 4 SWOT test ................................................................................................................................................................... 6

Ideas.................................................................................................................................................................................... 7 Skills sharing................................................................................................................................................................ 7 The oven design .......................................................................................................................................................... 7 Final design before workshop ..................................................................................................................................... 9

Make ................................................................................................................................................................................. 10 Preparation ................................................................................................................................................................... 10

The materials ............................................................................................................................................................ 10 Inviting participants .................................................................................................................................................. 11 The foundation ......................................................................................................................................................... 11

The workshop starts ..................................................................................................................................................... 13 The base of the oven ................................................................................................................................................ 13

Evaluation ......................................................................................................................................................................... 20 Product ......................................................................................................................................................................... 20

Input Output testing ................................................................................................................................................. 20 Tweaks ...................................................................................................................................................................... 22

Peers ............................................................................................................................................................................. 22 Building and learning ................................................................................................................................................ 22 Organisation and people .......................................................................................................................................... 23 Food .......................................................................................................................................................................... 24 Accommodation and venue ...................................................................................................................................... 24

Personal ........................................................................................................................................................................ 24 My own learning about the workshop ..................................................................................................................... 24 Participation.............................................................................................................................................................. 25 Children on the building site ..................................................................................................................................... 25 Expectations on time management .......................................................................................................................... 25 Venue ........................................................................................................................................................................ 25 My learning about the oven ..................................................................................................................................... 25 Community ............................................................................................................................................................... 26

Process .......................................................................................................................................................................... 26 Permaculture ethics at work ............................................................................................................................................. 27 Diploma Criteria ................................................................................................................................................................ 28


Flex oven design

The problem

This design aims to explore a “flex oven” design, its

implementation and evaluation.

My new, old house Kattekærhus has electric panels for

heating and a wood burner. Electricity is expensive and

not the most sustainable resource of energy. The wood

burner was of a type assessed to be not of the most

efficient kind. I want to change my heating system to

something that fulfils different needs such as:

Ethical and sustainable,

heating efficiently and evenly over time,

incorporating a baking oven,

a stove top for cooking,

a place to sit and keep warm,

visibility of the fire,

a place to heat water,

a place to dry clothes in winter,

inexpensive.

Resources available

A chimney is already in use and checked by the

chimney sweeper for any faults.

The place of the old wood burner is in the

middle of the house next to a brick wall, an

optimal position for distributing heat to most

rooms, see plan below.

Budget is very limited and expenses should be

kept to a minimum.

Time available is limited, but I am prepared to

make time for building, maintenance and firing

the oven.

I have a number of friends and contact to

people who are experienced stove builders.

Schedule

June and July: work out design brief, start

research on appropriate oven types. Select

builder.

This design uses the PRIME design cycle

Problem (Design Brief) The design brief is a summary of the problem and what is

needed to fix it. It also includes the limitations of the

project to be undertaken.

Research During the research stage all the tools needed are

identified and/or listed. Similar problems that have been

solved by others can also be researched. Anything

related to the problem is also researched. Experts on the

topic can be consulted.

Ideas In this stage all possible solutions for the problem are

explored. Also draft solutions are made, in preparation

for the ”make” stage.

Make This is the stage where the actual product/solution is

made. By this stage the final draft has been decided on.

Evaluate During the “evaluate” stage the final copy of the solution

is compared to the design brief and criteria. It also

includes a study on how well the designer stuck to the

PRIME design process. Other people besides the

designers can view and evaluate the work as well.

Source:

https://sites.google.com/site/technologypodcastingportfolio/th

e-prime-design-cycle-1


August: invite participants

September: prepare materials and venue.

1-5 October: Building workshop.

Afterwards: Observe and test oven capacity.

Tweak if necessary. Finalise plaster.

Research

I have participated in building flex ovens, rocket stoves

and mass ovens and have lived with a number of

different heating solutions such as electricity, wood

burner (normal), gas stoves, petroleum stoves, district

heating, and mass oven.

Of the different solutions for heating, I preferred the

mass oven for a number of reasons, reflecting at least

three permaculture principles: “Use and value

renewable resources and services”, “Catch and store

energy” and “Each element performs many functions”:

The mass of the oven absorbs the heat from the fire

and releases it over 24 hours; the clay and brick has

attributes of giving off and absorbing moisture,

creating a good interior climate; the mass oven is

made from mostly recyclable materials; it is ethical

and sustainable; it has an oven; it can be coupled with

heating water; I can be part of the process of building

it; I can share the skills with other by having a

workshop; it is like a secure monument in the living

room and becomes a good friend and you need to get

to know it to get the best out of it. Some

disadvantages were also identified: Quite expensive to

build and requires time to fire and to get firewood.

