Improving woodstove efficiency: Rocket Stoves & Masonry Heaters

Improving woodstove efficiency: Rocket Stoves & Masonry Heaters:

Editor’s introductory note: Masonry heaters, many of them self-built, warm millions of homes in the former USSR, where Alex Chernov grew up. Now working as a certified heater mason in Canada, Alex designs and builds heaters and ovens, and consults on projects all over the world through his company, Stovemaster (his website offers a wealth of background info). In the article below, he combines his professional expertise with his own background and experience in a culture where most people have long experience heating with wood, and where building one’s own heater was not unusual.

Testing the Limits – Adobe Heaters in Argentina

I have recently built three single-skin masonry heaters in Argentina using unfired bricks and would like to share some thoughts and an account of the experience.  All three were based on the design presented by Alex Chernov at the 2012 MHA Annual Meeting at WildAcres, with minor modifications to accomodate brick sizes, hardware, and site considerations.

I have spent the past 4 years living in the Patagonia region of Southern Argentina.  Natural gas is cheap and widely distributed, but many people here, and in neighboring Chile, continue to live with wood fires as part of daily life for much of the year.  Unfortunately, Patagonia has virtually no culture or technology related to efficient wood-burning.  There are random kachelofens or grundofens to be found in the aging mansions of European immigrants and a few rocket heaters in the newly built homes of the sustainable-living bourgeoisie, but the vast majority of wood-burners in the Southern Cone of South America are using iron cookstoves (“cocina economica”) or artisanal woodstoves (“salamandra”) made from gas-tanks and scrap metal.  Frightening, in my opinion, is the fact that when these folks do “upgrade” to a fancy stove it is invariably to one of the tight-sealing “slow combustion” stoves that are taking the market by storm with glossy brochures and hollow buzz words like “double combustion” and “healthy heat.”  They beam with pride as they tell you how they can make the fire smolder all night long.…

Cob + Firebrick = Masonry Heater Experiment

When I was 27, I moved back to my hometown in northern Minnesota to start a small organic vegetable farm. I sold produce to the wife of a stone mason, and he was looking for help in the winters. I told him I didn’t know anything. “Don’t worry,” he calmly replied, “I’ll train you.” I learned, of course, that hauling an endless supply of block and stone from one place to another doesn’t take much training. But he also handed me a copy of David Lyle’s history of masonry heaters. Three years later I was working for Albie Barden, building heaters for Maine Wood Heat Company, and dreaming of small things, simple things, handmade things.…