Pellet stoves: what you need to know
Last updated 1/23/2020
A pellet stove is a type of biomass heating device that burns compressed wood pellets to generate heat. Pellet stoves are similar to a traditional wood-burning stove but typically are a more efficient and environmentally friendly option. In fact, pellet stoves can be considered “carbon-neutral” by some metrics, as the carbon dioxide released from their use is close to the amount of carbon released by wood naturally decomposing in forests.
- Pellet stoves burn compressed wood pellets to generate heat
- Pellet stoves can be used as a whole-home heating option
- You can install a pellet stove as a fireplace insert or as a freestanding unit
Types of pellet stoves
There are two main classes of pellet stoves: freestanding and insert stoves. They are generally similar in heat output, cost, and efficiency, but the layout of your home is an important consideration when comparing these two options.
As their name suggests, freestanding pellet stoves are fully self-contained units that can be placed anywhere in a room. As such, they are often easier to clean and are more flexible from a room design perspective. In comparison, insert pellet stoves can only be installed in an existing fireplace. This will save floor space, though it makes the stove more difficult to reach for cleaning.
How do pellet stoves work?
In some ways, pellet stoves are similar to traditional wood-burning stoves: wood goes in and heat comes out, and the appliances themselves tend to look similar. However, pellet stoves are much more sophisticated devices, operating with electricity to precisely heat your property.
Wood pellets are loaded into a hopper, either on the top or bottom of the stove. Connected to the hopper is the auger, a long, screw-like device that delivers pellets from the hopper to the stove. The speed of the auger’s rotation determines how hot your stove will burn. The auger drops wood pellets into the burn pot, where a flame is ignited and the pellets burn.
As pellets combust in the burn pot, the stove convection blower pulls in cool air from the surrounding space and passes it over the burn pot, which allows the pellets to burn efficiently while heating the air. This heated air is moved across a heat exchanger, which transfers the heat from the stove to clean air outside the pellet stove, which is then blown into the room.
Lastly, an exhaust blower pushes waste gases out the back of the stove, usually into an existing chimney or through a small wall hole.
Pellet stoves are controlled by a thermostat that controls the number of pellets being fed into the burn pot/combustion chamber by the auger. The more pellets being fed in, the hotter the stove will burn.
Biomass heating is a renewable and often inexpensive alternative to fossil fuel heating systems such as oil or gas boilers. The term “biomass” can be used to refer to any organic material that can be processed and burned as fuel, from wood agricultural residues (such as grass clippings and leaves) to animal waste and sewage. Biomass heating most often refers to methods of heating using woody biomass, mainly pellet stoves.