I continued my research with four different masonry

oven builders. The prices of building were too high for

my budget. Doing a workshop would reduce costs

somewhat, but I did not feel like putting on a proper

workshop, because of time constraints and the

expectations that I would have to manage. I also

researched a Finnish type mass oven in a kit, ready to

put up an then build the mantle around it. That would

also cut costs, and I considered it a possible option.

I also investigated the rocket mass heater, which is a

combination of a mass oven and a rocket stove. In

Denmark we usually call it a ”flex oven” – basically an

oven with the rocket effect and thermal mass to

Rocket stove and rocket mass heater design

A rocket stove achieves efficient combustion of the fuel

at a high temperature by ensuring a good air draft into

the fire, controlled use of fuel, complete combustion of

volatiles, and efficient use of the resultant heat.

A rocket stove's main components are:

Fuel magazine: Into which the unburned fuel is

placed and from which it feeds into the combustion

chamber

Combustion chamber: At the end of the fuel

magazine, where the fuel burns

Chimney: A vertical chimney above the combustion

chamber to provide the updraft needed to maintain

combustion

Heat exchanger: To transfer the heat to where it is

needed (cooking pot or other load).

The fuel magazine can be horizontal, with additional fuel

added manually, or vertical, with fuel automatically fed.

As the fuel burns in the combustion chamber, convection

draws new air into the combustion chamber from below,

ensuring that any smoke from smouldering wood near

the fire is also drawn into the fire and up the chimney.

The chimney can be insulated to increase the

temperature and improve combustion; according to

studies this can increase efficiency by up to two percent.

In a rocket mass heater, the heat is passed to a heat

exchanger to ensure the efficient use of the generated

heat.

Source: Wikipedia


absorb the heat and then in can have different other functions like a build in oven, water heating system, cook plate,

warm bench. I have before participated in building a flex oven, so I was familiar with the rocket effect and its benefits.

The rocket effect is the efficient burning of the fuel with optimal air flow making the combustion hot enough to burn

the volatile gasses released from the fuel to obtain increased efficiency and non-pollution. The combustion is said to

be over 800 degrees in this case. The rocket effect sounds like a rocket because of the gasses exploding inside the

combustion chamber.

I was not confident enough to build a rocket mass heater all on my own and would like to have someone more

knowledgable than me to make sure the design and implementation were correct, so I would not have any accidents,

like too much carbonmonoxide and poisoning.

I then talked to my neighbour and friend, who is a building engineer and has constructed a number of different rocket

stoves, rocket mass heaters and flex ovens. She was happy to work with me to make a rocket mass heater in my

house. Her price was very affordable. Most of the materials used in the stove were easy to find second hand. We

agreed that she would build it with me and we started working on design ideas.

A diagram of a generic rocket mass heater. Source: http://thesurvivalpodcast.com/forum/index.php?topic=23711.0

http://thesurvivalpodcast.com/forum/index.php?topic=23711.0


SWOT test

I decided to achieve more clarity over the three options to make the pro’s and con’s more clear with a test for

Strengths, Weaknesses, Opportunities and Threats.

Mass oven Strengths

Known product, tested

Efficient

Reliable

Increases thermal mass in house

Weaknesses

Expensive because of many fireproof stones in the core

Need professional builder

Can not fit in the centre under the ceiling because of height

Opportunities

Know some professional builders

Workshop to save money

Threats

Too expensive for budget

Not enough participants for workshop

Rocket Stove Mass Heater Strengths

Efficient

Flexible design

Adaptable

Inexpensive (uses vermiculite)

Many second hand materials possible

Can be built with bricks, cob


Weaknesses

Untested design

Oil drum used in Rocket Mass Heater – have not tried building with oil drum before

Opportunities

Can invite participants without pay

Threats

The oven doesn’t work

Bad design

Flex Oven Strengths

Efficient

Flexible design

Can be adapted to needs and location, i.e. baking oven built in

Inexpensive (uses vermiculite)

Many second hand materials possible

Can be built with bricks, cob


Have been part of building flex oven before so know it better

Weaknesses

Untested design

Opportunities

Know a builder who is a specialist in Flex Ovens

Can invite participants without pay

Threats

The oven doesn’t work

Bad design

In conclusion, the mass oven had two drawbacks: It was more expensive (possibly by factor 6!) and it would require

some tweaking to make it fit in the room.

