WHAT IS A MASONRY HEATER?
A masonry heater is a heating device built primarily of masonry materials that consists of a fuel fire box and a series of heat transfer channels or flues that capture all of the heat from a fire and gently radiate the heat into the home.
The basic principle of all masonry heaters is to use a small amount of fuel to burn a very hot fire that heats up a large mass of masonry which in turn heats a dwelling for a long period of time.
The heaters are designed to efficiently burn wood and its gases in a firebox after which the hot, low pollutant gases pass through a series of internal heat transfer channels heating the entire masonry structure.
The heaters are designed to burn 1-2 fires per day allowing the heaters to gently radiate heat for a 12-24 hour period, long after the fire is out.
Masonry heaters generally do not exceed 200F on the outside making them not only safe, but quite enjoyable to touch.
Heaters can be custom built to meet a homeowner’s needs.
Masonry heaters can be built in a variety of shapes and sizes and can contain bake ovens, cook stoves, and heated benches.
They can be built to heat entire homes, or smaller units can be built to heat individual rooms or spaces.
WHY CHOOSE A MASONRY HEATER?
Masonry heaters utilize one of our most abundant renewable energy sources.
Masonry heaters are the cleanest, most efficient and comfortable way to burn cordwood.
Masonry heaters are the heart of a home, providing a functional centerpiece where family and friends can gather.
Masonry Heaters only require 1-2 short fires per day, making heaters the safest, easiest, and most convenient way to burn wood.
Heaters work harmoniously with passive and active solar heating systems.
TYPES OF MASONRY HEATERS
Finnish: Finland has a long history of Masonry heaters. The Finnish stoves or Finnish fireplaces are most often called contraflow heaters. In these stoves, flue gases leave the firebox travel up through a throat and into a secondary combustion chamber where remaining unburned gases are burned before traveling back down heat exchange flues on each side of the heater. The gases then exit the stove through a chimney connection at its base. Contraflow heaters are often built with black or white bake ovens and/ or heated benches.
Russian: The Russian heaters we build are called bell heaters. Bell heaters work on the principle of free gas movement, which was first theorized for masonry heaters in the early 1900’s. The basic principle is that gases fill up a volume of space no matter the size or the shape with hottest gases rising to the top of the container and cooler gases sinking to the bottom. Using this principle in a stove, the container or bells can be made within a tolerance of sizes, allowing bell heaters to have an array of shapes and sizes, with much flexibility in design. Using free gas movement principles allows a stove to work without as much dependence on the draft of the chimney. This characteristic sets them apart from other designs. These heaters can also have black or white bake ovens and heated benches.
Swedish: Sweden has a very long history of masonry heaters many of which are beautiful ornate tile stoves. Swedish stoves are said to be the first stoves with down draft channels and Finnish stoves evolved from Swedish designs. A common design of Swedish origin is for flue gases to go up a throat down the front sides of a heater and back up the rear sides before exiting at the top of the stove. This is referred to as a Swedish Five Run.
Austrian: Austria has a very rich masonry stove history and is most famous for their kachelofens, though many of their stoves are actually grundofens. Kachelofen’s are tile stoves while grundofens are plaster/stucco heaters, but the core of the units are built in the same way. Austrian stoves are built using scientific calculations and the Austrian guild even has a computer program for calculating all dimensions of the firebox and flues. These stoves can be built in practically any shape or size but are traditionally only finished in tiles or plaster because of the way they are constructed. Soapstone can be easily adapted to work well for a veneer on Austrian style heaters.
Rocket Stoves: Rocket stoves have gained popularity as a low cost heater design. Rocket stoves originally consist of a top loading J shaped firebox/throat that exited into an upside down 55 gallon drum that release the gases into a long heated bench before exiting a chimney. Max Edelson has lead recent research on masonry rocket stoves which replace the 55 gallon drum with a masonry drum and double skin walls instead of the traditional single skin. These heaters parallel Lars Helbro’s heater designs in Denmark.