What are Pellet Fuel Appliances?

A Pellet Stove is a heating appliance much like a wood or gas stove that burns wood pellets as a fuel source.

How pellet stoves work

The new stove diagrams of Pellet appliances demonstrate that manufacturers set out to automate as many functions as possible. The most significant of these functions is fuel delivery. The heat setting made by the operator controls an auger or similar feed device that delivers regulated amounts of fuel from the hopper (bulk storage for the pellet fuel) to the fire. There are two types of feed device systems - Top Feed and Bottom Feed. Unlike typical woodstoves, automatic fuel delivery from the hopper in the pellet appliance frees the operator from frequent attention and loading, while providing clean burns and the desired comfort level. Additionally, pellet appliances require less “hands-on” attention to maintain the most efficient operations.

From the hopper the pellets enter the burn box. With just a few pellets, the appliance is able to generate a lot of heat and burn the pellets at incredible efficiencies. Combined with the relatively consistent and low moisture content fuel, the stove is able to burn each pellet up completely. It does this by blowing a jet of air across the burning pellets creating a little blast furnace. The effect is similar to that when using a woodstove all of the dampers are opened and the fire is allowed to draw in lots of air to fan the flame. This puts out lots of heat and burns the logs quite thoroughly, but the available fuel will be burned through quickly and will generate more heat than can be transferred into a room.

In comparison, a pellet stove is able to control how fast the fuel is added. By breaking the fuel into small, manageable units and the addition of technology the pellet stove to able extract the exact amount of heat desired while wasting as little fuel as possible.

The amount of air needed for optimum combustion efficiency is delivered automatically or with minor manual adjustments. In most designs, an electric fan delivers air to the fire and blows exhaust by-products out of a vent pipe that is smaller and typically less expensive than a chimney. The wood pellet fuel source leaves a less than one percent ash residue. Compared to woodstoves and fireplaces, this means less chimney cleaning.

A fan delivers heat to the home by blowing air through heat exchangers in the stove and out into the home. Heating efficiency is greatly enhanced by removing the heat from the appliance before it can exit the system.

Pellet appliances require electric service for fan and blower operations, and for optional electronic starters.

Pellet Stove Diagram

Wood pellets are placed into a hopper (1)

An electric auger (2) feeds the pellets into a burn grate (5) at a rate determined by the temperature control

Fire heats the air in heat exchange tubes (6) and a convection fan (3) blows this heated, uncontaminated air into the room where a stove is situated

There is an ash pan (4) below the burn grate into which the residue falls. Typically, a stove only needs to be filled once a day and the ash pan needs to be emptied only once or twice a year