Wood burning is not simply putting a log in your fireplace or using a refurbished wood stove to heat your home. Only stoves that employ advanced technology can burn wood cleanly, efficiently and over long periods. The types of wood-burning stoves that are high-tech are:
- Advanced combustion stoves
- Catalytic stoves
- Wood pellet and corn stoves
- Russian or masonry heaters
- Wood furnaces and boilers
The main objective of these stoves’ design and manufacture is clean, safe energy extraction that reduces wood usage and thus the cost of fuel, whether purchased, cut or processed. Increased efficiency comes from an airtight burning compartment that controls combustion. Even the smoke is burned through a secondary process of combustion before it goes to the chimney. (The masonry stove is an exception to this rule.)
EPA-certified stoves , fireplaces and their inserts give lower air pollution, lower fuel consumption, higher efficiency and enhanced safety. There are many benefits of the EPA wood heater certification program, the biggest of which is that certified models are over 30% more efficient than conventional alternatives and so save one-third of your wood cost and processing work.
It is important to have an airtight burning chamber to prevent too much oxygen in the fire. This increases burning time and evens out heat flow. Traditional fireplaces are less efficient because the energy they produce is often negated by cold air drawn from outside to keep the fire going. They also produce a lot of smoke and air pollutants, with possible chimney fires due to unburned fuel lining the chimney walls as creosote.
It may sound far-fetched to burn smoke before it reaches the chimney, but that is the aim of today’s wood-burning technology. These appliances capture unburned fuel in the smoke: a secondary burn is created with atmospheric oxygen, heat or catalytic components to provide more heat, less atmospheric emissions and savings in fuel dollars (and backache for people who chop their own wood).
Advanced Combustion Units
Advanced wood stoves came from the simple box stove concept which has long been in use. Simple stoves direct the smoke and heat straight up the chimney whereas the advanced combustion stove uses an “air injection” tube to add more air to increase the amount of oxygen in the smoke, causing immediate re-burning. As the smoke travels along its designated route to the chimney, it radiates heat. This is like putting a turbocharger in a car to generate more free horsepower from otherwise wasted exhaust.
Catalytic Units
Catalytic wood stoves work similarly to automotive catalytic converters. The smoke from any unburned wood is directed via a catalytic component, like a ceramic disk with honeycomb holes. The coated disk of specially blended rare earth metals lowers the exhaust gases’ combustion temperature when combined with more atmospheric oxygen. Along its journey, the smoke mixes with inlet oxygen to burn; the smoke is consumed to generate energy, leaving only wisps of steam.
A disadvantage of this catalytic technology is the need to turn off the operation manually when the stove reaches the desired temperature. This is a minor issue but neglect or