Improving Stove Performance with the Color of PM Filters
Dean Still
I use the emission hood almost every day trying to improve one stove or another. Right now we are working to make a least expensive, best performing side feed fan stove. The one we have is clean burning but the goal is to deliver a $10 design to the manufacturer. The new technique is simpler and uses a smaller fan and less metal.
Sam Bentson, the ARC lab manager, usually takes the raw data from a test and tells me the next morning what happened. Did the prototype get better or worse? When Sam went on vacation, I tried a simpler approach (See photo.)
I started the boiling and simmering test series with water at the same temperature (say 20C). Then it’s possible to see results by just looking at the darkness of the PM filter. The filters have to be very white to be ‘Tier 4’. When the filter is slightly darker the goal has not yet been reached.
All we have to do is to try, try again until success is achieved.
Right after the test I could look at the filter and see if the change I had made in the stove prototype was probably beneficial or not. I like immediate results!

Benjamin and Nathan Visit ARC from KIRDI
Trevor Cardwell
This week we’re honored to have two special guests from Kenya, Benjamin and Nathan, training with us on ARC emissions equipment and testing procedures. Each day they spend with us they will learn about testing practices, perform CCTs (Controlled Cooking Tests) and spend time face-to-face with ARC engineers.
A CCT, or Controlled Cooking Test, measures a cookstove’s ability in various areas by using the stove to cook a dish that would be commonly cooked in a specific region of the world. The cookstoves are used in conjunction with ARC emissions testing hoods, Laboratory Emissions Monitoring Systems (LEMS), so testers can quantify carbon monoxide, carbon dioxide, and particulate matter emissions in real-time utilizing a computer with sensors attached within ducting of the testing hood.
Nathan and Benjamin work at KIRDI (Kenya Industrial Research and Development Institute), an official member of the Global Alliance for Clean Cookstoves. Upon returning to KIRDI in Kenya, they will put their ARC CCT training to use by certifying and testing future cookstoves in their own lab.
It’s always a pleasure to have guests stay with us at Aprovecho and Nathan and Benjamin are no exception. As well as having great company in the lab, doing a CCT each day means a second lunch!