Masonry Stoves
Masonry stoves, usually called masonry heaters, are built with masonry, ceramic, tile or bricks. What distinguishes a masonry heater is the ability to store the heat from the fire in the masonry thermal mass, and then slowly radiate into your house for the next 12 to 24 hours.
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Masonry heaters are very efficient and do not require EPA certification.
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​Masonry heaters are an ancient technology and represent the oldest, high efficiency way of heating with wood. Designs from the 17th century can be as or sometimes even more efficient than most of today’s cast iron and steel wood stoves.
Masonry stoves are an extremely efficient way to heat your home and are very popular in Europe but remain only a very niche technology in the US and Canada. (One theory is that skilled masonry heater builders were always in high demand in Europe and very few emigrated to the US from 1500 to 1900.) Besides the lack of awareness about masonry heaters, the main hindrance of wider deployment is their cost and size. They start around $8,000 for factory-built models and often go up to $20,000 for site-built ones.
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Masonry stoves work by circulating the hot flue exhaust through a series of baffles that heats up the surrounding masonry, and greatly reduces the temperature of the exhaust leaving the chimney. Unlike wood stoves, fires in masonry stoves are burned hot and fast, for more complete combustion.
One market barrier for masonry heaters in the US is that the EPA has not designed an emissions certification program, allowing them to become certified. The EPA is generally very sympathetic toward masonry heaters and is working with that industry on testing protocols. However, since they are typically among the cleanest and most efficient wood heaters anywhere, Colorado and Washington states have compiled lists giving them better recognition and acceptance.
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​For more information, visit the Masonry Heater Association site and here for images of this gorgeous and ancient technology.
Factory Built Masonry Heaters
Factory built masonry heaters are growing in popularity as they are less expensive and can be added into nearly any home since they need less, or no structural support added under the floor. Their smaller size does mean that they are likely to hold heat for only 8 to 12 hours, need to be loaded twice a day - and won't entirely heat a larger home. Tulikivi is the leading supplier of factory-built heaters.
Site Built Masonry Heaters
Site built masonry heaters tend to be larger and more expensive as skilled masons need to be on site for 3 to 7 days to build it. They are best in new construction as the heater footprint, like stairways, is a major floor plan design element. Like factory-built masonry heaters, they can include baking ovens. The Masonry Heater Association maintains an international list of masons who can build heaters.