The option of the rocket mass heater or flex oven was alsmost the same. The rocket mass heater usually uses an oil

drum as it core, but I like to use bricks and to reserve the heat for the baking oven.


The deciding point was that my friend and builder would built it with me and the budget allowed me to have

participants coming for free for this first workshop at Kattekærhus.

Ideas

Skills sharing

I want to share knowledge and skills with others, honouring the fair share ethic of permaculture, so it was important

to invite other people along to the building of the oven. The builder was not interested in doing a course and be the

teacher, so the invitation was quite clear about what to expect from the workshop. No teacher, but participation in

working to build an oven. It suited me fine to have this level of engagement for the first workshop in my house to try

out how it worked and how the house could function with 10 people. I decided not to take any payment and did

provide people with food and accommodation.

The oven design

The placement in the house is important

for size of the oven, thermal mass,

options for connecting to a water

heater, and aesthetics. A diagram shows

the placement of the flex oven in the

room and the chimney. The oven should

be able to heat about 100 m2 of not so

well insulated house in two floors.

Different design options were available:

What functions should the oven have?

heating efficiently and evenly

over time, thus with a lot of

mass

incorporating a baking oven,

a stove top for cooking,

a place to sit and keep warm,

visibility of the fire,

a place to heat water,

a place to dry clothes in winter.

Accommodating all of these wishes was possible, but prioritising them was necessary because of the limit of the heat

from a fire, i.e. either a hot cook plate or a hot oven.


How should it be connected to the chimney?

Via the old chimney pipe through the kitchen (the

top pipe on the photo to the right)

Through a new hole in the wall, a warm bench, and

through a new hole in the chimney at the base in

the entry.

The first option seemed to be the easiest; least intrusive to

the house construction; and fastest. It would mean that

more heat would go into the kitchen than into the entry,

but that was fine.

What should it look like?

I had in mind:

A rounded shape

a symmetrical oven with benches on each side,

natural stones at the bottom

the fire chamber with ability to open below and above and heat riser behind on one side

the oven on the other side

small stones in front of fire chamber and oven


The illustration above shows the intended flex oven design with a 50 cm heat riser, which would make the oven about

80 cm high. The air intake and fuel magazine was in the same height as the heat riser. The oven was part of the smoke

channel and could be used after the fire, like in a mass oven.

How to design the firechamber and smoke channels?

I had in mind:

50 cm fire chamber

50 cm heat riser

Smoke channel through oven (cannot use it when there is fire in the oven)

The smoke passes into warm bench to the left and doubles back

The smoke passes through a vertical smoke channel and into the smoke pipe

The smoke passes through the existing pipe through the wall and into the chimney

I gave this information to the builder and she did some calculations on the proportions of the oven. It would come out

from the wall about 90 cm. The building regulations require a minimum of 30 cm from the fire chamber to burnable

material, in this case the wooden floor. They also require 20 cm from the cleanouts to burnable material, so the

smoke channels should either be raised 20 cm above the floor or be at floor level with 20 cm of fireproof material in

front. This meant that there should be a minimum af 120 cm from the wall to the wooden floor.

Final design before workshop

The builder made some calculations and we ended up with a design that looked like this:

The whole oven is raised 20 cm to make enough space for the cleanouts to be free of the wooden floor. The flex oven

with a 90 cm heat riser. The builder decided to make a heat riser of 90 cm instead of 50 cm to insure draft. She had

not been able to make it work with less than 90 cm. Steps needed to be formed to get the stove top to a reasonable

height. The stove top was moved from on top of the heat riser to form the roof above the baking oven. It was

assessed that there was not enough heat to have two places with stove tops and the top one was possibly too high up.

The fuel magazine has been changed into a slightly bigger fire chamber. The baking oven has an inset from a standard


electric or gas baking oven. The smoke channels go around the baking oven on all sides. Drawing: Caroline Meyer

White

The flex oven seen from above: The drawing is complex because there is a lot happening in the central area in several

layers. The flow goes through the fire chamber and into the heat riser and passes into the smoke channel downwards

towards the baking oven. From there another channel leads down to the warm bench and further into the vertical

smoke channel. However, to make it easier to get a good draft through in the beginning of lighting a fire, there is a

bypass next to the heat riser that leads directly to the existing smoke channel and then into the chimney. Drawing:

Caroline Meyer White

I could not really see the oven from my inner eye, but I trust the builder, so we went with this design.

