Executive Director’s Report – Celebrating Aprovecho’s 50th Anniversary I’ll always remember my first moments at Aprovecho 26 years ago. I had just graduated with a degree in mechanical engineering, newly aware of the realities of household energy poverty, and had completed my first solo cross-country road trip to Oregon to work with a small group […]
In our recent post “Improving Solar Distillation, Part 1,” we talked about the traditional design for a solar still and pointed out some design weaknesses. Here we show Dr. Larry Winiarski’s suggested improvements to address those problems. The distillation of brackish water is a two-stage process. Water is encouraged to evaporate and is then condensed. Sealing […]
A Four-Nation Design Collaboration On their recent trip to SSM in Shengzhou, China, Nordica and Jaden were reminded that many minds are always better than one. SSM were gracious hosts to ARC, OffgridSun from Italy, and Tango Energy from Tanzania for a week. Together, they designed a stove for Tanzania that addressed cooks’ needs, had […]
A typical DIY solar still. (Image from LSU Ag Center) In this type of solar still, salt water is put in a sealed box with an angled glass top. As sunlight entering the box heats up the water, it evaporates into fresh water, condenses on the glass top and runs down into a collector. Dr. […]
Google AI (Gemini) says that: “In a high-performance rocket stove, the average gas temperature within a pot skirt typically ranges between 800C and 1,000C. These gases lose temperature as they flow through the channel gap between the pot and the skirt, where they transfer heat to the water.” One of the interesting things that our lab […]
We are currently studying products that help households in rural developing communities to meet their basic needs. Our goal is to develop a catalog of the most affordable, durable, usable, functional products available that have been rigorously user-tested and optimized. To help us choose where to start, could you please take 5 minutes to let […]
HTE Design principles: Increase temperature and velocity of gases, exposed area in pot(s), radiation, proximity of gases to pot(s) without decreasing velocity. Use dry wood. Doubling temperature, velocity and area doubles heat transfer efficiency! Doubling radiation is much more effective! Wood Moisture Content: This is often a critical variable. Ideally, wood should have a moisture […]
The Stainless Steel Winiarski Stove Top The other day, I watched as Dr. Winiarski’s stainless steel stove top (sold by BURN and SSM) helped to force 43% of the heat from a hot fire into a 30cm in diameter flat bottom pot without a pot skirt. The improved stove top adds a lot to a […]
Although airtight biomass heating stoves in the USA on average emit a lot more smoke than Southern Hemisphere cook stoves per unit of time, legally mandated chimneys move it outside where it is diluted enough to generally meet WHO standards. That’s great! Anyone who uses a wood burning heating stove knows that a chimney is […]
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 […]