Technology

Many different stove design and manufacturing processes exist around the world. We took great care to develop a stove and production process that would yield great results for the people who need them. Our stove is based on the well-known ‘rocket’ concept, using an internal ‘chimney’ in the stove which directs air through the burning fuel and encourages the mixing of gases and flame above it. We also decided to manufacture our stove entirely in a factory and then transport them to villages as a finished product (in most cases). Another important component of the right technology is testing. Some cookstoves can actually emit worse emissions than the open fire or are so different from traditional cooking practices that cooks do not use them. For these reasons it is important to conduct Lab Tests and Third Party Field Tests of improved cookstoves.

Rocket Stove Design

For several decades, efforts to design, build and promote rocket stoves have been undertaken in many communities throughout the world. Some stoves are made by local artisans in or near the home using locally available materials such as mud, dried grasses and anthill/termite soil. These artisanal stoves may also include factory-produced elements, which are often made elsewhere and transported to villages, such as high-temperature bricks, liners made of red clay, or metal fuel shelves. Other stoves are manufactured entirely in factories, either domestic or international, and then transported to villages as a finished product.

The EcoZoom stove is a manufactured stove. We have found manufacturing to be a great option in many circumstances. It allows us to rapidly produce and distribute large quantities of stoves (after all, three billion people need them) and maintain the highest quality because each and every stove is as fuel efficient and clean burning as the one before it.

Our stove is based on the well-known ‘rocket’ concept, using an internal ‘chimney’ in the stove which directs air through the burning fuel, often biomass, and encourages the mixing of gases and flame above it. Precise internal stove dimensions (with tolerances of 1mm or less) are essential to achieve high combustion efficiency and transfer heat to the cooking pot. The material must have a specific density to provide good insulation. We also worked with cooks in several countries to ensure our stove would be culturally accepted by the people who need them. Here’s a little info about our stove and some of the components. You can find complete information for each stove on our Products page.

Importing stoves for greatest impact is only the start. If you’re interested in finishing or developing stoves in-country, contact us.

Lab Tests

Some cookstoves can actually emit more emissions than the open fire. For this reason it is extremely important to test stoves in a lab as well as in the field. Lab tests take measurements of many air pollutants that affect health and global climate. Some of those parameters include:

• Fuel consumption, energy efficiency, power;
• BC: aethalometer, transmissometer;
• EC/OC/TC: thermal-optical analysis;
• PM: gravimetric (with environmental chamber);
• PM, real-time: APS, SMPS, ELPI, nephelometer;
• Aerosol light absorption and scattering, in situ: PASS-3;
• CO, CO2: infrared analyzers;
• and CH4, THCs: FID analyzers.

Check out this presentation by Jim Jetter of the US Environmental Protection Agency for more details. The EcoZoom stove has been tested by the US Environmental Protection Agency and the Aprovecho Research Center among others. US Government Testing: Testing by the US EPA shows the EcoZoom stove to perform well in a lab setting with significant savings in fuel and reduction in smoke emissions in both high and low power. Contact us if you want to learn more about lab testing and receive additional results.

Third Party Field Tests

The EcoZoom stove has been tested by third party experts to ensure they are safer and more efficient cooking solutions. Experts test the speed of cooking local foods, ease of use, fuel consumption, emissions released, and response of the cooks. EcoZoom repeatedly performs well in third party testing of manufactured cookstoves. The most notable reports to date, completed by USAID and the Millennium Villages Project, are summarized below. The reports were completed before the creation of the EcoZoom brand and thus feature the previous brand name of StoveTec. EcoZoom is the exclusive distributor of Aprovecho designed stoves in developing countries, all future testing in developing countries will feature the EcoZoom brand.

USAID_Berkeley Air_Dadaab, Kenya: The results show that EcoZoom has a fuel savings of 54% while cooking 7% faster than the open fire. The EcoZoom stove was also highly recognized by cooks as being the most fuel-efficient, the safest, the most durable and the easiest to use. The stove was the most preferred in 2 of the 3 camps, coming in second in the other. This table, from page 5 of the report, shows results for several stoves that were tested. The results listed under StoveTec are for the EcoZoom stove.

USAID / Nexant (Haiti):The EcoZoom stove was the most efficient, saving 50% of fuel over the open fire without use of the fuel saving pot skirt, saving cooks $0.15 for one meal and being the most preferred stove.

Millennium Villages Project (Uganda and Tanzania): This study was the result of the partnership between Columbia University and the United Nations Development Programme. The EcoZoom stove saved 39% of fuel (without using the pot skirt) while being the most preferred stove by 96% of households. The EcoZoom stove did equally well in Tanzania averaging 39% fuel savings depending on the meal, while again being ranked as the most preferred stove by nearly two-thirds of the respondents. This graph shows stove user preferences in Tanzania. Again, StoveTec on this graph is EcoZoom.