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ARTI – Sarai Cookstove October 4, 2012 Alan McDonald

Appropriate Rural Technology Institute (ARTI) ARTI develops and teaches several technologies tailored to fit the lifestyle of rural India. Biogas- ARTI provides basic courses teaching the construction of low cost biogas digestors. Bamboo- ARTI has developed a process for treating bamboo so it lasts up to 20 years. Charcoal Production- ART I produces charcoal briquettes from agricultural waste. Improved Cookstoves- ARTI produces several different styles of improved biomass cookstoves


Indoor Air Pollution The World Health Organization estimates the 3 billion people, almost half the world’s population cook using a solid fuel stove. These stoves produce smoke that pollutes the air inside their homes leading to chronic lung disease, especially among women and children, who spend most of their time indoors. The World Health Organization identifies the development of affordable clean burning stoves as a contributing factor in reducing child mortality and promoting gender equality.


Sarai Cooking System The Sarai is an high efficiency stove that uses charcoal briquettes to heat a steam vessel holding up to three containers, giving the user the capability to heat three different foods at once with just 100 grams of charcoal. A complete meal of rice, lentils, and vegetables can be cooked in 45-50 minutes, producing negligible harmful emissions. However the Sarai’s success has been limited by slow sales, durability issues, and low perceived quality. Low income households have been slow to adopt the cooking system, limiting the Sarai’s ability to truly reduce harmful emissions in those households. The Sarai Cooking System is a perfect opportunity to apply design thinking to scale up ARTI’s efforts and reduce indoor air pollution in low income households.


Particulate Matter 2.5 are particals in the air less the 2.5 microns in size, long term exposure is linked to chronic bronchitis and lung cancer. Sarai produces negligible particulate matter emissions.


Carbon Monoxide is usually associated with the combustion of charcoal, however, the Sarai produces minimal carbon monoxide, well below the levels of other biomass stoves.

OUTCOME PLAN for: Appropriate Rural Technology Institute Project: Sarai System Redesign Owners: R.D. Deshmukh, N.J. Zende, Jed Farlow, Alan McDonald, Ramsey Ford, Kate Hanisian, Anuradha Pati Project Goal: Increase product acceptance and sales of Sarai cooking system to minimize harmful emissions Geographic/Demographic focus: Lower-income families; 70% of families in areas where charcoal is available Outcome

Design Goals

Improve indoor air quality and reduce harmful emissions for wood-fire users through increased adoption of Sarai system.

Improved core functionality

Activities • •

Increased usability and user approval

• • •

• Decreased smoke emissions during charcoal lighting

• •

Improved durability and Quality Control

• • •

Increased sales and recognition

• • •

Project Outcomes/Activities


Ongoing prototyping and testing of functional features Testing of core and specific functions

• •

>25% reduction in cooking time 90% of surveyed test users report no negative impact on flavor/ texture of food

Survey current Sarai owners on a range of use and satisfaction points Catalog and prioritize “pain points” Participatory Design charrette with current and potential Sarai users, designers and ARTI staff Survey test users on prototype systems

>75% of surveyed test users prefer redesigned system >75% reduction in occurrence of prioritized pain points

Test current system emissions including startup Ongoing testing of prototypes

Emissions tests demonstrate reduced particulate matter as compared to: --current Sarai --chulhas

Report on current sourcing and production system Generate process improvement / QC checklists Facilitate engineering workshops for production

• •

Decreased incidence of breakage complaints Batch testing of parts meet 100% of durability goals; a) Increase life span of Burner b) Reduce incidents of steam vessel leakage c) Reduce incidents of Tiffin Lifter breakage

Work with Samuchit / ARTI to create sales tracking system Report on current and potential user markets Brainstorm with SET/ARTI on distribution channels

ARTI/Samuchit reports 10% increase in sales within 1 year of redesign

Immersion -Intro to ARTI -Review Previous Fellow’s work -Review User Research -Adjust Project Plan Concept Generation -Generate new ideas based on Design Guidelines -Use Sketches, Models, and Digital renderings to communicate ideas Prototyping -Develop prototypes to test performance of Concepts -Refine Prototypes for User Testing

Project Timeline

Prototype Testing -Test performance of prototypes -Test emissions and efficiency User Testing/Research -Test prototype with users in Pune Phaltan and Konkan -Get user insight to use in marketing Refinement -Refine proven ideas for production Factory Visits -Visit factories in Pune and Mumbai to understand manufacturing capabilities -Build relationships with manufacturers -Develop quality control parameters

Production -Run initial production based on available budget Marketing/Distribution -Work with Samuchit / ARTI to create sales tracking system -Report on current and potential user markets -Brainstorm with SET/ARTI on distribution channels

Evaluation -Evaluate and report project outcomes -Make recommendations for Fortification

The current burner uses a stainless steel grate to hold the charcoal. This grate corrodes usually in less than 1 year from the initial purchase.

