Rocket Stove Group Winter 2014

Welcome to the Rocket Stove Group Page for Pete Schwartz’s Appropriate Technology class (UNIV 392), Winter 2014.
The idea for our group is to explore the possibilities of modifying the existing technology of rocket stoves to better fit a range of different areas and cultures around the world.


In poor areas in the global south in general, and Zambia in particular for this project, people currently use a “three stone stove” to cook their food, both outside and inside. The main problems this kind of cooking brings are inefficiency and health problems due to smoke and toxic inhalation. The smoke inhalation problem is most urgent, especially when these stoves are used inside.

Three Stone Stove

Worldwide facts about indoor air pollution:

  • Around 3 billion people cook and heat their homes using open fires and leaky stoves.
  • Nearly 2 million people die prematurely from illness attributable to indoor air pollution from household solid fuel use.
  • Nearly 50% of pneumonia deaths among children under five are due to particular matter inhaled from indoor air pollution.
  • More than 1 million people a year die from chronic obstructive respiratory disease (COPD) that develops due to exposure to such indoor air pollution.

Other impacts:

  • Fuel gathering consumes considerable time for women and children, limiting other productive activities and taking children away from school.
  • Non-renewable harvesting of biomass contributes to deforestation and thus climate change.

These facts are from World Health Organization (WHO), and can be found here:

WHO currently works on projects that involve Clean Cookstoves. We got introduced to this subject by Kirk Schauer, the international director of Seeds of Hope International Partnerships. They are interested in developing a Rocket Stove to their projects in Zambia, and we are interested in supporting their development from this Appropriate Technology class’ point of view.
The basic concept from the Rocket Stove technology can be seen in this graphic:


Geographically, the country is somewhat isolated and the population is widely distributed, however many of the rural communities have formed around urban developments. In most families, the women are responsible for taking care of the agricultural labor (much of the rural population consists of subsistence farmers) as well as domestic duties, including gathering fire wood for the stove.

Economically, Zambia had been previously named a middle-income country, but after over 3 decades of decline the country is now considered an extremely poor country. The beginning of this economic decline started during the 1970s when the international prices for copper (a major export) fell.

According to the Rural Poverty Portal, 3 out of 4 Zambians live in poverty and over half of this population that lives in poverty can be considered extremely poor, meaning they cannot meet basic needs. For extremely poor Zambians, food availability is an area of high concern.

The climate in Zambia is tropical and has a rainy season that lasts for about 6 months and a dry season that lasts for the other half of the year (from months May through November), although the monthly average temperature for the country is about 68 degrees Fahrenheit. Building an outdoor stove would be acceptable for the dry seasons, seeing that the temperature does not drop significantly, however for rainy seasons an indoor stove would be much more appropriate. This arises the question of ventilation. How do we create an indoor rocket stove that reduces disease associated with smoke inhalation?

A major food staple for Zambians is maize–the traditional dish of nshima, a type of porridge made from maize. Other traditional dishes include ifisash (vegetables in peanut sauce) and samp (maize and beans). After skyping with Kirk Schauer, he stressed the importance of having multiple burners of smaller pots versus one large cooking pot because the Zambians cook several different dishes (such as beans and maize). Kirk mentioned in his past studies and work on the Rocket Stove, the Zambians continued using older indoor stoves in addition to the newer Rocket Stove despite the risk of disease associated with smoke. The Zambian women were willing to unsafely cook using 2 stoves rather than 1 safe stove, again reinforcing the importance of having more than one burner. If we could create 3 burners from 1 fire, could this prevent Zambian women from continuing to cook unsafely?

We also conducted an interview with Kirk Schauer of Seeds of Hope to obtain a greater understanding of what this technology could mean to this specific group of people. We have been in contact with Kirk in order to figure out what the main problems are with both the technology addressed and culture’s current practices. His mains concerns were:

1. Health Problems from Smoke Inhalation
2. Cost of Fuel from Charcoal Used
3. Deforestation as a Result of Fuel Use
4. Size of Technology (Currently Heats One 60 Liter Pot)
5. 3 Pot Cooker for Cultural Cooking Practices.


The main goals in creating a rocket stove are a more efficient use of fuel and a reduction in the smoke produced in-home. Air is drawn in through the bottom of the fuel shelf and more completely burns the fuel by adding more oxygen, which makes the flame burn upward in a cyclonic motion to evenly heat the stove. The emissions produced are recycled through and kept in the stove, reducing the amount of smoke emissions produced. This reduction in the use of fuel is successful in significantly lowering overall emissions and helps to limit deforestation.

