ARTI – Sarai Cookstove

February 26th, 2013

Alan McDonald

Biogas- Provide simple easy to understand training to empower farmers to build their own biogas systems

Bamboo- Teach methods to treat bamboo, making it a suitable construction material.

Charcoal Production- Teach sustainable charcoal briquetting methods to meet India’s growing fuel needs

Improved Cookstoves- Develop and distribute lower emission biomass stoves to address the problem of indoor air pollution

Immersion

ARTI (Appropriate Rural Technology Institute) is an organization dedicated to developing and distributing sustainable solutions to address the needs of India’s rural population.

Sarai Cooking System

The Sarai is a low emission stove that uses charcoal to steam cook up to 3 different foods at the same time.

-Uses 100g of charcoal

-Cooks up to 600g of food in 45-60 minutes

-Produces 88% less particulate emissions than the World Health Organizations recommened safe level

-Costs about $30 US dollars

-Sold in low volumes, and is relatively unknown outside the current distribution network

The Sarai Cooking System is the perfect opportunity for a design intervention. By applying Design thinking to ARTI’s efforts, we can magnify the ARTI’s impact in reducing indoor air pollution.

Immersion

Immersion

Performed in-depth user research to gain consumer insight on the current Sarai model and identify areas for improvement.

Tested and analized performance of current model, and synthesized data in a readable format.

Developed higher performance burner and made design guidelines to continue the project.

Jed FarlowAs a Design Impact fellow from December-May 2012, Jed was the first DI Fellow to work with ARTI. He introduced ARTI to the design process, and his work continues to be the foundation for the project’s success.

These objectives were identified through user research and discussions with key stakeholders in the project. These objectives sometimes overlap, but many times are at odds. It’s important to prioritize these objectives to meet the overall project goal, which is to increase the adoption of the Sarai Cooking System in lower income households.

Durability- Most current users found out about through word of mouth, and the durability issues are widely known throughout this network. To be widely adopted the durability issues need to be addressed in an obvious way.

Value- Keeping in mind that the people most effected by indoor air pollution are those of lower income, it’s important that the new model be affordable for any household, but more importantly that it delivers value beyond lower emissions to justify the initial expense.

Performance- By improving performance, and reducing cooking time, the Sarai becomes a more viable option for daily cooking, and reduces dependance on LP gas and wood for cooking.

Usability- Other features such portability and washability aren’t necessarily selling points for the Sarai, but help enhance the user experience and ensure the long term success of the product.

Immersion

Design Objectives

SketchingBased on Jed’s burner prototype, I generated a number of different concepts to explore how this new style of burner could fit into a steam cooking system.

Concept Generation

Concept Generation

Concept GenerationARTI staff decided to explore an option that allows the outer cylinder to be removed from a base which holds the burner. This allows for more flexible cooking options

Prototype AssemblyWorking with a local tin smith, we put together a functional prototype to test the functionality of the concept. We modified already available pieces such as a stainless steel bowl, and parts from the original Sarai to save prototyping costs.

Prototyping

Prototype Testing

Prototype TestingThrough a number of timed tests, and side by side comparisons, the prototype out performed the original Sarai, heating up 30% faster with the same amount of charcoal.

Factory VisitWe took the prototype to the current Sarai manufacturer to find out if they had the capability to produce something similar. As we found out, the factory didn’t have the tooling to make all the components, but they agreed to modify the prototype to demonstrate what their production version would look like with the current tooling.

Factory Visit

Factory Visit

ManufacturerThe manufacturer uses a combination of skilled labor and heavy machinery. There is no automation, and every machine is operated by someone who has perfected their technique through years of experience

Factory Visit

Factory PrototypeUsing the available tooling, the Sarai manufacturer remade the prototype to more closely reflect what a production model would look like, but the results were less than flattering.

Side handles are thick and cumbersome. As a primary interaction point with the product, they should reflect the image of high end cookware

Large gap lets out heat and reduces efficiency. Without proper tooling, the manufacturer will never be able to get a consistent fit between these components.

The support legs are very long and flexible. This reduces the stability of the stove, especially while full. A more stable option needs to be explored.