Make

Preparation

The materials

I wanted to get most of the materials second hand

because I like to recycle when possible, and to save on

the budget. I managed to get:

What DKK

800 second hand bricks 500

1 second hand backing oven free


1 second hand wood burner 300

30 second hand leca-blocks free

3 new round cleanouts 1350

25 new chamotte bricks 467

8 bags of clay, 20 liters each 850

500 liters of 0-4 sand 800

Vermiculite plates 698

Fireproof mortar 180

1 bag of Glue mortar 109

1 bag of normal mortar 45

1 bag of Cement 45

Buckets 115

Food for 11 people 2000

Transport 2583

Builders 5000

Natural stones free

Total 15042

A total of 1592 GBP.

Inviting participants

The builder and her partner and two children were going to come. I wanted 3-5 participants to share skills with. More

people would be too many around the oven.

I announced at the Nordic Permaculture Festival that I was going to build and had enough participants interested

already. I kept email contact with these people and 5 of them would come.

The foundation

A new foundation was necessary to support the heavy mass of the oven. Normally 3-4 tons of mass is required for a 24

hour cyclus of burning and releasing heat. The dimensions of the foundation were determining the size and shape of

the oven, but I didn’t want to make a bigger hole than necessary in the floor. This was sorted out when I started

assessing the size and shape of the area for the oven.

The space between the two doors to either side of the wall were the oven would be placed was 250 cm. This would

give a diameter of 120 cm, exactly what was need for the oven. I decided to make the foundation a semi-circle,


because of the aesthetics and harmony and because of the flow of activity between the two doors. A shape with sharp

corners would give a less than optimal flow. I made the semi-circle with a radius of 126 cm from the wall to have a

little extra space.

The old foundation was removed with help from my father. The floor boards were cut with a jigsaw. Underneath was

a layer of sand 20 cm, a layer of fist sized stones 20 cm, and at the bottom big stones. Very common for old houses.

The layers were removed. I wanted 5 cm between the foundation and the top of the floorboards to make a finish of

small stones. The leca-blocks were each 9 cm thick without mortar. In total we dug about 25 cm deep under the floor

boards. The floorboards needed securing and we screwed rafters underneath and supported them with bricks.

The hole was tamped tight and levelled out with sand. Two layers of leca-blocks were put in. Leca-blocks are stable

and make a good foundation and they insulate well, so the heat would not pass into the soil, but into the room.


The leca-blocks were cut into the right shape to fit into the round hole.

The workshop starts

The base of the oven

I like natural stones and I wanted the base of the oven to be stone. That fit well with the design because the whole

oven was raised 20 cm. Some of the stones had been dug up when we made the foundation and other stones were

found on the property. They were selected for their beauty and shape. Blue lines indicate where there should be no

stones, big stones or 20 cm high stones. Most of the old cement foundation was reused as filler and thermal mass in

the base of the oven. Clay plaster (1 clay : 4 sand) was the mortar.


The clay plaster was a mix of 1 measure powered clay to 4 measures 0-4 mm sand. We used a big mixer to aid the

hard work of mixing. Fire proof mortar: 2 ash, 1 clay and a little water.

An old wood burner was selected for its doors. The iron frame needed to be cut out with a grinder. The old wood

burner is being taken apart.


The builder is explaining the design to the participants. The base of the oven is finished and the first row of bricks is

placed next to the existing wall. The “hill” in the middle is where the baking oven will be placed.

The smoke channel in the warm bench is getting started and the vertical smoke channel too.

The fire chamber is made from fireproof chamotte bricks, 50 mm, and the mortar used is made from ash and clay. To

the right, the smoke channel in the bench is almost covered.


The fire chamber is connected to the heat riser via an opening 15 cm * 20 cm. This is the minimum size of the smoke

channel all the way through the oven. The stone that will be placed in the channel between fire chamber and heat

riser can have a special form to concentrate airflow. The shape of the stone, with the “V” pointing toward the heat

riser, is said to increase the flow of air towards the centre of the channel, thus increasing oxygen level, combustion

and temperature.

The lower parts of the smoke channels and fire chamber are taking shape. To the right, the place where the baking

oven is going to be. The airflow has to come all the way around it, so the oven needs to be placed on pieces of brick

with a piece of tile underneath, so it does not displace itself in the still soft clay mortar.