The rocket stove’s efficiency is much greater than many of the traditional cooking methods found in many developing communities, such as the three rock cooking method. Installing a rocket stove in a family’s home in a poverty stricken area would decrease cooking time and increase sanitation. As we continue to develop the technology behind the rocket stove, we are beginning to ask question about how this technology can be applied and implemented in different cultures and fit a more broad range of uses.


(After research, it was decided that additional heat would want to be expelled in Zambia due to normally warm weather, leading to an exhaust system as opposed to exhaust being fed into a secondary use. Graffic created by Tony Webster.)

Design Matrix:

Design Matrix Tech.png

(After looking at multiple options, including the Seeds of Hope model that had a large metal construction, THAB System Stove that had very simple materials that are shipped in, the existing 3-stone technology, and a smaller, locally built stove.)

Our group meeting up to grab some coffee downtown:


From Right to Left: Lena Andersson, Amanda McCaulley, Rachel Pittman, Alex Horton, and Tony Webster (obnoxiously close to the front)

From Gapminder:

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(This graph shows the correlation between income and how it influences infant mortality rate. The loop back in the trend shows the economic downturn in the 1970s due to falling copper prices. Overall, as the income rises, the child mortality rate falls.)

Gapminder picture 2.png

(This graph shows the correlation between CO2 emissions and child mortality rates. This is important to our project because cooking with inefficient fires can lead to more direct CO2 emissions. When mothers are cooking, they will likely have infants near or around them, giving a direct connection between inefficient fires and smoke inhalation and health problems in infants.)

Labs expectations, outcomes, and pictures:

LAB #1 (01/28/14)

Today our main goal is to construct a study model of our Rocket Stove. The materials we plan to use to construct this model are a 1-gallon paint can and smaller wood stain can, along with a 4 fl. oz. PVC pipe cement can. The 1-gallon paint can will act as the base for our Rocket Stove and the smaller stain can will be the combustion chamber inside the paint can to hold the flame. We plan to create an opening towards the bottom and attach the 4 fl. oz cement can to serve as the feeder for fuel and anticipate having to fill the inside of the Rocket Stove base with rocks for stability. As our first attempt at building this Rocket Stove, the questions we wish to explore with our study model, include:

-How do we control smoke ventilation?
-How much heat can be reused from the exhaust? (Are there other functions the Rocket Stove could be utilized for besides cooking? Such as heated seating, shower water, or interior heating)

Getting some help from the Techs


LAB #2 (02/04/2014)

Today, we focused on creating a new working study model to aid in our understanding of the fundamental functions of the rocket stove. While the first attempt (the paint can model) was basically regarded as a failure, we decided to scale up in size in order to get a better understanding of how certain parts benefitted the overall function and efficiency of the rocket stove. Alex provided us with a large quantity of bricks and an instructional video of how to build a basic rocket stove. We got it assembled and working, but before running tests (boiling water) we decided to see if we could construct a second burner on the stove and have it burn while heating two pots of water. While the fire took a good while to get started, it seemed as though there was enough heat to have boiled water on both burners, though we did run out of time and were unable to bring either pot to a boil.


LAB #3 (02/11/2014)

After testing certain parts on the brick of the rocket stove last week, we have deemed the expansion of the combustion chamber as a priority in our design. The fire kept getting smothered by both not having enough ventilation and not having enough room to get a solid base started. We will work to expand the bottom to give the fire more room to burn, and keep the height we tested last week (five bricks high) for the main burner. Another expansion to be made it to add a third burner to fit the cultural needs of our target group who, according to Kirk, have three-part meals that require three cooking surfaces. We will be bringing in extra bricks to accomplish this. Again we will be testing the viability of each burner by whether or not we can boil water on any given burner.

Target Questions:
Will expansion of the combustion chamber aid the quality of the fire in terms of efficiency of fuel and time used to create it?
Will this model be able to support a three-burner system?

