Wood burning technology has come a long way since the day cavemen first discovered fire. Throughout time, wood burning has been used for warmth, comfort, security, and cooking. Today’s consumer is no different, however their choices for wood burning appliances are endless.
The first built-in fireplaces were built with stone or masonry. They usually included a huge firebox that was capable of holding a large amount of wood and producing a great deal of heat. These fireplaces were used as the primary heat source for the home, as well as the main cooking area. The traditional masonry fireplace was very inefficient and used air from inside the house as combustion air. This resulted in drafty fireplaces that pushed as much heat out the chimney as they provided to heat the house.
In the late 1700s, the fireplace industry was revolutionized by Count Rumford of Bavaria. Born Benjamin Thompson in 1754 in Massachusetts, he left the United States as a British loyalist and began his work as a physicist with the Bavarian government. Count Rumford redesigned the form and function of the masonry fireplace to retain more heat within the home. He redesigned the flue to create better air extraction and make lighting the fireplace much easier. As well as this, Earl Rumford made the firebox smaller and sloped the side and rear walls in such a way that the heat produced by the fire would radiate back into the house. This allowed fires to be built with a smaller amount of wood capable of providing more heat to the hearth. This work earned Benjamin Thompson the title of “Count of the Holy Roman Empire” and made him a legend in the home industry. The Rumford design is still used by manufacturers providing a medium efficiency solution for consumers looking for a large fire with moderate efficiency.
The next great advance in wood burning technology came with the invention of the freestanding wood stove. Stoves provided much easier installation as well as greater versatility in meeting cooking and heating needs. Wood stoves can be placed in almost any room in the house and were often used together. The single wall fireplace was ducted throughout the house and provided radiant heat to different rooms at the same time. Early single-walled chimney pipes posed a safety hazard, often overheating and starting chimney fires. Today, wood stoves are built and installed in accordance with strict safety regulations. They often use a double-walled black stovepipe from the unit to the first penetration into the building envelope and an insulated chimney from the roof or wall penetration to the termination cap. These units are installed by WETT certified installers and must comply with local and national building codes. WETT (Wood Energy Technology Transfer Inc.) is a non-profit certification company that governs the rules and regulations for wood burning appliances.
Built-in clearance fireplaces are now a common alternative to the traditional masonry fireplace. They take on many of the efficiency and safety qualities of a wood stove while providing the traditional look and beauty of a fireplace. These fireplaces are called zero clearance because they can be installed in wood constructed chimney flues with finishing materials up to the edge of the chimney. This provides the consumer with endless finishing alternatives and allows them to achieve any design ideas they may have for their home.
Manufacturers are always looking to use technology to achieve higher efficiencies, longer burn times, lower emissions, and greater comfort for their consumers. Options like gravity vent kits, heat zone kits, circulation fans, and controlled outdoor air intake make burning wood more convenient and affordable as an alternative home heat source.
I wonder if Earl Rumford could have foreseen the impact his research and designs would have on the heating industry around the world.