Using rocket science to create a warmer stove

• Local inventor improves on Alaska’s most important source of heat 
By Naomi Klouda
Homer Tribune

Photo provided - Lasse Holmes, far right, shows how to build the mass stove using several steps.

Photo provided - Lasse Holmes, far right, shows how to build the mass stove using several steps.

Wood heat feels primordially right when warming bones in Alaska’s chilly winters – even in certain summers. But the problem with conventional stoves is an inherently faulty design that leaks heat out the stove pipe along with the smoke. 
Lasse Holmes’ invention, building from a model by Ianto Evans, re-engineers the wood stove into a “rocket mass heater.” To understand, it first takes a primer in smoke, mass and how air gets heated.
“These burn really hot fires, and there is no smoke, except when they are warming up,” Holmes explains.  “Smoke is a fuel, smoke is waste, it is burnable.”
The proof of this is in the creosote, which cakes in flues and can set chimneys on fire. Imagine a stove that burns the creosote, consuming its own smoke and wood, and expelling vapor and co2 instead of dirty smoke. 
Now, with all the heat harvested in the stove, imagine it projected through a pipe built into a stone masonry bench. 
“You sit on it, and it warms you through. These are built into stone masonry couches that stay warm all winter. You’re not burning wood all the time – you’ll have a morning fire, and an evening fire, that evenly puts out heat throughout the day and night,” Holmes said. 
The stoves are encircled in a masonry arch made up of a clay mixture and fire brick. Holmes finds natural clay excavated from known areas, and mixes it with gravel and sand for a hardening matrix he calls “claycrete” in a play of words on concrete. Clay can be gathered and stored, even weathered outside in the elements for an easier mix with other materials. The couch surface can be dressed up with tile, glass or stones, or plain, as in the one used at the Yurt Manufacturing factory. That single stove heats an entire warehouse-like area.
The heating temperature inside the stove can reach 2,000 degrees whereas a conventional stove getting up to 900 degrees can set the house on fire. He uses three pipes – an outer one that is insulated from the inner-most one, and then a covering over both.
“The mass is in the bank of heat. The comfort level goes way up – you’re not heating air, you’re heating mass. You can sit on it and lay on it,” he said.
To perfect his design, Lasse kept tinkering with the features. So far, he has built five rocket mass stoves and helped dozens of others in his courses. With one of these kits and locally sourced materials the stove can be built for $2,000 to $4,000 depending on size. Frugal recycler types can even build one for less than $1,000. This is compared to a traditional masonry stove that might cost $20,000-$30,000.
Holmes, known in Homer for his Canyon Arts School of Natural Building, is hired as a contracting consultant for new housing designs. He brought his stainless steel welding skill and beer brewing expertise to Homer in 1996 and started Homer Brewing Company. Five years later he sold the brewery to his partners, and acts as a consultant for other Kenai Peninsula breweries.
“My grandfather and great-grandfather were inventors – it came naturally to me,” he said. His father worked for the post office and his mother was an occupational therapist. He was raised partly in Denmark where his mother is from. There he grew up around masonry stove models.  
Working with Dale Banks, also well-known locally for experimenting with  natural materials for a low-carbon footprint lifestyle, Holmes has come up with a brick made of straw, clay and sawdust for insulating homes. The original idea, insulating homes with straw bales, was reworked by Holmes to avoid the moisture concerns and rodent activity by mixing it with clay. It also eliminates the concern of fire that some people have about straw bale. This summer, he worked with the Ionia community in Kasilof to build a 20,000 square foot barn-workshop. The walls were built with the insulating straw-clay, a giant undertaking since the process is done by hand. It fits between the studs like insulation.
“We made an assembly line to get them all done. The building is timber-framed and insulated with straw/clay and has test walls to compare straw bale, saw dust/clay and rice hull/clay,” he said. “It’s possibly the biggest structure in the world made with these materials.”
Another project involving Holmes is looking at cooperatively purchasing land to set up a symbiotic community of businesses and nonprofits. Meetings will be announced this fall. Called the Canyon Confluence, one of the ideas is to establish a cooperative brewery and natural foods co-op.
This fall begins Holmes’ busy season with workshops. He holds one Friday-Sunday at the Kenai Fine Art Center, 816 Cook Avenue in Old Towne Kenai. Another is set for Homer at Bearcreek Sept. 28-30. The Friday workshops go 7-9 p.m., and weekends are 10 a.m. to 6 p.m. For more information, call 235-1355 or write to

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Posted by on Sep 19th, 2012 and filed under Headline News. You can follow any responses to this entry through the RSS 2.0. Both comments and pings are currently closed.

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