The baking oven had to be smoke tight, which meant that all the small and big holes from ventilator, lights,

temperature measurer and other parts had to be closed. We used a fire proof “glue” and bits of metal plate and mesh.

I will not recommend this procedure, but rather find an oven with fewer holes! However, we succeeded and the oven

could be placed with great care in its niche. It was fastened with big screws to the bricks behind in order not to fall out

of the niche.

Where metal touches brick a piece of glass fibre is inserted in between. Metal and brick work in different ways – metal

expands with heat more than clay. This would cause the mortar and bricks to crack with the expansion and

contraction of the metal with every fire. The glass fibre is a buffer that absorbs the movements and insulates. It comes

from the original baking oven.

To the right, the vermiculite insulation inside the heat riser is visible. The fire chamber has been covered with a metal

plate from the old wood burner and bricks will be put on top, hence the glass fibre patch.


Left: We are getting to the complicated part: The heat riser with vermiculite sticking out is at the back. The bypass we

welded ourselves is lying on top of the fire chamber. The first stone making the diagonal smoke channel between heat

riser and baking oven is seen in the middle of the photo to the left. Right: The heat riser is closed with vermiculite on

top. The diagonal smoke channel is covered with a lid made of a tile, 30*30 cm and below that some vermiculite

plates. Between the heat riser and the vertical smoke channel is the rod of the bypass where the bypass channel is

going to be.

The smoke channel sloping down held in place with a ruler and a hammer. Behind is the top of the bypass. The builder

inspecting the work while the vertical smoke channel is continued.


The two top clean out have been placed. It was decided to extend the vertical smoke channel to cover the pipe

through the wall, because it was a more stable solution. The bypass rod is mounted through a hole drilled in a brick.

Workshop participants enjoy the nearly finished oven.

The first fire! It is ok to make a fire as soon as the smoke channel is closed. The clay mortar just dries out. Participants

are waiting excitingly to see what happens in the first fire. Vapour is likely to come out of cracks and holes in the

mortar. It is easy to spot where the cracks are and to fill them with clay mortar, when they appear. We had 3-4 places

that needed a bit of fill and then it was fine.

The door to the fire chamber with the first fire. A big moment! The shiny baking oven door reflects like a mirror.


Not much clay was left, so the oven could not have a full layer of clay plaster all over, so we filled out some of the

more disharmonious parts. The final oven with its steps, towers, plateaus, slopes and rifts. A new element has been

born in Kattekærhus!

Evaluation To evaluate the design I have used the 4P model:

Product - Discuss if and how my product design solved my problem.

Peers – Reflections from the participants on the workshop: building the oven, the organisation, food

accommodation and learning.

Personal – Reflect upon how my personal learning and practical experience increased through the process.

Process - Discuss how I used the PRIME Design Cycle to assist in solving the problem.

Product The product satisfactorily solved my aim of getting a sustainable and ethical heat source. The flex oven is a hybrid

between the mass oven and the rocket mass heater and could therefore accommodate my needs.

One need was discarded during the implementation: the production of warm water. It was assessed that the water

storage in the bathroom was inadequate for coupling with the oven. Furthermore, the second hand radiator found for

putting inside the flex oven lacked adequate fittings. It was safer not to incorporate it into the oven and alternative

solutions found instead. The alternative solution to getting hot water is by building an outdoor shower, heated by a

smaller rocket mass heater and/or by tubes on the roof and/or solar panels on the east facing gable.

I have made around 20 fires in the flex oven until now and it works well. The oven is drying out and giving off more

and more heat for every burn.

Input Output testing

I tested a burn to get more insights on the inputs and outputs of the oven.

Inputs:


Newspaper: 130 g

Pine cones: 150 g (pine cones are very good fire starts when dry, because they are easy to light and contain

resin that burns hot for some time).

Small cut off wood pieces: 1500 g

Compressed wood chip briquettes: 4000 g

A total of 5780 g of combustible material

With this amount of material the oven is about as full as it can be.

Outputs: Firing the oven:

I started building up the fire at 8 pm and opened the bypass. There was 17 degrees in the room.

At 8.05 I lit it.

8.07 the rocket effect is audible and the flames are sucked through the fire chamber to the heat riser.

8.08 I close the bypass and the rocket effect continues.

8.09 I close the doors to let sufficient air in and no smoke out. The oven is sensitive to open doors and will

send smoke out the wrong way if kept open.

