Building Energy Efficiency with Clay and Concrete

Falconfire Pottery (Sharon Moen) partners with Solid Rock Masonry (Eric Moshier) to create ceramic tile stoves that heat homes and businesses with wood. These tile stoves — known also by their German name kachelöfen — offer an efficient heating system that steers clear of fossil fuels.

Our custom-made kachelöfen are built with refractory concrete and specialized clay tiles (kacheln). Eric and his crew pour and cure refractory concrete into forms. These concrete blocks are stacked in a way that creates heat-capturing channels and the capacity to store radiant energy. Sharon’s kacheln are made with hand-crafted molds, draw tools and slabs of clay. Some pieces are sculpted to create or deepen motifs. The tiles are dried, bisqued, glazed and then fired to maturity.

Advantages: Kachelöfen warm rooms more efficiently and cleanly than metal-based wood-burning stoves. The system of flues captures heat, which radiates into the house through the concrete and tile. This type of home heating technology doesn’t push dust through the air and doesn’t scorch dust, which can help people with certain allergies. The surface of the tile stove stays cooler than the surface of a metal stove or a radiator so the danger of burning yourself is minimal. Benches and drying racks can even be integrated into the design.

A tile stove requires more time to heat up than a metal wood stove, but it holds the heat much longer. Light the fire once or twice a day and keep it burning from a quarter of an hour to two hours and you’ll be snug. An average kachelöfen radiates heat for at least 12 hours. 

Thanks to its high energy conversion rate (80-90%), a modest tile stove heating a room of 60 square meters only needs 6 cubic meters of wood per year: about one tree.

More Information: A modest kachelöfen weighs at least 800 kilograms. Custom-built kachelöfen are more expensive than more common heating systems but since the energy consumption costs are much lower, and a well-built öfen lasts more than a lifetime, this investment pays off. In the meantime, you have a unique work of engineering and art that can be almost invisible or an impressive feature of the house. Contact Falconfire Pottery or Solid Rock Masonry to learn more and inquire about designs and pricing.

Apprentice Nick, Eric and Tracy (pictured, left to right) built this stove in Montana. The exterior of the kachelofen took 1,100 pounds of clay and two months to fabricate. Over 150 kacheln and 170 floor tile went into the final product.

“The Gentian” took 1,000 pounds of clay and about 130 kacheln went into the final product.

Masonry ovens have a long history in Russia, Scandinavia and Central Europe and they go by a variety of names:

For more information, check out this article about tile stoves by Kris De Decker in Low Tech Magazine (2008).

Keywords: wood-burning stove, tile stove, masonry stove, energy efficiency, home heating, wood