Principles of Operation

September 14, 2008 · Filed Under Pellet Stove Operation · 3 Comments 

A pellet stove will normally consists of these six basic components in some form:

  • A hopper
  • An auger system
  • Two blower fans (combustion and convection)
  • A firebox (with refractory panels, burn-pot, and ash collection system)
  • Various safety features (vacuum switch, heat sensors)
  • A main control box/board (or “brain”)

For pellet stoves to properly function they require electricity which can be plugged into a normal wall outlet. A pellet stove is a consistent heater consuming fuel that is fed evenly from a refillable hopper into the burn-pot (a perforated cast-iron basin), through a motorized system. The most commonly tpye of distributor used is called an auger, the system consists of a spiral length of metal encased in a tube. This mechanism is either located above the burn-pot or slightly beneath and guides a portion of pellet fuel from the hopper upwards until it falls into the burn-pot and begins to combust.

A fan systems is used for clean, economical performance. The flame produced is concentrated and intense as a combustion blower introduces air into the bottom of the burn-pot. Previously some pellet stoves were hot to the touch (especially on the viewing window), most manufacturers now utilize a series of cast-iron heat exchangers that run inside of thefirebox.

The first is a convection blower which  are used to circulate the room air through the heat exchangers and redirected back into the living space. This method allows for a much higher efficiency than the radiant heat of a hand-fed wood or coal stove, and this will cause the top of the pellet stove to be not more than warm to the touch. The other fan used is for convection air, an exhaust fan forces air from the firebox through special venting specifically made for pellet fuel. This cycle of circulation is an integral part of the combustion system as well, for the concentrated high-temperature flame will quickly overheat the firebox. Some of the possible problems associated with overheating are electrical component failure and flames traveling into the auger tube causing a hopper fire. All pellet stoves have built in heat sensors for safe guards so any unsafe conditions occur it will shut down.

Starting pellet stoves can either be lit manually or through an automatic igniter. The igniter piece resembles a car’s electric cigarette lighter heating coil. Most models have automatic ignition and can be readily equipped with thermostats or remote controls.

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