8.50 the rocket effect stops. I stir the fire and the rocket starts again momentarily. There is 140 degrees in the

baking oven. The warm bench is quite warm.

9.05 I stir the fire again, with some smoke coming out. The rocket starts again. 120 degrees in the baking

oven.

9.20 only smoldering in the oven, so I close the doors and keep only the vent in front open. 100 degrees in

oven.

11.00 A single glow left. I close the vent in front to keep the oven from cooling down. Room temperature 19

degrees.


12 hours later the oven is still warm in places. I weigh the ashes: 150 g. Room temperature 18 degrees.

In conclusion, a fire with about 6 kilos of material produces enough heat to keep the room temperature steady (27.

October). Outside temperature was around 10 degrees. When it gets colder more wood must be used and this means

firing twice per day or topping up the fire. A fire lasts about 3 hours. The heated area is about 100 m2.

I will monitor how many fires I start to calculate my need for firewood. A first rough estimate is 150 days of firing one

time per day and 100 days of firing a second time. Thus about 250 fires in a year using 6 kilos of material amounts to

1500 kilos of firewood.

I also produce ashes that will be used in the garden. From 250 fires I would get around 37.5 kilos of ash.

Tweaks

I may be able to improve the combustion with a grid inside the fire chamber to let air under the combustible

materials.

I will use more clay plaster on the oven and thus increase its mass, especially on the places that get very hot now. It

will also make it look more beautiful and complete and I can make decorations with for example small beach stones

on it to add personality.

Peers I got feedback from the builder and the participants of the workshop around building and learning about the oven, the

organisation, food, venue and accommodation. I asked for plusses and minuses for each area. The results are as

follows.

Building and learning

Participants expressed about the workshop:

Plusses:

Great to experiment with new techniques

Building in the baking oven was a new experience

Working with bricks and mortar was a new experience (instead of cob)

Super to see how the oven unfolded itself from being a childish castle to a full oven!

Exciting project!


It has given me some experience and courage!

Minuses:

Too crowded around the oven until the last day

when some people left.

More explanation of the process of building would

have been good

Sometimes difficult to find out how help was

needed, because I didn’t really know what we

were doing.

A bit careful with the work because it is the first

time and I have not tried it before. It got easier

over the days, when I got more overview of how things were to be done.

Organisation and people

Because the oven was not big enough for everybody to be

working on it at the same time, I had chosen some tasks

that people could do in the room, while still following the

process, i.e. cutting dried herbs for the herbal tea I make.

Plusses:

Good communication with participant before the

workshop

Getting to know more people and networking

Lovely, lovely people

Happy to help out not only with the oven, but also

in the garden

Grateful for being part of the project

Good that alternative work was organised

Nice with the two children

Nice to experience the local environment on Orø and the museum.

Fun

Minuses:

Distracted by the two children, much more peaceful when they left

Difficult with the children there

It feels like I was not able to give enough back for all the good food etc – a bit out of balance

Maybe a slight disagreement in relation to the work intensity and expectations between the builder and us

newbies. It seemed like they really wanted to be finished quickly and were pressing on most of the time. The

rest of us could drink another cup of coffee in the morning and be a bit slow. But – it didn’t give any bad vibes

and wasn’t something I noticed until I found out that they wanted to leave early.

Sometimes there were some different interests, I felt, in relation to whether the focus was on

building/food/social/exchange. But all in all, the work actually went really well, people supplemented each

other when they got tired and we could not all have been around the oven at the same time.


I didn’t perceive it as a workshop, but as a building project that needed to be carried out as quickly and fast as possible. It may have given some different expectations.

It was the first time I tried to bring the children to a task where I had to take care of them myself. I have decided not to do that again, unless it is a family with children where the children can be part of their lives. It was somewhat stressful for me to find the balance between the children’s flow and the participants flow.

Food

I designed a rotor for people to sign up for cooking and cleaning. This worked well. I had organised roughly what we

were going to eat each day and people seemed fine with

the challenges they were given.

Plusses:

Food was great!

Lovely food – vegetarian, all organic and good

vegetables.

Great that people could cook what they wanted

to, especially desserts.

Good way to use abundance of apples

Some skip-dived food – I support that 100%

Big PLUS

Minuses:

Missed a little protein for the physical work

Accommodation and venue

Plusses:

Room is nice

Great beach

Nice surroundings

Good environment in the house

Very good, big plus!

Great with singing morning and evening!

The conclusions from the evaluation are part of my personal reflection.

