That’s an Icy-Ball (and a younger Dean) in a photo from ARC in 1994. Dr. Larry Winiarski and I built 18 somewhat scary prototypes and eventually made ice. We had replicated a pre-rural-electrification 1920s ammonia/water absorption refrigerator. A fire heats the water/ammonia mixture and separates the ammonia out of the water (it turns into gas at […]
Information summarized via Google AI: In 2026, the Chinese carbon market (CCER) is generally a more hospitable environment for cookstove projects—defined as traditional improved biomass stoves that lack advanced digital monitoring—compared to UN or Western voluntary markets. While international markets now demand costly digital “metering” and stricter methodologies, the Chinese domestic market offers more flexibility for […]
To reach multiple, interlinked Sustainable Development Goals, the UN advises that “the share of the population mainly using improved cooking solutions like low-emission biomass stoves reaching Tier 3* or better needs to increase to 35 percent by 2030.” (ACHIEVING UNIVERSAL ACCESS AND NET-ZERO EMISSIONS BY 2050: A Global Roadmap for Just and Inclusive Clean Cooking […]
As we iterate changes in natural draft TLUDs and Rocket stove prototypes, trying to reduce emissions while maintaining high thermal efficiencies, one design principle keeps on suggesting itself: Don’t let the flame touch the pot. The pot is ‘cold’ and if the flame has not burned itself out and contacts the surface, we instantly see […]
Early Rocket Stove Research at Aprovecho Still Rings True A summary of Global Modeling and Testing of Rocket Stove Operating Variations, Nordica A. Hudelson, K.M. Bryden, Dean Still Department of Mechanical Engineering, Iowa State University, Aprovecho Research Center, 2001 In the summer of 2000, Aprovecho’s current Executive Director Nordica MacCarty spent a couple of months […]
An open fire Jet-Flame? We have been at Shengzhou Stove Manufacturer this November working on cookstoves for display at the annual ETHOS conference including: If stove projects do not have capable stoves, then project goals will not be met in the same way that some carbon credit projects fail to meet their impact goals when […]
Illustration from: Birzer et al. (2013) “An analysis of combustion from a top-lit up-draft (TLUD) cookstove”, Journal of Humanitarian Engineering 2(1):1-8 DOI:10.36479/jhe.v2i1.11 When Dr. Tom Reed and Dr. Larry Winiarski added short, narrow chimneys above the fire in TLUDs and Rocket stoves, they increased draft and created laminar flow flame in the tubes that could […]
One of the things that I like about the IWA Water Boiling Test is that it mimics the boiling and simmering functions of cooking food. Wood burning stoves are notorious for being too slow to boil big pots of water and for burning things like rice because they can’t be turned down enough to simmer. […]
Aprovecho Visits Tanzania In September, Jaden traveled to Tanzania to help set up a LEMS at the Bureau of Standards. Tanzania plans to set minimum standards for biomass stoves on the market, ensuring that more clean and efficient stoves are sold. She also visited Tango Energy, a stove manufacturer with whom Aprovecho has worked on […]
The diameter of sticks from the same species of wood (we use Douglas fir at ARC for testing) seems to have a dramatic effect on emissions and thermal efficiency. We used to use small diameter sticks of wood and experienced high thermal efficiency, low CO and high PM2.5. Small sticks make a lot of flame […]