The steam vessel is also subject to corrosion after years of use. Sometimes producing a leak, making the steam vessel useless.

In the corrosive-low oxygen environment of the steam vessel, the wire“Tiffin Lifters� can become brittle and break making it much more difficult to use the Tiffins.

Performance The current model cooks rice in about 45-60 minutes. When given the option, many women prefer to use another cooking method that takes less time, such as wood burning and LP stoves , which can cook the same quantity of food in 25-30 minutes. By reducing the cooking time for the Sarai, it becomes more competitive with other cooking methods, and users can focus more on the positive attributes, such as the convenience of cooking three types of food at once, and cost savings.


Design Objectives • Performance- Reduce the cooking time, and make the charcoal easier to light and use. • Affordability- The Sarai needs to be affordable so that cost won’t be a factor for even lowincome households. • Durability- Address durability issues so users see the Sarai as a quality product and a long term option for cooking • Portability and other features- Other features, such as portability are seen as positive, and enhance the user experience, but they aren’t motivating factors users consider when purchasing a Sarai.


Prototype Burner As a part of his fellowship, Jed Farlow developed a prototype burner designed to burn hotter and faster than the current model. The “nozzle� concentrates the heat, and forces the combustion gasses out the top. After testing, it was decided that this burner had the most potential to improve the performance of the Sarai cooking system


Sketching Based 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

Sketching From these concepts, we selected one to test by making a prototype. The concept we chose houses the burner in a dish that reflects the heat upwards, where the steam vessel rests.

Concept Generation

Dimension Drawings To overcome the language barrier, it was important to have simple, easy to understand drawings to communicate with the fabricator.


Prototype Assembly Working 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.


Prototype Testing To test the prototype, I measured the temperature at 5 minute intervals as it heatsed2.5 liters of water, and compared the results to the original Sarai. After showing improvement from the previous model, I tested the prototype’s ability to cook rice, lentils, and potatoes. Prototype Testing


35 minutes Rice, Lentils, Potatoes cooked


Prototype Sarai

Temperature (Celsius)


50 minutes Rice, Lentils, Potatoes cooked



Prototype Testing When compared to the original Sarai, the prototype heats up quicker, reaching its maximum temperature 15 minutes before the original Sarai.



When cooking the prototype also boils much quicker, with water initially boiling in 5-6 minutes, as opposed to 10-15 minutes in the original Sarai. This translates to a 30% increase in cooking speed.


20 Start







Minutes Prototype Testing







Concept Refinement To continue the development of the new Sarai, I began to focus on different aspects of the user experience, and how they might be improved with the new version.

Concept Generation

Mock Ups- One area identified for improvement was the tiffin lifter assembly. When hot, the lifter can be difficult to remove from the steam vessel. I experimented with different systems that incorporate the lid with the lifter assembly to avoid this problem.


Form Study I also experimented with different forms, demonstrating how changes in the shape of the outer cylinder effect the image of the entire product.


Product Rendering This digital painting illustrates what a new Sarai could look like. Though not finalized, it’s meant to communicate a vision of what the Sarai could become, a centerpiece in the modern Indian kitchen, saving the owner time, money, as well as reducing indoor air pollution.


Project Plan: November-January 2012 • Factory Visits- Visit manufacturers to find out the capabilities and costs associated with production. Work with manufacturer to prepare for production. • Refine Prototype- Develop prototype that looks and functions as a production ready model to test with users to get constructive feedback before production • User Testing- Test prototype with Sarai users, gain insight about the perception of product and other factors that will effect future marketing strategies. • Production Budget- Work with ARTI to develop a plan and budget for production.

Project Planning

Thanks. Contact:

Alan McDonald

Sarai Cook System: October 2012 Update  

Design Impact project update by Alan McDonald.

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