Personal

My own learning about the workshop

Three main minuses are apparent from the above evaluation: participation, children and expectations on time

management.


Participation

Some participants felt they couldn’t participate enough because of a lack of skills, instructions or space.

Skills: Participants are here to learn new skills, so it is part of the experience.

Instructions: I can prompt the builder to give more information about the building process. That will also help

people with fewer skills.

Space: Tasks were both outside and inside the first two days. On day three I set up a table inside for people

to be busy with their hands cutting dried herbs, while still able to follow the building process. Be aware to

have a diversity of tasks ready next time so that people feel that they can contribute enough.

Children on the building site

Personally I felt distracted by the children and their eagerness to participate and put dirty hands all over the house.

They want attention that can disturb concentration on the work, especially for the builder, who needs to be aware of

the children’s movements constantly. I agree with the fact that children should not be part of the workshop unless

they can be taken care of. I do appreciate the fact that they participate and learn from a very early age.

Expectations on time management

I was of the belief that the builder would stay for 7 days and we could have some relaxed time together. The builder

said on the first day that she would leave after five days, so that was a bit surprising. I also felt the tension between

the builder’s focus on working fast and the more relaxing tempo of the participants. I was happy to make it more fun

and relaxed and let the participants spend time on making nice food, because there was little room around the oven

anyway. I tried to coordinate the eating hours so that it would accommodate the children, but they had a rhythm of

their own and it never really got into synch. I would do this differently another time, i.e. not have children on a

building workshop unless they could be taken care of.

Apart from these three points, people were happy with the food, accommodation, communication, organisation and

venue. This is good, because they were my main areas of responsibility. The builder had the responsibility for making a

good product of the flex oven, which also happened.

Venue

I wanted to test the house to see if it was acceptable to have many visitors, in this case 9 adults and 2 children. For

meals it was fine, there was just enough seating for everyone. For cooking food, only 2 people should be in the kitchen

at the same time or they will be in each other’s way. Everyone seemed to be happy about their rooms and beds. There

were another 2 beds available in the “dorm” room and a double bed in the camper outside.

Toilet facilities were ok, the male participants were happy to pee outside, so that reduced pressure on the bathroom.

I have actually prepared for this workshop since I moved in: clearing out all the old things not needed, getting rooms

ready for participants, getting the living room/teaching space ready for building, preparing foundation and materials,

inviting participants. I like having deadlines, because it increases focus and I get things done. If the workshop with

participants had not happened, I might not have gotten the rooms ready for guests and certainly not the oven itself. It

felt like a great release to have it done, when it was finished. It is a warm up to see how training can take place here

and how a LAND centre would function at Kattekærhus.

My learning about the oven

Ever since I saw photos of the house for the first time, before I bought it, I knew that I would build some kind of mass

oven or flex oven in that place. It was one of the things that attracted me about the house – the ability to build the

oven.


Timing: It was important to get it done before the cold would set in. October was the latest time, because of the need

to have heating in the house from then on.

I did not participate as much as I would have liked in the actual building of the oven. I was more busy finding tools and

materials, accommodating everyone’s needs, cooking, making sure people got ingredients, cleaning, picking up

people, talking to neighbours and so on. However, I did get to lay a few bricks, fix some of the problems, of course

follow the whole construction and decide about changes in functionality. The next time I have a practical workshop

with this many people, I will not expect to be able to participate, but I will expect to be busy facilitating the process.

I enjoyed researching the different options available with a flex oven. One area that I don’t understand so well is the

hot water exchange systems. I had hoped that the builder or one of the participants had knowledge about plumbing.

However, I do not regret not having it as part of the oven, because I have alternative solutions that are simpler and

that I will feel comfortable managing myself instead of having to consult a plumber.

I also enjoyed finding the materials second hand and getting in contact with some eco-builders for the materials I

couldn’t find second hand. In my position at Birkegårdens Haver (see this design), I researched a lot of different

methods, materials, tools and options for green building, including rocket mass heaters, see for example my video

about Steen Møller’s flex oven with smoke washer: https://www.youtube.com/watch?v=Hfw2Ec1gKYw.

Community

During and after the workshop, local people in the village have been curious to come and see the oven. I enjoy the

connections to the community and especially around sustainable solutions.

I also shared a series of photos on facebook with descriptions of the different stages of building.

Process I used PRIME as my design tool for this design because it fit well with the purpose. PRIME is a fairly straight forward

tool that guided me nicely through the different steps of the design.