We focused on the combustion chamber, we did it wider to be able to get a better fire. The result of that was positive. Even though it took us too much time to make up the fire, the heat was better. We also extended the second chamber, the design still has two chambers, but the second one could provide two smaller pots with this design. Then we also collaborated with the briquette group, they burned their briquettes in our burner, and it worked out pretty well. And we were able to cook noodles. (see pictures below)

Collaboration with the briquette group

Cooked noodles

LAB #4 (02/18/2014)
What we are bringing from the last lab is the bigger burner, that was a good improvement. We want to evaluate and improve the technology of the chamber/chambers of the additional pots. We’re going to keep working with the bricks we have, because it feels like appropriate material and for now it works fine. What we need to think about during this lab is if it would work to have this type of rocket stove in a home in Zambia. And if we could come up with a solution for the exhaust, so we can solve the smoke inhalation problem. What we also have to think about is if this type of stove actually would be used, would it replace the three stone stove that currently is in use? Or what could we do to make it user-friendly?
Material we are bringing is better material to make up the fire with, so we don’t have to spend as much time on actually make the fire going. We are also bringing information from Kirk (Seeds of hope) that we are going to use in our development.

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Brick stove with 4 burners

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LAB 02/25/14

One of our ultimate goals for the rocket stove. We used bricks and cinder blocks to build this stove and came prepared to start a fire with firewood and fire starter. Bringing fire started was a huge help because we were able to spend more time focusing on our technology, rather than trying to kindle a fire. We did notice a large amount of smoke that comes out of the top openings of the stove (the burners). For this week’s lab, we want to address this issue and begin to develop a method of ventilation for the stove because we are intending that this stove be used indoors by the Zambians. The materials we plan on experimenting this week include soup cans and a dryer vent to act as the structure for our ventilation system. We also have some adobe today that we want to use to better insulate the stove and act as an adhesive for our vent.

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LAB 03/04/14

Last week we spent our lab developing an exhaust for our current 4 burner stove prototype. We sealed the cook top with clay, and added steel cans coming out the back as an exhaust. Once we had the fire started we sealed remaining cracks with clay. The modification proved to be successful in reducing the amount of smoke that was coming off of the fire. Hot air was coming out of the exhaust that had little to no soot or smoke in it. Although we were successful at reducing the smoke, the fire burned relatively fast and hot, and consumed quite a bit of wood. For next week we will work on ways of reducing the amount of wood needed and the rate at which it burns but increasing the retention time of the heat coming off of the fire. The longer path the heat has to take to escape out the exhaust, the more heat will be captured, and the more efficient our design will be. The challenge is doing this without extinguishing the fire or making it impossible to get going.

Additionally, we will continue to develop different cook tops. The metal we have been using has proved inconsistent at best, and we are going to explore other available options including adobe.

Implementing our design at the Cal Poly Organic Farm

LAB 3/11/2014

Last week was a week of transition and problem solving. We decided to move our design up to the organic farm in an attempt to create a final prototype for the class. It all started with picking a spot out of the way, as to avoid wind drafts that would affect the efficiency of our fire. We chose a spot at the base of a berm that would restrict wind flow. The only problem we had with the spot was drainage, so we created a small swale system behind the base of where our stove was to sit. We removed the vegetation in the immediate area in order to give us a flat, level surface on which to work. We added soil as needed in order to help create a stable and flat building pad to work on. A good potion of our day was spent on preparation and moving of our vast amount of materials. After the preparations were complete, we built the model of the stove that we had been working on, along with some modifications to the exhaust and overall structure of the design. We found some additional material that would aid in the efficiency of our design, including a new solution for the cook top to be improved upon this week.

This week, the plan is to take our existing stove model and complete it, finishing the improved stovetop and covering the entire thing in adobe. The adobe will serve to both insulate and seal the structure In place. We will make the exhaust upright and create a cooking surface with a grate covered in adobe, with holes big enough for pots to sit down inside.

Moving the materials

Removing some weeds and grasses

All plants removed, beginning to stamp down a level pad

Swales running behind the pad to help with drainage

Final Thoughts on Lab Results:

Overall, for our target community, we feel as though we accomplished most of our goals. We were able to create a reasonably sized rocket stove with cheap materials that had three burners. It was well insulated and was able to burn hot and did not require much wood to burn. All of the wood we used for the test was collected around our final site, replicating what the people using the stoves would have. We did have some overall problems with our final design, including the final appearance. We encased our final product in adobe for insulation, and we made the adobe ourselves. None of us had experience creating adobe, so the the outside looked cracked and a bit messy. The insulation was not affected, but it is still something to consider. Another problem we experienced was smoke escaping from the holes our pots were meant to fit in or cover. This was due to the fact that we did not have enough experience using adobe or enough pots on hand to create reliable molds. This could easily be fixed by spending more time creating molds where the pots can actually fit down inside. Outside of these main problems, we would consider the experiment to have been successful in creating a low budget rocket stove for Zambia. This project could be taken to a much deeper level using the information we have gathered, if a group chooses to do so in the future.
Another thought about how to further develop the stove we designed, is to take a deeper look at the materials. See what materials that currently exist in Zambia, and what could be made locally. Could it perhaps be possible to start a business out of this rocket stove project in an attempt to get people out of poverty? One thought we have is to manufacture the bricks for the stove locally by local people. There is a technique, currently used in New Mexico, where they make bricks out of adobe and build up stoves and buildings by using them. A technique that could be implemented in the manufacturing of this rocket stove.