Factory Visit

Spin stainless steel containers of various sizes

Give containers a bulge to make them stackable

Give containers a ridge to make them stackable

Roll the edge of the containers to create a lip

Create a flange for the containers edge

Stainless steel rod up to 3mm Diameter

Stainless steel straps of various widths

Can combine methods to create simple handles

Factory Capabilities

Sketches

Refined GenerationBased on the available tooling, we explored different variations of how the new model might be put together, without sacrificing performance or quality.

Rendering

Proposed ConceptBy utilizing the existing tooling, production costs are kept low, ARTI can source some components from other manufacturers, such as a glass lid, specialty handles, or a cast iron burner grate. These details enhance the percieved value amoungst users, making the Sarai much more marketable in the long run.

Rendering

ComponentsEvery piece is made with proven methods the manufacturer has incorporated in other products, or is sourced from a specialty manufacturer

Glass lid- sourced from another manufacturer, lets users see if the food is done without letting out heat.

Steam vessel- currently made by manufacturer, handles are adapted from “straps” and welded into place

Outer cylinder- shortened to save material, flanged upper rim gives the piece stength, while handle is easily managed with just one hand.

Burner grate- Sourced from a local cast iron manufacturer, could last 10x as long as current stainless steel grates

Burner – Allows for proper airflow, and radiates heat upwards

Base- Sturdy base, easily manufactured with current tooling, clips into outer cylinder to create one cohessive piece

Refined Prototype

Refined PrototypeWe revised the prototype to better match the capabilities of the manufacturer. We eliminated some of the angles, and added a tab that fits into the base piece, making the entire unit more portable and easier to handle.

Refined Prototype

TestingTo ensure that performance hadn’t been sacrificed with the changes made, we tested the newly developed prototype and compared the results. Initially we heated 2.5 liters of water, measuring the temperature every 5 minutes, to track the burners heat output.

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Prototype

Sarai

Recipes

Prototype testingTo get a better understanding of the new prototype’s cooking performance, I worked with ARTI staff who have experience cooking with Sarai to teach me Indian cooking methods, as well as give me input on the current improvements.

Recipes

IdliSteamed rice pattys, eaten for breakfast with a spicy dipping sauce. Cooks in Prototype in about 25-30 minutes.

DhokalaAn Indian cornbread, commonly eaten for breakfast. Cooks in Prototype in about 40 minutes.

CakeA delicacy in rural India, eaten only for birthdays and special occasions. Cooks in Prototype in 50-60 minutes.

PotatoesCan be used for a number of different dishes, common in India Cooks in Prototype in 35-40 minutes.

RiceA main staple for the Western Indian diet, served at most meals. Cooks in Prototype in 30-35 Minutes.

DalA lentil-like dish served with most meals. Cooks in Prototype in about 35-40 minutes.

Evaluation

After the Design Impact Summit in January, I met with members of ARTI’s Board of directors to evaluate the progress, and develop a plan for moving forward.

We decided the best plan would be to develop refined prototypes to perform extended user testing before moving into full production.

Since we were still in the development phase, ARTI wanted to use local resources, and explore the capabilities of local manufacturers before traveling to larger factories of Mumbai.

Utensil Market

To better understand what is available in the Pune area, we went to the market where stainless steel utensils of all kinds are available.

This was an opportunity to see what is already on the market, what the expectations are for stainless steel cooking utensils, but also to look for prototyping parts, and get ideas for how we can increase the percieved quality of the Sarai.

Local Manufacturers

We set up meetings with local manufacturers to explore options for production, as well as building prototypes for extended user testing.

Most of the manufacturers in Pune are specialty shops, setup to manufacture a very limited selection of products. None have the capabilities to manufacture all the pieces needed. For example ,one factory manufactures stainless steel buckets. They could easily manufacture the outer cylinder of the Sarai, but not the internal components. Similarly, one factory makes stainless steel containers that would be ideal for the steam vessel, but they don’t have the tooling to produce the other components.

Factory Visit

Cast IronFor increased durability we had cast iron grates made, but they were too thick and heavy, so we had them machined to the correct size.

