Anatomy of a woodstove
Although there are many different models of wood stoves, there are several basic components in all stoves.
Parts Found in All Wood Stoves
Every stove includes some type of lever, dial, or handle, used to adjust the amount of air entering the firebox, regulating heat output.
A baffle is anything that slows or changes the direction of the gasses in the stove. Most baffles are steel, cast-iron, or refractory brick plates installed at the top of the firebox. Smoke and gasses must move around the baffle before exiting. This increases the amount of time the gasses remain in the stove, allowing time for more complete combustion.
This is where you build the fire. Some are lined with masonry firebricks or refractory cement, while others are lined with steel or cast-iron panels.
The flue collar is the opening in the top, rear, or side of the stove (usually round or oval), to which the stovepipe is connected, and through which exhaust is vented from the stove.
A door to the firebox, used for adding fuel to the fire.
Parts Found in Some Wood Stoves
Virtually all new stoves have a glass panel in the front door. Unlike older designs, in which this glass tends to blacken quickly from condensing wood smoke in the firebox, the new stoves use an air-wash system to help keep the glass clean.
The air wash consists of an opening for combustion air along the top or along the bottom of the glass. Combustion air is focused against the inside of the glass, reducing condensation of smoke and keeping the glass clean.
A pan located under the firebox, used to collect ashes, making it easier to ash the stove.
A ceramic insert with numerous small channels, or tubes, running through it. (It looks like a honey comb.) Applied to the surface of the ceramic is a layer of a catalytic chemical, generally platinum or palladium, which reacts with smoke passing through the channels, reducing the ignition temperature of the smoke, and causing the smoke to burn.
A damper is a moveable plate that regulates the flow of gasses through the stove. Older stoves sometimes incorporated a pipe damper, a round valve in the stovepipe, which the user closed or opened to reduce or increase the flow of gasses through the stove.
New, catalytic stoves have a bypass damper in the stove itself. This is a metal plate in the stove, which, when open, allows smoke and gasses to bypass, that is, move around, the catalytic unit. When the stove is heated to the correct temperature for the catalytic unit to operate, the user closes the bypass damper, forcing the smoke through the catalytic combustor.
Many new non-cat stoves are designed without any damper.
Secondary Burn Tubes
These are perforated metal tubes located inside the firebox at the top that allow combustion air to enter the firebox. Unburned gasses moving up from the fuel load mix with oxygen from the tubes and ignite. Smoke that would have been lost up the flue in an older stove is burned, increasing efficiency and reducing smoke emissions.