Our finished product

Preparing for our final presentation

Tony making quesadillas for the final presentation


Amanda McCaulley:
I have become aware of the large amount of water wasted in the shower, so I have challenged myself this week with taking showers that last no longer than 5 minutes. My roommate works for PowerSave Campus and heard about my intervention, so she gave me a PowerSave timer that I use to make sure I don’t go over 5 minutes and waste precious water. So far, I feel that this intervention could lead to permanent change. After doing some research, I found out that my shower head gives off 2.5 gallons of water per minute, so by cutting back on shower time, I can save several gallons of water each time I shower. That’s enough motivation to shut the water off.
After reflecting post-intervention, I can ask myself whether shortening my shower time really changed the way that I do things? My honest answer is no, it did not significantly change the way I go about living–I still shower. But it did, however get me to think about the way that I live and why I live the way that I do. Shortening my shower time was much easier than I expected it to be. Using more than 5 minutes worth of water is unnecessary I have found and from this intervention, I have decided to limit my shower time from here on out. Although a small change, I think this small step will get me to continue to look at other areas of my life and examine any unnecessaries in the way that I live.

Tony Webster:
For my intervention, I decided to go a week without my wallet, therefore eliminating my purchasing power as a consumer, my ability to drive, among other things. I spent my week relying on the practice of reciprocity, exchanging tasks and services performed by myself for rides, food, and other things. This was an interesting experience to say the least, as it directly connected to my studies in another class I am taking this quarter, Anthropology 201: Cultural Anthropology. We have learned about different levels of human culture and development of society, and I took interest in the lives of hunter/gatherers, considered the lowest and “original” form of human interaction. These societies, or “bands,” practiced different forms of reciprocity, or equal exchange of goods and services between members of said band. These actions are in theory meant to be equal, though you members typically do not care if there is a slight difference in worth. I ended up not spending any money the entire week, and either walked or got rides places. I exchanged services or favors for food and other things from my closest friends, who i considered my “band.” As someone who constantly goes out to buy food, drive everywhere, and does not keep much food at the house, it helped me to realize how much I take advantage of having things readily available to me. It made me aware of how much I constantly am using resources that do not need to be used. It made me feel like i have more control of myself, and that I do not need to constantly be wasting resources and falling into the trap of being a consumer.

Alex Horton:
Starting Monday February 24th I have decided to become a vegetarian by not eating meat or seafood. I have heard that the amount of green house gas emissions resulting from raising animals for food is 40% more than all the planes, cars, and trucks on the planet combined (1). I feel strongly that humanity needs to take action against global warming, and going vegetarian seemed like an easy and direct way to do that. So far it has been a week since I switched, and it has been fairly successful. I do not crave meat unless it’s being cooked in front of my face. I can’t say I feel better or happier, maybe just a bit hungrier sometimes. All in all it hasn’t been too much of a challenge. Giving up cheese, eggs, and milk to go vegan sounds like challenge; a challenge that I need to work up to. A daily meat eater who doesn’t drive still causes more carbon emissions than a vegetarian SUV driver (1). I am an SUV driver, so maybe my next intervention is to sell my car.

It has now been two weeks since I started my intervention to become a vegetarian. It is now becoming apparent that this switch is going to take a practice. Just like anything, it takes time to get better at and do properly; making sure that I am getting enough nutrition. I am happy about the simplification of food choices that vegetarianism brings about. The limitation of only being able to select from a certain type of food has allowed me to further explore all the varieties and possibilities that exist in the vegetarian diet. I have thought of new food combinations and new ways to eat dinner. Cooking has become simpler and less messy. I now only crave meat in the context of being hungry and not having any alternative to eat, but I do not crave meat in and of itself. Overall, I think I will stick with it for now until I can properly formulate and ethos around eating meat. Right now, my consumption of meat feels morally ambiguous, because I often do not know where my meat is coming from. If I could see where my meat came from, then I could more easily make and informed decision based off of the knowledge of the consequences of my decision.

