Entries by Kim Still

Appropriate Technology as Craft

Before I met Dr. Larry Winiarski I was a boat builder, but I had already realized that my love for making boats was mostly supported by rich people. And when my friends and I built a 36’ ocean going sailboat it was great but after several years of exploring it started to be a bit […]

Back to Basics – Fire, part 2

In our Nov. 24 newsletter, we shared a basic description of how wood burns from Samuel Baldwin’s book “Biomass Stoves: Engineering Design, Development, and Dissemination” (1987). Here are more details about the process from the same book: “The temperature of the hot gas above the wood is typically around 1100ºC and is limited by radiant […]

Introducing Aprovecho’s New Executive Director, Dr. Nordica MacCarty 

Aprovecho Research Center is pleased to announce that Dr. Nordica MacCarty has accepted the role of Executive Director. Dr. MacCarty takes over the position from Dean Still, who continues on as Research Director. Dr. MacCarty is also an Associate Professor of Mechanical Engineering at Oregon State University where she will continue teaching and directing the […]

Back to basics – FIRE!

Sometimes it’s good to step back and review the very basis of stove work – fire. Samuel Baldwin gives a good description of how wood burns in his book “Biomass Stoves: Engineering Design, Development, and Dissemination” (1987). “The combustion of wood and other raw biomass is very complicated but can be broken down crudely into […]

A Culture of Daily Experimentation

What do I like most about Aprovecho Research Center? We have created a “culture of daily experimentation.” Scheduling two to three experiments every morning means that we can try less-likely-to-succeed variations. That’s great because experiments that don’t succeed in improving a stove often reveal interesting and possibly unexpected results. And that can lead to new […]

Video: Lighting a Fire With The Jet-Flame – No Smoke

The Gates funded Global Health Labs and ARC/SSM invented the Jet-Flame Shengzhou Stove Manufacturer manufactures the Jet-Flame (jet- flame.com) that is being field tested in over 30 locations. Our lab helped to create this accessory that is designed to reduce emissions while increasing thermal efficiency and reducing time to boil. 30 pre-heated primary air jets shoot up into […]

Secondary Air Jets in Charcoal Stoves?

Charcoal stoves are batch loaded like TLUDs (top loaded up draft stoves), but they differ greatly in how air flow is used to encourage combustion. A charcoal stove has lots of primary air blowing up into the fuel. A TLUD uses a small amount of primary air to create a relatively constant amount of woodgas […]

Cooking With The Sun

  Last week we shared info about retained heat cooking. It’s frequently paired with solar cooking for feeding folks with no earth-generated fuel expenditure at all. But does it work? The cooks at ARC think that it’s great  – in the summer time when we have lots of sunlight. Our preferred solar oven was invented […]

Retained Heat Cooking

While at ARC we focus on how to cook most efficiently with biomass, it is good to remember that some cooking can continue without consuming fuel. A retained heat cooker (RHC), also known as a Haybox, is a great way to save on fuel for appropriate cooking tasks such as simmering rice or beans. How […]

0.75 Constant Cross Sectional Area: A Winiarski “Rule of Thumb”

The Uganda 2-pot stove that is described on page 26 in the EPA publication “Test Results of Cook Stove Performance” is a natural draft stove that also uses much less fuel to cook and protects health. The document can be found at: https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P100EKU6.TXT.  Has it been a while since you looked at this book, a comparison […]