However, it appears that both these methods produce the most heat per fuel used, have the cleanest emissions and are environmentally defensible if not laudable, especially in our present day in which typical household heating systems are using either natural gas or electricity still largely produced by fossil fuels.

Masonry heaters have not achieved the public attention of other wood-burning devices, Smith says, because they require specialized builders and each must be designed for a specific house and climate. The Masonry Association’s 130 or so members built just about 1,000 of them annually in the United States, and the uniqueness of each model is part of what’s kept the EPA from being able to rate or say much about this type of heating, which depends on so many variables, he said.

A masonry heater is best built with the house in mind because to be effective, the heater must be placed where air circulates around it so it can radiate heat to the largest possible area. (Though the units can be incorporated into an existing house; Frisch has used existing fireplaces as a starting point.) It’s also bulky and requires a large concrete foundation to support its multi-ton weight, though models designed to heat a room or two are smaller in scale.

Such heating has long been used in Scandinavia and other parts of Europe, dating back several hundred years, but failed to become a norm in the U.S. where pioneers built simple, straight chimney fireplaces and fed them with abundant wood, Frisch said. Nothing changed over time as the United States moved onward to rely on heating using oil and gas, also historically inexpensive and plentiful.

“We’re a spoiled society. Gas and oil were cheap. In Europe they’re more practical. They have a history of having them (masonry heaters),’’ said Frisch, a Missouri native who has spent a lifetime building, designing and improving masonry heaters from his longtime home in Washington state . He has built four masonry heaters for himself, two in his house and two in his cabin, including one made of top-notch soapstone, a good heat conductor.