OSMAAD Engineering

OSMAAD Engineering is a industrial manufacturer of packaging machinery. The owner, Mr. Kunjir is a friend of ARTI and a long time Sarai user.

Mr. Kunjir agreed to help us by letting us use his workshop to build prototypes, and his son Shrijit, a Mechanical Engineer, is helping with the design and assembly as well.

Their interest in the project isn’t financial, it’s because they believe in the Sarai Cooker, and believe in the change it can make in people’s lives. We’re very fortunate to have people like this invested in the project.

After meeting with Mr. Kunjir for the first time and explaining the project, he told me I could bring in the drawings and his workers would help me make it a reality.

Dimension Drawings

Outer Cylinder

Burner

Base

Laser Cutter Layout

With these drawings, we created patterns to be cut out with a laser cutter, and later assembled

Back in the work shop the sides were then rolled on a large roller to the diameter needed. The tabs and support legs were bent and the edges were prepared for welding

Mr. Kunjir introduced me to a local laser cutting facility. With the pattern we’d made, the pieces were cut out of stainless steel using a laser cutter, giving us the ultimate precision.

All the components were welded into place, and the prototypes were assembled, and the new Sarai Cooker finally came to life

Refined prototyping

Prototype testingWe built two initial prototypes, to test different locking mechanisms, and try out other features.

Refined prototyping

Prototype 1This prototype uses a stainless steel tabs to lock into the base. These tabs also provide stability for the outer cylinder, and keep the steam vessel center in the stove. The lid has been sourced from another manufacturer

Refined prototyping

Prototype 2This prototype uses a “twist and lock mechanism to lock into place. Tabs welded to the outer cylinder slide into place to lock into the base. This gives the system stability, and makes the entire unit effortlessly portable. The lid has been modified from an original container lid, a window has been cut, with a piece of glass added for visibility

Refined prototyping

Mr. Kunjir in the workshop with the new prototypes

Shrijit trying out a new lid design for the Sarai cooker

ARTI Staff evaluating the new Sarai prototypes

Refined prototyping

What’s Next?ARTI is planning to take one of the prototypes with them to a new exposition in Delhi this coming weekend. This will be an opportunity to show off the work we’ve done, gain exposure for ARTI and reach out to potential buyers.

In March, we’re planning on building 10 more Sarai stoves to distribute in different parts of India for more extended testing, and user research.

User Preference- Determine whether current users prefer the new model or are more comfortable with the old, and why they feel that way. Interview potential users to determine whether the new model has more potential to penetrate unreached markets, and determine what are the key selling points for the Sarai system.

Added Value Features- Ask users how much they think the new model should cost, then determine the value users put on specific features. For example “Would you pay 200 rupees more for a glass lid?” “Would you pay 50 rupees more for a cast iron grate?”

User Profiles- Put together a user profile of who is most likely to purchase the Sarai for marketing purposes. This should include information about family income, occupation, household expenditures, and overall lifestyle patterns.

Research ObjectivesAs we move forward, it’s important to plan user research to help us determine whether what we’ve done is meaningful to the end user and develop a plan moving forward. ARTI has agreed to perform extended testing in urban Pune, rural agricultural areas, and the Konkan coastal region. We will leave prototypes with families for an entire week, to give them a chance to use the new model in a comfortable setting.

This plan gives us a chance to interview users before and after using the new Sarai. The first meeting will introduce users to the new prototype and give us an opportunity to build a general user profile. The second meeting will encourage a deeper discussion focused on the new Sarai and its’ features. Though this research will is bound to give us unexpected insights, there are three main objectives we want to achieve with this trial;

User Interviews/Research- Use prototypes to communicate with users and guage enthusiasm for new design and gather data to use for developing a marketing strategy.

Production- Work with ARTI to run a limited production for market testing. Build connections with manufacturers to run a larger scale production.

Marketing/Distribution- Work with ARTI to search out new distribution channels, and develop a marketing materials to support the Sarai.

Evaluation- Evaluate project outcomes and make recommendations for ARTI and Design Impact for fortification.

Project Plan

March April May

Production

Marketing /Distribution

Evaluation

User Research

Thanks.

Contact:

Alan McDonaldalan.mcdonald@d-impact.orgwww.d-impact.org