In 2014, the World Health Organization (WHO) issued the first-ever health-based guidelines on clean fuels and technologies for household cooking, heating and lighting: INDOOR AIR QUALITY GUIDELINES: HOUSEHOLD FUEL COMBUSTION 2014 From section 5.4.1 Roles of clean fuels and lower emission solid fuel stoves “As recognized in these guidelines, and specifically in Recommendation 2, which addresses policy […]
Regardless of the velocity of secondary air, flow rate, or the angle at which air is injected into the fire, secondary air tends to lower the temperature of gases. Researchers have found that injecting secondary air into the side of the flame in a Rocket stove results in most effective mixing.* The Jet-Flame, on the […]
If protecting health and climate are important in stove projects, why not monetize the reductions of health/climate pollutants in carbon-offset projects? Only the reduction in fuel use earns carbon income now! With equal heat transfer efficiency, dirty burning stoves earn as much as clean burning stoves. Dirty burning stoves are less expensive. “Market demand” reinforces the use […]
Champion (2021) average energy emission factors (g/MJ) from ISO high, medium, and low tests. Lab testing can quickly compare emissions from stoves. The EPA and ARC labs now measure the climate emission factors, not just PM2.5 and CO. It has been proven that only field tests show real world performance. Together, lab and field tests help […]
Primary air usually controls the rate of reactions: How fast the solid biomass changes into wood gas. Jets of primary air into the charcoal beneath the biomass add mixing while raising temperatures. Secondary air jets into the side of the flame can also supply needed mixing but tend to lower temperatures. Metering the gas supply […]
Dr. Sam Baldwin describes the use of a pot skirt in his book “Biomass Stoves: Engineering Design, Development, and Dissemination (1987).” Changes in the length and diameter of the channel gap (between the pot and the interior of the skirt) result in dramatic changes in heat transfer efficiency. “In fact, the channel efficiency, defined as […]
That the days are shorter is easy to attest to here at Blue Mountain. Our campus is wedged between parallel rows of 100-foot tall Fir trees. Yesterday, the rare sun fell down below the celestial horizon at 2PM. We envy the valley farmers whose day lasts until around five. On the other hand, being surrounded […]
“The concept of black boxes has been around since the early days of systems theory though some attribute the first use to the field of electrical engineering. It is a simple concept and has a straightforward definition: we know the inputs and subsequent outputs to a system but the internal workings of the system are […]
The great and upsetting thing about YouTube videos is that they don’t go away! A lot of this old video now seems incomplete: Our understanding of how to come closer to complete combustion has changed and includes details missing before. The following describes a hopefully less wrong set of design principles. David Evitt is currently deep […]
The U.S. Department of Energy (DOE) Bioenergy Technologies Office (BETO), in collaboration with Brookhaven National Laboratory (BNL), Lawrence Berkeley National Laboratory (LBNL), and the Alliance for Green Heat, today announced the winning teams for the Wood Heater Design Challenge (WHDC). Aprovecho Research Center, from Cottage Grove, Oregon, came in second place and won $25,000 with a novel burn pot, airflow configuration, and sensor package for pellet heaters. […]