The first step – identifying the problem and making the design brief, was shared with the builder. This including

photos of the spot where the oven would be placed and an overview of the house structure with the existing wood

burner and the chimney. Her and my design ideas for the oven could form themselves based on this information. I also

forwarded this information to the chimney sweeper for his approval.

The second step - the Research on different ovens and how to build them - was done both as literature and web

research about different options, and also consulting with five different eco-builders about their experiences,

recommendations and time frames for doing the work. There were many different options at this stage and I had to

prioritise, select the most appropriate way and make decisions on my budget.

The research also included prices of different options, i.e. Finnish mass

oven kit, masonry mass oven and different options for the flex oven. It

was a good moment when I finally decided for the builder I chose and

with her the type of flex oven she could make. I am content with the

price I had to pay in all and the outcome of the workshop.

The third step Ideas was a phase of bouncing different ideas between the

builder and me, taking the limitation of the placement into consideration

along with the budget and skills available. Also different ideas around the

https://www.youtube.com/watch?v=Hfw2Ec1gKYw


workshop and participants were at play.

The fourth stage Make included setting up the workshop, final adaptation to the design and actually building the flex

oven. One idea were rejected, i.e. the water heating system, because it was not realistic to implement. A design is only

as good as the skills to implement it.

The fifth stage Evaluate brought focus onto the “product” and its functions. I look forward to doing more observations

during the winter. Hopefully the oven is powerful enough to heat the required space. If not, I have an alternative plan.

Anyway, the flex oven is already being enjoyed.

Permaculture ethics at work All ethics are important in this design and all decisions made thought about in the light of the ethics.

Caring for the Earth is seen through the choice of materials. All materials are organic, natural and/or second-hand.

Production of building materials require energy, which in most cases increase pollution with greenhouse gases and

other pollution results as well. Using second hand materials reduces the energy spent, and using clay and sand instead

of burned bricks also reduces the emergy of the materials in the oven. I have taken care when I use my car for getting

materials and always made sure I combined as many errands or functions as possible when out driving.

The flex oven uses wood as fuel. Wood is a renewable energy source and is more sustainable than many other energy

sources. The house was heated with electricity before. The mass in the oven keeps the house warm for a long time,

evening out temperature differences depending on the amount of mass in the oven. These properties of the oven are

also part of an earth care ethic.

Caring for People is especially about caring for me as the inhabitant of the house. The different functions of the oven

are all about people care. Keeping me warm is the most important function of the oven. Caring is built into the oven’s

design for example by having a sitting area for warming up on a cold day. There is a baking oven and a stove top to

keep the tea warm. Changing from expensive electricity to less expensive firewood, some of which can be harvested

on site, leaves a surplus of money, good for my care of myself. More time will need to be spent in harvesting and

chopping wood etc. but this is work that I look forward to doing, because it is nice physical activity that will keep me

healthy and fit.

The oven is made mainly from clay, which has unique health properties and said to be de-stressing. The clay regulates

humidity in the room so it doesn’t get too dry and uncomfortable or too humid. Both great properties for people care

and I will use clay wherever I can in the house.

The most important aspect of fair share is the sharing of knowledge and skills through the workshop. Photos of the

workshop have been shared on facebook and I got a lot of nice feedback from that because people seem to enjoy

watching the process.

The work of making food and cleaning was shared equally by everyone, again to be true to this ethic.


Diploma Criteria

Demonstrating Design Skills

Applying permaculture in my own life

- PRIME design model

- Input Output testing

- 4P evaluation model

Building a hearth in a house is the start of setting

roots and feeling at home.

Learning from and developing your permaculture practice

Applying permaculture to my work and projects

I have learned more about mass ovens, rocket mass

heaters and flex oven through this design. I have

lived with different types of ovens and wood

burners and I am happy to build on my experience

with ovens, being so central to our comfort and

well-being. I feel quite confident in explaining and

demonstrating different oven types. Being able to

demonstrate with my own personal and quirky flex

oven is a big step forwards in making Kattekærhus a

demonstration site for permaculture.

Using Holmgren’s domains this project has elements

of “Building”, “Tools and technology”, “Education

and culture”, “Health and spiritual well-being” and

touches upon “Finances and economics”.

With regards to the permaculture categories this

design would be mainly in site design and

development.

Geoliv.dk November 2014 Dolleris is licensed under a...

Documents

Transcript of Geoliv.dk November 2014 Dolleris is licensed under a...