How Does A Coal Stove Work?
There are a few different types of coal stoves: the hand fired (or batch), the direct vent/stoker, and the natural draft versions. Regardless of the stove type, they all require grates and an ashpan. Coal will produce up to 10 times more ash than a wood stove, and the pan will need to be emptied regularly.
- HAND FIRED
Also known as batch coal stoves, this is not the type of stove that you can leave unattended for more than half a day. Much like a wood stove, the coal is fed into the stove by hand every 12 hours. When loading the stove, the coals will also need to be raked with quick, aggressive strokes, and the ash pan will need to be emptied. Although stove coal is considered a clean burning fuel source, this resource does produce sulfur dioxide when it is burned. It also has a high carbon content, which is the reason for its terrific burning capabilities and the main reason it is able to burn up sulfur dioxide gases. With a hand-fired coal stove, a regular chimney is required for smoke and remaining gases to exit.
- DIRECT VENT/STOKER
A direct vent coal stove uses rice coal or buckwheat as its fuel source. The hopper, which is usually located at the bottom of the stove, should be filled. The stove needs to be plugged in to an electrical outlet in order to run; however, it does not utilize an electronic ignition. The thermostat controls the amount of coal that is being fed into the combustion chamber (firebox), and a shovel system pushes the coals over a grate. The blower controls the air flow going in and out of the stove. The ash pan (located below the burn pot) needs to be emptied and cleaned regularly.
There is no need to vent with a natural draft chimney with this particular stove. In fact, they can be installed very quickly (quite similar to a pellet stove).
- NATURAL DRAFT
The natural draft coal stove is similar to the direct vent coal stove, but with a different ventilation system. This non-electric, EPA-certified stove also burns rice coal or buckwheat, but does not need a blower to assist with combustion. The natural draft coal stove operates and circulates air via gravity and natural convection currents and drafts. This stove continues to work even if the power goes out. From our experience, these stoves are very easy to operate and maintain, with less cleaning required. The chimney may be a bigger investment, compared to those used by other coal stove versions, but it is well worth it.
Coal stoves heat by way of convection, which is the transmission of thermal energy generated by the movement of hot and cold air currents within the unit. The convection blower (located only in certain stove models) pulls cold air in from the surrounding environment, directing it over the burn pot. Once the cold air combines with the heat generated by the burning coals, the flames become hotter, which allows for a more efficient burn. This mechanism delivers clean air via the room blower (hand-fired and stoker models) and also acts as a furnace when used in combustion. In turn, this keeps the outside of the stove from becoming hot.
Gases exit (with the help of an exhaust blower on stoker and some hand-fired models) out of a pipe located at the back of the stove. This vertically-angled pipe can be vented directly through a wall or via an existing chimney (although a masonry chimney is not a requirement).