Lena Andersson:
My intervention is actually my roommate’s idea. The first thing she said when I told her about it was “stop using Facebook.” That was not the first thing I thought about. She thinks I spend way too much time using Facebook. For me, it’s not that obvious. I see it as a medium to keep contact with my friends back in Sweden, be involved in their lives, and see what’s going on at home. But after thinking about it for a while, I realized that my roommate might be right. How involved can you be in a friend’s life through Facebook? And I do keep contact with many of my friends, but I could find out ways to do that in other ways as well. I recently read an article about “Facebook-loneliness,” which also was eye-opening for me. It was about the use of social media, and how it affects us. The content that is relevant to my intervention is that using social media for interaction with other people is not bad, from a personal well-being aspect, but the part of social media that allows people to passively look at peoples’ lives without any real interaction often has negative effects. Scrolling through peoples Facebook lives, where you only see the parts people are willing to share such as all happiness in life, or traumatic experiences can contribute to a feeling of loneliness, and also dissatisfaction over your own life-situation.

Approximately I am normally active at Facebook 2 hours per day. Above that I am normally passively active, by being logged in while doing other things at my computer. I often open Facebook the first thing in the morning, or while eating breakfast, while studying to take pauses, and it is also the last thing I’m doing before I fall asleep. I have also realized that I can look at Facebook while I’m hanging out with friends, which is a thing I hate when friends do, and while watching a movie because I am restless. I think Facebook has become an addiction, and now I’m actually excited about doing something about this, to change a habit that in somehow has taken control of me.

So, my intervention is to not use Facebook at all for a week. My main goal is to get rid of this bad habit, to take control of my use. Other goals are getting up earlier and get ready faster in the mornings, be more productive while studying, and communicate with friends in another way. My goal is also, of course, to make a change in my life, and to not go back to the old pattern. I’m going to start right now, March 5th, after letting my friends know that they from now have to reach me through another media. After this week I’m going to evaluate my experience, and see what I can do to take control of my future Facebook use, if there even is a future use.

Before I started my intervention I had a bad feeling, not so much because of the fact that I personally shouldn’t been able to use Facebook, more that over the fact that my friends not were going to be able to contact me in the way they are used to. To overcome that bad feeling I wrote on my wall about the intervention, and that they simply had to contact me in another way. Then I just started. The first day was tough, because I’m used to “take a look now and then.” I had to log out from Facebook at the computer, and get rid of the app on my phone. I managed to not log in during the entire week, ad it was easier and easier for every day that passed. After some days though, I got e-mails from Facebook, telling me I had “3 unread messages, 24 new happenings” and so on. That made me curious, and made me feel a little left outside a part of my own life, in the same time as I found it annoying. Who is Facebook to tell me to use it? Anyway, all of the sudden the week had passed, and I started use Facebook again. It showed out though that only 4 out of the 24 new happenings actually were interesting.

What I am bringing from this intervention is that I am for sure going to do changes with my use of Facebook. I’m going to “clean it up,” hide news flows that doesn’t interests me, leave groups that doesn’t give me anything, and so on. And, I guess the biggest thing would be to not download the app again. That makes it tougher to use Facebook on the phone, which automatically reduces my use, and it makes my phone soak less battery. By not using Facebook/ Internet that much, the phone’s battery can last for two days instead of one, which in the end reduces my use of electricity a little bit.

Rachel Pittman:
My intervention was to stop driving completely. I already don’t drive very much but it was harder than I thought it was going to be. One of the biggest challenges was that I had to walk to get groceries. That meant I couldn’t carry very much and I had to go more often. I started planning ahead and walking by the grocery store on the way home from school. This really forced me to think about how easily we have access to food and how little thought we have to put into our meals. Another maybe obvious sticking point in my intervention was that I couldn’t go anywhere I couldn’t walk. This was ok because I live very close to everything I needed every day, such as school and food, but severely limited my ability to do things with friends or go anywhere across town. So, the second week of my intervention I started allowing myself to drive as long as I was carpooling. In that way I was still really limiting my carbon emissions but not limiting my lifestyle. This intervention has really opened my eyes to my privilege and the availability of resources to me and how easy it is to overuse those resources. The hardest part of this intervention was the limits it put on my friendships but as soon as I could carpool it was totally doable. I think this is a change I can continue with long term.